Triacylglycerol storage in the adults of two selected strains of the brownplanthopper, Nilaparvata lugens

In the brown planthopper, Nilaparvata lugens, triacylglycerol (TG) content and its fatty acid composition were analysed by GLC and compared during thr ee days after the final moult. This analysis compared long and short-winged morphs, which were derived from predominantly macropterous and brachyptero us strains, and allowed to feed but not mate. For both sexes, the levels of TG on a dry weight basis in the long-wing form were 1.6 times higher short ly after adult eclosion for both sexes than those in the short-wing form. T he ratios of TG content between the two wing-morphs increased to 2.8 times for females and 3.7 times for males two days after eclosion, the stage esti mated to be the most adapted to migration. Thus the macropters apparently s tore considerably more fuels for flight than the brachypters. In female mac ropters, TG per dry weight decreased slightly during the pre-feeding period but returned to the initial level two to three days later due to feeding, possibly providing energy for migration. In contrast, TG level per dry weig ht in brachypters continuously declined, maintaining TG content per individ ual with gradual weight gain during this period, suggesting the storage of materials other than TG by feeding for ovarian development. In males, TG le vel declined more in brachypters than in macropters, possibly reflecting gr eater adaption for copulation in the former and migration in the latter. Fa tty acid compositions of TG were essentially the same for both morphs and a lso both sexes at the time of adult emergence, but the composition in brach ypterous males changed greatly after one to two days of adult life.