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Extension Entomology

Author: kansasbugs

Wheat – Aphids

Posted on by kansasbugs

—by Dr. Jeff Whitworth and Dr. Holly Schwarting

Aphids, mainly bird cherry oat and greenbugs continue to migrate into wheat fields throughout north central and south central KS (see photos). When temperatures are warmer and winds are from the south, these aphids are migrating/blowing in, in significant numbers. However, we did note some mummies (parasitized aphids) in these fields so these little wasps are active and will probably help control these pests if insecticides are not used in these fields.

difference between aphid species

 

 

Alfalfa – Weevils and Aphids

Posted on by kansasbugs

—by Dr. Jeff Whitworth and Dr. Holly Schwarting

Alfalfa weevils continue to be very active in north central Kansas. The recent cooler weather has slowed down development a little but they are still feeding. We determined development from larvae collected on 20 and 22 April. Here is what the population breakdown looks like:

20 AprilNo. larvae   23 April No. larvae
12 1st Instars 4
25 2nd Instars 16
15 3rd Instars 30
   numerous Pupae numerous

alfalfa weevil

So what does this mean? Alfalfa weevil larval feeding will continue for another 7-10 days, depending on the weather. Egg hatch and consequent larval feeding has been going on since 13 March in north central KS. Insecticides applied since that time have provided adequate protection, for the most part.

field trial

This photo shows KSU chemical efficacy trials with many different products being tested, and the obvious untreated plots plus the border around the plots. The rest of the field was treated with Stallion® by MKC in Abilene, KS and, as illustrated here seemed to work relatively well with 1 application. Remember, feeding will continue for at least another week and therefore treatment (or re-treatment) may still be appropriate.

Alfalfa aphids, mainly pea aphids, are becoming more numerous throughout north central Kansas. Treating for alfalfa weevils probably pretty much decimated the natural enemies/beneficials and they will not repopulate as quickly as the aphids migrate in to infest fields.

 

HopGuard II Section 18 Approved for Kansas

Posted on by kansasbugs

—by Sharon Dobesh

For Kansas beekeepers interested in using HopGuard II for varroa mite control, the 2015 section 18 was approved effective April 13, 2015 through December 31, 2015. The active ingredient in HopGuard is 16% potassium salt of hop beta acids, which offers an alternate chemistry against varroa mites and is considered to be a more natural or ‘softer’ chemistry.

The use directions for HopGuard II in the colony at a rate of one strip per five deep frames covered with bees in each brood chamber. Strips must be opened and hung over the frame, two strips per ten frame super. There is a maximum of three applications per year per super (i.e. six strips per year super) is allowed. Application should occur based on varroa mite levels in the colony. For optimal results, little to no brood should be present in the colony.

Inspections

The Kansas Department of Agriculture needs beekeepers, who are current users of HopGuard, to volunteer for required Section 18 inspections. If you use HopGuard and would allow KDA to come inspect HopGuard use in your hive(s), please contact Judy Glass, judy.glass@kda.ks.gov. Judy will need your name and contact information to follow-up. These inspections should not take longer than an hour to complete (probably less), but are required data for EPA in order for Kansas to continue to apply for Section 18 status. All volunteers may not be inspected.

Contact Sharon Dobesh (sdobesh@ksu.edu or 785-532-1340) if you have any questions regarding the section 18 approval, need a copy of the HopGuard II label, or the KDA inspections.