Disturbed acid and alkaline phosphatase activities in desert locust Schistocerca gregaria (Forskal) (Orthoptera: Acrididae) by extracts from the khella plant Ammi visnaga L. (Apiaceae).

The present study aimed to investigate the effects of fruit extracts from toothpick weed Ammi visnaga on the acid (ACP) and alkaline (ALP) phosphatases in haemolymph and fat bodies of Schistocerca gregaria. LC50s of ethanol, petroleum ether and n-butanol extracts (21.0, 12.0 and 22.5%, respectively) were applied for penultimate instar nymphs. The enzyme activity was determined in the last instar nymphs (of three ages) and newly emerged adult females. Both ethanol and petroleum ether extracts promoted the ACP activity in haemolymph throughout nymphal life and newly emerged adults. In contrast, n-butanol extract caused a drastic reduction in the enzyme activity in haemolymph of nymphs and adults. With regard to ACP activity in fat bodies, a considerable induction in both early- and late-aged nymphs was achieved by each of ethanol and petroleum ether extracts and vice versa for n-butanol extract. Enhanced enzyme activity was estimated in newly emerged adults, regardless the extract. ALP activity in haemolymph was significantly reduced throughout the nymphal life after treatment with petroleum ether extract or n-butanol extract. The n-butanol extract exhibited an inhibitory effect on the enzyme activity in only early-aged nymphs. Increasing ALP was measured in the newly emerged adults, irrespective of the extract. Ethanol extract suppressed ALP in fat bodies of early- and mid-aged nymphs and n-butanol extract prohibited it only in early-aged nymphs. The newly emerged adults had significantly stimulated ALP activity by all extracts.