Stadial and seasonal occurrence of gregarines and nematomorphs in two New Zealand cockroaches

Abstract

Twoendemic New Zealand cockroaches, Parellipsidion pachycercum Johns, 1966 and Celatoblatta peninsularis Johns, 1966, each have a different species of gregarine and a nematomorph. Gregarine infection prevalence was low (4% in P. pachycercum, 11% in C. peninsularis). In C. peninsularis, incidence, intensity, and gametocyst production were high only in early winter; in P. pachycercum, three peaks of incidence, intensity, and gametocyst production corresponded to early autumn, mid-winter, and mid-summer. Only 0.5% of P. pachycercum and 0.26% of C. peninsularis had one or two nematomorphs. In P. pachycercum, nematomorphs were found in late spring and summer, whereas in C. peninsularis they were found only during mid-winter.