Integrated management of rugose spiraling whitefly in coconut

The rugose spiralling whitefly (RSW), Aleurodicus rugioperculatus Martin (Aleyrodidae: Hemiptera), a new invasive insect pest in Bangladesh was first identified in May 2019 on coconut plants in Jashore by BARI Entomologists. It is widely distributed in Bangladesh, causing severe economic damage to coconut and other crops. Considering the above facts, the project was undertaken to develop and popularize sustainable options for managing the rugose spiralling whitefly in coconut crop.

Field surveys were conducted in Gazipur, Barishal, Patuakhali, Jashore, Satkhira, Bogura, Rangpur and Noakhali districts to identify and assess the abundance of natural enemies of rugose spiralling whitefly attacking coconut crop. Three field experiments (each in two locations) were carried out to select suitable biopesticide, microbial biopesticide and reduced-risk insecticide against rugose spiraling whitefly

Results of the survey indicated that two species of parasitoids were found parasitizing RSW nymphs in the studied areas and identified as Encarsia guadeloupae Viggiani and Encarsia dispersa Polaszek. One predatory beetle and one predatory mite were also recorded as the predators of RSW. Predatory beetle was identified as Nephaspis oculata, but predatory mite species is yet to be identified. Results of the field experiments conducted (at RARS, Jashore and RARS, Barishal) to test the efficacy of different bio-pesticides revealed that bioclean 5% SL (D- limonene) offering 67-71% efficacy could be a promising biopesticide. Application of insecticide Imunit 15 SC (Teflubenzuron+alpha-cypermethrin) (70-75% efficacy) and Gladius 10 SC (Flometoquin) (69-71% efficacy) were found promising from the field studies conducted (at RARS, Jashore and RARS, Barishal). On the other hand, field studies conducted (at RARS, Barishal and BARI, Gazipur) to evaluate different microbial biopesticides against rugose spiraling whitefly infesting coconut indicated that microbial pesticides offered moderate level of efficacy ranging 52 – 61%.

Bangladesh being a tropical country with a warm and humid climate and free of trade and movement of agricultural commodities has always been vulnerable to threats of exotic or alien pests. RSW is a new invasive pest. Research on development of management technologies against this pest must be continued to increase coconut production in a sustainable way.

Biointensive management technology developed through this project will be disseminated to DAE and farmers through distribution of factsheets, field days, workshop etc. As a result, bio-intensive management package against RSW will be available for use by the farmers. Farm productivity and income of coconut growers will be increased.

i. Continuation of research & development works with BARI’s own program. ii. Mass rearing of natural enemies. iii. Taking steps for registration of biopesticides for higher availability. iv. Farmers’ training and other promotional programs to be continued.