%0 Journal Article
%T Effect of temperature on local and Philippine isolates of Metarhizium anisopliae and their virulence on larvae of Oryctes rhinoceros, a pest of coconut in Sri Lanka
%J -
%D 2013
%R 10.4038/cocos.v20i0.5798
%X The effect of temperature on mycelial growth and spore production in Sri Lankan (local isolate) and Philippine isolates (DRC) of Metarhizium anisopliae (Metsch.) Sorokin and their virulence to larvae of the black beetle, Oryctes rhinoceros L. were compared in the laboratory. Mycelial growth and spore production in each isolate were evaluated at 25ˇăC, 27.5ˇăC, 30ˇăC and 32.5ˇăC. Healthy third instar larvae of black beetle were inoculated with spore suspensions of 106spores/ml of each isolate to compare the virulence. There was no considerable difference between the two isolates with respect to mycelial growth at the end of the experimental period of 40 days. However, the mycelial growth of the local isolate significantly differed among the four temperatures, with the highest growth at 27.5ˇăC and lowest at 32.5ˇăC. The growth of DRC isolate was similar at all temperatures. The two isolates differed significantly in spore production. Spore production was extremely low at 32.5ˇăC in both isolates. The local isolate produced a significantly higher number of spores at other three temperatures than that of the DRC isolate. In the local isolate spore production was higher at 25ˇăC and 27.5ˇăC and in the DRC isolate it was highest at 25ˇăC. Both isolates caused death in black beetle larvae, the local isolate recorded a significantly higher mortality (67%) than the DRC isolate (42%), 17 days after inoculation. The LT50of the local and DRC isolates were 14 and 18 days respectively. The study reveals that the local isolate has more desirable characteristics than the DRC isolate for use in the management of black beetle larvae in Sri Lanka.  COCOS Vol. 20: 49-58 (2013
%K Coconut
%K Metarhizium anisopliae isolates
%K mycelial growth
%K Oryctes rhinoceros
%K spore production
%K temperature effect
%K virulence
%U https://cocos.sljol.info/articles/10.4038/cocos.v20i0.5798/