Indian Journal of Entomology

A study made on the mealybugs infesting the roots of Nendran banana in Kerala, revealed two species viz., Geococcus citrinus Kuwana and G. coffeae Green. The biology of the former when studied on potato sprouts revealed that the females secreted loose cottony white waxy filaments before laying eggs, and the eggs were laid inside this cottony mass. On an average, 79.4 eggs were laid by a female and these were elongate oval, pearly white and measured 0.32 x 0.15 mm; the incubation period was 8 days during March-April and 11.6 days during November-December; and hatching was 91.92%. The duration of first instar nymph (crawlers) was 11.6 days. Cream coloured crawlers lacked mealy cover and after four to five days of congregated feeding, these dispersed and started secreting the mealy cover; crawlers measured 0.34 x 0.15 mm while the second and third instar nymphs measured 0.72 x 0.27 mm and 1.03 x 0.48 mm, respectively. From second instar onwards, the nymphs appeared white with mealy cover. Adult females were elongate oval, creamy white, measured 2.1 x 1.16 mm, with two prominent, sclerotized anal lobes each terminating in a stout spine like apical setae; these possess six segmented antennae and well developed legs; and males wer not observed. In the field, the egg laying adults, egg masses and different stages of the nymphs were present simultaneously, indicating overlapping generations.