« PreviousContinue »
NORTH AFRICA: EGYPT (As A. fischeri: Audouin 1826, Savigny 1827, and Lavoipferre and Riek 1955. "Hoogstraal 1952A). TUNISIA (Colas-Belcour 1933B).
WEST AFRICA: FRENCH WEST AFRICA: Although reported as A. vespertilionis by Marchoux and Couvy (1912A,B, 1913A,B), there is some likelihood that some or all of these specimens may have been those subsequently used as the types of A. boueti. Rousselot (1953B). GOID COAST (Simpson 1914). "
CENTRAL AFRICA: BELGIAN CONGO (Schoenaers 1951A).
EAST AFRICA: SUDAN (King 1911, 1926; in part. Hoogstraal 1954B).
KENYA (HH collecting in crater of Mt. Menengai).
SOUTHERN AFRICA: ANGOLA (Larvae from Dundo, Lunda, northeastern Angola, CNHM). MOZAMBIQUE ("Brumpt's Precis"). SOUTHERN RHODESLA (Jack 1932. Bedford 1934).
UNION OF SOUTH AFRICA: South African adults described and illustrated by Nuttall et al (1908) as A. vespertilionis represent A. confusus. Howard (1908), Dönitz (1910B), # (1932B,1934) elso confused these two species as probably also did Cooley (16%) cf. Hoogstraal (1955B, p. 586) for details. Dr. G. Theiler has sent a female and nymph of A. vespertilionis from Pretoria and Grahamstown. These were among larger numbers of A. confusus and A. boueti. No specimens of A. vespertilionis were included with material of A. confusus and A. # from collections of the South African Institute for Medical Research, recently sent for identification by Dr. F. Zumpt. These observations lead one to suspect that A. vespertilionis may be less common in South Africa than A. confusus.
OTHER AREAS: Available material referable to this group is from England, Netherlands, Sweden, Spain, Germany, Korea, China, Philippines, and Ceylon. The group is also known to occur in Southern India, Cambodia, Australia, France, Italy, and Russia. Differences between African and European specimens and those from Australia and Asian areas are very slight indeed.
Almost any bat, whether it lives in large colonies or in small groupe, may be parasitized by A. vespertilionis. All stages probably infect the same kinds of hosts.
Three species of chiropteran hosts are thus far known from
the Sudan (records above). The Angolan larva is from Pipistrellus nanuz. In Egypt, we find larvae chiefly on Otonycteris # her:chi, *Iropoma hardwickei cys and E. Eicrophy I Capiszcus E2×2 and Z. Erzeźis, Nycteris E. EEEEica, Eide a. 22EETEE and T. ETEEEETITThey are Tess merous on #. clivosus Brachygnatus, R. mehelyi, Asellia t. triedens, Prezzi: arriers Chris EI, PIEEtrelius E. Kuhri, and Rouse:
- # EE-ZEFTE BET FTE: Eys: Era and TE:al
Nymphs and adults on several occasions have attacked us in caves and we easily induce it to bite ourselves in the laboratory (Hoogstraal 1952A, 1955B).
In our laboratory, Mr. Sobhy Gaber successfully rears specimens of A. vespertilionis at #. to 90°F. and 40% R.H. to 50%. R.H. Egg # consist of thirty to fifty eggs, one-fifth or one-sixth of which usually do not hatch. Larvae emerge from sixteen to twenty days after the eggs are laid and some will feed as quickly as four days afterwards. The duration of larval feeding varies from fourteen to 31 days, but is usually seventeen to nineteen days. Five to ten days later larvae molt to nymphs, which are capable of feeding three or four days after this and after subsequent molts. Usually two feedings are indulged by
nymphs, followed by a molt eight or nine days after the first meal and twelve to fourteen days after the second meal. Nymphs
become replete in from twenty to fifty minutes, usually in thirty to forty minutes. Males may emerge from the first nymphal molt, but usually nymphs, molt twice before becoming adults. Males and females may feed within seven days after molting. Duration of adult feeding is thirty or forty minutes. No female has oviposited within six months after the nymphal-adult molt, even though she has been with a male continuously and both have had two to six blood meals. The first egg batch follows a blood meal by about a week. The first oviposition appears to trigger a physiological release mechanism for, in several instances, three months afterwards females have deposited a fertile egg batch with or without a meal. We are at present attempting to ascertain whether the long interval between molting and oviposition is peculiar to these laboratory observations or whether it is a usual feature in our local populations.
A. # is more lethargic than A. boueti. Adults,
if undistur while imbibing from a vein in the Wing membrane of a bat, may remain attached for as long as five hours after engorgement is apparently completed. The feeding tick remains motionless with all legs down but, when fully distended without release of mouthparts from the host skin, it usually raises the fore legs to an antennalike position. During engorgement the beak is disengaged from the host skin only after considerable disturbance.
Large blood clots form at the site of the bite, both on the bat's body and in the wing membrane. This phenomenon, on bats, is in marked contrast to that observed by Lavoipierre and Riek (1955), using ticks from our collections, and laboratory rodents. The greater avidity with which these ticks attack bats probably accounts for the more conspicuous sequelae in these animals.
Larvae may be found anywhere on the body or wing membranes, but most commonly at the edge of the hairy parts, seldom on the head, feet, tail, or trailing edge of the wings.
European and African populations of this tick, which thus far cannot be morphologically differentiated, withstand a wide
range of temperature and humidity conditions. Host flight habits account for the wide distribution of A. vespertilionis, but we are not aware that host migration is a £### populations from widely differing ecological situations.
European and South African populations exist under temperate climatic conditions with pronounced seasonal changes and with moderate to heavy rainfall. Those of Egypt and of northern Sudan normally tolerate the most extreme arid niches in which any arthropod is known to survive. Their engorged larvae, however, are found usually among moist dung or in dung between crevices of bats' retreats. Just where females commonly oviposit in nature and where unengorged larvae rest before seeking a host has not yet been satisfactorily determined
Throughout Europe and Africa interstices in the walls of batinfested caves and buildings are the most common habitats of A. vespertilionis. They may also be found in tree holes and in other situations frequented by certain bats. In Cairo a specimen, recalling Robert Burns" wee louse, has been taken from a worshipper during church service by an observant but distracted friend sitting behind. In Iraq, Patton (1920) reported the same or a closely related species in Bedouin tents in which bats presumably rested by
Egyptian specimens hide alone or clustered in large or small groups usually well concealed between shale or in crevices of walls. Some individuals are observed wandering openly on the walls. Unconcealed individuals are noted much more frequently in those caves or niches that only erratically harbor a few bats than in large caves where many bats usually roost. Possibly our entry into caves infrequently visited by any animals induces these ticks to investigate the possibility of a meal.
Small numbers of the round bat-argas frequently are found in niches in the most unexpected cliffsides where a few old pellets of dung indicate that hermit bats such as Otonycteris h. hemprichi occasionally spend the day. These ticks lead a most uncertain existence and often wait months on end for a host, as revealed by their compressed bodies and by the age and scarcity of hosts? dung in these places.
In Egypt, A. vespertilionis occurs with the more common A. boueti and with the less common A. confusus and A. transgariepinus
A. vespertilionis and the other two species are rare, however,
in the comparatively humid situations in Cairo favored by the fruit-bat parasite, Ornithodoros salahi.
MAN: Mild itching resulting from a bite may persist for several weeks.
BATS: Large blood clots form at the site of the bite, both on the host's body and on the wing membrane.
It has been stated that this tick is a vector of a spirochete of bats but reports of conclusive supporting evidence have thus far not been located.
In the Cairo area blood of a few of these ticks has been found to contain a most interesting organism resembling, according to Dr. P. C. C. Garnham (correspondence): "the sporozoites of a Haemoproteid; they are not unlike the sporozoites of Leuco# ..... described ..... from the abdominal cavity of imulium flies." Unfortunately, it has thus far been impossible to undertake further study of this phenomenon.
Egyptian specimens examined in NAMRU-3 laboratories have been negative for spirochetes, viruses, rickettsiae, and Shigella organisms.
REMARKS The taxonomy and biology of bat-infesting Argas ticks is presently being studied and the first report, on A. boueti and
A. confusus has been presented (Hoogstraal 1955B). The second section will deal with the confounded status of Argas (Carios)
vespertilionis. Some workers have considered Carios as a full genus, indiscriminately including in it features of a variety
of species based on vague and ambiguous remarks in the literature.