نوع مقاله : مقاله پژوهشی
نویسندگان
1 مرکز تحقیقات کشاورزی و منابع طبیعی استان چهارمحال و بختیاری، شهرکرد
2 مؤسسه تحقیقات جنگلها و مراتع کشور، تهران، ص. پ.: 116-13185
چکیده
کلیدواژهها
عنوان مقاله [English]
نویسندگان [English]
Grasshoppers are accounted as important pests of agricultural crops, rangelands and forests. There are various native grasshoppers on range plants and field crops in Chaharmahal and BakhtiaryProvince. Bradyporus latipes is the most important pest, with rapid increase in population. In the course of study carried out in rangelands of Douto-Shahrekord region and Ben city during 2000-2002, life cycle of the pest was investigated in field plots and in laboratory conditions. Further to that, a comparative experiment was conducted to apply the insecticides, Carbaryl, Phenithrothion, B.T.Deltaplus and Dimilin and two different methods of spraying and toxic baits against the pest. The data were analyzed by factorial design on the basis of a completely randomized design. The comparisons of means were conducted by Duncan multiple range test. The results indicated that insect had one generation in a year. The pest overwinters as eggs in soil. The activity period started in April and lasted till June. The pest had five instars and was polyphagous with around 40 hosts of different plant families. Low temperature in April and continual rain in spring caused high mortality on nymphs of the pest. Starlings, sparrows, crows, larvae of blister beetles and robber flies were predators, while wasps of the family Sphecidae and two sarcophagid flies (Sarcophila meridionalis and Wolfhartia bella) were parasitoids of this grasshopper. In comparison of the insecticides, results indicated that mortality percent in spray treatment method was higher and statistically different with bran bait method (p<0.05) and in terms of mortality rate, insecticides were statistically different (p<0.05). Phenitrothion had the highest, while B.T. and Deltaplus had lower mortality percent. Dimilin and Carbaryl were placed in two statistical levels between Phenithrothion and B.T.Deltaplus. In addition, the mortality percent of oily Dimilin were higher and more effective than powdery Dimilin. Mortality rate between male and female grasshoppers for all insecticides in two different treatment methods was not statistically different (p<0.05).
کلیدواژهها [English]
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