Entomology research in western Nebraska

By Gary L. Hein, Former Extension Entomologist
Panhandle Research and Extension Center
Now Director of UNL Doctor of Plant Health Program

Entomology was established early in the history of Panhandle Research and Extension Center, with numerous insect studies occurring during the first 50 years. These efforts encompassed numerous insects, but focused on potato insect pests.

Studies were undertaken by entomologists who primarily spent summers or shorter periods working in the Panhandle. Their work had a significant impact on the potato industry, but also impacted other agricultural commodities through the development of cultural and chemical recommendations for managing numerous pests.

Full-time entomologist

In the late 1950s, the importance of entomology research was recognized and an entomologist became one of the few disciplines to warrant a full-time position. Art Hagan began at the Panhandle Station in 1957, and his responsibilities at first were predominantly research. However, the demand from clientele for information resulted in his becoming more involved in extension, and his efforts eventually developed into a split assignment in both research and extension.

Hagan provided support for all aspects of entomological expertise. He became the expert on western bean cutworm on corn and dry beans in the 1960s, as this insect became established as an important pest on these two crops in the region. Hagan also made an impact through his work on the identification, feeding and management of grasshoppers, one of the most important insect problems in western Nebraska. He generated information on the management of numerous other insect pests of sugarbeet, dry beans, and other crops. Hagan provided consistent entomological expertise for the Panhandle until 1987, when he moved to North Platte to become survey entomologist.

Changing Pest Issues

Through the years insect pest issues in the Panhandle have constantly evolved. The Russian wheat aphid was introduced into Nebraska in 1987, and the rapid occurrence of this devastating pest was an important stimulus for the hiring of the next entomologist in 1988. Gary Hein began as entomologist at the Panhandle Center in 1988 with a 50 percent research and 50 percent extension appointment.

Wheat

The severity of the Russian wheat aphid in the late 1980s required a rapid response. Research and extension efforts were targeted at establishing threshold, sampling, and control recommendations to manage this serious threat. Later efforts have also documented the importance of natural enemies in limiting the continued seriousness of this pest.

In 1993, serious wheat streak mosaic infections in Cheyenne County brought about efforts to investigate the virus’s vector, the wheat curl mite. Extensive research efforts have provided better understanding of the mite’s ecology and movement and have resulted in improved recommendations for managing the mite and virus. In addition, efforts to screen resistant varieties have resulted in the release of Mace, a variety with much improved virus resistance.

Another new pest of wheat was found in the Panhandle in the mid 1990s. The wheat stem sawfly became a serious issue in fields along the Wyoming border. Investigations into the timing of emergence of the insect led to recommendations for managing this insect. However, this insect slowly continues to spread into additional wheat growing areas in western Nebraska.

Dry Dean Insects

Beginning in the mid-1990s, mild winter conditions led to the Mexican bean beetle becoming a more serious pest of dry beans in the North Platte Valley. Research has established an egg mass sampling plan, improved thresholds, and better understanding of the insect’s biology and management.

Western bean cutworm has been an important pest across the region in both dry beans and corn. Efforts in the 1960s began to uncover important aspects of the biology of the insect. Research through the last 15 years has increased our knowledge and helped to improve the efficiency of management of this insect in both crops. Recent movement of this insect into the central and eastern Corn Belt has increased the importance of this insect and increased the impact of the work done on the western Nebraska pest.

Sugarbeet Insects

A serious insect problem in sugarbeets was first observed in the North Platte Valley with the introduction of the sugarbeet root maggot in the late 1970s. Research efforts in the 1980s and 90s identified the extent of the spread of the maggot and management options. Further understanding of the biology of the maggot has explained the recent reductions of this insect since 2000 due to drought conditions and the potential for the return of the problem with adequate spring rains.

Serious infestations of sugarbeet root aphid in 1997 brought about extensive effort to establish the value of resistant varieties and develop better aphid screening procedures. The result was an increased emphasis on the use of varieties resistant to the aphid and better management recommendations.

Insect Diversity

Numerous other insect pests have been studied through the years in an effort to maintain effective and up-to-date recommendations on their management. These efforts have targeted insect pests that affect both commonly grown crops as well as some of the specialty crops being developed and grown in the region.

In addition, the Center entomologist deals with the public in identifying and explaining often dramatic occurrences of insect issues in the Panhandle. Many of these insect issues are unique to the region, and they can often be spectacular. Perhaps the most impressive insect invasions that occur in western Nebraska are the cyclical infestations of grasshopper hoards. But one of the more troublesome insect events in the Panhandle is the annual migration of “millers” to the mountains. The migration is often preceded by invasions of crops, gardens and/or buildings by the millers’ immature form, the army cutworm. Amazing entomological invasions have occurred from time to time, including the carabid beetle invasion of downtown Sidney, mayflies that descended on Scottsbluff, or the almost regular infestations of houses by a series of nuisance invaders. The often spectacular flights of dispersing winged ants in late summer after a significant rain stirs questions of potential invasions, but more practically, the cleaning of greasy windshields.

The diversity of insect occurrences in the panhandle keeps the entomologist’s job interesting with no lack of problems to pursue. The torch of entomological research and extension work has recently been passed (January 2010) to Jeff Bradshaw, who became only the third entomologist to work in the Panhandle in the last 50 years.

Through the years, the efforts of the entomologist have been supported by numerous technicians and summer students. These individual have contributed greatly to these accomplishments. During the last 22 years, a trio of technicians (Rick Patrick, John Thomas, and Susan Harvey) has combined for over 50 years of service to the entomological efforts in the Panhandle.

The severity of Russian wheat aphid damage is seen in this wheat field after introduction of the insect in the late 1980s.

Rangeland devastation (note light vs green areas) caused by army cutworm in Sioux County.