Although we did not record the proximity of any
ootheca to any other when doing the searches in 2005, we did not see such obvious clustering of egg cases as Eisenberg and Hurd (1990) report; only in blackberry thickets were egg cases occasionally clumped in such proximity.
The formation of hyphae and penetration into the ootheca occurred on the third day (Figures 1D and 1E) through holes present in the tegument of the ootheca.
The penetration occurs through the cuticle of the ootheca and the pathogenic action culminates with the fungus extrusion.
Ultrastructural study of the crest in the ootheca of Periplaneta americana using a scanning electron microscope.
Table 2--Total mortality (TM) death confirmed by the fungus (DF), extrusion (EX), average time of fungal extrusion (TFE), total number of hatched nymphs (NN) and average number of nymphs hatched per ootheca (NNO) of P.
Numbers of eggs and ootheca produced by each female Averagely each female deposited 1.820.17 ootheca (1 to 6).
where the females (derived from the larvae that were monitored since the 4th stage) deposited less ootheca than those derived from larvae monitored since stages 5 or 6 (pless than 0.05).
The mean number of eggs per ootheca was 18.691.96 (0 to 61).
Table III.- Number of ootheca per female number of eggs per ootheca eggs and ootheca dimensions on Manihot esculenta and Vernonia amygdalina.
Fecundity was rather low, as the number of eggs per
ootheca was three times lower than in control animals.
They poke out through openings in the
ootheca (left).
While translocation of
ootheca to northern sites may create new populations within the developing potential tolerance range, population movement S is more problematic.