Page images
PDF
EPUB

The larva and nymph have been described by Roubaud and Colas. Belcour (1933) and in more detail by Hoogstraal (1955B).

[graphic]

Figures 35 and 36, 9, dorsal and ventral views

AP.GAS (CHIROPTERARGAS) CONFUSUS

Egyptian specimen

PLATE XII

- 97

ARGAS (CHIROPTERARGAS) CONFUSUS Hoogstraal, 1955 (B).

[merged small][merged small][ocr errors][ocr errors][ocr errors][merged small][merged small][merged small][merged small][merged small][merged small]

As A. vespertilionis (in part): Khartoum and Northern Provinces (King 1911,1926).

[blocks in formation]

confusus is recorded from scattered localities from Egypt to the Cape of South Africa. Additional collecting will undoubtedly reveal its occurrence elsewhere on the continent. This species is thus far not known outside of Africa.

NORTH AFRICA: EGYPT (Hoogstraal 1955B).

EAST AFRICA: SUDAN (In part as A. vespertilionis: King 1911, 1926. As A. vespertilionis group: Hoogstraal 19543. As A. confusus: Hoogstraal 1955B).

KENYA (Hoogstraal 1955B).

*Host name on label, identity not checked by authority in host group.

SOUTHERN AFRICA: SOUTHERN RHODESIA, BASUTOLAND, and BEC HUANA LAND (Hoogstraal 1955B). UNION OF SOUTH AFRICA [For details con cerning A. confusus reported as A. vespertilionis by Nuttall et al (1908), Howard (1908), and Bedford (1934), and for more recent records, see Hoogstraal (1955B). Subsequently, Dr. Zumpt has sent additional specimens from Bloemfontein, Orange Free State, and from Lady Frere, Cape Province.

HOSTS

At the present time we have definite evidence of larval A. confusus from only a few species of insectivorous bats; Chaerephon major and Taphozous perforatus haedinus (Equatoria records above); questionably (host field determinations not checked by a specialist) from Eptesicus pusillus and Pachyotus sp. (Equatoria records above); and from Eptesicus capensis, Pachyotus sp., Miniopterus natalensis arenarius, Taphozous p. perforatus, T. (L.) nudiventris, Otonycteris h. hemprichi, Nycteris t. thebaica, and Tadarida a. aegyptiaca

Hoogstraal 1955B). Nymphs and adults found in bat infested caves and buildings probably feed on the same species of hosts as do larvae.

The record of A. confusus = A. vespertilionis) attacking pen guins in Queenstown, Cape Colony (Nuttall et al 1908) must be regarded as questionable (Hoogstraal 1955B).

BIOLOGY

Life Cycle

A. confusus has been reared in our laboratory at temperatures between 800F. and 900F. and at relative humidities between 40% and 50%. A single egg batch consists of from forty to seventy eggs with fifty to sixty the most common quantity. Eggs hatch from 21 to 25 days after being laid. Larvae have commenced feeding five to 26 days after hatching. The duration of larval feeding varies from five to fifty days but most larvae drop from the host in two or three weeks. Afterwards, larvae remain quiet for seven to twelve days before the nymphal molt.

Four nymphal instars are invariable in our numerous observa tions. Nymphs, like adults, feed for from 25 to fifty minutes. The first nymphal instar, however, never feeds; it molts to the second instar usually in ten to thirteen days (range eight to 21 days). One to three weeks later the second instar nymph feeds and molts to the third instar some two weeks later (range eight to 23 days). The third instar nymph takes food between three and 35 days afterwards and molts three or four weeks later (range fifteen to 59 days). The fourth instar nymph feeds between five and 36 days afterwards and molts to the adult stage three or four weeks later (range seventeen to forty days ).

Note that although there are many morphological similarities between A. confusus and A. boueti, the biology of the nymphal stage of each is distinct.

In this species, the observed period between nymphal molting and feeding is quite variable. Some accept food within five to seven days although two to three weeks, or longer, is more common for this and for other bat-parasitizing argasids. Also noteworthy is (1) the average two week postfeeding period of second instar nymphs in contrast to the three or four week average postfeeding period of the two subsequent instars, and (2) the nonfeeding first instar.

Adults placed together shortly after molting have been observed to mate only after feeding which may occur from eight to sixteen days after molting. The feeding period varies from forty minutes to two hours. No egg batches have been deposited before three and a half to four months after molting. Further studies on the Fı generation are in progress.

Ecology

We have collected, with considerable and strenuous effort, several hundred specimens of A. confusus in Eeypt. This species, together with A. transgariepinus, is the most secretive of bat in festing argasids. It wedges itself deeply into the narrowest crevices of caves and of hillside crannies in which bats rest. It is never found easily or in groups of more than two to a maximum of twelve specimens. We know of only a single exceedingly small population in Cairo, where bats roost in buildings that are more humid than desert caves, In the environs of Cairo,

« PreviousContinue »