Larvae of the blow fly Caiusa testacea (Diptera: Calliphoridae) as egg predators of Polypedates cruciger Blyth, 1852 (Amphibia: Anura: Rhacophoridae)

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W.G.D. Chathuranga
K. Kariyawasam
Anslem de Silva
W.A.Priyanka P. de Silva


We investigated the impact of dipteran predators on eggs in foam nests of the Common Hour-glass Tree Frog Polypedates cruciger Blyth, 1852 (Anura: Rhacophoridae) in central Sri Lanka.  Foam nests (n=24) of P. cruciger were examined at their natural breeding habitats and infected (n=8) and uninfected spawns (n=16) were identified.  Emerging tadpoles were collected in a water container hung under each spawn and the average number of tadpoles (N) hatched from infected spawns (N=0) was compared with that of uninfected spawns (N=354 ± 67).  Three severely infected spawns were brought to the laboratory and the fly larvae were reared until they metamorphosed to adults.  Morphological and molecular identification of the flies confirmed them as belonging to Caiusa testacea Senior-White, 1923 of the family Calliphoridae.  The infected spawns were completely destroyed and an estimated average of 400 P. cruciger eggs per spawn were lost.  The results revealed a high impact of Caiusa testacea on egg and embryo mortality of P. cruciger.

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