Several species of flies are found commonly in houses. Some of them so closely resemble the true house fly
that it requires very careful observation to distinguish them from it.
One of these is the biting stable fly (fig. 1). It occurs frequently in houses and differs from the house fly in
the important particular that its mouth parts are formed for piercing the skin. This fly is so often mistaken for
the house fly that most people think that the house fly can bite.
Carboxypeptidases were purified fromguts of larvae of corn
earworm (Helicoverpa armigera), a lepidopteran crop pest,
by affinity chromatography on immobilized potato carb-oxypeptidase inhibitor, and characterized by N-terminal
sequencing. A larval gut cDNA library was screened using
probes based on these protein sequences. cDNA HaCA42
encoded a carboxypeptidase with sequence similarity to
enzymesofclan MC [Barrett,A.J.,Rawlings,N. D.&
Woessner, J. F. (1998)Handbook of Proteolytic Enzymes.
Academic Press, London.], but with a novel predicted spe-cificity towards C-terminal acidic residues....
Insect development is driven by the action of ecdysteroids on morphogenetic
processes. The classic ecdysteroid receptor is a protein heterodimer com-posed of two nuclear receptors, the ecdysone receptor (EcR) and Ultraspira-cle (USP), the insect ortholog of retinoid X receptor. The functional
properties of EcR and USP vary among insect species, and provide a basis
for identifying novel and species-specific insecticidal candidates that disrupt
this receptor’s normal activity.