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Extension Entomology

Tag: north central Kansas

Corn Update

Posted on by Sharon Schroll

By — Dr. Jeff Whitworth, Dr. Holly Schwarting

Most corn has been planted in SC and NC Kansas, although some has been struggling somewhat with the cooler temperatures, wet soils, etc.  Whatever the case, please remember insecticide seed treatments do a good job of protecting the seed and germinating plants, but not forever.  About 3-4 weeks of protection from the time of planting can be expected but after that, wireworms, white grubs, etc. may affect the seedlings, especially under less than ideal growing conditions.

Alfalfa Update

Posted on by Sharon Schroll

By — Dr. Jeff Whitworth, Dr. Holly Schwarting

Alfalfa continues to be problematic in NC Kansas.  There seems to be many fields of good alfalfa, apparently treated in an effective manner from both an insecticide and a timing standpoint, and not affected by the freezing temperatures earlier this spring.  Many of these fields have been, or are being, swathed.  However, there are some fields that have had, or are having, a difficult time overcoming the combination of alfalfa weevil larval feeding, early season dry conditions, and the early spring freezing temperatures.  In all fields, the early season warmth sped up alfalfa weevil development and feeding, then the cooler temperatures slowed it back down.  Alfalfa weevil larvae were 1st detected in NC Kansas in early March.  Small, 1st instar larvae are still being detected in some fields.

AW larvae 13

Some larvae pupated and developed into adults as long as three weeks ago, and they are still in the alfalfa fields.  So, NC Kansas still has a significant number of adults.  Treating for adult alfalfa weevils is rarely effective, but swathing within 7-10 days should help manage both larvae and adults without an insecticide application.

AW adult

Adult potato leafhoppers have also been noted in alfalfa fields.  These usually migrate into Kansas between the 2nd and 3rd cuttings, so they are about a month early this year. Leafhopper adult (2)

Wheat

Posted on by Sharon Schroll

–by Dr. Jeff Whitworth and Dr. Holly Schwarting

 Still finding aphids in wheat throughout NC and SC KS. But in all fields sampled last week there were many lady beetles and mummies, indicating the beneficials are also very active. Spraying aphids will kill most of the aphids at the top of the plants– but won’t kill all the aphids down in the canopy just because the leaves in the canopy intercept the spray. But it will, typically anyway, kill all the beneficials as they move around searching for aphids to consume. Therefore, it is rarely a good idea to add an insecticide to a fungicide application to save application costs UNLESS the insecticide is warranted-not “just in case”

 

Wheat Update

Posted on by Sharon Schroll

–Dr. Jeff Whitworth and Dr. Holly Schwarting

Last week wheat aphid populations were active and had increased considerably from the previous couple of weeks in north central Kansas.  Populations of bird cherry-oat aphids, English grain aphids, and greenbugs were all reproducing and still migrating in.  This week however, in fields we sampled in north central Kansas, the aphid populations had decreased drastically and the beneficials, especially lady beetles, had increased greatly.

Lady beetle larva 2

lady beetle adult

Last week these English grain aphids were inadvertently identified as greenbugs.

English grain aphids

Wheat Update

Posted on by Sharon Schroll

–by Dr. Jeff Whitworth and Dr. Holly Schwarting

Received a report from north central Kansas about a small wheat field infested with ca. 20 aphids/tiller, but the aphids weren’t identified.  All wheat fields we visited in the last week had aphids, including bird cherry-oat, English grain, and/or greenbugs.  However, we were only finding about 1/10 plants or less and beneficials (lady beetles, lacewings, and parasitic wasp activity) were present in all of these fields.  Most wheat averaged Feekes 6-8 and no other pests really have been noted.

Chinch Bugs

Posted on by Sharon Schroll

–by Dr. Jeff Whitworth and Dr. Holly Schwarting

Chinch bug populations are rapidly increasing in north central Kansas.  Until now, only adults have been detected, but that has now changed.  Very small nymphs (see pic) are starting to hatch and can now be found feeding behind leaf collars at the base of plants.  Adults (see pic) are still mating so chinch bug populations should be increasing for at least another month.  For more information on chinch bug biology and control, please visit:  http://www.bookstore.ksre.ksu.edu/pubs/MF3107.pdf

chinch bug numphs

 

chinch bug adults