Temporal relationships between leaving food, ecdysone release, mucoprotein extrusion and puparium formation in Drosophila virilis

The time sequence of various developmental processes at the end of larval life in Drosophila virilis larvae is reported. If reared at 25·3°C the larvae leave their food about 140 hr after oviposition; 6·6 hr later ecdysone release occurs, while 8·5 to 9 hr after leaving food the mucoprotein, synthesized and stored in the salivary gland cells, is extruded into the lumen of the gland. Puparium formation takes place 11·2 hr after leaving food. Changes in the puffing activity are correlated with these processes.