On a New Genus and Species of Bat-fleas from the Pelorus Islands and New Zealand
[Communicated by Dr. D. Miller; received by Editor, April 30, 1946.]
The unique specimen of a species of Bat-flea in the collection of the Cawthron Institute submitted to me for identification by Dr. David Miller is very closely related to a group of Australian species which have hitherto been regarded as belonging to the genus Ischnopsyllus Westw., 1833. When revising the classification of the Bat-fleas of all countries (so far as made known), it became soon evident, however, that the similarity of these Australian fleas to the Palearctic and African Ischnopsylli was superficial. The differences from Ischnopsyllus and all other genera are numerous, present in both sexes and easily perceived, there being no difficulty at all in recognising a flea as belonging to this group of the Far East I therefore place the five species known to me (four from Australia and the new one described below) into a separate genus, Porribius gen. nov. The previously described species are: (1) P. caminae (C. Roths.), 1903, from West Australia; (2) P. reductus (C. Roths.), 1903, from New South Wales; (3) P. bathyllus (M. Roths.), 1936, and (4) P. earinus (M. Roths.), 1936, both from West Australia. The specimen described in 1903 as the female of P. reductus belongs to P. bathyllus and represents perhaps a new subspecies. The material of Porribius in the British Museum collection, consisting only of three males and eleven females, is inadequate for the study of the variability of the five species.
Porribius gen. nov.
Genotype: Ischnopsyllus caminœ C. Roths., 1903.
Frons with deciduous tubercle, leaving a scar (Fig. 1); posterior part of the pale area deflected; the dorsal area about it bearing two placoids and a few minute hairs is without short longitudinal striæ; below the pale area a well-defined darkish band from near anteoral corner to near antennal groove, contrasting with the sides of the frons and being divided by pale transverse bars extending from the minute hairs downwards; apex of genal process rounded and pale, behind the vestigial eye the process traversed internally by barlike sclerotization which projects into the antennal groove as a short tooth. Occiput with four or five rows of bristles. On the pronotum two rows of bristles and anteriorly a few additional bristles representing a third row. Sclerotized ridge of propleurum almost horizontal, anteriorly projecting above the base of the procoxa (Fig. 1). Upper angle (an) of lower portion of anterior margin of meso- and metasterna incrassate (lateral aspect). Metasternum without squamulum. Comb of abdominal tergum I reduced to 1 to 5 very short
spines (on the two sides together), in one specimen altogether absent. At the side of the apical cone bearing the long antepygidial bristle no minute bristle. Femora with one subapical subventral bristle each side.—Male: Tergum VIII (Fig. 5, VII.t.) small, laterally consisting of a narrow setiferous process; sternum VIII larger, rounded dorsally, ventrally produced distad each side into a lobe (val) bearing long bristles; dorsal inward projection of tergum IX broad and as long as the manubrium (M) of the clasper; body of clasper (Cl) elongate-elliptical, bearing ventrolaterally in front of the digitoid (F) a narrow process (rl) which has at the end two long bristles corresponding to the acetabular bristles of other fleas.—Female: Striation of basal abdominal sternum strongly curved backward below middle and then forward-downward (Fig. 2); at or near apex of sternum VIII (Fig. 3) a short ridge extends upward-forward, either forming with the ventral margin (lateral aspect) a sharp hook or being more or less semicircular.
The dark band behind the pale frontal stripe bears two or three rows of minute hairs and varies in width according to species or sex, being a little narrower in the male than in the female; the pale bars in the band are usually more regular and more distinct than in the male, from which Fig. 1 is taken; the anterior ante-oral spine is much shorter than the second (proportions about 2:3); the ventral apical angle of the maxilla projects much more than the dorsal angle. The ventral outline of the prosternum abruptly curves upward a short distance from apex, as shown in Fig. 1, with the exception of the single known specimen of P. earinus, in which the apex of the prosternum narrows more gradually (due to-pressure in mounting?). Sterno-episternal internal ridge of mesothorax (Fig. 1, step) sharply defined and broader than the sterno-epimeral strut (str); The metasternum has no bristle in front of the sterno-epimeral composite strut (stem). Hindcoxa elliptical, with the base subtruncate. The tibiæ and tarsi similar to those of Ischnopsyllus. The apex of sternum VIII of the female (Fig. 3) is either pointed and projects beyond the hook-mark or forms a rounded lobe above the hook; it remains as yet doubtful whether this difference is specific or individual. All specimens have a minute bristle above the ventral backward extension of the mesosternal ridge (step), an example of the persistence of a morphological distinction which is apparently of no great value in the life of the insect. The short striæ in the dorsal area of the frons mentioned above occur only in Ischnopsyllus Westw., 1833, Myodopsylla J. and R., 1911, and Oxyparius Jord., 1936, being very numerous in all species.
Porribius pacificus spec. nov. (Figs. 1–5).
One male and two females from the Pelorus Islands, taken off spirit specimens of Chalinolobus morio in the British Museum by the late Oldfield Thomas; and one female taken off a native bat near Masterton, New Zealand, by Dr. A. Hosking in March, 1915.
All four specimens agree with P. caminae, P. reductus and P. earinus in the dark band of the frons being much narrower than in P. bathyllus and the dorsum of the head, thorax, and anterior
abdominal segments less selerotized; they differ, however, from the Australians in the occiput bearing four instead of five long and longish bristles. In the male the apical dorsal process (P) of the clasper is more strongly concave on the underside (Fig. 5) and the free process (rl) shorter than in P. caminœ and P. reductus (male of P. earinus not known); digitoid (F) narrowed to apex as in P. reductus, but one-fifth shorter; ventral apical lobe (val) of sternum VIII longer; hood (hd) of phallosome (phal) with the apex truncate as in P. reductus. In the female the pale tip of sternum VIII (Fig. 3) extends beyond the hook; the angle of the hook larger in the specimen figured than in the two others (the size of the angle perhaps depending on the pressure of the coverslip); sternum VII partially torn in all three females, its apical margin is incurved and the angle above this sinus probably as much effaced as in P. caminœ. The number of spines in the combs is somwhat greater in the female than in the male, as is also the case in Australia, being most marked in the posterior combs. The numbers of spines in the eight combs are: Male—21, 21, 1, 17, 15, 12, 14, 13; in females from Pelorus—23, 23, 2, 21, 19, 19, 18, 18 and 22, 24, 8, 23, 21, 20, 19, 18; and in New Zealand female—24, 24, 4, 25, 22, 18, 19, 20. Spermatheca (Fig. 4) smaller than in the Australian species. Length : male 1.9, hindfemur 0.31 mm.; female 2.1–2.2, hindfemur 0.32–0–36 mm. Type male.
I am greatly indebted to Dr. D. Miller for having lent me the New Zealand specimen. Only one other flea is known to me from New Zealand, a male of Notiopsylla kerguelensis (Taschenb.), 1880, which M. Daneford obtained on Antipodes Island on Platycercus unicolor. Several other fleas may be expected to occur in the nests of penguins, puffins and other sea-birds. The native rat, too, may have a special flea, and as Australia is rich in species of the genus Echidnophaga, small stick-tight fleas found on mammals and birds, it would not be surprising if the genus were discovered in New Zealand.
Jordan, 1936, Novit. Zool., 40, 86.
Jordan and Rothschild, 1911, ibid., 18, 88.
—— 1914, l.c. 21: 219.
Charles Rothschild, 1903, ibid., 10, 323.
Miriam Rothschild, 1936, ibid., 40, 14.
Taschenberg, 1880, Die Flohe, 67.
Westwood, 1883, Entomological Magazine, 4 (1), 359.
Fig. 2–Basal abdominal sternum of female Po
ilus pacificus. 132 X.
Fig. 3.–Apex of sternum VIII, same species. 198 X.
Fig. 4.–Spermatheca, same species. 132 X.
Fig. 5.–Male genitalia, same species; Cl, clasper; P, dorsal apical process of clasper; rl, free lateral process; M, manubrium of clasper; F, digitoid; Phal, phallosome; val, apical ventral lobe of sternum VIII; hd, apical hood of phallosome. 132 X.