Protein Disturbance in the Haemolymph and Fat Body of the Desert Locust Schistocerca Gregaria as a Response to Certain Insect Growth Regulators

After treatment of the newly moulted last (5th) instar nymphs of the desert locust Schistocerca gregaria with 1000.0 or 62.5 ppm of the insect growth regulators (IGRs): pyriproxyfen (juvenoid), tebofenozide (ecdysone agonist) and lufenuron (chitin synthesis inhibitor), protein content was determined in the haemolymph and fat body of nymphs and adults. An inhibitory action on haemolymph proteins was generally exhibited by all IGRs along the nymphal stage with an exception of the day after treatment (1-day old nymphs) at which pyriproxyfen and lufenuron enhanced the nymphs to attain increasing proteins. Pyriproxyfen was comparatively the strongest IGR for preventing the midand late-aged nymphs to gain the normal protein content. In connection with the disturbed protein content in the fat body of nymphs, IGRs exhibited various degrees of reducing action with an exception of pyriproxyfen which slightly promoted the 1-day old nymphs to gain more proteins in fat body. Depending on the present results, it can be concluded that all adult females had been subjected to serious inhibitory action of all IGRs on the haemolymph protein content. The most drastically depleted protein content was recorded after treatment with pyriproxyfen. Also, the adult females were deprived to gain proteins in their fat bodies as control congeners. The strongest reducing effect on the fat body protein content of 1-day old adults was exhibited by pyriproxyfen but of 4-day old adults was exhibited by lufenuron.