Uncategorized

Once again, Drs. Dave Voegtlin (retired entomologist, Illinois Natural History Survey) and Dave Hogg (Professor of Entomology, University of Wisconsin) conducted their annual spring survey of soybean aphids. From May 12-17, they looked for soybean aphids on the primary host — common buckthorn, Rhamnus cathartica. At some sampling locations, they also examined the glossy buckthorn, Frangula alnus. The overall assessment by these entomologists — there were fewer soybean aphids this spring as compared with the previous 2 years.…

Larry Bledsoe and his Purdue University entomology colleagues have a long tradition of being the first to report the annual hatch of western corn rootworm larvae. Larry  indicated to me and some other entomologists that hatch began to occur on June 2 on one of the research farms near the Purdue University campus.
Provided below is a list (19 years) of western corn rootworm hatch dates (for central Illinois and central Indiana) taken from previous Pest Management and Crop Development Bulletin articles (since 1996) and based upon observations by Larry Bledsoe and other  Purdue University entomologists.…

Reports of potato leafhoppers in alfalfa typically begin to increase in late May and early June. Many entomologists consider potato leafhoppers to be the most significant economic insect threat to profitable alfalfa production. Recently a team of entomologists from the University of Wisconsin, the Illinois Natural History Survey, and the USDA ARS authored a peer-reviewed pest profile of potato leafhoppers. This profile offers up-to-date information on the biology, life cycle, injury, hosts, and management options for this key pest in alfalfa.…

There have been scattered reports of armyworm infestations in southern Illinois wheat with some fields receiving an insecticide treatment. I encourage producers to review the biology, life cycle, and management information in the University of Illinois fact sheet on armyworms. With respect to economic thresholds, there is some variation from state to state. Provided below are thresholds from four land grant universities for consideration. They share some common features. If an insecticide rescue treatment is warranted,…

Significant flights of black cutworm moths were reported in several counties of Illinois during mid-April. Based upon these captures of moths in pheromone traps, projected cutting dates are offered for the following counties: Champaign (May 20), Fayette (May 11), Logan (May 14), Madison (May 11), Pike (May 17), and Warren (May 18). Fields most at risk to economic infestations include those that are planted late and infested with winter annuals. Weedy fields are often targeted for egg laying by these strong migratory moths.…

On August 24, 2012, in cooperation with Dr. Aaron Gassmann’s laboratory, Iowa State University, I confirmed the evolution of field resistance by western corn rootworms to the Cry3Bb1 protein in some problem fields located in northwestern Illinois (Henry and Whiteside Counties). During the summer of 2012, Dr. Joe Spencer, Illinois Natural History Survey, received suspected Bt-resistant western corn rootworm adults that had been collected in continuous cornfields in McDonough, Mercer, and Sangamon Counties. Eggs were obtained from these adults in the laboratory.…

The winter of 2013-14 will long be remembered as one of the snowiest and coldest since the late 1970s for many midwestern states. Not surprisingly,  many questions have surfaced regarding the impact of these cold temperatures on the overwintering survival of western corn rootworm eggs. Research on this topic has only sparingly occurred. In my estimation, one of the best field studies on this challenging research area, was undertaken by an Iowa State University graduate student,…

On February 20, 2014, a webinar was presented by five land grant entomologists (see below) concerning western corn rootworm management challenges and recommendations. As we move forward this year, there remain many lingering concerns regarding the root protection performance of some Bt hybrids in light of the evolving resistance to certain traits. The live webinar was well received (over 300 participants); however, for those unable to take part in this session, you can now view the recorded session. …