Bemisia tabaci is becoming a serious threat again in cotton. The resurgence issue if any related to present day insecticides viewed to be seriously.Post your experience.
Several researcher discussed the resurgence issue for Bemisia tabaci. my point of view, the lack of applied IMP strategies, control tactics, effective chemical use and avoidance, adoption, B biotype , sampling, multi-component pyramid, Insect growth regulators (buprofezin and pyriproxyfen; insect growth regulator (IGR)) in cotton and imidacloprid use in vegetables. Action thresholds and resistance management guidelines. planting and harvest dates, post-harvest sanitation, and host-free periods along with strategic use of insecticides implemented cooperatively were key to the recovery of this agroecosystem. A concept of bioresidual, suppression. Organized and sustained grower education for adoption and deployment of successful IPM strategies.
George W. Ware. 2013. Reviews of Environmental Contamination and Toxicology: Continuation of Residue Reviews Springer Science & Business Media,Pp.257. ISBN146847071X, 9781468470710
Douglas L. Murray. 2010. Cultivating Crisis: The Human Cost of Pesticides in Latin America. University of Texas Press, ISBN0292788045, 9780292788046
Khalid Rehman Hakeem. 2015. Crop Production and Global Environmental Issues. Springer,Pp.598. ISBN3319231626, 9783319231624
The major tactic for the control of whitefly is still depended on the use of chemical insecticides. Because of its highly adaptive capacity to changing cultural practices and high reproductive potential, frequent chemical treatment to every generation are necessary to bring the population of the insect under control. Unfortunately, in addition to having potentially harmful consequences on the environment vis-à-vis human health, these insecticides may have detrimental effects on the natural enemies of whitefly. In general, the natural enemies, especially parasitoids and predators, are more sensitive to most chemical insecticides than their host. The destruction of natural enemies, in part, by chemical insecticides can cause a resurgence of population, but the insecticides themselves can cause resurgence through stimulation of reproduction, a situation known as ‘hormoligosis’. Synthetic pyrethroids such as cypermethrin and deltamethrin reduced the total phenols content of leaves to a greater extent and thus confirmed the behavioral hormoligosis in oviposition preference that induced by these broad spectrum insecticitides in B. tabaci, which may be one of the causes behind its resurgence on plants repeatedly treated with these insecticides.
The double edge sword of white fly resurgence is the result of the selection of whitefly with genetic resistance to pesticide and in addition the beneficials are many times lost by the insecticide treatment. The use of insecticidal soaps and oil do not give a mode of action that will stimulate genetic selection for resistance and are not bad for beneficial insects in large part.
If chemical controls are the route of choice their application should be according to measured level of populations above the threshold on yellow sticky cards and insecticide rotation should be used. These should replace a blind schedule which does not consider the pest levels and need and does not consider rotation mode of actions. Soaps and oils done in a prescribed way could be part of an organic certifiable system.
I studied in apaper that Cypermethrin caused marked resurgence within this species probably as a consequence of its detrimental effects on natural enemies.
Pesticides eradicates only weak and susceptible insect and their natural enemies whereas resistant insect left behind surviving and then they keep on multiplying sporadically in the absence of natural enemies