Multiple engorged tick nymphs (n= 6) were collected from an injured spotted wood owl (Strix seloputo) in Kelantan, Peninsular Malaysia. Morphological identification of the nymphs revealed that the ticks were Haemaphysalis wellingtoni, based on several distinctive features: (1) internal edge of palpal article III extending far beyond the internal edge of palpal article II; and (2) four feathery and closespaced infrainternal setae. Subsequent molecular analysis of a randomly selected nymph targeting the mitochondrial 16S gene corroborated with the species identity of the tick. To date, this is first report of the infestation of H. wellingtoni on S. seloputo. Future studies are needed to determine whether native or endemic birds may serve as disseminators of ticks and tick-borne diseases.
Extensive usage and heavy reliance on insecticides have led to the development of insecticide resistance in the German cockroach, Blattella germanica (L.). Six field-collected strains of B. germanica from Singapore were used to investigate resistance to fipronil and dieldrin. The three strains (Boat Quay, Cavenagh Road, and Ghimmoh Road) with greatest resistance to fipronil were subjected to selection with fipronil bait up to the F5 generation. Synergism assay and molecular detection of a target site mutation were used to elucidate the mechanism of fipronil resistance in these strains. With the exception of the Cavenagh Road strain, all parental strains were susceptible to dieldrin. This strain exhibited resistance to dieldrin and fipronil with resistance ratios of 4.1 and 3.0, respectively. Piperonyl butoxide and S,S,S-tributylphosphorotrithioate were antagonistic toward fipronil toxicity in all strains. Bait selection significantly increased fipronil and dieldrin resistance in the three chosen strains, either in topical bioassay or bait evaluations. There was a significant positive relationship [y = (6,852.69 +/- 1,988.37) x - (708.93 +/- 1,226.28), where x = fipronil toxicity and y = dieldrin toxicity] between dieldrin and fipronil resistance levels, indicating significant cross-resistance between the insecticides. High frequencies of individuals possessing the Rdl gene mutation were found in the F5 generation of the three strains selected with fipronil bait. The synergism assays indicated that monooxygenase and esterase were not involved in fipronil resistance in the strains studied herein. The A302S Rdl mutation was the major mechanism contributing to fipronil and dieldrin resistance in these strains.