Nitric oxide (NO) plays various roles in insect immunity: as a cytotoxic component and as a signalling molecule; and immune-reactive lysozymes (IrLys) provide a first line of humoral immune functions against invading bacteria. Although there is considerable literature on eicosanoid and biogenic monoamine actions on insect immunity, there is no information on the role(s) of these chemicals in inducing NO and IrLys. We addressed this gap by challenging third instar Sarcophaga (Liopygia) argyrostoma (Robineau-Desvoidy) with the Gram-positive bacterium Micrococcus luteus. Here, we report that bacterial challenge induces elevation of NO and IrLys concentrations in haemocytes and in the fat body. The plasma pool content is comparatively low. Eicosanoid biosynthesis inhibitors (EBIs) lead to suppression of both NO and IrLys levels. Control larvae have low constitutive levels of NO and lysozyme concentrations. Octopamine (OA) elicits elevation of NO and IrLys concentrations. A similar effect is obtained by 5-hydroxytryptamine (5-HT) for NO. These data indicate immune-mediating roles of eicosanoids, OA and 5-HT in NO and IrLys activities.

—The flesh fly, Sarcophaga ruficornis Fabr., was fed on thiotepa, and it was found that a 1% thiotepa solution produced complete sterility, which was due to the damage to the follicle cells and nurse cells. The passage of the female protein, ‘vitellogenin’, was blocked. Therefore, no trace of yolk granules was visible in the treated oocytes, but the oocytes and cytoplasm of the nurse cell contained vacuoles, and their nuclei were characterized by clumped chromatin contents.

Coprophagous beetles belonging to two genera, Onitis and Heliocopris, were collected and fed on proglotids and eggs of Taenia saginata. The beetles' faeces was collected after 24 hr onwards and examined for Taenia eggs. The flight range and behaviour of the beetles was investigated using cow rumen contents as bait for starved marked beetles. Results indicate that coprophagous beetles could play a role in dissemination of taeniasis.