JUVENILE-HORMONE METABOLISM IN THE OVARY, GUT, HEAD AND CARCASS AFTERBLOOD-FEEDING IN THE SOUTHERN HOUSE MOSQUITO, CULEX-QUINQUEFASCIATUS

The regulation of JH epoxide hydrolase, JH esterase and 1-naphthyl ace tate (NA) esterase activity was studied in ovary, gut, head and carcas s after blood feeding in Culex quinquefasciatus. The combined tissues had the greatest JH epoxide hydrolase and JH esterase activity from 24 -36 hr after a blood meal. JH epoxide hydrolase activity per female wa s 2.1-, 1.8- and 1.1-times greater than the JH esterase activity at 24 , 36, and 48 hr after blood feeding, respectively. JH epoxide hydrolas e activity per unit protein was also the major route of primary JH met abolism at most time points examined, and peak JH epoxide hydrolase ac tivity per unit protein in the gut, head and carcass was approximately 2-times the highest JH esterase activity per unit protein in correspo nding tissues and 4-times the peak JH esterase activity in the ovary. The differential expression of JH epoxide hydrolase versus JH esterase in specific tissues and between tissues suggested that regulation oi JH metabolism is tissue specific. Two isoelectric forms of JH esterase were found. The juvenoid, (RS)-methoprene, interfered with the regula tion of JH esterase activity, but failed to change the activity levels oi JH epoxide hydrolase and 1-NA esterase.