New record of a microsporidian parasite from the teak defoliator, Hyblaea puera Cramer (Lepidoptera: Hyblaeidae).

For the first time a microsporidium was isolated from the defoliator of teak, Hyblaea puera Cramer, collected fromKanakpura in Karnataka. The spores of the microsporidium were observed to be ovo-cylindrical in shape with a mean spore size of 5.2±0.18 µm x 2.8±0.06 µm. Inoculation of the microsporidium resulted in a cumulative mortality ranging from 37.50 to 100%,respectively from 10³ to 10⁶ spore loads, indicating a relatively high degree of virulence of the parasite against the teak defoliator.The LC ₅₀ of the microsporidium estimated for H. puera was 5.4382 x 10³spores/larva. There was severe adverse effect on the growthand development of the larvae due to infection of the microsporidium as indicated by the slow and much less increase in body weightof the infected larvae during development. The increase in body weight of larvae from the day of inoculation to the day beforepupation was only about 15 times in the 10⁵ spores inoculated batch against 35 times in the control larvae. The spore yield per insect,obviously, was higher at higher spore loads. Beyond 10³ spore load, the increase in spore yield was however, appreciably higher.More significantly, the spore yield at 10⁴ spore load was almost a hundred times more than the spore yield at 10³. The sporesproduced corresponding to the spores inoculated was almost a thousand times in the case of 10⁶ spore inoculated batch, while only135 times in the case of 10² spore inoculated batch. The present observations indicate potential of this parasite as a possiblebiocontrol agent for the management of  H. puera

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