1a. Objectives (from AD-416)
Objective 1: Develop novel technologies and techniques to detect and identify insect pests and determine relative composition with emphasis on the stink bug complex and boll weevil. Subobjective 1A. Improve sensitivity of capture using boll weevil lures. Subobjective 1B. Develop remote sensing techniques to detect and map cultivated and uncultivated areas of volunteer and re-growth cotton plants that may contribute to boll weevil abundance. Subobjective 1C. Adapt technology and techniques for rapid identification and biochemical characterization of pollen attached to boll weevils. Subobjective 1D. Identify spatial and temporal distributions of adult stink bugs in fruiting stages of cotton, corn, soybean and non-cultivated plants. Objective 2: Improve knowledge of pest reproduction, diapause, behavior, and dispersal with emphasis on the stink bug complex and boll weevil. Subobjective 2A. Examine pathogen ingestion and transmission by stink bugs in cotton and soybean. Subobjective 2B. Characterize flight behavior and flight activity of stink bugs and lepidopterans in the laboratory and between and within cotton, corn, soybean and the agricultural landscape. Subobjective 2C. Develop improved and novel methods for understanding the reproductive and diapause biology of stink bugs and boll weevils. Objective 3: Develop and verify novel pest management strategies with emphasis on the stink bug and lepidopteran pests. Subobjective 3A. Evaluate non-cultivated plant hosts for use as trap plants to attract and retain stink bugs. Subobjective 3B. Develop biostable, bioavailable mimics of regulatory NP that can disrupt critical life processes to provide effective and environmentally sensitive control of stink bugs, boll weevils, bollworms, and budworms.
1b. Approach (from AD-416)
Improve sensitivity of capture using boll weevil lures. Develop remote sensing techniques to detect and map cultivated and uncultivated areas of volunteer and re-growth cotton plants that may contribute to boll weevil abundance. Adapt technology and techniques for rapid identification and biochemical characterization of pollen attached to boll weevils. Identify spatial and temporal distributions of adult stink bugs in fruiting stages of cotton, corn, soybean, and non-cultivated plants. Examine pathogen ingestion and transmission by stink bugs in cotton and soybean. Characterize flight behavior and flight activity of stink bugs and lepidopterans in the laboratory and between and within cotton, corn, soybean, and the agricultural landscape. Develop improved and novel methods for understanding the reproductive and diapause biology of stink bugs and boll weevils. Evaluate non-cultivated plant hosts for use as trap plants to attract and retain stink bugs. Develop biostable, bioavailable mimics of regulatory NP that can disrupt critical life processes to provide effective and environmentally sensitive control of stink bugs, boll weevils, bollworms, and budworms.
3. Progress Report
This is a new project that replaced 6202-22320-002-00D and which is continuing and expanding upon the work of the precursor project. Work under this project during FY 2011 resulted in significant progress in monitoring the landscape distribution and physiological condition of cotton insect pest populations, and exploiting this information to describe the presence and abundance of pest species relative to host crops and uncultivated plants. Release rates of volatile attractants (pheromones) from commercially available lure dispensers were evaluated in a range of atmospheric conditions to establish performance characteristics of lure dispensers available for use in boll weevil eradication programs. Project work developed a new pheromone blend that performed as well as or better than the commercial pheromone blend in attracting boll weevils in traps in south-central Texas. An electronic nose instrument was found to be useful for detecting differences in the release rate of pheromone from boll weevil lure dispensers. Spectral reflectance signatures of cotton plants, other row crops, and weeds have been previously obtained with ground-based sensors, and a new data fusion technique applied to aerial- and ground-based remotely sensed data improved classification accuracy. Work is underway to examine the seasonal composition and abundance of stink bugs in the four major crops (corn, cotton, sorghum, soybean) produced in the Brazos River Valley of Texas to determine which crops may be contributing to stink bug species that commonly occur in cotton. A biophysical model was derived to calculate potential feeding penetration depths for all nymphal stages and both adult sexes of southern green stink bugs. We established that after southern green stink bugs feed on cotton bolls contaminated with three plant pathogens, only two bacterial pathogens resided within two body locations that would promote the transmission of these pathogens to uninfected cotton plants. Project work established that a nematode discovered in stink bugs may be exploited as a potential biological control agent in protecting crops from stink bug infestations. Project research established differences between pollen of various cotton species, which may enhance the precision of locating source areas of invading cotton pests. Similarly, the retention of weed pollen by tarnished plant bugs may result in new techniques to identify seasonal distribution patterns of this important cotton pest and ultimately to new management tactics. Neuropeptide research in FY 2011 identified differences in how neuropeptides regulate the critical processes of water and mineral balance in two stink bug species that are pests of cotton and soybean, and in a beneficial insect (spined soldier bug) that preys on stink bugs. These differences can be exploited in the development of neuropeptide mimics that can selectively disrupt water balance in stink bugs without impacting the beneficial insects. More than 70 regulatory neuropeptides were identified in the mosquito Aedes aegypti; these findings will aid in the design of novel strategies to manage these pest- and disease-transmitting insects.
1. Improved pest detection for boll weevil eradication programs. Boll weevil eradication has been achieved in all of the U.S. Cotton Belt except for areas in southern and central Texas. Continued progress toward complete eradication of weevils from these areas hinges on optimizing detection of weevils with pheromone traps to ensure timely insecticide applications. During the past several years, substantial weevil infestations have been detected in many fields but adjacent pheromone lure traps have failed to detect these weevil populations. ARS scientists at College Station, TX, analyzed the pheromone content and release rate from both lure traps and live weevils in an eradication zone that had been experiencing trap detection failures. Chemical analyses revealed that a substantial proportion of lures contained an insufficient dose of pheromone and that a single weevil could release as much pheromone as a one-week-old lure with the standard dose. Consequently, recommended protocols for checking initial lure dose, and doubling the lure quantity or decreasing the lure replacement interval, were immediately adopted by the Texas Boll Weevil Eradication Foundation. Adoption of these protocols has been instrumental in significantly advancing eradication progress in a chronically infested eradication zone. Improved protocols for chemical analysis and lure replacement help protect the multi-billion dollar investment in efforts to eradicate boll weevils from the U.S.
2. Improved visualization of stink bug fat body cells. Stink bugs have reached elevated pest status in cotton following the success of boll weevil eradication efforts. Because fat bodies are critical resources for insect survival, reproduction, and other life processes, elucidating the biology and ecology of stink bugs is foundational to development of effective control procedures and protocols. ARS scientists at College Station, TX, developed a user-friendly guide that more accurately identifies various types of fat bodies associated with the physiological condition of southern green stink bugs. This accomplishment will greatly enhance the understanding of the biology of this cotton pest and of related species, and will directly guide science-based decisions for effective management of these important cotton pests.
3. A new class of potent aphicides based on neuropeptide hormone technology. The pea aphid causes hundreds of millions of dollars of crop damage every year, and many populations have already acquired resistance towards multiple conventional and modern insecticides, making a search for alternative strategies urgent. ARS scientists at College Station, TX, in collaboration with scientists in Belgium, have developed a novel strategy for the control of pest aphid populations based on stabilized versions of internal hormones known as neuropeptides (NP). These hormones regulate critical life processes such as water balance, digestion, and satiety in aphids and other pest insects, but are rapidly inactivated by enzymes within the insects. The stabilized NP versions (mimics) are resistant to inactivation by body enzymes and demonstrate anti-feedant activity and high mortality when fed to aphids. This work extends our earlier discovery of new and potent NP-based aphicides to the discovery of a second new set of aphicides, based on a different NP class. Mimics of this new class are even more potent than earlier mimics; some exceed the potency of several commercial aphicides.
Esquivel, J.F. 2011. Improved visualization of fat body conditions and abundance in the southern green stink bug (Hemiptera: Pentatomidae). Journal of Entomological Science. 46:52-61.