Publications by Colleges and Departments (MSU - Bozeman)
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Item Laboratory Host Range Assessment of a Predatory Pentatomid, Podisus maculiventris(Hemiptera: Pentatomidae) for Field Release on Guam(2011-12) Reddy, Gadi V. P.; Kikuchi, R.Predation by Podisus maculiventris (Say) (Hemiptera: Pentatomidae) was evaluated with Erionota thrax (L.) (Lepidoptera: Hesperidae), Pericyma cruegeri (Butler) (Lepidoptera: Noctuidae), Pareuchaetes pseudoinsulata Rego Barros (Lepidoptera: Arctiidae), Papilio polytes (L.) (Lepidoptera: Papilionidae) and Eudocima phalonia (L.) comb. nov. (Lepidoptera: Noctuidae). Both free-choice and no-choice experiments indicated that the P. maculiventris attacked and consumed all the larvae of the 5 species included in the tests. Although the larvae died at different intervals, most of them were dead within 24–120 h of the introduction of the predatory species. Since the P. maculiventris is polyphagous in nature and the present findings indicate that these predators will feed on the introduced biocontrol moth, P. pseudoinsulata, it is recommended not to take the predators out of the quarantine laboratory for the field release on Guam. Additionally, P. maculiventris will feed on some native species as they become available.Item Bioactivity of Selected Eco-Friendly Pesticides Against Cylas formicarius (Coleoptera:Brentidae)(2012-12) Leng, P. H.; Reddy, Gadi V. P.Seven low risk pesticides including 1.2% azadirachtin (Azadirachta indica), extracts from Morinda citrifolia, petroleum oil 97%, Beauveria bassiana strain GHA, mixed essential oils (rosemary oil: 0.25%, peppermint oil: 0.25%, thyme oil: 0.25%, clove oil: 0.25% and other ingredients: 99.00%), spinosad and malathion, were evaluated against adults of the sweetpotato weevil, Cylas formicarius (Fabricius) (Coleoptera: Brentidae) to determine potential insecticidal, repellent and feeding deterrence effects. Among the pesticides tested, A. indica and spinosad showed high insecticidal, repellent and feeding deterrence activity against C. formicarius. Spinosad, A. indica and malathion showed significantly higher insecticidal activity against C. formicarius. Similarly, these pesticides showed high repellency activity against adults, particularly 3–4 h after the treatment. The lowest food consumption was observed with the A. indica (0.8 g/adult/192 h), and the highest (9.9 g/adult/192 h) was with the petroleum oil spray. The other tested pesticides showed comparable activities. The chemicals we tested—particularly neem and spinosad—are therefore promising candidates as ecofriendly chemicals that could potentially replace broad-spectrum synthetic neurotoxins for control of C. formicarius.Item Action Threshold Treatment Regimens for Red Spider Mite (Acari: Tetranychidae) and Tomato Fruitworm (Lepidoptera: Noctuidae) on Tomato(2013-09) Reddy, Gadi V. P.; Tangtrakulwanich, KhanobpornThe tomato fruitworm, Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae), is the foremost pest of tomato in the Mariana Islands. Similarly, the red spider mite, Tetranychus marianae McGregor (Acari: Tetranychidae), is a chief pest of vegetables particularly on tomato, Solanum lycopersicum L. (Solanaceae). However, the infestations by T. marianae are heavy during the early stages of crop growth, while infestations of H. armigera become prominent at later stages. Because no threshold levels are available for these pests, many growers apply up to 15 chemical applications per tomato cropping period. To reduce the regular spray schedules chemical applications and to prevent damage to foliage and fruit quality, the present study was undertaken for the development of action threshold levels for the timing of chemical applications for T. marianae and H. armigera on tomato in the Mariana Islands. Therefore, different threshold levels were evaluated for timing applications of Sun-spray 6E® horticultural oil against T. marianae and Aza-Direct®, neem against H. armigera on tomato in the wet and dry seasons at 2 locations, Dededo and Inaranjan, in Guam, USA during 2011 and 2012. Based on T. marianae infested leaves, incidence of T. marianae and yield levels, the plots sprayed at 8–12 mites/leaf in the dry season and 8–14 mites/leaf during the wet season had significantly lower leaf damage and T. marianae densities compared to a greater number of mites/leaf, regular based sprays and control plots. Likewise, an initial spray scheduled when 2 eggs of H. armigera were detected on 10 of the samples, followed by an added spray only if 2 damaged fruit or H. armigera larvae were detected per 50 immature fruit resulted in lower percent fruit damage and higher marketable yield compared to other threshold levels or a regular spray schedule.Item Registration of ‘Egan’ Wheat with Resistance to Orange Wheat Blossom Midge(2014-08) Blake, Nancy K.; Stougaard, Robert N.; Bohannon, B.; Weaver, David K.; Heo, Hwa-Young; Lamb, Peggy F.; Nash, Deanna L.; Wichman, David M.; Kephart, Ken D.; Miller, John H.; Eckhoff, Joyce L.; Grey, William E.; Reddy, Gadi V. P.; Lanning, Susan P.; Sherman, Jamie D.; Talbert, Luther E.Egan' hard red spring wheat (Triticum aestivum L.) (Reg. No. 1102, PI 671855) was developed by the Montana Agricultural Experiment Station and released in 2014. Egan is intended for production in areas of Montana infested with the orange wheat blossom midge (OWBM) (Sitodiplosis mosellana Géhin). Egan is resistant to OWBM due to antibiosis conferred by resistance gene Sm1. Egan also contains a chromosome segment originally introgressed into wheat from T. turgidum ssp. dicoccoides containing a gene for high protein (Gpc-B1) and a gene for stripe rust (caused by Puccinia striiformis Westend. f. sp. tritici) resistance (Yr36). Egan has shown high yield potential and high grain protein in nurseries grown under OWBM pressure in the Flathead Valley of Montana. Egan is the first hard red spring wheat cultivar with resistance to OWBM developed for Montana.Item Field Evaluation of Petroleum Spray Oil and Carbaryl Against Tetranychus marianae (Acari: Tetranichidae) on Eggplant(2014-03) Reddy, Gadi V. P.; Miller, R. H.Tetranychus marianae McGregor (Acari: Tetranychidae) is a pest of several perennial crops and is widespread in the Pacific Basin, including the Mariana Islands where it was first reported. The mite is also present in the West Indies, Bahamas, southern USA, Nicaragua, Argentina, Brazil and Southeast Asia. Eggplant growers apply carbaryl 10 to 15 times against this pest during each cropping period. Some growers no longer cultivate eggplant and tomato because of uncontrollable mite infestations. Previous indoor studies have shown petroleum spray oil (PSO) to be effective against T. marianae. We therefore examined the comparative effectiveness of PSO (Sun-spray 6E®) at the rate of 5mL/liter, and carbaryl at the rate of 1.5 mL/liter, against T. marianae on eggplant at 2 locations in Guam. The mean percentages of mite infested leaves and the population densities of T. marianae at both the locations were significantly higher in control plots than in treatment plots. PSO treatments with 6 and 15 sprays more effectively reduced the number of T. marianae-infested leaves and populations of T. marianae than carbaryl treatments. Marketable yields of eggplant from PSO treated plots were significantly higher than from the other plots. We recommend 6 applications of PSO at 15, 25, 35, 45, 55 and 65 days of after transplanting for managing T. marianae on eggplant.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.