Insecticide resistance in five major insect pests of cotton in India

Arthropod pest resurgence: an overview of potential mechanisms

Resistance to three organophosphate and four pyrethroid insecticides was monitored from 1992 to 2000 in field populations of adult whiteflies, Bemisia tabaci, from Pakistan using a leaf-dip method. There was generally a very high resistance to dimethoate and deltamethrin, and a moderate resistance to monocrotophos during 1992 to 1996. From 1997 to 2000, resistance to these insecticides dropped to low levels because of less reliance on them for whitefly control, and introduction of new chemistries with novel modes of action that had no cross-resistance to conventional insecticides. Concurrently, whitefly resistance to acephate, fenpropathrin, lambda-cyhalothrin and bifenthrin mostly remained low. An insecticide resistance management strategy is recommended that particularly emphasizes the rotation of still-effective insecticides from different chemical classes along with the use of novel chemicals and other tactics of integrated pest management.

Cotton whitefly (Bemisia tabaci) resistance to organophosphate and pyrethroid insecticides in Pakistan.

The Panel on Plant Health conducted a pest risk assessment for Bemisia tabaci and the viruses it transmits, including an evaluation of risk reduction options and an assessment of the effectiveness of the special requirements linked to B. tabaci and the viruses listed in Council Directive 2000/29/EC. B. tabaci and a large number of viruses transmitted by this polyphagous insect occur in subtropical and tropical climates around the world. Five entry pathways for B. tabaci and associated viruses were identified, with the plants for planting pathway being most significant and rated for entry of insects and viruses as likely and moderately likely, respectively. The most invasive B. tabaci species and several of its associated viruses responsible for severe diseases in major European food crops are established outdoors in coastal Mediterranean regions. Because of similar climate requirements and host plant preferences, B. tabaci and associated viruses currently not present in Europe are likely to establish within the temperature limits set for B. tabaci. Trade between European Member States allows B. tabaci to reach greenhouses in northern Europe, including those in areas with protected zone status. Because of the cool climate, establishment and spread outdoors of B. tabaci is rated unlikely for northern Europe. This situation is likely to continue even under a climatic scenario with an increase in temperature of +2 °C. B. tabaci -transmitted viruses cause severe diseases with major negative impact on crop production when risk reduction measures are not used. Risk reduction options will also apply to B. tabaci and viruses new to Europe. Risk reductions options are evaluated in terms of reducing B. tabaci populations, crop infestations, virus incidence and the impact of diseases. © European Food Safety Authority, 2013

Scientific Opinion on the risks to plant health posed by Bemisia tabaci species complex and viruses it transmits for the EU territory

Cassava mosaic disease (CMD) is caused by whiteflyborne viruses of the genus Begomovirus (family Geminiviridae). The disease has long been regarded as the most important of those affecting cassava in sub-Saharan Africa, and has been the subject of much research, especially since the onset of the current very damaging pandemic in eastern and central Africa. This review considers the main features of CMD and the various possible means of control. The main emphasis to date has been on the development and deployment of virus-resistant varieties. These are widely adopted in countries where CMD has caused serious problems, and provided a powerful incentive for farmers to abandon some of the most susceptible of their traditional varieties. Only limited use has been made of phytosanitation involving CMD-free planting material and the removal (roguing) of diseased plants. Cultural methods of control using varietal mixtures, intercrops or other cropping practices have also been neglected, and there is a need for much additional research before they can be deployed effectively. Nevertheless, the severe losses now being caused by CMD in many parts of sub-Saharan Africa could be greatly decreased through the application of existing knowledge.

https://bsppjournals.onlinelibrary.wiley.com/doi/pdf/10.1111/j.1365-3059.2005.01282.x

S.O. Hassan

Papers

Sudanese cotton and the whitefly: a case study of the emergence of a new primary pest

Development of a new primary pest of cotton in the Sudan: Bemisia tabaci, the whitefly