USDA scientist looks for natural enemies in Asia to control invasive plants

By Sharon Durham, Agricultural Research Service

This June, Agricultural Research Service (ARS) ecologist Melissa Smith traveled to Asia to collect insects that can control the spread of several invasive plant species in the United States that originated in Asia.

Predator and prey co-evolve in nature’s “arms race” for survival. When plants and animals are moved from their native habitats to new locales where they have no natural enemies, their populations can grow unchecked. Continue reading

Cover Crops Can Help Control Pests by Fostering Natural Enemies

by Candace Pollock, Southern SARE

Cover crops used as refuge crops in vegetable production can control insect pests by fostering populations of natural enemies and competitor non-virus vectoring species, based on the results of USDA-ARS research.

Research entomologists Stephen Hight with the USDA-ARS Insect Behavior and Biocontrol Research Unit in Florida, and Stuart Reitz with Oregon State University, led a Southern Sustainable Agriculture Research & Education-funded project from 2012 to 2014 to study whether bidens and blue lupine can control Western flower thrips and tobacco thrips in tomatoes, peppers, and cucumbers. The study explored more sustainable methods of pest management than insecticide use. Continue reading

Alabama researchers find pest exclusion system that allows for natural enemies

by Ayanava Majumdar, Alabama Cooperative Extension System

The concept of High Tunnel Pest Exclusion (HTPE) system has been explained in many other articles listed at the end. Basically, pest exclusion is a feasible IPM strategy where a sturdy structure can be modified with fabric to serve as a barrier between insect pests and host plants. HTPE can be very an effective strategy for organic and conventional high tunnel producers that aim at preventing insect pests. However, the HTPE system raises questions about the unintended consequences of this technology, such as the exclusion of natural enemies. With this in mind, we conducted laboratory-based assays to evaluate natural enemy exclusion using HTPE models fitted with 30, 40, and 50 percent shade cloths sold by Poly-Tex (MN), Grainger (IL), Green-Tek (WI), and Farmtek (IA). HTPE models were covered in glass cages during the tests. Farmtek shade cloths have fine openings (knitted monofilament) whereas the shade cloths from other vendors have wide (v-shaped) openings.  Continue reading

Clemson study finds a natural enemy for kudzu bug

published by AgFax

By Denise Attaway, Clemson University

Kudzu bugs may have met their match in one Clemson University graduate student.

The kudzu bug is an invasive soybean pest first discovered in Georgia in 2009. It has since spread to 13 states and Washington, D.C. Research by Francesca Stubbins, an entomology graduate research assistant at the Edisto Research and Education Center (REC), shows for the first time that mermithid nematodes can infect and kill the insects. Stubbins’ research involved collecting kudzu bugs from soybean fields. Nematodes — long, slender, parasitic worms — were found in the abdomens of some of the dissected female insects. Continue reading

Research team finds that natural enemies help delay insecticide resistance, protect Bt crops

Despite the controversy over them, transgenic crops have helped growers fend off some of the most destructive pests. The higher yield that results has provided consumers more affordable food. When used properly as a part of an integrated pest management program, transgenic crops can be an effective and economical way to manage certain pests, diseases and weeds. Unfortunately, as the failures of Roundup Ready crops have shown, transgenic crops are not sustainable when used as the sole pest management tactic.

When Bt technology came out, the Environmental Protection Agency instituted a requirement to have a “refuge” plot of crops not protected with Bt to maintain a population of pests that were not exposed to the Bt toxin. The refuge could be treated with an insecticide; it just couldn’t be treated with Bt. The theory behind the refuge was that having a plot of the crop that was treated with a different insecticide would give the pest species a non-Bt alternative, so that those individuals would still be susceptible to Bt, mate with individuals who had been exposed to Bt and pass on their Bt-susceptible genes to the next generation, therefore delaying resistance. Continue reading

Farmscaping and IPM: Benefits accrue but are difficult to measure

Because of their potential to increase the number of natural enemies, farmscapes can be beneficial to an IPM program, but it’s difficult to measure how much, according to a recent article in the Journal of Integrated Pest Management.

Farmscaping is an ecological approach to farming with the purpose of increasing the presence of natural predators and beneficial organisms. The approach involves diversifying plantings to include ornamental or non-cash crops, living mulches, fence rows or borders, or island patches of grass within a field.

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Predators delay pest resistance to Bt crops

Crops genetically modified with the bacterium Bt (Bacillus thuringiensis) produce proteins that kill pest insects. Steady exposure has prompted concern that pests will develop resistance to these proteins, making Bt plants ineffective.

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