A SCANNING ELECTRON MICROSCOPE STUDY OF THE EGGS OF THREE STICK INSECT SPECIES OF RAMULUS (PHASMATODEA HETERONEMIIDAE) FROM SOMALIA

SUMMARY The eggs of three Somalian species of the genus Ramulus (Heterone- miidae Pachymorphinae) namely R. sansibarus (Stai), R. lingulatus (Scali & Capra) and R. affinis Schulthess-Schindler, have been investigated by the scanning electron microscope (SEM). R. sansibarus and R. lingulatus appear to be close species having a similar egg capsule organization and a chorionic pattern given by a similar network of prominent ridges. Nevertheless, many opercule and capsule characters appear to be species-specific. The R. affinis egg is much more elongated, has a different micropylar plate, shows a polar mound and has a markedly different chorionic pattern with prominent flakes and no ridges. These SEM egg characteristics together with the general body morphology and the chromosomal complement indicate a rather large taxonomic distance between the latter species and the two preceding ones. These findings suggest that at present the genus Ramulus includes species which differ too greatly from each other for incl...