THE EGG OF THE STICK-INSECT BACILLUS ATTICUS CAPRAI NASCETTI & BULLINI: A SCANNING ELECTRON MICROSCOPE STUDY (CHELEUTOPTERA BACILLIDAE)

SUMMARY The morphology of the egg of the stick-insect Bacillus atticus caprai Nascetti & Bullini (Insecta Cheleutoptera Bacillidae), the Italian member of the parthenogenetic B. atticus complex, was observed with the scanning electron microscope (SEM). A structural organization common to all the Cheleutoptera so far investigated at the SEM level is described. Peculiar and diagnostic characters, concerning mainly the sculpturing of the capsule and the morphology of the operculum, were found, which differentiate B. atticus caprai from the other Bacillinae so far studied, B. rossius (Rossi) and Clonopsis gallica (Charp.). A summary of the main differences between the eggs of these three species clearly shows that B. atticus caprai is more related to B. rossius than to C. gallica. A comparison of the egg of B. atticus caprai with those of the other parthenogenetic members of this complex, as well as with the more closely related bisexual species, is expected to clarify both the taxonomic status and the phylog...