Precocene II (P II) was applied to the adult females of 2 Pyrrhocorid bugs —
Pyrrhocoris apterus (insensitive to P II) and
Dysdercus cingulatus (sensitive to P II)-subjected to allatectomy and intraspecific or interspecific reimplantations of corpus allatum (CA). The failure of P II to inhibit ovarian development in
P. apterus appears to be caused by both a low sensitivity to P II of the CA itself and unknown
anti-precocene mechanisms
outside the CA.
Precocene II was kindly supplied by Zoecon.