عنوان
پدید آورنده
موضوع
رده
کتابخانه
محل استقرار
TL49502
انگلیسی
Biological Control of Pest Grasshoppers with Fungal Entomopathogens
[Thesis]
Wahid H. S. Dakhel
Latchininsky, Alexandre V.
University of Wyoming
2016
136
Committee members: Islam, Anowarul M.; Jaronski, Stefan T.; Legg, David; Waggoner, James
Place of publication: United States, Ann Arbor; ISBN=978-0-355-13399-8
Ph.D.
Renewable Resources
University of Wyoming
2016
Grasshoppers (Orthoptera: Acrididae) cause about 25 percent of the annual losses in available forages in the western United States (U.S). Biological control, or the use of microbial pathogens to control grasshopper pest infestations, is one of the leading alternatives to traditional chemical pesticides for crop and rangeland protection from these pests. Fungal pathogens are among the most commonly used agents in grasshopper biocontrol. Metarhizium acridum and Paranosema locustae are both fungal entomopathogens of grasshoppers. Another Metarhizium isolate, Metarhizium brunneum F52, has been registered in U.S., but for control of other insects. To assess the susceptibility of third instar nymphs of migratory grasshopper Melanoplus sanguinipes, different treatments with two pathogens, M. brunneum F52 and P. locustae were applied on wheat bran bait alone, or in combination, in the laboratory and greenhouse conditions with three specific objectives: 1) to evaluate the effect of P. locustae combined with M. brunneum F52 versus each pathogen alone for control M. sanguinipes nymphs in the laboratory; 2) to evaluate the effect of P. locustae combined with M. brunneum F52 versus each pathogen alone for control M. sanguinipes nymphs in the greenhouse conditions; 3) to evaluate the virulence (speed of action) of these two pathogens, alone and in combinations. The results indicated that treatment with combination of pathogens at high and low concentrations generated respectively 76.7% and 75% mortality in grasshoppers after two weeks of exposure under laboratory conditions. In contrast, lower mortality was observed at high and low concentrations of M. brunneum F52 alone - 68% and 15%, respectively. There was no mortality in grasshoppers treated with P. locustae alone two weeks post-treatment. In the greenhouse, where the grasshoppers were exposed to sunlight and could thermoregulate to inhibit the fungal infection, combination of the two pathogens at high and low concentrations resulted in grasshopper mortality of 50% and 60%, respectively. In comparison, grasshoppers treated with M. brunneum F52 alone at high and low concentrations resulted in 45% and 20% respective mortality two weeks post-treatment. P. locustae alone caused very low grasshopper mortality only 16 days post-treatment. In both experiments, based on the speed of lethal action, the combination of M. brunneum F52 with P. locustae was more virulent to grasshoppers compared to the treatments of each fungus alone. In addition, the lowest concentration of this pathogen combination treatment produced a synergistic effect on nymphal mortality under greenhouse conditions. The tested pathogens appear promising for developing a biopesticide formulation for rangeland pest grasshopper control.
Biology; Entomology
Biological sciences;Entomopathogenic;Melanoplus sanguinipes;Metarhizium brunneum F52;Paranosema locustae;Pathogen combinations;Synergism
Beckman, Daniel
Latchininsky, Alexandre V.
Renewable Resources
University of Wyoming
1938258038; 10248438
مطالعه متن کتاب p
[Thesis]
276903
a
Y
