Juvenile hormone analogue and egg development in the blowfly, Phormia regina (Meig.)

Abstract

Application of a juvenile hormone analogue (JHA) to allatectomized Phormia regina caused a lowering of protein concentration in the haemolymph, an elevation of two protein bands and restoration of egg development when the blowflies were fed a reproductive diet of meat. There was a fluctuation in the haemolymph volume of JHA-treated flies. In contrast, control flies that were similarly allatectomized but treated with acetone showed a persistently high concentration of protein in the haemolymph and a haemolymph volume which was higher than that of experimental flies. As a consequence, the total haemolymph protein in the control flies was higher than that in the JHA-treated flies. However, control flies never matured eggs and their haemolymph showed low levels of two protein fractions (3 and 4). Protein fraction 3 is invariably lacking in the haemolymph of male flies, while fraction 4 is at a persistently low level. These two fractions appear in the extract of the oocytes. JHA treatment to the blowflies maintained on a nonreproductive diet of sugar and water resulted in an advancement of the follicles beyond the characteristic resting stage. Thus the initial arrested stage of the follicles is a consequence of a deficiency in a juvenile hormone titre.