Corpora allata are the defined site of juvenile hormone (JH) biosynthesis in reproductive adult insects and their activity is regulated by intrinsic and extrinsic factors. In the adult lady beetle Coccinella septempunctata, it has been well established that the development of ovaries is controlled by JH (Guan 1987). The present study aims at the elucidation of the influence of some factors regulating reproduction of the lady beetle. They include topical application of JH analogues, presence of neuropeptides in the extract from the brain, as well as the development of ovary and type of food on CA activity. JH synthesis in CA is monitored with radiochemical assay and immunoelectrophoresis.

Using cell whole mount preparation and ultrathin section technique, the ultrastructure of the flagellum in the sperm of Coccinella septempunctata L. was examined with transmission electron microscope. The flagellum is made up of a classic 9+9+2 axoneme containing two similar crystallized mitochondria1 derivatives, two accessory bodies, which are divided in to two portions, an osmiophilic dense crescent and a spongy one, and a non‐crystalline body. At the end of the flagellum, only the axoneme is present, it loses the two central microtubules but retains the nine doublets with dynein arms and the nine accessory microtubules.

The fatty acid (FA) compositions for total lipids from fat body, hemolymph and flight muscle of the armyworm moths, Mythirnna separata, at rest and after tethered flight for 1 h were determined by GC and GC‐MS. The composition in these tissues comprises myristic acid (1%‐2%), palmitic acid (more than 35%1, palmitoleic acid (9%‐11%), stearic acid (less than 1%), oleic acid (about 32%), linoleic acid (12%‐17%) and linolenic acid (3%‐6%). After flight, FA level in the fat body, compared to that at rest, shows a significant decline at about 20 μg/mg tissue.h‐1; the concentration of FAs in hemolymph rises evidently, but change of FA content in flight muscle appears to be small. From the changes of proportional composition of FAs in fat body, hemolymph and flight muscle, it is found that the FAs selectively utilized for flight in flight muscle are predominantly the palmitic acid and oleic acid.

No abstract