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Extension Entomology

Tag: stink bugs

Soybean Update – Green cloverworms and Stink bugs

–by Dr. Jeff Whitworth and Dr. Holly Schwarting

Green cloverworm adults are quite numerous and are laying eggs in alfalfa and soybeans.  So, there are, or will soon be, small larvae present.  Feeding by green cloverworms will probably not impact alfalfa or most soybean fields unless there are significant larval populations in really late planted fields.

 

 

Stink bug populations seem to be increasing in north central Kansas but most beans should be far enough along in their development that stink bugs should be of little concern.

 

For management decisions for all soybean pests, please refer to the 2017 Soybean Insect Management Guide: https://www.bookstore.ksre.ksu.edu/pubs/MF743.pdf

Soybean Update – Thistle caterpillars, Stink bugs, and Soybean Aphids

–by Dr. Jeff Whitworth and Dr. Holly Schwarting

Thistle caterpillars have mostly vacated their webbed cells and are or have pupated.  That is why there are huge numbers of painted lady butterflies flying around on most rural roads throughout north central Kansas.  Hopefully, these butterflies will head south for overwintering and will not start laying eggs in soybean or sunflower fields.  However, fields need to continue to be monitored for small thistle caterpillars, especially double-cropped soybeans. Additionally, monitor for the continued presence of green cloverworms, although these populations seem to be declining quite rapidly around north central Kansas.

 

Phytophagous stink bugs, both brown and green, are increasing in many soybean fields.  Either may insert their mouthparts into the seed within the pods and suck out juice from the developing seed.  However, there are also brown stink bugs that are predatory on pests like the yellowstriped armyworm (shown below) which has been killed and is being utilized as a food source by this beneficial stink bug.

 

Soybean aphid populations are still present in all fields examined this week in north central Kansas, but are not increasing in density or coverage.

 

 

For management decisions for all soybean pests please see the 2017 Soybean Insect Management Guide: https://www.bookstore.ksre.ksu.edu/pubs/MF743.pdf

 

Soybean Pest Update

— by Dr. Jeff Whitworth and Dr. Holly Schwarting

Green Cloverworms in Soybeans

Remember a few weeks ago when there was considerable concern relative to all the green cloverworms causing irregular holes in leaves? Even skeletonizing some areas of some fields until treated with an insecticide and/or and entomopathogenic fungus started decimating the larval populations?   Well, the surviving larvae pupated and now are annoying little aerodynamically shaped dark brown moths flying around lights at night or trying to get in through doors and windows.

gcw-close

gcw-defol

gcw-fungus

gcw-adult

These moths will mate and then begin ovipositing in soybean and/or alfalfa fields.  Eggs hatch in approximately 10-14 days and the larvae will again start feeding on leaves of either crop.  By this time of year, the larval feeding is usually of little consequence relative to yield.  However, really late planted soybeans, and all alfalfa fields, should be closely monitored to ensure leaf feeding in either crop does not affect pod fill in soybeans or leaf area in alfalfa.

 

Soybean Podworms

These insect pests seem to be on about the same developmental schedule as green cloverworms.  So, late planted soybeans may be at risk for bean feeding within the pods.

cew-adult

cew-pod-damage

 

Adult bean leaf beetles, while probably not as numerous as in past years, may still be feeding on the pods themselves.  This can cause yield reductions.  For more information on bean leaf beetle biology and control, please visit: https://www.bookstore.ksre.ksu.edu/pubs/MF2824.pdf

blb-adult

blb-feeding-pod

Woollybear Larvae

Another leaf feeder that can cause concern this time of year is woollybear caterpillars.  There are several different species but all are foliage feeders although they rarely cause any economic problems.

woollybear-white

woollybear-orange

 

Stink Bugs

Hopefully, most soybeans are past the stages that are succulent enough for stink bugs to be feeding on.  However, there are still some late planted beans setting pods with seeds that may be vulnerable to stink bug feeding.  So, until pods are turning yellow or brown, fields probably should continue to be monitored for soybean podworms, adult bean leaf beetles, and stink bugs.

green-stink-bug

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