Aspects of the biology of Bathycoelia thalassina (H-S): reproduction and growth of immature stages


ABSTRACT: Copulation in Bathycoelia thalassina lasted 3-6 hours. Mated females laid on average of 92 eggs (range 34 – 181 eggs) during a mean oviposition period 0(26 days (range 11-35 days). Eggs were laid in batches of 5 – 21 (Mean 11). Oviposition took place mainly during the night between 18.00 hours and 06.00 hours.
Incubation period for eggs of B. thalassina varied between 3 and 6 days (mean 4.7 days) under insectary conditions of 25 – 35°C and 70 – 85% rh. Between 73 and 100% of all eggs in a batch hatched, moulting was successful in over 90% of 1st instar nymphs but mortality exceeded 57% among 2nd instar nymphs. Morphometric studies were carried out using freshly killed specimens from insectary cultures. The early nymphal instars (Ist – 3rd) had higher growth ratios than the later nymphal instars (4th and 5th). An overall growth ratio of 1.24 was obtained.

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