Biology And Host Range Of The Chinese Grasshopper, Oxya Chinensis Thunberg

Dely  P. Gapasin,; Bimbo  T. Mandras,

Biology And Host Range Of The Chinese Grasshopper, Oxya Chinensis Thunberg

Abstract:

The biology of the Chinese grasshopper, Oxya chinensis Thunberg, was studied in the laboratory. The eggs are laid in masses inside the gabi petiole with 1-2 egg masses laid at a time. The newly-laid egg is elongate, clear yellow and 3-4 mm in length. Just before hatching, the egg turns grayish or nearly black. Incubation period is from 19-24 days with 79.8% hatchability. The total developmental period for both sexes did not differ, with a mean period of 54.3 and 54.7 days for the male and female, respectively. There are 5 nymphal instars with each stadium lasting from 5.3 to 9.4 days for the second and fifth stadium, respectively. A male to female ratio of 1.36: 1.00 was recorded. Females lived longer than males with a difference of 11.3 days between sexes. A total mortality of 27.8%, which was mainly due to disease, was observed during the nymphal period. Five species of natural enemies were observed to attack the Chinese grasshopper at different stages of development. Aside from taro, which is the preferred host, O. chinensis can complete its development on 8 alternate host plants.

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