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Extension Entomology

Month: October 2015

Commercial Applicator Recertification Training Programs

–by Frannie Miller, Pesticide & IPM Coordinator

November 10, 2015 – Right-of-Way, Industrial Weed and Noxious Week Category 6, 7C and 9A – 8:00am to 5:00pm Abilene Civic Center, Abilene, KS.

November 12, 2015 – Right-of-Way, Industrial Weed and Noxious Weed Category 6, 7C and 9A – 8:00am to 5:00pm Agricultural Research Center, Hays, KS.

November 16, 2015 – Aquatic Pest Control Category 5 – 8:30am to 4:30pm McPherson Extension Office, McPherson, KS.

Sugarcane Aphids

–by Dr. Jeff Whitworth, Dr. Holly Schwarting and JR Ewing

Sugarcane aphids were still active in north central KS on 23 and 27 October, as were the beneficials (see pics).  Fields were being harvested and getting acceptable yields (growers reported 80 to 160 bu/acre, which they said was usual for the fields involved) without much interference caused by the stickiness of the honeydew (and it is sticky).

SCA Oct_leaf

 

SCA oct head

 

beneficials - aphids

Below are the results of sugarcane aphid efficacy trials conducted in Saline Co.  Aphid populations were, in our opinion, ideal for conducting trials of this nature because there were enough aphids to show any differences caused by the treatments, but not so many that the plants were overwhelmed or that the grower sprayed the field (thereby over-spraying these plots).

SCA efficacy trial 1

 

Means within a column followed by the same letter are not significantly different (P>0.05; PROC ANOVA; Mean comparison by LSD [SAS Institute 2003]).

SCA efficacy trial 2

 

Means within a column followed by the same letter are not significantly different (P>0.05; PROC ANOVA; Mean comparison by LSD [SAS Institute 2003]).

Wheat Pests

–by Dr. Jeff Whitworth, Dr. Holly Schwarting and JR Ewing

Worms (fall armyworms and armyworms) are still active in wheat and can be for another month, depending upon the weather.  If growing conditions are good, the wheat should be able to outgrow feeding caused by small worms.  Large worms have probably caused most of their feeding damage already, and hopefully, won’t be able to pupate, emerge as adults, lay eggs and have those eggs hatch again this fall.  Winter grain mites may cause some concern in the next month or so, especially under dry conditions. However, insecticide applications are rarely warranted or impact next year’s yield.  Again, good growing conditions will mitigate winter grain mite feeding damage.

Current Status of Emerald Ash Borer in Kansas

–Dr. Bob Bauernfeind

Emerald ash borer surveillance activities began in 2008 when USDA APHIS PPQ in Topeka received purple prism traps from the US Forest Service (USFS).  From 2008 through 2015, PPTs have been deployed throughout Kansas in a cooperative program between USDA APHIS PPQ and Kansas Department of Agriculture (KDA) personnel.  This year, Lindgren traps were also utilized in trapping efforts.  THERE WERE NO EAB BEETLES COLLECTED FROM TRAPS THIS YEAR!  This was the final year of trapping efforts by USDA APHIS PPQ and Kansas Department of Agriculture (KDA) personnel because the US Forest Service will be contracting out trapping efforts.

Additionally, in an attempt to enhance the early detection on EAB presence, KDA workers initiated tree girdling activities in 2013 — the premise being that removal of an 8-12 inch portion of bark and phloem tissues encircling the entire trunk disrupts the translocation of water and carbohydrates (tree nutrients) creating a stress which causes a change in the aromatic chemicals produced and released by the bark, leaves and wood.  Also, tree foliage becomes more attractive to beetles due to altered coloration (reflected light wavelengths). Increased beetle presence equals increased egg laying which equals increased larval activities.  Substantiation of the presence of EAB would be based on the recovery of larvae in the subsequent peeling of the bark from branches and trunks.  On September 30, EAB larvae were recovered from a girdled tree in the town of Eudora.  Thus the intrastate quarantine in place for Wyandotte, Johnson and Leavenworth counties was expanded to include Douglas County.

In an interesting note, in 2014, no EAB larvae were recovered from a trap tree at the same site.

#8

Note the Red Arrow —- That was this year’s girdled trap tree from which the current larvae were recovered.  Old gallery patterns were indicative of the presence of EAB already in 2014.  Obviously that tree was initially attacked by EAB without its having been girdled to attract beetles.  Also, looking at the trees lining the street, EAB are likely present and responsible for their deterioration.

#9

“The Wheels On The Bus Go Round And Round” — A Rite Of The Fall Season — Wheel Bugs

–Dr. Bob Bauernfeind

This common musical refrain comes to mind each fall as BIG YELLOWS  roar back into action picking up and delivering kiddos to and from school.  Another commonly encountered fall harbinger is a large assassin bug which possesses a distinct dorsal thoracic crest:  the wheel bug.

#4

 

Actually, wheel bugs are frequently first noted in the beginning of summer.  However, they are not recognized as such due to their radically different appearance.  Wheel bug nymphs hatching from overwintered eggs are small, possess a red abdomen which is held in an elevated position, rapidly move about on long “spidery” black legs, and lack the adult’s characteristic “wheel”.  Wheel bug nymphs are the basis for reports of “small red biting spiders”.

#5

 

The proboscis is the “action end” of wheel bugs (both nymphs and adults).  Like the earlier described minute pirate bugs, wheel bugs are predators.  They use their piercing/sucking mouthpart to pierce through the integument of their prey.  During this probing process, they introduce a bit of paralytic saliva which immobilizes their prey as well as aiding in the liquefaction of internal elements which then are withdrawn.  Wheel bugs are opportunistic feeders and capable of rapid movement.  However, given the slooooow movement of caterpillars which are a known “favorite food” of wheel bugs, speed-of-capture would seem irrelevant.

Despite their reputation for inflicting a painful bite, they can be carefully handled.  It should be stated that wheel bugs are not aggressive in the sense of attacking people. If one offers a finger or a hand for a wheel bug to crawl onto, their first tendency is to shy away/hide.  However they may choose to lazily climb aboard.  Let them wander, and when tired of such, quickly flick them off.  Do not grab/hold onto them for that will invite a bite (actually, not a bite/chomp per se, but rather a defensive jab).

Just as a person can safely handle a snapping turtle by properly grasping onto the base of its tail, if one wishes to get a closer look at a wheel bug, while it is on a hard surface, use your index finger and thumb to properly grasp the wheel bug on the sides of its hardened thorax.  Use a toothpick or piece of straw to maneuver its proboscis forward, and you may see a small bubble produced at its tip —- this is the saliva which it uses to paralyze its prey (and that which causes the pain/sting on the receiving end of a defensive poke).

Another interesting feature has to do with the female wheel bug.  While in your finger-thumb grasp, as an expression of her annoyance, she may react by everting her reddish/orange anal glands which produce a substance with a distinctive odor.  This may be a defensive tactic.  It has also been suggested that it may act as a repellent offering protection to newly deposited egg masses.

#6

While the wheel bug is the most widely recognized assassin bug, there are many other species.

They vary in size and body shape.  While most are rather non-descript and dark-in-color (varying shades of brown or black), others can be brightly colored and patterned.  Although most prey upon insects, several species require blood meals for development and egg production.  The eastern bloodsucking conenose (Triatoma sanguisuga) is the representative species found in Kansas.  Typically feeding on a wide variety of mammalian wildlife, they have been known to also seek a blood meal from humans.  People may have heard about “kissing bugs” being responsible for transmitting Chagas Disease.  This is of significance in tropical countries where other Triatoma spp. are the major vectors.  Thus Kansans can be-at-ease.

#7

Yikes! What’s Biting Now? + Pepper-In-My-Paint = Minute Pirate Bugs (MPB)

–Dr. Bob Bauernfeind

Saturday afternoon as I was doing some house painting, I was feeling occasional “little irritations” on my arms and legs.  Looking at the points of discomfort, I recognized my little visitors:  minute pirate bugs – Orius spp.  And, looking in my paint bucket, more were “stuck” on the surface of the paint.

#1

Actually, this was nothing that I hadn’t experienced in the past.  I usually have a spring and summer list of projects.  I seem to put painting (not my chore of choice) off until the heat-of-summer is past, and then gallop to complete the task trying to beat colder weather.  Thus, mid- to late fall is when I am visited by MPB.  What draws them?  It’s not the paint color.  Whether ultra-bright white (for trim), or Coronado Tint Base 410-35 + B20C24F9 (a color for which there is no name) for the body of the house, they show up.  I surmise that the attractant is the paint odor being carried in the air.

Those that land on me take-a-taste.  This is not an unusual.  One way an insect determines whether it has landed on a “choice” food source is to take-a-taste.  While an insect with chewing mouthparts takes-a-bite/chomp, an insect with piercing/sucking mouthparts (such as a MPB) takes a “jab-and-sip”.  They must not get an instant result, because I have watched individuals lingering after their jab caught my attention.  But eventually, because I didn’t qualify as a satisfactory food source, they withdrew.  The fate of those in the paint bucket?  Given their small size, they are painted into and become a part of the coat of paint on my house.

#2

Are MPBs pests or not-a-pest?  While their bite (in my estimation) is but a minor irritation, in their proper place, MPB’s would be considered to be beneficial insects in their role as predators.  Close-up, they are distinctively marked.

#3

Given their small size (1 – 1 ½ mm), their natural prey are correspondingly small —- preferably insect eggs, mites, scale crawlers, thrips, aphids, small stage caterpillars. Using their styet-like mouthparts, they impale their prey and withdraw the body fluids.  They then abandon the spent carcass and search for their next victim.

MPBs mostly go unseen due to their small size.  Yet, they are common and can be found on flowering shrubs and weeds where they subsist on plant juices in the absence of prey.  However, in the presence of arthropod hosts, their true feeding preferences take over.  Both nymphs and adults have been cited to consume 30 or more spider mites per day.  And often times, adult MPBs are drawn to corn silks where they feed on/destroy eggs deposited by corn earworm moths.  MPBs are commercially available and can be useful when released in enclosed facilities such as greenhouses.  But for home gardeners, purchase-and-release tactics are impractical because released MPBs would likely take wing.  Rather, rely on their natural abundance to allow them (on their own) to find their way into home landscapes and gardens.

 

Wheel Bug: Be On The Look-Out For This Distinct “Bug”

by–Dr. Raymond Cloyd

If you have spent any time outdoors in the last month, you may have noticed a very distinct, grotesque looking insect on trees, shrubs, or near homes. This insect is the wheel bug (Arilus cristatus), which is common, and widely-distributed throughout Kansas and the USA. Wheel bugs, also referred to as assassin bugs, are predators that prey on insect pests. However, both the nymphs and adult can inflict a painful bite when handled by humans.

Adult wheel bugs are 1.0 to 1.25 inches long, robust with long legs and antennae, and have a stout beak and large eyes on a narrow head (Figure 1).

newFigure1WheelBugsMatingMaleonTopofFemale

 

Figure 1: Wheel Bugs Mating Male on Top of Female.
Figure 2: Wheel Bugs with Crest or Wheel on Thorax.

They are dark-brown to gray in color. The adults possess a wheel or crest with 8 to 12 protruding teeth-like structures (tubercles) on the thorax that looks like a cogwheel (Figure 2). Wheel bugs have two long, slender antennae that are constantly moving or weaving around. Females are typically larger than males. Females lay eggs that resemble miniature brown bottles with white stoppers (Figure 3).

newFigure3WheelBugEggs

 

Figure 3: Wheel Bug Eggs.

The eggs are laid in clusters of 40 to 200, and are glued together and covered with gummy cement, which protects the eggs from weather extremes and natural enemies (e.g. parasitoids and predators). The egg clusters are primarily located on the trunk or branches of trees or shrubs. The eggs hatch into nymphs that are bright red in color with black markings. The nymphs do not have the wheel or crest. The life cycle, from egg to adult, may take 3 to 4 months to complete. Wheel bugs are active day and night. They are very shy and tend to hide under leaves. The wheel bug has one generation per year and overwinters as eggs.

Wheel bugs are voracious predators and feed on a wide-variety of insects, including caterpillars (Figure 4), beetles, true bugs, sawflies, and aphids. Unfortunately, wheel bugs will feed on beneficial insects such as ladybird beetles and honey bees.

newFigure4WheelBugReadyToAttackCaterpillar

 

Figure 4: Wheel Bug Ready to Attack Caterpillar.

The mouthparts are red-brown in color and resemble a tube or straw that is located underneath the head (Figure 5) and extends out when ready to “stab” prey. Wheel bugs paralyze prey with their saliva, which contains a toxic substance that immobilizes prey within 30 seconds. In addition to feeding on insects, wheel bugs are cannibalistic, and will feed on each other.

newFigure5WheelBugsWithMouthUnderneathHead

 Figure 5: Wheel Bugs with Mouth Underneath Head.

Parsleyworm Or Black Swallowtail Caterpillars

by–Dr. Raymond Cloyd

This is the time of year we start getting inquiries regarding the parsleyworm or black swallowtail (Papilio polyxenes) caterpillars. The caterpillars primarily feed on the leaves of dill, fennel, and parsley although they will sometimes feed on plants such as Queen Anne’s lace, celery, and similar plants in the carrot family (Apiaceae or Umbelliferae). Young caterpillars are mottled black and white, which results in them resembling bird droppings. Mature caterpillars possess bands of green, yellow, white, and black. Furthermore, there are six yellow spots within each black band. Full-grown caterpillars can be up to 2.0 inches in length.

newFigure1Parsleyworm Caterpillar

Figure 1: Parsleyworm — October 2015

Parsleyworm overwinters as a pupa or chrysalis attached to the bark of trees, sides of buildings, or other protected habitats. Adults typically emerge in May and June, and mated females deposit eggs on plants in the Apiaceae or Umbelliferae family; laying several eggs per location. After eggs hatch, caterpillars feed for 3 to 4 weeks during which time they undergo a series of color changes as they mature. Full-grown caterpillars eventually move off plants to find a place to pupate. The caterpillars form gray pupae, which blend in with the surrounding background. After about two weeks, adults emerge from the pupa or chrysalis.

newFigure2Parsleywom Caterpillar

 

Figure 2: Parsleyworm Caterpillar

Adults are large black swallowtail butterflies with a wingspan of 2.0 to 3.5 inches. They are shiny black in color, occasionally with iridescent blue; and yellow bands or spots along the edge of the forewings and hindwings. The adults feed on the nectar of many different flower types. Females and males mate, and then females lay eggs that will result in the occurrence of the second generation sometime in August. There are usually two generations per year.

 

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