Abstract:
The rugose spiralling whitefly (RSW) Aleurodicus rugioperculatus is a serious pest that causes
substantial economic losses in Sri Lankan coconut plantations. Chemical based approaches have
been commonly employed to manage severe whitefly infestations; but, the emergence of
biocontrol agents provides a promising alternative. Encarsia guadeloupae has been identified as
the most common natural enemy for RSW. The study initiated taxonomic identification for RSW
and E. guadeloupae, followed by an investigation into their mass rearing on six host plant species
viz Coconut (Cocos nucifera), Banana (Musa spp), Fan palm (Livistona chinensis), Poinsettia
(Euphorbia pulcherrima), Canna (Canna indica) and Ground nut (Arachis hypogaea) under
controlled laboratory conditions. The primary objective was to determine the most suitable host
plant species for rearing RSW and promoting the growth and development of E. guadeloupae. In
order to evaluate the suitability of different host plants, parameters such as oviposition
preference, life cycle development, and percentage of parasitism were examined. According to
the results, fecundity estimates indicated that the oviposition preference of RSW was highest on
coconut followed by banana. RSW successfully completed its lifecycle on all host plants except
groundnut. Both coconut and banana proved to be conducive to the growth and development of
E. guadeloupae. Parasitism levels of E. guadeloupae did not exhibit significance in whiteflyinfested
coconut (49.86%) and banana (52.71%). Based on our findings, coconut was identified
as the most suitable host plant for mass raring of RSW. Additionally, both coconut and banana
were effective in promoting the growth and development of E. guadeloupae. These findings would
contribute to the development of sustainable and effective biological control practices for RSW in
coconut plantations.
