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Extension Entomology

Category: Household

Japanese Beetles Are Back!

–by Dr. Raymond Cloyd

Japanese beetle adults are out in full-force in certain regions of Kansas feeding on different plant species, but especially roses (Rosa spp.). The means of dealing with the adult stage of Japanese beetle are limited, and have been for many years, with the use of insecticides still being the primary plant protection strategy. Japanese beetle, Popillia japonica is native to Japan and was first reported in the United States in 1916 in the state of New Jersey. Currently, Japanese beetles are established from Maine to Georgia and in nearly every state east of the Mississippi River and several mid-western states.

Figure 1. Japanese beetle adult (Author-Raymond Cloyd, KSU)

Japanese beetles are established in eastern and central portions of Kansas, and are slowly moving westward. Japanese beetle adults are one of the most destructive insect pests of horticultural plants in both landscapes and gardens. The larvae or grub is a major turfgrass insect pest in home lawns, commercial settings, and golf courses.

Japanese beetle adults are 9/16 of an inch in length and metallic green with coppery-brown wing covers (Figure 1). There are about 14 tufts of white hair present along the end of the abdomen (Figure 2). Adult Japanese beetles emerge from the soil and live from 30 to 45 days feeding on plants over a four-to-six-week period.

Figure 2. Japanese beetle adult. Note tufts of white hair on the end of the abdomen (Author-Raymond Cloyd, KSU)

Adults feed on many ornamental plants including: trees, shrubs, vines, herbaceous annual and perennials, and of course—roses. Plant placement in the landscape and volatiles emitted by plants are factors that can influence adult acceptance. Moreover, Japanese beetle adults produce aggregation pheromones that attract individuals (both males and females) to the same feeding location. Adults can fly up to five miles to locate a feeding site; however, they tend to fly only short distances to feed and lay eggs.

Japanese beetle adults feed through the upper leaf surface (epidermis) and leaf center (mesophyll), leaving the lower epidermis intact. Adults usually avoid feeding on tissue between leaf veins, resulting in leaves appearing lace-like or skeletonized (Figure 3).

Figure 3. Lace-like or skeletonized damage to leaf caused by Japanese beetle adult feeding (Author-Raymond Cloyd, KSU)

They are most active during warm days, feeding on plants exposed to full sun throughout the day, which is likely why roses are a susceptible host plant because roses require at least six hours of direct sunlight in order to flower. Japanese beetle adults start feeding at the top of plants, migrating downward after depleting food sources. Japanese beetle adults aggregate in masses on rose flowers (Figure 4). Although adult beetles feed mainly on flowers, they will also feed on leaves (Figure 5). Adults chew holes in flower buds;

Figure 4. Japanese beetle adults aggregating on rose flower (Author-Raymond Cloyd, KSU)

 

 

Figure 5. Japanese beetle adults feeding on linden (Tilia spp.) leaf (Author-Raymond Cloyd, KSU)

preventing flowers from opening or causing petals to fall prematurely. Furthermore, adults will consume entire rose petals, and feed on the pollen of fully-opened flowers.

Japanese beetle adult management involves implementing a variety of plant protection strategies, including: cultural, physical, and insecticidal. Cultural is associated with maintaining healthy roses through proper irrigation, fertility, mulching, and pruning, which are important in minimizing “stress, which may possibly decrease susceptibility. In addition, removing weeds such as smartweed (Polygonum spp.) that are attractive to Japanese beetle adults may alleviate infestations. Physical involves hand-picking or collecting Japanese beetle adults from roses before populations are extensive. The best time to hand-pick or collect adults is in the morning when ambient air temperatures are typically “cooler.” Adults can be easily collected by placing a wide-mouthed jar or bucket containing rubbing alcohol (70% isopropyl alcohol) or soapy water underneath each adult, and then touching them. Adults that are disturbed fold their legs perpendicular to the body, and fall into the liquid and are subsequently killed. This procedure, when conducted daily or every-other-day, particularly after adults emerge, may substantially reduce plant damage. The use of Japanese beetle traps (Figure 6)

Figure 6. Japanese beetle trap (Author-Raymond Cloyd, KSU)

 

is not recommended since the floral lure and synthetically-derived sex pheromone (Figure 7) may attract more adults into an area than would “normally” occur. Japanese beetle adults may also feed on roses before reaching the traps, which increases potential damage.

Figure 7. Floral lure (on left) and sex pheromone (on right) associated with Japanese beetle trap (Author-Raymond Cloyd, KSU) (PICTURE NOT SHOWN)

 

Spray applications of contact insecticides will kill Japanese beetle adults. However, repeat applications will be required; especially when populations are excessive. In addition, thorough coverage of all plant parts will increase effectiveness of the application. The insecticide carbaryl (Sevin®) and several pyrethroid-based insecticides including those containing bifenthrin or cyfluthrin as the active ingredient can be used to suppress Japanese beetle adult populations. However, most of these insecticides also directly harm many natural enemies (parasitoids and predators) so their continual use may lead to secondary pest outbreaks of other pests including the twospotted spider mite (Tetranychus urticae). Furthermore, these insecticides are directly harmful to honey bees and bumble bees. Therefore, applications should be conducted in the early morning or late evening when bees are less active. In general, systemic insecticides, are not effective because Japanese beetle adults have to feed on leaves and consume lethal concentrations of the active ingredient. If extensive populations are present, then damage to plants may still occur.

The battle against Japanese beetle adults requires patience, persistence, and diligence in order to prevent adults from causing substantial damage to roses and other susceptible plants.

 

Bagworms are Here!

–by Dr. Raymond Cloyd

Bagworms are Here!

Now is the time to start taking action against that “infamous” insect pest known as the bagworm (Thyridopteryx ephemeraeformis). Throughout Kansas, bagworm eggs have hatched and the young caterpillars are feeding on both broadleaf and evergreen trees and shrubs. Bagworms are primarily a pest of conifers but have expanded their host range to include a number of broadleaf plants, including: rose, honeylocust, and flowering plum. Hand-picking small caterpillars (along with their accompanying bag) and placing them into a container of soapy water will kill them directly. This practice, if feasible, will quickly remove populations before they can cause substantial plant damage.

For those not interested in hand-picking, a number of insecticides are labeled for use against bagworms including those with the following active ingredients (trade name in parentheses): acephate (Orthene), Bacillus thuringiensis subsp. kurstaki (Dipel/Thuricide), cyfluthrin (Tempo), lambda-cyhalothrin (Scimitar), trichlorfon (Dylox), indoxacarb (Provaunt), chlorantraniliprole (Acelepryn), and spinosad (Conserve). Many of these active ingredients are commercially available and sold under different trade names or as generic products. However, several insecticides may not be directly available to homeowners. The key to managing bagworms with insecticides is to apply early and frequently enough in order to kill the highly susceptible young caterpillars that are feeding aggressively on plant foliage (Figure 1). Older caterpillars that develop

 

Figure 1. Young Bagworm Feeding On Conifer (Author-Raymond Cloyd, Kansas State University)

 

later in the season (Figure 2) are typically more difficult to kill with insecticides. Furthermore, females feed less as they prepare for reproduction, which reduces their susceptibility to spray applications and any residues. The bacterium Bacillus thuringiensis subsp. kurstaki is active on young caterpillars; however, the active ingredient must be consumed to be effective, so thorough coverage of all plant parts and frequent applications are required. This compound is sensitive to ultra-violet light degradation and rainfall, which reduces residual activity. Spinosad is the active ingredient in a number of homeowner products, including: Borer, Bagworm, Tent Caterpillar and Leafminer Spray; Captain Jack’s DeadBug Brew; and Monterey Garden Insect Spray. These products work by contact and ingestion (stomach poison) although they are most

 

Figure 2. Older Bagworms (Author-Raymond Cloyd, Kansas State University)

 

 

effective when ingested and can be used against older or larger bagworm caterpillars (Figure 3). Cyfluthrin, lambda-cyhalothrin, trichlorfon, chlorantraniliprole, and indoxacarb may be used against both the young and the older caterpillars. However, thorough coverage of all plant parts, especially the tops of trees and shrubs, where bagworms commonly initiate feeding, and frequent applications are required. The reason multiple applications are needed when bagworms are first detected is because young bagworms “blow in” (called ‘ballooning’) from neighboring plants on silken threads. If left unchecked, bagworms can cause significant damage, and ruin the aesthetic quality of plants. In addition, bagworms may actually kill plants, especially newly transplanted small evergreens, since evergreens do not usually produce another flush of growth.

 

Figure 3. Captain Jack’s DeadBug Brew (Author-Raymond Cloyd, Kansas State University)

If you have any questions regarding the management bagworms contact your county horticultural agent, or university-based or state extension entomologist.

 

 

Carpenter Bees

–By Dr. Jeff Whitworth and Dr. Holly Schwarting

Carpenter Bees have been very active all across the state for the preceding 7-10 days and the noticeable activity may continue for another week or two.  These large (3/4 to 7/8 inch) black and yellow bees are most often mistaken for bumble bees.  However, carpenter bees, even though around the same size and flying at about the same speed, have bare abdomens while bumble bees have hairy abdomens.  Carpenter bees thus have shiny, dark blue to black abdomens while most bumble bees have hairy yellow abdomens.

Most folks do not want to get close enough to any large bee to make these distinctions, and they are even more difficult to distinguish when they are flying.  But, if you have large black and yellow bees hovering around any wooden structures and they are ‘dive bombing’ or buzzing around intruders into their area, i.e. you, neighbors, pets, etc. they are most likely carpenter bees.  It is the males that are buzzing intruders and they can be distinguished by their ‘bald faces’ which appear to have a yellow triangle in the middle of a black face.

These males cannot sting; they are just very territorial because they are waiting for a female bee to emerge from one of the holes in the wood so they can mate with her. This dive bombing behavior will continue until all the new females have mated, then the males will die and the noticeable activity will cease.  These females will then excavate new holes or extend established ones located in older, untreated, unpainted wood where they provision cells with nectar and pollen and then deposit eggs.  The larvae feed on these provisions throughout the summer, and then pupate.  The next generation of adults typically does not become active until the following spring.  While carpenter bees are not social bees, populations may build up in favorable locations and over years of repeated excavating, can weaken even structural wood.  For more information on carpenter bee biology and management, please visit: https://www.bookstore.ksre.ksu.edu/pubs/MF2946.pdf

Beneficial Insects – Instructional Videos

— Dr. J.P. Michaud – Hays, KS

We have produced a series of short, instructional videos on the various beneficial insects contributing to biological control of sugarcane aphid.

These videos describe how to identify various life stages of the important groups of predators and provide information about their basic biology, ecology and life history.

 

Lady beetles: https://youtu.be/3kz2OcF76pU

Hoverflies: https://youtu.be/9GxUWy1Rk2E

Lacewings: https://youtu.be/q0R6D-PX8-k

The interplay between host plant resistance to aphids and biological control: https://youtu.be/KxI7CQ7DYt0

 

Termites vs Ants

–by Dr. Jeff Whitworth and Dr. Holly Schwarting

Termite and ant colonies have been very active over the past week or so and are producing reproductives or ‘swarmers’.  We have seen flying/fluttering individuals every place we have stopped throughout north central Kansas, as long as it was between about 10am and 4pm.  Thus, we have received many calls regarding the differences between reproductive ants versus reproductive termites, in both cases often just referred to as ‘swarmers’.  This swarming behavior seems to be initiated about the same time each year for both ants and termites as the same type of warm, wet weather evidently triggers both.  Thus, it is imperative to be able to distinguish the two as they do very different kinds of damage and consequently require different management plans.

Termite reproductives, or swarmers, are dark brown to black, with transparent or translucent wings of equal size, and the dark body is cigar shaped, having no noticeable body divisions or waist.  Termite antennae are straight and lack a club on the end.  Ant reproductives, or swarmers, are also dark brown to black with transparent or translucent wings, but the fore or front wings are a little longer than the bottom or back wings.  Ant antennae are elbowed, coming out perpendicular to the head then bending forward at a 90 degree angle.

For more information on ant identification, biology, and control, please visit:  https://www.bookstore.ksre.ksu.edu/pubs/MF2887.pdf

For more information on termite identification, biology, and control, please visit: http://www.bookstore.ksre.ksu.edu/pubs/mf722.pdf

 

 

European Elm Flea Weevil

–by Dr. Raymond Cloyd

   

We are seeing damage on elm (Ulmus spp.) trees caused by the larval stage of the European elm flea weevil (Orchestes alni). Larvae are cream-colored, legless (Figure 1),

Figure 1. European elm flea weevil larva

and found in the mines of leaves. Adults are 3.0 mm in length, red-brown in color with black spots or markings on the abdomen or wing covers (Figure 2).

Figure 2. Adult European elm flea weevil.

 

The mouthpart is shaped-like a snout (Figure 3)

 

Figure 3. European elm flea weevil adult (note the snout-like mouth)

since they are weevils and the hind legs are thickened and enlarged, which allows the adults to jump when disturbed. Adults are initially active in May, and after mating, females lay eggs in the large mid-veins of new leaves. Eggs hatch into larvae that tunnel through the leaf as they feed (which is occurring now), creating serpentine-like mines that enlarge as larvae mature (Figure 4).

Figure 4. Serpentine mines created by European elm flea weevil larvae.

Larvae eventually transition into a pupal stage, and then adults emerge in May and June. Adults primarily feed on leaf undersides creating small holes on young leaves (Figure 5).

Figure 5. Feeding damage caused by European elm flea weevil adult.

 

The feeding damage caused by both the larvae and adults will not kill an elm tree; however, extensive feeding may ruin the aesthetic appearance. Adults overwinter under loose bark and in leaf litter under previously infested trees. There is one generation per year in Kansas. Nearly all elm species are susceptible to feeding by the European elm flea weevil especially Siberian elms (Ulmus pumila) and certain elm hybrids with Asian parentage.

Management of European elm flea weevil involves maintaining proper tree health by means of watering, mulching, pruning, and fertilizing. Insecticides may be used to minimize damage; however, insecticides may be difficult to apply to large trees. Insecticides must be applied in May and June in order to suppress adult populations. A number of insecticides may be used including: acephate (Orthene), imidacloprid (Merit), or carbaryl (Sevin). However, if damage is not extensive, especially on large trees, then there be no rationale for using insecticides. For more information regarding European elm flea weevil management contact your county or state extension specialist.

 

 

 

 

 

Clover Mite

–Dr. Raymond Cloyd

We have received inquiries regarding homes being invaded by populations of the clover mite, Bryobia praetiosa. This is the time of year when clover mites can be found entering homes, apartments, and commercial buildings, with large numbers crawling around and causing people to “freak out.” In general, clover mites enter buildings from the sunny-side or southwest exposure. They can aggregate in large numbers in the corners of buildings (Figures 1 and 2). Clover mites are primarily considered a nuisance pest because they do not bite humans. However, clover mites will leave a red stain when purposely or accidently crushed.

Figure 1. Cluster Of Clover Mites In Corner Of Building

 

Populations of clover mites only consist of females since males have never been found (we may need to look harder). Adult clover mites are slightly larger than a pinhead (1/30-inch long), red in color, with extremely long, pink front legs that may be used to distinguish clover mites from other mite pests. Clover mites overwinter as eggs in protected locations and there is usually one generation per year. Adults feed on over 200 plant types including: clover, grasses, ivy, honeysuckle, apple, and elm. Clover mite populations can be extensive in well-fertilized turfgrass near foundations, and their feeding will cause turfgrass to appear silvery or frosty.

Figure 2. Extensive Population Of Clover Mites Entering Building

The management of clover mites involves the following: 1) remove turfgrass near building foundations; 2) place an 18 to 36-inch wide band of an inorganic mulch around the foundation; 3) mow and trim turfgrass as short as possible; 4) avoid over-fertilizing turfgrass, especially with water-soluble nitrogen-based fertilizers; 5) remove weeds growing around the foundation; 6) remove or limit the growth of ivy or other host plants growing around the foundation or walls; 7) use plants near the foundation that are not typically attractive to clover mites, including: marigold, petunia, geranium, arborvitae, and/or yew; and 8) caulk or seal cracks or openings in the foundation or around window seals. Clover mites inside a home or building can be vacuumed up, however, be sure to avoid crushing them. Applications of insecticidal soap (potassium salts of fatty acids) will kill clover mites on contact. You can trap/capture clover mites on saran wrap (Figure 3) or a hardened surface coated with a sticky substance and position by openings such as window seals. If necessary, consult with a pest management professional for recommendations regarding perimeter treatments of pesticides (miticides) to keep clover mites from entering homes or buildings.

Figure 3. Clover Mites Captured On Saran With Sticky Substance

 

 

European Pine Sawfly

–Dr. Raymond Cloyd

Yesterday (April 17, 2017) European pine sawfly, Neodiprion sertifer larvae were detected feeding on my “indicator pine” in Manhattan, KS (I was totally excited!). Young caterpillar-looking larvae are 1/4 inch in length and olive-green in color with a black head (Figures 1). Mature larvae are >1.0 inch long with green stripes. The larvae are gregarious or feed in groups on needles of a variety of pines, especially Scotch, red, and mugo pine. When disturbed, each individual larva will arch their head and abdomen (last segment of an insect body) back, forming a “C-shape” (Figure 2), which is a defensive posture to ward-off predators.

Figure 1. Young European Pine Sawfly Larvae

Eventually, larvae will strip the needles of mature foliage, leaving only the central core, which is white and then turns brown (Figure 3). In general, larvae complete feeding by the time needles emerge from the candelabra. Therefore, those really is only a minor threat of branch or tree death resulting from sawfly larval feeding. However, the loss of second- and third-year needles will be noticeable in landscape trees; thus ruining their aesthetic appearance. In late spring, larvae drop to the ground and pupate in brown, leathery cocoons located at the base of trees. Adults, which are wasp-like, emerge in fall and lay eggs in needles prior to the onset of winter. There is one generation per year in Kansas.

Figure 2. European Sawfly Larvae In A Defensive Posture (Arching Head And Abdomen Back)

Sawfly larvae look-like caterpillars; but, they are not caterpillars (Order: Lepidoptera). Sawflies are related to ants, bees, and wasps (Order: Hymenoptera). The primary way to distinguish a sawfly larva from a caterpillar is by the following: 1) sawfly larva have prolegs (fleshy abdominal legs) on every abdominal segment whereas caterpillars are missing prolegs on the abdomen and 2) caterpillar larva have hairs or crochets on their feet whereas sawfly larva do not have hairs or crochets on their feet.

Figure 3. Feeding Damage To Pine Caused By European Pine Sawfly Larvae

Sawfly larvae are not caterpillars, therefore, the bacterial insecticide, Bacillus thuringiensis subsp. kurstaki (sold as Dipel) will not directly kill sawfly larvae. Dealing with sawfly larvae involves hand-picking (you can wear gloves if you wish) or dislodging larvae from plants by means of a forceful water spray. If necessary, there are a number of insecticides that may be applied to suppress European pine sawfly populations including: acephate (Orthene), azadirachtin, carbaryl (Sevin), spinosad (Captain Jack’s DeadBug Brew and Conserve), and any pyrethroid insecticide (e.g., bifenthrin, cyfluthrin, and lambda-cyhalothrin). Be sure to read the insecticide label to make sure that sawflies are listed. For more information regarding European pine sawfly management contact your county or state extension specialist.

 

Ash/Lilac Borer: Don’t Get “Bored-Down” By This Caterpillar Borer

–by Dr. Raymond Cloyd

 

        The time of year has come to be thinking about dealing with the ash/lilac borer (Podosesia syringae). First, you need to understand that this is not the same insect pest as the Emerald ash borer (Agrilius planipennis), which was recently discovered (March 31, 2017) in Doniphan County (Kansas now has 7 counties under quarantine). Emerald ash borer is a wood-boring beetle whereas the ash/lilac borer is a wood-boring caterpillar. Ash/lilac borer adults are generally active from mid-April through early-May. Adults are brown, clearwing moths that resemble paper wasps (Figure 1). Peak moth activity commonly occurs from May through June; however, this depends on temperature. Adult females lay tan-colored, oval-shaped eggs in cracks and crevices, or wounds at the base of plant stems. A single female may live approximately one week and lay up to 400 eggs. Below are the major life history parameters and management strategies affiliated with the ash/lilac borer:

Figure 1. Ash Lilac Borer Adults Mating

 

* Larvae cause plant damage by creating tunnels and feeding within the bark (cambium). Moreover, larvae may bore further into the wood and feed within the sapwood and heartwood.

 

* Feeding by the larvae restricts the flow of water and nutrients causing shoot or branch dieback. Ash/lilac borer primarily feed near the base of plant stems creating swollen areas or cracks at the base of plants, and where major branches attach to the trunk.

 

* Evidence of larval feeding includes the presence of light-colored sawdust that accumulates at the base of infected trees or shrubs.

 

* Ash/lilac borer overwinters as a late-instar larva located in feeding tunnels or galleries.

* To determine if trees or shrubs are or have been infested with ash/lilac borers check for the presence of brown papery pupal cases that protrude from the bark (Figure 2). These are the pupal cases where adults emerged from.

 

* In Kansas, there is generally one generation per year.

Figure 2. Pupal Cases of Ash Lilac Borer Protruding From Tree Trunk

 

* The way to avoid problems with ash/lilac borer is to minimize “plant stress” by properly implementing cultural practices, such as; irrigation (watering), fertility, pruning, and mulching. Stressed plants are more susceptible to attack than so called “healthy plants.” A two to three foot wide mulched area around the base of trees and shrubs prevents injury from lawn mowers and weed-trimmers. In addition, avoid pruning plants in late spring through early summer (under usual weather conditions), because this is when adults are typically present and the volatiles emitted from pruning cuts may attract adult females.

* Insecticides containing the active ingredients, permethrin or bifenthrin can be applied to the bark, at least up to six feet from the base, in order to prevent ash/lilac borer larvae from entering plants after eggs hatch. Clear-wing borer larvae crawl on the bark searching for entry points, which exposes them to insecticide residues.

 

* Pheromone traps are commercially available for capturing adult males (Figure 3), which helps to determine when females will be laying eggs. Pheromone traps help in timing insecticide applications. Insecticide spray applications should begin seven to10 days after capturing the first adults. Be sure to also check pheromone traps two to three times per week and record the number of newly captured adult males.

 

Figure 3. Pheromone Trap Used To Capture Ash Lilac Borer Adult Males

 

* For more information regarding ash/lilac borer management contact your county or state extension specialist.

Ant and Termite Swarms

— by Dr. Jeff Whitworth and Dr. Holly Schwarting

It is that time of year again when termites and ant colonies start producing ‘swarmer’s’.  Swarms of flying ants have already been noted in the last week.  After all of the moisture, and as the temperatures warm into the 70s°F and above, both ant and termite swarming will become more apparent.  Only the adult reproductives of both ants and termites have wings and can fly.  These flights, or more rightly probably called flutters, are of short duration and usually start mid-to-late morning as temperatures warm into the 70’s.  These swarms can contain up to thousands of winged individuals and often attract the attention of birds and other predators that take advantage of these poor flyers for an easy meal.  It is important to distinguish between ants and termites because termites can be very destructive of just about anything made out of wood while ants are more of just a nuisance.  The following can help distinguish between ants and termites.

 

For more information regarding ant and termite biology and control please see these publications:

ANTS – https://www.bookstore.ksre.ksu.edu/pubs/MF2887.pdf

TERMITES – http://www.bookstore.ksre.ksu.edu/pubs/mf722.pdf

 

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