Observations on Hunterellus sp. (Hymenoptera: Encyrtidae) parasitizing Haemaphysalis bispinosa Neumann, 1897 (Acarina: Ixodidae)
Geevarghese, G.; Sreenivasan, M.A.
Indian Journal of Medical Research 61(7): 992-997
1973
ISSN/ISBN: 0019-5340 PMID: 4758004 Document Number: 62388
Parasitism by an Encyrtid of the genus Hunterellus of nymphs of Haemaphysalis bispinosa Neum. in cattle sheds in and around the area of India where Kyasanur forest disease occurs is recorded. The parasite is believed to be undescribed. Of 700 engorged nymphs of H. bispinosa collected, 88 yielded parasites, but no Encyrtids emerged from 480 larvae or 5 adults. The adult parasites paired about 15 min after emergence, and the females oviposited in tick nymphs immediately afterwards. The eggs did not start to develop in unfed tick nymphs, but larvae of Hunterellus could be dissected out from fed nymphs on their first day of detachment from the vertebrate host. Pupae and larvae in different stages of development could sometimes be seen in the same nymph. External signs of parasitism could be seen 5-10 days after detachment, and nymphs began to die on the 7th day. The total developmental period of the parasite from egg to adult, excluding the dormant period in the unfed nymph, varied from 30 to 36 days under laboratory conditions. Usually 1-3, but sometimes 5 parasites emerged from a single nymph. In addition to nymphs of H. bispinosa, those of H. spinigera Neum., H. turturis Nutt. & Warb. and H. papuana kinneari Warb. [cf. 59, 393] were also parasitised in the laboratory, but those of Boophilus microplus (Can.) were not. The parasites were collected in all months of the year. Fed nymphs of H. bispinosa were collected from 49 of 59 villages searched, and 71.4% of the 49 were positive from Hunterellus. The rate of infestation of the ticks ranged from 0.3 to 48.9%.In a field investigation, 1888 inactive infested nymphs of H. bispinosa were released in a forest naturally infested with ticks and 1880 inactive Haemaphysalis nymphs were collected 10 and 15 days later. Of these, 1050 fed on chicks and were examined for parasites; 2 were found to be infested, each with 4 parasites. It is unlikely that the nymphs were naturally infested, and further investigations of the possibility of using the Encyrtid to control ticks are thought desirable.