Publications by Colleges and Departments (MSU - Bozeman)
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Item Efficacy of Entomopathogenic Fungi and Nematodes, and Low Risk Insecticides Against Wheat Stem Sawfly, Cephus cinctus (Hymenoptera: Cephidae)(2014-04) Tangtrakulwanich, Khanobporn; Reddy, Gadi V. P.; Wu, Shaohui; Miller, John H.; Ophus, Victoria L.; Prewett, JulieEntomopathogenic nematodes, fungi, and low risk insecticides were evaluated for the management of the wheat stem sawfly, Cephus cinctus Norton, in winter wheat at two locations (Devon and Western Triangle Ag Research center) in the Golden Triangle area of Montana (USA) in 2013. Two fungi (Beauveria bassiana and Metarhizium brunneum), four nematodes species (Steinernema carpocapsae, Steinernema kraussei, Steinernema feltiae, and Heterorthabditis bacteriophora), an insect growth regulator (diflubenzuron/dimilin), and a botanical-based chemical (azadirachtin/Aza-direct) were used as foliar sprays. These control agents significantly reduced damage caused by C. cinctus larvae, compared to the untreated control or treatment with water alone. No yield differences were observed among entomopathogenic fungi, nematodes, and low risk insecticides. The effectiveness of azadirachtin, diflubenzuron, the entomopathogenic fungi, and the nematodes persisted at the 28th day post application, by which time the wheat had been harvested. Stubbles collected after harvest showed significantly fewer sawfly larvae in the plots treated with entomopathogenic fungi, nematodes, diflubenzuron, and azadirachtin compared to the untreated and water spray plots, indicating that these biorational pesticides have potential to be used as alternatives to conventional pesticides for controlling the wheat stem sawfly larvae.Item Potential Application of Pheromones in Monitoring, Mating Disruption, and Control of ClickBeetles (Coleoptera: Elateridae)(2014-01) Reddy, Gadi V. P.; Tangtrakulwanich, KhanobpornWireworms, the larvae stage of click beetles (family, Elateridae), are serious soil dwelling pests of small grain, corn, sugar beet, and potato crops globally. Since the 1950s, conventional insecticides such as lindane provided effective and inexpensive protection from wireworms, and little integrated pest management research (IPM) was conducted. The removal of these products from the agricultural market, particularly Lindane, has resulted in increasing levels of wireworm damage to small grain, corn, and potato crops. The wireworm damage has become an increasing problem for growers, so the demand for a meaningful risk assessment and useful methods to restrict damage is increasing. However, due to the cryptic habitat of the wireworms, pest control is very difficult and leads to unsatisfying results. The prospective appropriateness of sex pheromone traps for employing management strategies against wireworm’s populations was first suggested with experimentation in Hungary and Italy. Simultaneously, considerable work has been done on the identification and use of pheromone traps to monitor population of click beetles. The work has been mostly done in European and former Soviet Union countries. For this paper, we reviewed what work has been done in monitoring the click beetle which was considered as pests and how the pheromones can be used in IPM to monitor and control wireworms/click beetles. Also, the possibilities of using the pheromone-baited traps for mating disruption and control tested in the fields were summarized.Item Module of Integrated Insect Pest Management on Tomato With Growers’ Participation(2014-04) Reddy, Gadi V. P.; Tangtrakulwanich, KhanobpornTomato, Lycopersicum esculentum L. (Solanaceae), is an important vegetable crop in the Mariana Islands (Guam, Saipan, Rota and Tinian). Because tomato is heavily attacked by both the tomato fruitworm Helicoverpa armigera Hübner (Lepidoptera: Noctuidae) and the red spider mite Tetranychus marianae McGregor, research was begun in 2011 to develop an integrated pest management program to better protect the crop from these pests. Our previous studies have indicated nominal threshold levels for T. marianae to be 8-12 mites/leaf in the dry season and 8-14 mites/leaf during the wet season, while for H. armigera the threshold was found to be 2 eggs per 10 of the plants, followed by an additional pesticide application only if 2 damaged fruit or H. armigera larvae were detected per 50 immature fruits. Other studies have found the IPM package used here of petroleum spray oil (PSO), BotaniGard, neem, and DiPel applied 15, 30, 45 and 60 days after tomato transplant to be a viable approach, significantly reducing the pest complex and giving higher tomato yield compared to both the growers’ current practice (carbaryl or malathion, 15 applications per cropping season) and control plots. The current field study was conducted at two locations in Guam (Yigo and Inarajan), USA, in 2012 and 2013 to compare this IPM package with the growers’ current practice in larger plots designed to educate the growers. The IPM package significantly lowered the pest complex and gave higher tomato yield at both the locations. Tomato growers were invited to attend an informal IPM training program on December 16, 2013 at the University of Guam, which was attended by 48 growers from four Mariana Islands. Of these growers, 41 (85%) were aware of and understood the risks associated with traditional insecticides and recognized the concept of using an IPM package in managing tomato pests before the workshop. However, all the attendees understood the concept and benefits of IPM after the workshop. Follow up with these tomato growers found that 35 (73%) later adopted the IPM program using PSO, BotaniGard, and Dipel at 15, 30, 45 and 60 DAT in the Mariana Islands.