Abstract:
Fruit crops are an important source of income for the rural people. The quality and
yield of fruit production may be reduced by insect pest damage. At present whitefly is
one of the serious pests in Sri Lanka, which attacks numerous crops including fruit
crops. As these insects developed resistance to several groups of insecticides, high cost
of insecticides against new bio-types, the elimination of their natural enemies by abuse
and misuse of insecticides and their wide host range have make it difficult to control
this insect pest. The increasing demand for insecticides free products and self defense
of consumers for toxicity of insecticides force the cultivators to take bio-control
strategy to control the whitefly outbreaks.
Two fruit crops banana and guava were identified as the host-plant of whitefly,
Aleurodicus dispersus in the Batticaloa district during the study period from June 2007
to September 2007. Whitefly infested leaves were collected and parasitized and non parasitized pupae were separated based on their colouration; the parasitized pupae were
black in colour and non-parasitized pupae were pale in colour. Non-parasitized pupae
of whitefly were brushed out and parasitized pupae were kept with leaves into the vial
until the emergence of parasitoids. Morphological characteristics of emerged
parasitoids were recorded to identify the species of whitefly associated parasitoids with
the help of the pictorial guide and taxonomic guide. Three hymenopteran parasitoids
namely, Encarsia guadeloupae, Encasia cibcensis and Eretmocerus mundus were
recorded as the parasitoids of the whitefly species, Aleurodicus disperses, infested the
fruit crops in the Batticaloa district.
