Kudzu bugs on caneberries?

Kudzu bugs (Megacoptera criberia) on raspberry plants at the Piedmont Research Station, Salisbury, NC. Photo: PRS.

My Monday morning  began with two phone calls about the same thing: kudzu bugs on caneberries.  Both calls came from western North Carolina, but kudzu bugs are widespread throughout the southeast.  See here for a map of kudzu bug distribution from the Megacoptera Working Group.  Kudzu bugs (Megacoptera criberia) are yet another invasive species from eastern Asia that has been detected in the southeastern US in recent years.  Kudzu bugs appear to specialize on legumes, including cultivated beans and kudzu, and can cause cause economic damage to soybeans.  My NC State Entomology colleague, Dominic Reisig, has published extensive information on kudzu bug at his blog.  Interestingly, both caneberry sites that prompted my morning calls were also near soybeans.

Raspberry plants at the Piedmont Research Station, Salisbury, NC. Photo: PRS.

Kudzu bugs are also nuisance pests.  Like multicolored Asian ladybeetles and brown marmorated stink bugs, they congregate in structures to overwinter.  Also like these other two home invading invasives, kudzu bugs release stinky defensive chemicals when disturbed.  Migration to overwintering sites is likely happening right now, and this may be at least part of the reason we are currently seeing them on caneberries.  Primocanes may be attractive because they are relatively young when compared other surrounding vegetation.

Kudzu bug aggregation on a home. Photo: Danial Suiter, University of Georgia, via Bugwood Network.

It's unclear if kudzu bugs will feed on blackberries and raspberries.  Kudzu bugs have piercing mouthparts, so damage is often not visible right away.  Following kudzu bug feeding in soybeans, lesions appear on stems (their preferred feeding site).  Despite the fact that adult kudzu bugs can be present in soybeans in very high numbers, they do not appear to cause economic damage in that crop unless they are reproducing and nymphs are present.  Nymphs look markedly different than adult kudzu bugs.  They are smaller and fuzzy (see below). The treatment threshold in soybeans is 15 nymphs per 15 sweeps.  Soybean plants are extremely good at compensating for damage throughout their growing season, which likely contributes to this relatively high threshold.

Kudzu bug feeding lesions on soybean stem. Photo: Dominic Reisig, NC State Entomology

 

Late season kudzu bug damage on soybeans at the Sandhills Research Station. Photo: Jeremy Martin, Superintendent.

Kudzu bug nymphs on soybean. Reproductively active kudzy populations (where nymphs are present) can cause damage in soybeans.

If kudzu bugs are observed on caneberries, scout stems for lesions and nymphs.  If either are present, this would represent a new host for this insect, and that information should be communicated to me and your extension agent.  If kudzu bugs are not feeding on caneberries, they may just be stopping en route to their overwintering sites (structures, leaf litter, and other sheltered areas). This past spring, kudzu bugs were observed aggregated on several non host plants after exiting their overwintering sites.

SWD detections increase

Spotted wing drosophila (SWD) detections in the upper Midwest continue to increase.  SWD adults and larval damage is now confirmed from :
Illinois
Iowa
Minnesota 
Wisconsin

I'll have a detailed update on our SWD research, extension, and education efforts next week.

Welcome, Bill Cline!

Bill Cline describing Blueberry Stunt, Red Ringspot Virus, & Stem Blight the 2011 Blueberry Field Day. Photo: HJB

As you may have noticed below, NC State Plant Pathologist and overall blueberry expert, Bill Cline has joined the blog and will be posting updates on blueberry insects.  Bill is much closer to the heart of North Carolina blueberry production than I am, so I am excited that he will be able to share insect sightings as they happen.

Flea beetle damage on blueberries

Flea beetle damage has been observed on unsprayed blueberry plots at the NCSU Horticultural Crops Research Station in Castle Hayne.  Feeding is mostly on new succulent shoots that have emerged following post-harvest summer pruning (hedging), so these are next year's bearing shoots that need to retain their leaves in order to set flower buds for the 2013 crop. Much of the damage is cosmetic, but where shoots are completely defoliated, or the shoots themselves are eaten, yield will be reduced in 2013.

 Flea beetles are rarely a problem on blueberry in North Carolina, but are more widely observed (and reported) on blueberry in Florida and Georgia.

Another reason to appreciate bees & wasps in grapes

At last Friday's vineyard tour, one of the most common insect questions I get from grape growers again came up. "What can I do about wasps and (less commonly) bees in my grapes?"

My feelings are clear on this subject. I think there is little to be gained from using insecticides against these mostly beneficial insects and significant harm that could be done, both through extending your harvest window and by harming predators and pollinators.  You can read my thoughts on this subject and what growers can do instead of spraying, here.

Today, I read about an even better reason to appreciate wasps, in particular, in your vineyard.  NPR's The Salt blog highlights research from Italy that demonstrates that wasps move wine-fermenting yeasts throughout vineyards and have likely contributed to the evolution of these important yeasts.  You can find the full article here.

More information
What to watch for - Bees and wasps in grapes
Thank the simple wasp for that complex glass of wine - The Salt
Role of social wasps in Sacromyces cerevisiae ecology and evolution - Proceedings of the National Academy of Sciences

Spotted wing drosophila detected in Arkansas

On July 9th, Donn Johnson at his team at the University of Arkansas detected the first spotted wing drosophila adults in Arkansas.  You can read about this find here and see the trap capture data at the SWD*VMN.

Spotted wing drosophila biology and management in North Carolina strawberries

The third in my summer series of spotted wing drosophila (SWD) factsheets focuses on strawberries.  Please note, factsheets are shared via Google Documents, which is great for quickly and easily posting files but does sacrifice image quality.  If you would like a printer quality digital copy of this factsheet. Please email me.


You can find the first factsheet on SWD biology and management in North Carolina caneberries here and the second on post harvest SWD significance and sampling here.



This Thursday I will be attending a strawberry field day in Watauga County, NC at a farm that grows day neutral (summer fruiting) strawberries and sharing information from this factsheet as well as results from our spring strawberry SWD management experiments at the Central Crops Research Station. Day neutral strawberries present unique SWD management challenges because they fruit through fall, when the highest SWD populations of the year occur.  You can read more about day neutral strawberries at the North Carolina Strawberry Association's blog.

More information
Strawberry field day - Watauga County Cooperative Extension