Metabolic activity of the chitin synthesis inhibitor, Flufenoxuron, on the desert locust Schistocerca gregaria (Orthoptera: Acrididae)
Hamadah, Kh. Sh
After treatment of the newly moulted last (5th) instar nymphs of Schistocerca gregaria with a high (1000.0 ppm) or a low (62.5 ppm) concentration level of the chitin synthesis inhibitor, Flufenoxuron, the main metabolites were determined in two tissues: haemolymph and fat body of 5th instar nymphs and adult females. The effect of flufenoxuron on the haemolymph protein content of early- and midaged nymphs exhibited a reducing effect at the high concentration level but an inducing one at the lower concentration level. On the other hand, flufenoxuron prohibited the late-aged nymphs to gain normal protein content. Moreover, the inhibitory effect was extended to the adult stage. The proteins in fat body of late-aged nymphs were pronouncedly diminished, while proteins of mid- or late-aged nymphs varied depending upon the flufenoxuron concentration level. Slightly decreased content of proteins in fat body of adults (at low concentration level) was estimated. A little inducing effect of flufenoxuron, only at its low concentration level, on the lipid content in haemolymph and fat body of both early-aged nymphs and newly formed adults was detected. However, nymphs and adults of other ages suffered an inhibitory effect in both tissues. Only the early-aged nymphs and 1-day old adults had been subjected to an inhibitory effect of flufenoxuron on the carbohydrate content, in haemolymph. Other than these ages, all nymphs and adults were promoted to gain more carbohydrates. With regard to the fat body carbohydrate content, a dominant promoting action was recorded.