Parasites

Both species of New Zealand bat carry external parasites. Fleas are known from both, but till now records of mites exist only for Mystacina. Several observers refer to this bat as being "infested with vermin" and Grubner (personal communication) , who reports "a large spidery thing, reddish brown, and about ⅛in or more in size" from a captive bat, states that the animal was able to scratch any portion of its back with the foot.

Most specimens, juvenile and adult, of Chalinolobus examined during this study carried fleas (Order Aphaniptera). These occurred in the fur on all portions of the body, being commonest on the ventral surface in the axillary and pubic regions. From four animals (3 females, 1 male) which were thoroughly combed 23 fleas (17 females, 6 males) were obtained. All were Porribius pacificus described by Jordan (1947) for New Zealand bats. Only one flea was obtained from the twelve Mystacina examined. It was a female P. pacificus. Jordan includes five species in the genus Porribius, all as parasites of Australasian bats. Host species include Eptesicus pumilus, Nyctinomus (= Tadarida) australis, and Chalinolobus morio (Rothschild, 1936). Although the number of specimens from which the fleas were obtained was small the striking difference in infestation between the species could suggest that P. pacificus is at present in the process of transferring to Mystacina.

Grubner's description of a parasite of Mystacina as "spidery" and "about ⅛th inch or more in length" is strikingly suggestive of the family Nycteribidae, Order Diptera. Allen (1939) describes these bat parasites as being spidery in appearance and states that they are a common parasite, especially of Old World bats.

Mites (Order Acarina) were common on Mystacina, as many as 15 being obtained from a single specimen. The three species recognised belonging to the family Laelaptidae (Mesostigmata), suborder Sarcoptiformes (perhaps family Acaridae) and the group Parasitoidea (Mesostigmata). The laelaptid mite species was the most common. Only a single specimen of the last was obtained. Mites were present in the fur and none were found on the membranes.

A single specimen of a large mite was obtained from a juvenile Chalinolobus from Pelorus Valley (Marlborough). A member of the suborder Trombidiformes, the extremely dense coat of setae on the dorsal surface of this mite suggest that it belongs to the family Trombiculidae. Three genera of this family are recorded (Domrow, 1959) from Australian bats with Trombicula thomsoni known from Chalinolobus gouldii.