OVARIAN DEVELOPMENT INDUCED IN DECAPITATED FEMALE CULEX-PIPIENS PALLENS MOSQUITOS BY INFUSION OF PHYSIOLOGICAL QUANTITIES OF 20-HYDROXYECDYSONE TOGETHER WITH AMINO-ACIDS

Infusion of 20-hydroxyecdysone into the hemocoel of unfed decapitated female Culex pipiens pallens mosquitoes, at a very low rate of 500-200 0 pg per day, often stimulated oogenesis of this species, when the hor mone was infused together with amino acids. The hormone alone or amino acids alone showed no such stimulatory effect. Previous reports that using an abdomen ligated immediately after a blood meal for hormone in jection reduced the quantity of 20-hydroxyecdysone needed to activate unfed female Aedes aegypti by a few thousand times, are therefore due mainly to a sufficient supply of amino acids from the midgut in the is olated abdomen. (C) 1998 Elsevier Science Ltd. All rights reserved.