Abstract:
The coconut whitefly, Aleurotrachelus atratus Hempel (Homoptera; Aleyrodidea) is a highly
invasive pest of coconut and ornamental palms (Arecaceae). In Mozambique, it was first
detected in 2011 and 100% of infested plants have been reported. Currently, biological control is
the most preferred, safest and nontoxic method in controlling invasive pest species, such as A.
atratus. A study was conducted to evaluate the occurrence of parasitoids associated with A.
atratus as a basis for the introduction of classical biological control in Inhambane province.
Coconut leaflets were collected from five districts of the province including; Zavala, Inharrime,
Jangamo, Morrumbene and Massinga districts in September and December 2015. Whitefly
pupae were counted after which samples were kept in the laboratory for at least 15 days.
Emerged parasitoids were identified, counted and recorded. Four parasitoid species were
recovered during the study period including; Encarsia basicincta, Eretmocerus cocois, Encarsia
sp. and Signiphora sp. with parasitism rates of; 4.08%, 0.22%, 5.99% and 0.45% respectively.
Overall parasitism was 10.74+2.03% varying significantly among districts. The recovery of
Encarsia basicincta and Eretmocerus cocois for the first time in Mozambique from the coconut
whitefly is an indication that A. atratus was introduced with parasitoids considered efficient for
the suppression of its population in its native range and it may constitute potential biological
control agents against the invasive whitefly in Mozambique. The national phytosanitary
authorities should consider development of integrated pest management (IPM) including
classical biological control and augmentative approaches to reduce the pest population, crop
damage and yield loss. |
