Making Management Decisions for Pests: Past, Present, and Future Approaches

Proper pest management is essential for profitable and environmentally sound crop production. And at the heart of pest management is the issue of decision making. An important tenet of pest management is that some levels of pests are tolerable: it is neither profitable nor environmentally safe to try to eliminate all pests. Consequently, the major pest management decisions that need to be answered are what levels of a pest are tolerable and what levels require control. Depending on the pest, answering these questions may be trivially easy to horribly complex

Early Season Soybean Insects: Past Problems and Future Risk

The spring of 1994 saw many early season insect problems on soybeans in Iowa and, indeed, across much of the Midwest. Although early season problems on soybeans are not uncommon, certainly the scale of problems we saw in 1994 was unusual. Undoubtedly, many of these problems followed from weather, in particular the heavy rains of 1993. In this paper, we will briefly review some of the reasons behind the events we saw in 1994 and focus on the potential for future problems and their management. In particular, with the possibility of many acres coming into production out of the Conservation Reserve Program (CRP), there is a potential for specific insect problems that should be recognized

Behavioral niche partitioning in a sympatric tiger beetle assemblage and implications for the endangered Salt Creek tiger beetle

How behavioral patterns are related to niche partitioning is an important question in understanding how closely related species within ecological communities function. Behavioral niche partitioning associated with thermoregulation is well documented in tiger beetles as a group. Co-occurring species of salt flat tiger beetles have adapted many thermoregulatory behaviors to cope with this harsh ecosystem. On first examination these beetles appear to occur in overlapping microhabitats and therefore compete for resources. To determine if behavioral niche partitioning is allowing multiple species to occur within the same harsh salt flat ecosystem we observed Cicindela nevadica lincolniana, Cicindela circumpicta, Cicindela fulgida, and Cicindela togata between 8:00 h and 21:00 h and recorded all behaviors related to thermoregulation using a digital voice recorder. Results of this study strongly indicate that competition among these species for resources has been reduced by the adaptation of different thermoregulatory behaviors such as spending time in shallow water, avoiding the sun during the hottest parts of the day, and by positioning their body against or away from the soil. The endangered C. n. lincolniana appears to rely most heavily on the shallow water of seeps for their diurnal foraging behavior (potentially limiting their foraging habitat), but with the advantage of allowing foraging during the hottest times of the day when potential competitors are less frequent. Ironically, this association also may help explain C. n. lincolniana’s susceptibility to extinction: beyond the loss of saline wetlands generally, limited seeps and pools even within remaining saline habitat may represent a further habitat limitation within an already limited habitat

Using the World Wide Web to Educate and Inform the Public about Risk and Agricultural Biotechnology

The University of Nebraska and AgBios, Inc. launched the AgBiosafety website (http://agbiosaftzy.unl.edu) with the purpose of educating the public about agricultural biotechnology risk and safezy issues through science-based content. This article discusses the creation ofthe website, its components, and data gathered from usage statistics and a web-delivered survey. Also included is a discussion of the results ofdata gathered and recommendations for future web-based educational efforts in biotechnology safety and risk assessment

A STUDY OF THE STATISTICAL PROPERTIES OF TWO MEASURES OF COMPETITION

In competition studies, two species are studied, generally in ratios of 1:0, 3:1, 1:1, 1:3,and 0: 1. The standard measure of competition is the Relative Crowding Coefficient (RCC)..

Using the World Wide Web to Educate and Inform the Public about Risk and Agricultural Biotechnology

The University of Nebraska and AgBios, Inc. launched the AgBiosafety website (http://agbiosaftzy.unl.edu) with the purpose of educating the public about agricultural biotechnology risk and safezy issues through science-based content. This article discusses the creation ofthe website, its components, and data gathered from usage statistics and a web-delivered survey. Also included is a discussion of the results ofdata gathered and recommendations for future web-based educational efforts in biotechnology safety and risk assessment

Behavioral niche partitioning in a sympatric tiger beetle assemblage and implications for the endangered Salt Creek tiger beetle

How behavioral patterns are related to niche partitioning is an important question in understanding how closely related species within ecological communities function. Behavioral niche partitioning associated with thermoregulation is well documented in tiger beetles as a group. Co-occurring species of salt flat tiger beetles have adapted many thermoregulatory behaviors to cope with this harsh ecosystem. On first examination these beetles appear to occur in overlapping microhabitats and therefore compete for resources. To determine if behavioral niche partitioning is allowing multiple species to occur within the same harsh salt flat ecosystem we observed Cicindela nevadica lincolniana, Cicindela circumpicta, Cicindela fulgida, and Cicindela togata between 8:00 h and 21:00 h and recorded all behaviors related to thermoregulation using a digital voice recorder. Results of this study strongly indicate that competition among these species for resources has been reduced by the adaptation of different thermoregulatory behaviors such as spending time in shallow water, avoiding the sun during the hottest parts of the day, and by positioning their body against or away from the soil. The endangered C. n. lincolniana appears to rely most heavily on the shallow water of seeps for their diurnal foraging behavior (potentially limiting their foraging habitat), but with the advantage of allowing foraging during the hottest times of the day when potential competitors are less frequent. Ironically, this association also may help explain C. n. lincolniana’s susceptibility to extinction: beyond the loss of saline wetlands generally, limited seeps and pools even within remaining saline habitat may represent a further habitat limitation within an already limited habitat

G93-1167 Spider Mite Management in Corn and Soybeans

This NebGuide describes the two common spider mites found in Nebraska corn and soybeans, their natural enemies and management. Two species of spider mites, the Banks grass mite and twospotted spider mite, commonly feed on Nebraska corn. Banks grass mites (BGM) feed almost exclusively on grasses, including corn and sorghum. Twospotted spider mites (TSM) not only feed on many species of grasses, but also on soybeans, fruit trees and a variety of vegetables and ornamental plants. Although these two species are somewhat similar in appearance, they differ in several biological characteristics and in their susceptibility to pesticides. Banks grass mites usually appear earlier in the season, feed mostly on the lower leaves of the corn plant, and in Nebraska are moderately susceptible to many of the commonly used miticides. On the other hand, TSM tend to appear in mid to late season, increase rapidly, feed over the entire plant, and often are not consistently controlled by available pesticides