| abstract | The genus Dipolaelaps (Laelaptidae) was established in 1960 by Zemskaya & Piontkovskaya, and contains so far only one species, namely D. ubsunuris, a parasite of the Mongolian five-toed jerboa, Allactaga sibirica, from the Tuva Autonomous Region in U.S.S.R. The new species herein described was obtained from a field-vole and its nest in Szechwan, China.
Dipolaelaps hoi, sp. nov.
Female (Figs. 1-3): Idiosoma oval, about 598-624µ long, 415-422µ wide. Dorsal plate bearing 39 pairs of setae, of these, M11 are the longest; F1-F3, V, Et1-Et2, T1-T2, Sc, S1-S3 and M1 being rather shorter; the other pairs being very minute. In front of the third pair of frontal setae with a slit-like pore on either side; with three pairs of sensory rounded spots, two pairs of which are situated on either lateral side near the posterior margin of the dorsal plate, the other pair near the vertical setae.
Sternal plate broader than long, with its anterior margin convex between first pair of sternal setae (St), its posterior margin being concave; three pairs of sternal setae subequal in length; slit-like pore three pairs in number, two on plate, other one being free from it, vertical and minute. Genitoventral plate long, rounded and enlarged posteriorly, bearing with two setae (Vl1) on narrowed portion, the other three pairs (Vl2-Vl4) being free from its plate, but very near it. Anal plate broader than long, triangular, with its anterior margin slightly concave and much broader than the enlarged portion of genitoventral plate, both lateral margins forming a continuous deep arc; adanal setae located a little below the horizontal level of center of the anal slit; postanal seta gross and strong, situated just above the cribrum, naked portion of the venter bearing 13-15 pairs of spine-like setae. Metapodal plate elliptical in form. Peritremal plate usually reaching forward and ending in front of coxa I.
Legs stout and strong, on the outer margin of femur I bearing one linear spine-like seta. The others very short.
Gnathosoma broad, about 100µ wide. Chela gross, rather short, its movable chela broad, bearing 2-3 small teeth; fixed chela short and narrowed apically. Pilus dentilis somewhat rod-like.
Male (Figs. 4-8): Idiosoma about 522µ long 344µ wide. Dorsal plate with 39 pairs of setae, which are of four kinds according to the form and size as showing in Figure 4. Sensory rounded spots three pairs in number, their positions being the same as those in female.
Holoventral plate large, with its anterior margin concave, both the lateral angles long and linear. In the middle of the plate contracted into a narrow portion and immediately expanded just below coxae IV, with the posterior end produced forming a short tail-like projection; with 11 paired setae plus one postanal seta on plate, the first anterior 5 pairs long and 6 posterior ones short; Approximately 8 pairs of setae on the naked portion of venter, 3 pairs of these are very long and curved.
Legs stout and strong. Tarsus II to IV bearing a subapical spur in each, truncate on tarsi II and III, pointed on tarsus IV; all on the dorsum of femur, genu and tibia of legs III and IV bearing strongly long setae, but variable in number and different in size.
Gnathosoma broad. Movable chela broad and stout, both lateral margins rolling up inwardly and forming a longitudinal canal throughout the entire length and curved apically; fixed chela narrow and pointed.
The holotype (♀), allotype (♂) and paratypes (3♀♀) collected from Microtus sp. and its nest in the year 1959 from Szechwan Province, China. Types deposited in the Institute of Epidemiology & Microbiology, Chinese Academy of Medical Sciences, Peking.
The present species may be quite readily distinguished from Dipolaelaps ubsunuris Zemskaya et Piontkovskaya by the posteriorly enlarged portion of genitoventral plate, the form of the anal plate in the female and the greater expansion of holobentral plate inthe male.
The writers take great pleasure in naming this interesting new species in honour of Professor Ho Ch’i, of the Institute of Parasitic Diseases, Chinese Academy of Medical Sciences, Shanghai |