Glen M. Kohls

Observations on Hybridization of Three Species of North American Dermacentor Ticks

Female Dermacentor andersoni Stiles confined on the host with male D. variabilis (Say) later produced infertile eggs, whereas the reciprocal cross sometimes yielded progeny of both sexes. Meiotic chromosome pairing, karyokinesis, and cytokinesis in some of these hybrid males suggest various degrees of chromosome homology. Certain morphological characters of the hybrids appeared intermediate while others resembled one parent species more than the other. Hybridization between D. andersoni X D. occidentalis Marx produced no progeny when male D. andersoni mated female D. occidentalis, but the reciprocal cross yielded offspring. Dermacentor variabilis is common east of the Rocky Mountains in the United States, in parts of California, Oregon, Idaho, Mexico, and Canada. D. occidentalis is prevalent from central Oregon to lower California. D. andersoni occurs in the Rocky Mountain States, western North Dakota, South Dakota, and Nebraska, south to New Mexico, California, and parts of Canada (British Columbia, Alberta, and Saskatchewan). The ranges of these taxa overlap in certain areas, yet there are some differences in apparent preferences for bioclimatic zones (Rapp, 1960; Wilkinson, 1967). Although peak activity of adults of one species might be out of phase with another (i.e., peak of D. variabilis activity is often a month later than that of D. andersoni), both species might simultaneously parasitize the more widely traveling hosts, such as ungulates and carnivores. On the host, there may be differences in preferred site of attachment as observed with D. andersoni and D. albipictus (Packard) on deer (Wilkinson, 1970), but Dermacentor males actively seek out receptive females (Berger et al., 1971) and could encounter individuals of both species. Thus there is some practical relevance to studReceived for publication 31 August 1971. * Acari: Ixodidae. t Supported in part by Public Health Service Research Grants AI-06169 and AI-09556 from the NIAID (principal investigator, James H. Oliver, Jr.). t Callaway Professor, Department of Biology, Georgia Southern College, Statesboro, Georgia 30458. ? Research Scientist, Research Station, Canada Department of Agriculture, Lethbridge, Alberta. II Sanitarian Director, Retired, U. S. Public Health Service, Rocky Mountain Laboratory, Hamilton, Montana 59840. ies of the outcome of crosses among these important disease vectors. MATERIALS AND METHODS Ticks were fed on rabbits, guinea pigs, and sheep by confining them in capsules on clipped areas of the hosts or in ear bags on rabbits (Bailey, 1960). Details of geographic origin of the species and particulars of each experiment are presented with the results of each experiment. Each of us conducted experiments unaware of similar experiments by the others. Experiments were conducted at Hamilton, Montana; Lawrence, Kansas; Berkeley, California; and Kamloops, British Columbia, and span a period from 1954 to the present. Preparation of tissues for cytological studies consisted of removing males from hosts 3, 4, 5, and 6 days after initial attachment and placing them in modified Carnoys fixative for approximately 24 hr, before storing in a refrigerator. Subsequently, testes were removed, stained with acetocarmine, and typical squash preparations made.

Southeast Asian Haemaphysalis ticks (Ixodoidea, Ixodidae). H. (Kaiseriana) papuana nadchatrami ssp. n. and redescription of h. (K.) semermis Neumann.

Adults of Haemaphysalis (Kaiseriana) semermis Neumann and H. (K.) papuana nadcha- trami ssp. n. closely resemble each other, frequently are taken on the same host animal, and have con- sistently been misidentified in literature and museum collections as H. hystricis Supino. Clear, constant, structural characters readily differentiate these three taxa. Adults and nymphs of the first two forms are described and numerous data are provided. H. (K.) hystricis, a very distinctive species, is redescribed in the following paper in this series. The name H. semermis is resurrected after study of the holotype. H. semermis and H. papuana nadchatrami ssp. n. are common, widely distributed, and active through- out much of the year in forests of certain islands of Indonesia, and in Borneo, Singapore, peninsular Malaya, and parts of Thailand. Hosts of adults of both forms are the human, tiger, leopard, wild dog, wild boar, bearded pig, tapir, and domestic dog; H. p. nadchatrami has also been collected from the hog-badger, domestic pig, horse, buffalo, and cow, and the former from the clouded leopard, Malay bear, sambar deer, barking deer, and water hog. Immature stages of both forms infest a variety of forest rodents (Rattus spp.) and other small mammals. H. hystricis is absent or ecologically very re- stricted in the geographic area occupied by these two ticks. Comparative studies on competition, feed- ing behavior, seasonal activity, and population dynamics of H. semermis and H. papuana nadchatrami ssp. n. should be rewarding to the biologist. A number of biological properties of these ticks cause them to be highly suspect as reservoirs and vectors of pathogens, and their epidemiological potential merits careful investigation.

Southeast Asian Haemaphysalis ticks (Ixodoidea, Ixodidae). H. bandicota sp. n. from bandicoot rats in Taiwan, Thailand, and Burma.

Both sexes and nymphs and larvae of Haemaphysalis bandicota sp. n. are described from the bandicoot rat, Bandicota spp., in Burma, Thailand, and Taiwan. This species is related to the H. doenitzi and H. erinacei groups of Asian, African, and southern European ticks that parasitize birds and small mammals, and should be an interesting subject for epidemiological investigations. The Haemaphysalis species described herein is a component of a complex that is probably common in humid tropical and temperate Asia and outlying islands, as well as in Africa and southern Europe, but is infrequently collected. Host-relationship, distributional, ecological, and epidemiological studies of species in this group, which characteristically parasitizes certain birds and small mammals, should be especially interesting. We are grateful to Captain Robert E. Kuntz, USN, formerly of the United States Naval Medical Research Unit Number Two, Taipei, Taiwan, and to Major John E. Scanlon, USA, of the SEATO Medical Research Laboratory, Bangkok, Thailand, for much of the material reported in this study. Colonel Robert Traub, USA, kindly furnished specimens collected by Mr. R. E. Elbel in Thailand. Received for publication 28 November 1964. * From Research Project MR005.09-1402.3, Bureau of Medicine and Surgery, Navy Department, Washington 25, D. C. The opinions and assertions contained herein are the private ones of the authors and are not to be construed as official or reflecting the views of the Navy Department or the naval service at large. t Head, Department of Medical Zoology, United States Naval Medical Research Unit Number Three, Cairo, Egypt, U. A. R. + Sanitarian Director, United States Department of Health, Education and Welfare, Public Health Service, National Institutes of Health, National Institute of Allergy and Infectious Diseases, Rocky Mountain Laboratory, Hamilton, Montana. Haemaphysalis bandicota sp. n. The Bandicoot Rat Haemaphysalid

Ixodes (Exopalpiger) jonesae sp. n. (Acarina: Ixodidae), a Parasite of Rodents in Venezuela

The female, male, nymph, and larva of Ixodes (Exopalpiger) jonesae, sp. n. are described from rodents in the state of Merida, Venezuela. All of the collections were from Thomasomys laniger except for a single larva from Oryzomys minutus. This new species and I. (E.) andinus Kohls, 1956 of Peru are the only representatives of the subgenus known from the Western Hemisphere. The new species described herein was found among ticks that were collected by personnel of the Smithsonian Institution/U. S. Army Venezuelan Project in the state of Merida in western Venezuela during February and March 1966 and submitted to the senior author for identification. The species is dedicated to Mrs. Eleanor K. Jones, Biological Laboratory Technician, Rocky Mountain Laboratory, who first recognized that the species differed from the only other representative of the subgenus Exopalpiger known from the Western Hemisphere, Ixodes (E.) andinus Kohls, 1956. All measurements are given in millimeters. In the description of the nymph and larva the numbers in parentheses refer to the number of specimens that were measured. Terminology for larval chaetotaxy is that of Clifford and Anastos (1960). Ixodes (Exopalpiger) jonesae sp. n. Figs. 1-14 Holotype: Female, from Thomasomys laniger, 4 km S, 6.5 km E Tabay (La Coromoto) 3,170 m elev., Merida, Venezuela, 12 March 1966, N. E. Peterson (RML 47372). Deposited in the Rocky Mountain Laboratory. Allotype: Male, data as for holotype except 11 March 1966 (RML 47369). Deposited in the Rocky Mountain Laboratory. Paratypes: Total 1 9, 7 nymphs, 50 larvae. 1 9, 1 larva, data as for holotype except 13 March 1966 (RML 47376); 3 larvae in 2 lots, data as for holotype except 11 March 1966 (RML 47370, 47371); 2 nymphs, 37 larvae in 4 lots, data as for Received for publication 13 August 1968. * U. S. Department of Health, Education, and Welfare, Public Health Service, National Institutes of Health, National Institute of Allergy and Infectious Diseases, Rocky Mountain Laboratory, Hamilton, Montana 59840. t Biology Department, Old Dominion College, Norfolk, Virginia 23508. This study was supported by a grant, AI 07082, from the National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland. holotype (RML 47372, 47373, 47374, 47375); 7 larvae in 3 lots, data as for holotype except 13 March 1966 (RML 47377, 47378, 47379); 1 larva, data as for holotype except 16 March 1966 (RML 47380); 1 larva from Oryzomys minutus, data as for holotype except 18 March 1966 (RML 47381); 5 nymphs in 3 lots from Thomasomys laniger, 3 km W Timotes (near Paramito) approximately 3,200 m elev., 14-16 February 1966, N. E. Peterson (RML 47363, 47364, 47365). Paratypes are deposited in the Field Museum of Natural History (Chicago, Illinois) and the Rocky Mountain Laboratory.