Volume 4, Issue 2 (6-2015)
Abstract
Laboratory and field experiments were conducted to determine the efficacy of some insecticides on the control of Sarta longhorned beetle, Aeolesthes sarta Solsky adults and larvae. In the laboratory, three pairs of mated and non-oviposited adults were released on the logs of field elm, Ulmus minor Mill that had been treated with chlorpyrifos, carbaryl, permethrin or imidacloprid. In the field experiments, artificially infested U. minor var. umbraculifera Rehd trees were treated by imidacloprid and oxydemeton-methyl through soil and trunk injection. In the laboratory test the best results were obtained from imidacloprid and permethrin applications, because of occurrence of high adult mortality after short period and also preventing egg laying. Despite a few eggs that were laid on the chlorpyrifos treated logs, there were no living larvae in the sprayed logs. Results of the field tests showed that the number of living larvae did not differ significantly between oxydemeton-methyl and control treatment, however, imidacloprid injection was effective in controlling this pest.
Volume 23, Issue 1 (1-2021)
Abstract
The pistachio green stink bug, Brachynema germari Kolenati (Hemiptera: Pentatomidae), is one of the most important pests of pistachio nuts in many pistachio-growing regions in Iran(Mehrnejad 2001; Bigham & Hosseininaveh 2010). This insect harbors a gammaproteobacterial symbiont, related to the genus Pantoea, in the numerous crypts of its posterior midgut, which is vertically transmitted by infection of the egg masses and orally acquired by newborn nymphs. In the present study, the effects of the symbiont on host morphology, emergence rates, and mating frequency of B. germari were explored. For this purpose, two symbiont elimination strategies, high temperature and egg surface sterilization, were used and their effects were compared. We found external morphological changes (e.g. abnormalities in notum and wings) as well as significantly fewer emergence rates (in all stages, except for the first instar) in the surface-sterilized and heat-treated insects compared with the controls. Also, the second, third, and fourth regions of the midgut exhibited remarkable morphological changes in the aposymbiotic insects compared with the controls. Besides, less mating frequency was observed in the aposymbiotic population compared with the control. Together, these results provided a close relationship between the bacterial symbiont and B. germari and suggested the importance of the symbiont for the morphogenesis, development, and reproduction of the insect host.
