Partial characterization of acidic proteinase in the midgut of parasarcophaga surcoufi larvae [Diptera: Sarcophagidae]

Activity of acidic proteinase in the midgut of larval Parasarcophaga surcoufi was investigated and partially characterized. Larval midgut extract showed a moderate acidic pH [pH 4] optimum for hydrolysis of hemoglobin. The proteolytic activity of the larval midgut was estimated by hydrolysis of hemoglobin and was found to be inhibited by pepstatin [aspartic proteinase inhibitor], dithiothreitol [DTT] and mercaptoethanol, while it was not inhibited by soybean trypsin inhibitor [STI] and EDTA. These characteristics may imply that cathepsin D-like proteinase is an effective acidic proteinase present in the Parasarcophaga surcoufi larval midgut

Radiorespirometric determination of contribution of pentose phosphate cycle to metabolism of glucose in dermacentor andersoni

The contribution of both pentose phosphate cycle [PPC] and glycolytic-citric acid cycle [GCAC] to metabolism of glucose by different physiological states of Dermacentor andersoni female was evaluated. The radiorespirometric method was used after injection of glucose 3,4-[14]C [G[3,4]] glucose-1-[14]C [G[1]] and glucose-6-[14]C [G[6]] into the hemocoel of separate females of different physiological states and following by the expired [14]CO[2], was trapped for 7 hrs. at 1 hr. intervals. The contribution of PPC to glucose metabolism is 23, 50 and 84% in the unfed, unmated-partly fed, and ovipositing females respectively. Accordingly, the GCAC contribution is 77, 50 and 16% in the same physiological states respectively. The greatly increasing trend in PPC activity from the unfed to the ovipositing state is attributed to increasing need to requisite two-carbon unit intermediates for other metabolic processes. The metabolic products of PPC used in biosynthetic processes associated with feeding and oogenesis is a reliable reason for the active operation of this metabolic pathway

Induction of adult tick molting by ecdysoids

The fed female argasid tick Argas [Persicargas] arboreusmolts when topically applied with 1 micro g ecdysterone, inokosterone or cyasterone per tick. This is not observed in case of the female ixodid tick Rhipicephalus sanguineus even at 100 micro g amount per tick. This is suggested to be due to a difference in specific genetical instruction in their epidermal cells and also to a complementary state of their neurosecretions