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Extension Entomology

Category: Lawn and Garden

“Float like a butterfly, sting like a bee!” “They’re here”. —- Monarch Butterflies

–by Dr. Bob Bauernfeind

Pushing the envelope (as I often do), how does one use Muhammad Ali’s  “Float like a butterfly, sting like a bee”, epitomized boxing style, and  the movie Poltergeist tagline, “They’re here”, as an introduction to a Kansas Insect Newsletter article?  I spent time on Saturday and Sunday doing yardwork.  It was Sunday afternoon that (out of the corner of my eye) I frequently glimpsed monarch butterflies lazily/lightly floating by.  I had noticed none the day before.  So, “They’re here” refers to their arrival in Kansas (well, Manhattan) on Sunday as they were on their southward migration to their overwintering grounds in Mexico.

There are individuals with passionate interests in the status of monarch butterfly populations and activities.  Avid monarch-watchers access websites which better document the current presence/movements of migrating monarchs.  My sighting certainly has no official status in terms of documentation —- just a “casual” observation on my part.

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Carpenters Build with Wood —– Carpenterworms Destroy Wood

–by Dr Bob Bauernfeind

A second spark was in the form of an e-mail received from Dr. Sarah Zukoff at the Southwest Research and Extension Center in Garden City: carpenterworms.

 

Over many years of operating blacklight traps throughout Kansas, I have collected hundreds of carpenterworm moths.  Female moths are large (wingspread up to 3 ¼ inches) and rather drab in appearance. Male moths are smaller (wingspread ½ that of the female) and also appear drab when wings are folded.  But upon spreading the forewings and exposing the hindwings, the coloration and pattern of the male’s hindwings is strikingly different from that of the female.

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As common as the moths are, I have only been “on-site” once.  On 10/04/2010, I arrived in McPherson in response to a resident’s request.  It was apparent that carpenterworms were at work. They were creating tunnels and expelling large amounts of sawdust (a combination of wood chewings and frass) which was accumulating at the base of a large green ash situated next to a house.  Given that carpenterworm life cycles are lengthy (2-3 years depending on environmental factors), the currently-present carpenterworms originated from eggs deposited in 2007 or 2008.

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This tree has been under attack over a period of years as seen by extensive scarring of the bark.  While the scarred bark surface presented a “healed appearance”,

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it concealed the extreme underlying damage accrued by previous carpenterworm activities.

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While carpenterworms seldom kill tree hosts, their extensive feeding damage reportedly can structurally weaken trees resulting in the breakage/falling of limbs and entire trees.  This was the concern of the homeowner given the proximity of the tree to her house.  Granted that while I am not a bona fide “tree person”, my unqualified assessment was that the tree was structurally sound.  The local arborist disagreed and recommended removal.  I was not present at the time of removal (December), but I did travel back shortly thereafter.  The size of the borer tunnels were impressive in a cross section from the trunk.  Yet, it was interesting to note that despite the ominous presence of carpenterworm activities, their tunneling activities were dismissive in comparison to the amount of solid wood.  The tree was structurally sound.

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A little background regarding carpenterworms.  Although most people probably are not familiar with carpenterworms, they are not a “new pest species”.  We are approaching the second century anniversary of the year in which they were first reported to damage trees (1818).  Carpenterworms attack a wide variety of tree species including ash, birch, black locust, cottonwood elm, maple, oak and willow.  Fruit trees such as apricot and pear are also listed, and possibly (by extension) would also include most any fruit tree species.

The carpenter worm developmental life cycle varies depending on their geographical latitude:  1-2 years in the Deep South to 4 years in the Northern States and southeast Canada.  In Kansas (being somewhat in the middle), the carpenterworm life cycle probably lies between 2-3 years.  However in any given year, overlapping generations are likely to occur.

Given a 3-year scenario:  Female carpenterworm moths reportedly produce between 200 and 1,000 eggs which are preferably deposited in protected/hidden sites (bark crevices, under lichens, and near wounds and scars) on tree trunks and main/larger limbs.  Newly hatched larvae penetrate the bark, or enter through existing openings.  They create shallow tunnels in the inner bark in which they overwinter.  Feeding resumes in the spring at which time larvae extend and widen tunnels.  Moving inward, they form upward-slanting tunnels into and through the sapwood and then into the heartwood where they form vertical tunnels in which they overwinter.  In the third summer, the vertical tunnels are extended (up to 9 inches long) and expanded (over ½-inch diameters).  In the fall, larvae return to the area of the exit hole in the bark and produce a silken layer which lines the gallery walls and forms a curtain over the exit hole.  Larvae then overwinter a final time.  In spring, larvae move close to the exit hole and are transformed into pupae.  Just prior to moth emergence, pupae will wiggle and force their way through the silken curtain.  With the anterior of pupae thusly exposed, moths emerge outside of the tree where they will harden and be “free” to take flight.

Carpenterworms have a negative impact on lumber production.  Individual or cumulative damage associated with extensive tunneling, staining and wood decay may seriously degrade the quality and quantity of lumber from individual trees.  Fortunately, however, carpenterworm distribution (and consequently damage) within fully forested lumber production areas appears to be less than that seen on open-grown shade trees, roadside trees or trees in shelterbelts and edge-of-the-woods trees.

Due to the unpredictable appearance/occurrence of carpenter worms, little can be done in a preventative sense.  The presence of carpenterworms usually is detected late (the third year) in their developmental cycle when excessive sawdust accumulations catch one’s attention.  While the damage has already occurred, some people will attempt to kill larvae by inserting a wire probe into the carpenterworm’s tunnel.  Depending on the larva’s position in the tunnel system, this may or may not work.  If a person attempts to force a stream of insecticide into the tunnel, care should be taken to avoid a backsplash of the insecticide stream.  Because carpenterworms seem to prefer repeatedly attack the same tree and ignore nearby trees, the “magnet tree” can be removed, thus eliminating the major local source of carpenterworm moths.

 

In My Yard —- Twig Girdler (at last)

–by Dr Bob Bauernfeind

There are times when I struggle coming up with a “timely topic” for the Kansas Insect Newsletter.  But then I encounter something that “ignites the fire”.

The spark? – Yesterday morning (Labor Day), I went out to water my tomatoes.  I noticed a portion of a branch lying on the ground.  Picking it up, the end/break point had the characteristic smooth buzz saw cut pattern of a twig girdler.

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 Why, “at last”?  Over the years, I have collected fallen branches from various sites in the Manhattan area.  Why (in the 22 years that I have lived here) had I never experienced twig girdler activities around MY HOME?  As I often relate to people when trying to explain insect activities, “There is no valid explanation. Sometimes that’s just the way things happen”.  But as an entomologist (and paraphrasing Bruce Willis’ Diehard character), Yippee-ki-yay!

 

The following is a cut-and-paste from a previous Kansas Insect Newsletter.  So possibly (for some) this will be “old news”, but a useful review.  For first time readers, this hopefully will be interesting and informative “new news” regarding the seasonal activities of Oncideres cingulata, the longhorned beetle commonly called the twig girdler.

Given its name, the image below shows a “fresh girdle”.

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One has but to look at the head of a twig girdler to realize that it is well-equipped for the girdling task.  The head is compressed from front to back, and somewhat elongate from top to bottom —- just right for allowing it to fit into the V-shaped girdle it creates.  Under magnification, her mandibles resemble the “jaws-of-life” rescue equipment —- stout and strong, ready to cut/girdle branches ranging in size from 6 to 13 mm in diameter —- apparently dependent on the size of the individual female beetle whose legs are uniquely positioned —– her 4 front legs to encircle/grasp, and her hind legs positioned rearward and utilized to anchor against.

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The girdling process is not a complete shearing of branches.  Rather, the smooth cut stops, but an intact central core remains, thus preventing the branch from dropping.  However, because girdling severs vascular elements, the portion of the branch beyond the girdle dies and dries out.  This results in the central core becoming brittle.  It is at this point, then, the weight of the branch (with or without the aid of the wind) overcomes the ability of the core to support the branch.  The core snaps and the branch falls to the ground.

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Twig girdlers have a wide host range including hickory, pecan, dogwood, honeylocust, oak, maple and hackberry.  While hackberry is listed as “high” on the list of hosts, in Kansas, most reports of littered lawns occur beneath elms.  This preference for elm over hackberry was exemplified in an observation of side-by-side girdled elms and untouched hackberry trees.

Several questions arise regarding girdlers:

Why do they girdle branches?  The larvae of twig girdlers require a “drier wood” for their growth and development.  Beetles deposit their eggs beyond the “cut” thus ensuring the survival of the larvae in the fallen branches.  Beetles gnaw through the bark (creating an ovipositional scar) and deposit an egg just beneath the bark.  Egg sites can easily be detected by closely examining areas near twig side shoots.

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Of what harm are girdlers?  This depends on where and what they are girdling.  In nut production orchards, twig girdlers can be detrimental when damaging newly transplanted trees or stymieing/setting back young trees not yet in production mode.  In harvestable orchards, there have been reported incidences of reduced nut production and reduced yields following extensive twig girdler activities the previous season.

Can people monitor for the presence of twig girdlers and apply an insecticide treatment to eliminate them before their girdling activities?  This is impractical.  There is not a single succinct time of beetle appearance.  Rather, their emergence pattern is lengthy, spanning from late August into October.  This being said, the impracticality continues.  It is not possible to inspect large trees for the presence of beetles.  And while twig girdlers have a very distinctive appearance, they can be easily overlooked because they blend in to the background.

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For homeowners, twig girdlers are more of a nuisance in causing the aforementioned branch litter.  The recommendation is to gather up and dispose of branches.  This will eliminate those beetles which emerge the following year.  However, this does not mean that twig girdlers won’t appear the following year:  look up, and you may see many more dead branches still attached or caught up in tree canopies.

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For certain, there is one site where girdling activities have ceased.

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BE ON THE LOOK-OUT FOR GOLDENROD SOLDIER BEETLES

–by Dr. Raymond Cloyd

If you haven’t noticed yet, hordes of goldenrod soldier beetle (Chauliognathus pennsylvanicus) adults are feeding on goldenrod (Solidago spp.) and other flowering plants such milkweed (Asclepias spp.). Adults are extremely abundant feeding on the flowers of chive (Allium Schoenoprasum), and can also be seen feeding on linden trees (Tilia spp.) when in bloom. In fact, adults may be observed both feeding and mating (occasionally at the same time). The goldenrod soldier beetle is common to both the western and eastern portions of Kansas.

Figure 1 Adult Goldenrod Soldier Beetle.pptx

Adults are about 1/2 inch (12 mm) in length, elongated, and orange in color with two dark bands on the base of the forewings (elytra) and thorax (middle section). They are typically present from August through September. Adult soldier beetles feed on the pollen and nectar of flowers, but they are also predators and may consume small insects such as aphids and caterpillars. Flowers are a great place for the male and female soldier beetles adults to meet, get acquainted, and mate (there is no wasting time here). Soldier beetle adults do not cause any plant damage. Sometimes adults may enter homes; however, they are rarely concern. The best way to deal with adults in the home is to sweep, hand-pick, or vacuum.

Figure 2 Adult Goldenrod Soldier Beetles Mating

Adult females lay clusters of eggs in the soil. Larvae are dark-colored, slender, and covered with small dense hairs or bristles, which gives the larvae a velvety appearance. Larvae reside in the soil where the feed on grasshopper eggs; however, they may emerge from the soil to feed on soft-bodied insects and small caterpillars.

Figure 3 Adult Goldenrod Soldier Beetles Feeding

‘Tis the Season Already? ……. 8 legged creatures?

–Dr. Bob Bauernfeind

Currently, we are only in mid-summer —- quite a ways away from consistently cool fall weather.  Yet because we have had a couple days and evenings of unseasonably cool weather, people project forward and express concerns about spiders entering homes.  And on my evening walks this past weekend, I noticed spiders resting on the roadway and in the gutters presumably soaking up the stored heat-of-the-day.  These spiders are “hunters” (as opposed to webbing species – to be presented later) who are seeking prey.  And hunting spiders are the types that are more likely to wander and roam and possibly/eventually enter homes later in the season.

There are various groups of hunting spiders.  Unless people are especially observant, crab spiders (so named for their crab-like appearance and gait) escape detection due to their camouflaging ability, blending in to the background of the flower upon which they lay-in-wait to ambush unwary insects attracted to the flower.  Given their habits, crab spiders are unlikely to enter homes.

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Jumping spiders probably are more tolerated due to their non-menacing appearance.  They are small (½ or less) and “cute” (colorful and somewhat fuzzy).  They have a sort of herky-jerky walking motion.  Jumping spiders are “visual hunters” and therefore possess quite large eyes which provide them with the visual acuity required to locate and leap/jump atop their prey.  With a quick bite, they immobilize their prey. Occasionally jumping spiders enter homes.  But because of the aforementioned traits, they tend to be regarded as “harmless”.

 

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The anxiety when it comes to outdoor spiders entering homes usually applies to “wolf spiders”.  Perhaps it is because of their name that the heebie-jeebies set in —- wolves bite so wolf spiders must automatically set out to bite (not so!).  Perhaps it is because some of the many wolf spider species are large — body length in excess of 1¼-inches (I personally have never encountered one even reaching 1-inch).  They may appear even larger given their long legs —- splayed out, spanning 3½ inches (that one I do have in a riker display).  They are hairy (scarier than fuzzy).  They are dark/sinister in appearance, being varying shades from brown to grey to black with some mottling — this coloration enabling them to blend into their habitat background and thus escape detection.

Wolf spiders are solitary hunters with excellent vision that is useful for detecting prey as they roam about.  Some species create burrows where they lay-in-wait at the entrance, snatching prey that wander too close.  Female wolf spiders attach and carry their egg sac to the spinnerets on the rear of their abdomen.  When the spiderlings hatch, they climb on to their mothers backs who then carry them until they are ready to depart and be on their own.

Wolf spiders (like most spiders) tend to be shy and timid/non-aggressive.  If provoked, they may deliver a justifiable “defensive bite”.  However because their venom is mild, only redness, some swelling, mild pain and itching occur.  Yet, if one wishes an added sense of relief, consult with and receive advice from a personal physician.

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The following may seem like déjà vu.  It isn’t.  If you read Kansas Insect Newsletter #17 (two weeks ago), you saw much of the following text except that I have inserted the word spider for cricket.

The most successful approach for preventing spider “guests” is to EXCLUDE THEM!  Spiders (as well as any other commonly named “fall guests” such as boxelder bugs, elm leaf beetles, multicolored Asian lady beetles, rollie pollies, crickets) gain entrance via any available crack/crevice/hole/gap.  Attempt to insect-proof houses and buildings by thoroughly inspecting and identifying entry points. Check for cracks and gaps in structure foundations, ill-fitting doorways and garage doors, overhang louvers, chimney vents, roof ducts, soffits, air conditioner connections, outdoor faucets and siding. Use caulk to seal cracks and crevices, weather stripping to make doorways and garage doors tightfitting, and metal screening over/under/behind other entry points.

An oft-asked question is with regard to the effectiveness of barrier insecticide treatments around the outside perimeter a home.  Although handbooks and manuals recommend such an approach, the wording is vague and noncommittal as to the effectiveness of such applications.  I am not aware of any quantitative data validating the effectiveness of perimeter treatments.  Given the speed and movement of spiders, I think it doubtful that they spend an adequate amount of time on a treated surface sufficient for insecticides to have effect.

 

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Aside from spiders entering homes/buildings, the other objection to their presence is just that — their mere presence.  Fear of spiders is a learned response —- being raised in an environment where being fearful of spiders is taught.

Also, unsightly webbing is an aesthetic objection to the presence of spiders.  We are at that time of year when spiders are becoming more evident.  While spiderlings have been secretively feeding/growing/maturing throughout the summer (and webs were small and unobserved), now is when fully-grown females construct “noticeable” webs.  Webs seemingly occur anywhere and everywhere.  In bushes, lawns, gardens.  Under eaves and other nooks and crannies of homes and buildings.  Although there is no reason to do anything about webs, if people deem them to be unsightly, simply remove them.

 

For many years, my junipers and mugos have been home to funnel weavers.

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Funnel weaving spiders themselves are secreted away in a tubular portion of their web where they await the arrival of a visitor.  Vibrations sensed by the spider cause her to react by rushing out to capture her prey.  You can bait a web and watch the action.

In lawns and other low grassy areas, similar “sheets” of webbing are also made by sheetweb weavers.  These spiders wait beneath the webbing and bite their victims from below, after which they are pulled through the sheet where they are then consumed.

A third category of spiders (orb-weavers) produce beautiful symmetric webs designed to ensnare intruders which (by chance) happen by.  There are many species of orb weavers.  No one description fits all.  Some have a daily routine of constructing temporary webs.  With the approach of sunrise, “used silk” is taken

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down/gathered and consumed.  With the approach of evening dark, she constructs her new web, recycling the silk from her previous web.  Others orb weavers construct permanent webs which require repair from time to time.

Depending on the species, some orb weavers hide by day.  If you encounter an in-tact orb web during daylight hours, the web’s owner usually can be located nearby, perhaps in a curled up leaf or in some out-of-way concealed location.  Or, if you know where an orb weaver has its “nightly web”, during the day, you can find her “snoozing away” as she awaits night’s return.

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Others (such as the golden garden spider) do not hide during the day.  Rather, they are continually present, positioning themselves head-down in the central hub of their web.  This offers ample opportunity for people/kids to “interact” with them.  Especially interesting is the speed with which a spider detects and instantly moves towards her prey, and the dexterity and speed with which she enwraps her catch.  She will then feed at her leisure.  When no longer of food value (“sucked dry”), she will cut loose her depleted prey to then simply drop to the ground.

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Webbing spiders are opportunistic generalist feeders.  Whatever blunders into a web becomes a meal.  If the victim happens to be regarded as a pest species such as the ensnared  grasshopper (above) or a male bagworm moth (to the right), we think,

“GREAT!”

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If the captured insect is (in of itself) considered a beneficial insect (a praying mantid), we utter,

Awww.    Geez.”

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But again, spiders are opportunists regardless of how we might view their victims.

The capture/demise of individual insect pests might be used by some individuals as evidence/proof to point to and express, “See?  Spiders are important for biological control!”  While hypothetical calculations have been used to extoll the benefits of spiders as biological control entities, in truth, such expectations likely are unrealistic.  Again, because spiders are indiscriminate feeders, they are not “pest specialists”.  Additionally, not being socially adept (rather, viewing any neighboring kin as “food”), spider populations are not sufficiently dense to accomplish meaningful biological control of insect species deemed “pests”.    This being said, allow them their existence and space.  Simply, respect them for their beauty and fascinating habits.

An update on my spider friends?   As of today (as I write this), the landscape people are busy at my home.  I expect to see a very different picture when I arrive home after work.  My original 1993 plantings will be gone —- so no more “home sites” for my spider friends.

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Old “Defoliated” Friends Revisited

–by Dr. Bob Bauernfeind

One of my favorite most succinct introductory slides simply says:

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While attentiveness, care and pampering are especially important in the early years after newly transplanted trees first become “family members”, there does come a point-in-time when they become “Big Boys and Girls”.  Look at mature trees lining city streets, in park and recreation areas and in the countryside —- all thriving on their own.  This despite having to contend with different insect pests.

Most alarming for homeowners is the compromised appearance of trees when foliar feeding species come-to-town.  The situation is such that their presence first becomes apparent (after-the-fact) when the offending species are approaching the end of their feeding phase-of-development — a time at which they are of such size that they ravenously feed on and rapidly deplete available foliage thus drawing attention to their presence.

Defoliations may vary in intensity from a few bare branches to the entire canopy.  As alarming as a complete defoliation might appear, it should be regarded as but a cosmetic issue.  Probably more objectionable is the visible and audible “rain-of-frass”, as well as streams of descended mature larvae roaming about in search of pupation sites.  Early-season defoliations are of temporary duration because trees rapidly produce a new flush of growth restoring normalcy.  On the other hand, new foliage production is scant late in the season at a time when leaf abscission is imminent after the cessation of seasonal photosynthetic activities.  Come springtime, trees again will fully leaf out — seemingly none the worse-for-wear.

People may ask, “What did I do wrong?  Couldn’t I have prevented this?”, to which I would respond, “You did nothing wrong.  Outbreaks are unpredictable!”. As mentioned earlier, a person is unaware of the presence of specific pests which (as “wee ones”) scrape and nibble away not producing any noticeable foliar damage to give away their presence.

Come the questions, (1) “Well, once I notice the damage, shouldn’t I spray?”, to which there is not an absolute response.  Consider the size (and possibly) number of trees, and the unlikely capability of an individual to apply/achieve thorough spray coverage. (2)  “Well couldn’t I hire a service to spray for me?”, to which the response might be, “If the service provider is “booked” and unable to get to your tree(s) in a timely fashion, by the time they do arrive, caterpillars/larvae may have already completed and ceased feeding —- little point in spraying at that point.

Balancing the cost of hiring a spray service against what-is-to-be-gained by spraying at a time that tree appearance has already been compromised may make the decision to be to simply allow the situation to run its course.

“Is there a need to “kill-them-now” to prevent a repeat?”  While this seems to be a logical thought, in reality, we really have little control over future events.  Nature sort of has its own checks-and-balances.  Whether unfavorable environmental conditions or biological entities (diseases, predators, parasites) reduce or eliminate potential future “seed” for pest populations, or, if pests themselves naturally disperse, one may never again experience a repeat situation.  Individuals who have experienced defoliations and who have seen their trees recover are convinced of the need to let nature run-its-course.                            

Defoliations:  before and after

Greenstriped Mapleworms on silver maples

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Yellownecked Caterpillars on oak 

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             Walnut Caterpillars on black walnut (red arrow = limb pruned out in 2011)

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Foliar Dessication:  Before and After

Some foliar-feeders are relatively small in size and therefore incapable of skelotinizing and defoliating tree hosts.  Rather, their feeding activities are reduced to nibbling/consuming the epidermal tissues of leaves.  Both the upper and lower epidermis (with their thicker “waxy” cuticles) protect the more delicate inbetween high-in-moisture-content internal cellular layers. Deprived of their protective outer layer, leaf dessication leads to leaf death — the resultant being the unsightly browned/burnt appearance of trees.

Mimosa Webworms on honey locust

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Elm Leaf Beetles on elm

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In this incidence, I do not have a current image of the trees above.  They no longer exist.  However, not due to to the depredations of elm leaf beetles.  Rather, simply, they were in the way of progress.  A highway expansion project necessitated their removal.  They were no match against “man”.  Soooo painful to watch trees ripped out roots-and-all by powerful excavating equipment.  But again, the lesson being that the asthetically unacceptable foliar appearances resulting from insect activities are but an occasional temporary fleeting occurrences …. leading to the following:

On a return trip to Manhattan Monday, I noted the presence of fall webworms along the roadway — sometimes one or two in an occasional tree here and there, or  (in this instance) numerous web masses.

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These did not develop “overnight”  Judging by their size, these colonies likely were initiated 4-5 weeks earlier.  Again under the banner of defoliators, people may worry about the impact of feeding depredations.  Minimal!  Probably a more verbally expressed concern is the unsightlyness created by the webbing, as well  “creepy” clumps of caterpillars within.

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A common recommendation is to prune out webbed branches.  One must consider the accessibility of web masses — those beyond reach simply allowed to remain.

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Pruning might be doable if just a branch or two —- but possibly unacceptable and disfiguring when trees are heavily infested with web masses.

If within reach, consider an implement (of sorts) to “rake out”/remove  webbing.  And what implement could be more handy (yes, pun intended) than one’s own hand.  There is no need to fear the dry webbing and/or dried fecal deposits and squirmy caterpillers within.  As webbing is removed, also removed will be the objectionable dead/dry foliage and the fallwebworms.  Simply dispose of the gathered material.  All that is left behind is the leafless (but still living) branch and it’s intact buds which will produce the ensuing year’s foliage.

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Uninvited Guests – Crickets

–by Dr. Bob Bauernfeind

While I certainly do not want to create any hysteria as did Henny Penny when she ran around the town shouting, “The sky is falling.  The sky is falling”, it may be that we are in store for impending cricket invasions, at least based upon what I am currently seeing (for the first time ever that I can recall) in-and-around my yard and home: crickets, crickets and more crickets.  Actually thinking back earlier this year, I recall saying to myself, “Huh, look at these little crickets!”  While I cannot account for their observed numbers (no official counts per se), perhaps this year’s adequate moisture may have been favorable for their survival and development.

 

Crickets subsist on a wide range of food sources.  As generalist omnivores, they are opportunistic feeders deriving nourishment wherever on whatever is available including plant, dead organic plant and animal matter, algal, fungal and bacterial sources.

 

The mere presence of crickets can be annoying.  In addition, while the chirping of male insects may be considered beautiful music-in-the-night out-of-doors, indoors it may be regarded as noisy and disruptive.  Although not bona fide fabric pests, being what they are (insects with chewing mouthparts) and doing what many insects do (test/taste-their-surroundings), crickets may be responsible for creating holes in and leaving stains on light-colored fabrics (curtains/sheers the oft-cited areas showing damage).

 

When people think about crickets in the home, logically the name house crickets comes to mind.  And there are crickets officially called “house crickets”.  House crickets are brown in color and about an inch in length. Whereas they naturally occur in the warmer climates of southwestern Asia, they have no special overwintering stage as would be required for surviving winters in temperate regions where they are commercially reared and marketed as food for amphibians, birds, reptiles and other arthropods.  While they now have become established worldwide, survival of escaped adults is minimal (but possible) in and around heated areas.  It is unlikely that “house crickets” will be paying you a visit.

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Rather, the crickets which enter homes will likely be “field crickets”.  Mature field crickets approach an inch in length.  The female, is easily identifiable by the presence of her prominent ovipositor measuring another ¾-inch.  Most field crickets are all black in color, but some may have a lighter appearance due to their coppery-colored wings.

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A third type of cricket is a smaller-in-size “ground cricket” commonly called the striped ground cricket.  These are the small “summer crickets” that occasionally are attracted to commercial districts and businesses illuminated by high intensity lighting which acts as a beacon to these crickets capable of flying to the distant glow of city lights and business-lit areas.  Their life cycle differs in that they attain adulthood during mid-late summer.  Eggs are already deposited and most adults died before the onset of cooler fall weather.

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With regard to seasonal life history, field crickets overwinter as eggs deposited in the soil.  Currently, field crickets are now in their mid-development stages, and for the most part go unnoticed.  By the time cooler fall weather moves in, field crickets will have reached their adult stages.  Before and after mating and depositing eggs, crickets move towards sources of heat such as homes and buildings whose exteriors “soak up” the sunlight/heat.  Crickets are capable of detecting heat gradients and thus are drawn in.  Once on-the-doorstep, they are a hop away from secretly moving in through any available crack/crevice/opening.

 

How does one go about attempting to prevent cricket “visitors” in homes and possibly business establishments?  The first thought might be the outdoors use of insecticides to kill crickets.  When cricket populations are large and there is the likelihood of impending invasions, reduction of their numbers may be achieved with insecticide applications as barrier treatments applied to a 6- to12-foot band around the perimeters of homes and businesses.  Once inside, insecticides registered for indoor use against crickets or (in general) indoor invasive species can be applied per labeled instructions.  Indoor applications may be general surface, spot, mist or crack and crevice treatments.

 

According to NPIRS (National Pesticide Information Retrieval System, currently in Kansas, individually clicking onto striped ground crickets, house crickets, field crickets and crickets, there are 4, 44, 84, 1392 products, respectively.  Collectively clicking onto all of the mentioned categories, there are 1,410 products.  So there are plenty of insecticide options.  However, even if a person sprays, sprays, sprays outdoor areas until they glow that does not guarantee against eliminating all potential invaders.

 

Perhaps a more successful approach for preventing cricket “guests” is to EXCLUDE THEM!  Again, as previously mentioned, crickets (as well as any other commonly named “fall guests” such as boxelder bugs, elm leaf beetles, multicolored Asian lady beetles, spiders) gain entrance via any  available crack/crevice/hole/gap.  Thus sealing these portals of entry is a recommended method of exclusion.  Attempt to insect-proof houses and buildings by thoroughly inspecting and identifying entry points. Check for cracks and gaps in structure foundations, ill-fitting doorways and garage doors, overhang louvers, chimney vents, roof ducts, soffits, air conditioner connections, outdoor faucets and siding. Use caulk to seal cracks and crevices, weather stripping to make doorways and garage doors tightfitting, and metal screening over/under/behind other entry points.  Such simple words.  Yet, in all practicality when looking at my home (which I consider sound-and-sealed), I know that there are (still remaining) untended access points.  I expect that like many other people, I will have “fall visitors”.  Sort of a fact-of-life that one must accept.

Bagworms —- Current Status, and What to Do

–by Dr. Bob Bauernfeind

For the past several weeks, in Ward Upham’s compilation of Hot Topics, bagworms have been mentioned.  Last week, they were designated as Pest of the Week.   This is not a real surprise given the time of the year.  Why?  As pictured below, the colored time frames are indicative of bagworm feeding capabilities.  Smaller (generally overlooked) larvae in the green and yellow zones represent periods when larvae are small “nibblers” — negligible visible feeding damage.

The orangish/amberish represents “caution” — larger larvae becoming more destructive but not necessarily causing noticeable damage.  But now (August) is the red danger zone where (as is typical for all lepidopteran larvae) rapidly growing larvae in their last feeding stages consume the greatest amount of foliage (create the most noticeable damage) that has people reacting to the presence of bagworms.

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The question now is, “Is it too late to spray for bagworms?”  Currently, it is not too late to spray!  Notwithstanding their size, as long as bagworms are actively foraging, they can be effectively controlled.  Those directly hit by an insecticide spray will be killed by contact action.  Those withdrawn into their bag at the time of the spray application will likely succumb after coming-in-contact with treated foliage, but most certainly after consuming treated foliage.

How does one determine if bagworms are actively feeding?  OBSERVATION!  “Active bags” can be identified by newly-clipped greenery at the bag opening.  Also, with a bit of patience, simply watch for a bagworm to reopen its bag, poke out its head, and resume feeding.

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When is it too late to spray for bagworms?  That also is easily determined.  When a bagworm completes its feeding cycle, it anchors its bag to the host plant with a distinct, highly visible white silken “tie”, after which it permanently closes the “front door”.  Spraying at this point-in-time is futile because the thick leathery bag protects the bagworm within.

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According to NPIRS (National Pesticide Information Retrieval System), currently in Kansas, there are 500 products registered for use against bagworms.  Some active ingredients currently contained in insecticides available for purchase and use by homeowners include acephate, Bacillus thuringiensis, bifenthrin, carbaryl, cyfluthrin, cyhalothrin (gamma and lambda), deltamethrin, malathion, permethrin and spinosad.  In various trials, I have used the bolded AIs and found them all to be effective against bagworms, even those considered large and close to the end of their feeding cycle.  Some homeowners may still be in possession of discontinued products with the active ingredients chlorpyrifos, dimethoate and/or diazinon.  All were effective against bagworms in trials.  Although it does not appear to have been written into any legalized directive (per personal communication with the KDA), discontinued products may still be used if done in accordance with the instructions appearing on the product label.  Residents may not share or give partial containers to neighbors as this would be considered distribution.

Excluding products containing Bacillus thuringiensis (minimal effectiveness against larger instar larvae), regardless of which product/AI is applied, the critical factor for successful bagworm population reduction is THOROUGH COVERAGE TOP-TO-BOTTOM!  Hastily applied light/misty sprays to tree and shrub peripheries will lead to disappointing results.

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What’s in a Name? Caterpillars

–by Bob Bauernfeind

Within the last two weeks, I received e-mails with attached images of caterpillars feeding on various landscape ornamentals.  The senders requested identifications of the caterpillar species.  Of course, as entomologists, we are expected to come through with positive identifications, as well as recommendations on how to address situations where caterpillars are feeding on prized plants.

Identifying caterpillars can be easy-as-pie for a those species of common occurrence (recently, caterpillars of whitelined sphinx moths, cercropia moths and walnut caterpillar moths), but more difficult for the many many many caterpillars of species encountered on but an infrequent basis.  While there are various books with page upon page showing images of butterflies and moths, similar publications picturing the larvae of the same butterflies and moths are limited.  The following references would be good additions to one’s book shelf.  However, they do not necessarily guarantee accuracy for identifying caterpillars.  But at least these references provide a useful starting point when attempting to identify caterpillars.

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Four recent submissions were images of rather spiny/bristly looking caterpillars.  Almost immediately, one suspects that they likely are caterpillars of butterflies in the taxonomic family Nymphalidae, most of whose caterpillars are adorned with spiny tufts, and rows of branched spines. The collective common name applied to nymphalid butterflies is “brushfoot butterflies” —– so named because (in general) of their hair-covered front legs which are reduced in size, held close to the body, and not used for walking.  This largest family of butterflies includes  commonly recognized species such as the many that comprise the fritillaries and checkerspots, anglewings (question mark and comma butterflies), thistle butterflies (painted ladies and red admirals), tortoise shells (morning cloak), admirals (white, viceroy and red-spotted purples), milkweed butterflies (commonly, monarchs), hackberry and tawny emperor butterflies, and satyrs and wood nymphs.

Of the most recent inquires, one (an image that I was unable to retrieve) was that of a morning cloak butterfly caterpillar. The accompanying image shows (in detail) the exquisite array of spines and hairs, the dark body with multitudes of small white dots, and the prominent orangish-to-red dorsal patches.  Listed hosts include elm, willow, hackberry, poplar, wild rose and Hawthorne.

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The next was the unmistakable larva of the dotted checkerspot butterfly.  It is always nice when an ID seems to be so clear-cut based on an exact match between the actual specimen and the pictured specimen.  Matt McKernan has received numerous reports of these being feeding on Echinacea which includes cone flowers (purple cone flowers being popular garden varieties).

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The next 2 examples may be more typical in terms of complicated identifications.  Jenae Ryan’s image was of caterpillars on zinnias.  Paging through the images in Caterpillars in the Field and Garden, I settled on the only closest match:  caterpillars of the Meadow Fritillary.

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The complications?  The listed host plants were violets, not zinnia.  And, Kansas is well outside of the range indicated on the accompanying distribution map.

Mark Ploger submitted this image of caterpillars found on cone flowers.

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Assuming that they likely were from the same egg mass, this exemplifies differences in appearances between siblings.  As hard as I tried and squinted, there were no matching images in-the-books.  So the simple response was, ”Larvae of a Nymphalid butterfly”

The complications?  The listed host plants were violets, not zinnia.  And, Kansas is well outside of the range indicated on the accompanying distribution map.

The point to be made is that although it is well-and-good to submit actual caterpillar specimens and/or images for identification to satisfy the curiosity of “What is it?”, regardless of knowing their exact identity, if the caterpillars are causing intolerable damage, they need to be eliminated. People have their own levels of tolerance ranging from zero (preferring perfection of plant appearances), to live-and-let-live (preferring to enjoy the beauty of expectant butterflies).

 

Wasps and Cicadas

–by Dr. Bob Bauernfeind

Yesterday morning (July 7) as I walked out the back door of Waters Hall, two men were servicing a couple of AC units.  They were being intimidated by BIG WASPS.  I asked them if they were worried to which one responded, “Look at the size of them things.  I don’t want to get stung!”

Aha!  The proverbial “teachable moment”.  I went back to my office and got an insect net.  Back outside, I netted a wasp and reached into the net and grabbed the wasp.  The workers gave me a quizzical look, like, “What are you?  Nuts?”   But I explained to them that this was a male cicada killer wasp — and that male wasps (of any species) do not possess a stinger.  I then had each of them grasp the wasp and then take a close look at it.  “See?  No stinger”.  They were relieved to know that they could work carefree and would not be on the receiving end of a painful sting.

So, yes cicada killer wasp activities are in full swing.  Already long-gone are the periodical cicadas (well, “long” depends upon how one defines long).  So how will cicada killer wasps survive?  They will rely upon their yearly supply of “annual cicadas”.

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Currently, two early-summer species are singing away.   I heard my first Tibicen pruinosus the evening of June 24, and first T. lyricen mid-day on July 2.

In comparison to the recent periodical cicadas, both of T. pruinosus and lyricen are larger and thicker-bodied with impressive wingspreads.

Both T. pruinosus and T. lyricen are tree-inhabiting species. But side-by-side, they are visually inseparable based upon their individual distinct body patterns and coloration.  By far, T. pruinosus surpasses T. lyricen in terms of population levels, their wider distribution in Kansas, and their longer period-of-activity which extends well into Fall (T. lycerin’s “run” is completed by mid-August).  The familiar ZzuhWhee ZzuhWhee ZzuhWhee ZzuhWhee (typically beginning in the late afternoon into the evening) is the most familiar sound heard coming from high-in-trees in cities and towns throughout Kansas.

But back to cicada killer wasps.  Digging back in the vault-of-time and dusting off and somewhat modifying a previously used Kansas Insect Newsletter article —- good then and good now:

There are many types and species of wasps.  Vespid wasps (including the familiar paper wasps, yellow jackets and baldfaced hornets) live in “colonies” consisting of a single egg-laying queen and her attendant female workers who will defensively protect the colony against intruders/people who (even if) accidentally disturb the nest/nesting site.  In contrast, sphecid wasps (most familiar and recognized are mud daubers which build “mud nests”) are solitary species with just a single female tending her nest.  Sphecid wasps are docile and unlikely to sting unless provoked by being carelessly handled or accidentally stepped on.

Thus, cicada killer wasps (despite their appearance and large size) are nothing to be feared.   The female uses her stinger to paralyze a cicada.  The cicada remains a “juicy” (as opposed to becoming dried out) food source for the wasp larva.

Male-female cicadakiller

Male cicada killer wasps do not possess a stinger (as already mentioned above).  Never-the-less, they appear menacing due to their erratic swarming as they establish territories and seek female mates.  While occasionally one might accidentally bump into a person, it is not “attacking”.

Once a male has established his own small territory, he will be on active patrol protecting against interlopers.  Buzzing about, he may hover and circle a person.  While this may be intimidating, again, he cannot sting!

Cicada killer wasps have a 1-year life cycle.  Whereas males do little more than mate, you have to admire female cicada killer wasps —– they do all the work.  She selects a preferred site (often a bare sandy area) in which to construct her burrow.  Nests are 8 to 20-inches underground.  Using her mandibles and legs, she digs/loosens/”kicks out” soil particles which results in the creation of a dirt mound at the burrow entrance.    There is a central tunnel off of which are separate side cells/chambers.

After the structural completion of the nest, she begins the provisioning process.  Each chamber contains a single-to-several paralyzed cicadas.  After depositing a single egg, the cell is sealed off with dirt.  Within the cell, a newly-emerged larva feeds and matures.  By mid-summer, it forms a cocoon inside of which it spends the remainder of the summer, the fall and winter.  In the late spring, the larva pupates.  “New” cicada killer wasps emerge in early summer, mate, and repeat the cycle.

It is not coincidental that nesting areas tend to be close to wooded areas.  Given that many cicada species are arboreal, trees are ideal sites for locating cicada hosts.  Another advantage of trees?  They provide a high point.  That is, because a cicada far outweighs the female cicada killer wasp, she is already high enough that she can spread her wings and be airborne.  Should she fall short of reaching her nest, and because she cannot take off from the ground with her heavy “cargo”, she will drag her cicada up another tree (or some other convenient high point) to again become airborne.  The last part of her journey may be on foot when she is close enough to the nest entrance.  She then drags her captured cicada to the entrance of, and into the burrow.  This process is repeated time after time after time after time until all of the chambers are provisioned, eggs deposited, chambers sealed and the burrow entrance closed.

A point of interest:  females use their middle pair of legs to wrap around/hold the paralyzed cicada.  Furthermore, the tibia of the female’s hind legs possesses a pair of hook-like appendages (see image above) used to hold/maintain the cicada parallel to its body when in flight.  In an experiment where those appendages were removed, the middle legs still secured the cicada although it dangled beneath the wasp as she flew.

Comes the question, “How do I get rid of the cicada killer wasps around my house?  I’m worried about being stung!”  If you have read through to this point in this article, you already know that you need not be overly concerned about, “….. being stung!”  But still, if there is the desire/need to do something, the best procedure would be to observe and identify where the nest openings are.  Wait until the female departs.   Between that time and when she returns, apply an insecticide into the entryway.  (There currently are 795 different products registered for use in Kansas against wasps.  Shop-the-shelves at local retail outlets for product availability in your area.)  When the female wasp returns, contact with the insecticide will probably lead to her eventual demise.  Whether the insecticide will kill the developing larvae is questionable as they are protected by the dirt wall closing off its underground incubation chamber.

The practicality of the above?  One or two mounds/nests?  Doable.  Many mounds/nests? Probably impractical.  It is up to an individual’s best judgment as to what to do.  But maybe consider altering “the attractiveness” for next-year’s bout.  Renovate lawn areas —- restore a thick vigorous turf which would have females searching elsewhere for a thin/bare area in which to raise her brood.  Also, maintain a moist soil as that would tend to deter her from wanting to expend maximum excavation efforts.  In flower bed areas, a layer of gravel or mulch may dissuade her from setting-up-house.

From the viewpoint of an entomologist:  take the opportunity to watch and be fascinated by these harmless creatures.  If adventurous, put your hand next to her burrow entrance.  When “Madam” exits, she may crawl onto your hand.  You’ll find yourself talking to her.  She may move her head this way or that as if to say, “Nice chatting with you.  But I must be off.  I have more work to do.”