Batrachomyia krausi Evenhuis

Evenhuis, Neal L., 2006, First record of the frog parasite genus Batrachomyia Krefft from New Guinea (Diptera: Chloropidae), Zootaxa 1351, pp. 53-59 : 54-58

Batrachomyia krausi Evenhuis , sp. nov.

Type material: Holotype (Ento. BPBM 16,668) and 2 paratypes of third (final) instar larval specimens from: Papua New Guinea: Fergusson Island: Oya Tabu [= Mt.

Kilkerran], 900–1000 m, [9.45ºS, 150.78ºE], 20–24 Aug 2002, F. Kraus et al., collectors (Vert. BPBM 16339). Other paratypes: 3 third (final) instar specimens, topotypic, same data as holotype (Vert. BPBM 16341); 2 third (final) instar specimens, topotypic, same data as holotype (Vert. BPBM 16337). Holotype deposited in BPBM; paratypes in AMS and BPBM.

Batrachomyia species Frog species Family Country Uperoleia laevigata Keferstein Myobatrachidae Australia

sp. Crinia signifera Girard Myobatrachidae Australia

Geocrinia laevis (Günther) Myobatrachidae Australia

Geocrinia victoriana (Boulenger) Myobatrachidae Australia

Heleioporus albopunctatus Gray Myobatrachidae Australia

Litorea citropa (Duméril & Bibron) Hylidae Australia

Litorea infrafrenata (Günther) Hylidae Australia

Pseudophryne corroboree Moore Myobatrachidae Australia

Pseudophryne dendyi Lucas Myobatrachidae Australia

Pseudophryne pengilleyi Wells & Myobatrachidae Australia Wellington

Larval Description. Length: 12.5–16.9 mm (n = 8). Greatest width (at level of segments 5 and 6): 5.0–6.0 mm. Body generally depressedly fusiform, tapered somewhat similarly at each end; lateral edges (when viewed dorsally) somewhat serrate in shape as a result of the general triangular shape of segments 3–9. In lateral view, larva flat on ventral surface, dorsal surface markedly convex with greatest girth and width at 5th and 6th segments. Head retracted into thorax leaving small visible cervical membrane anterior to anterior spiracles, mouthparts situated on ventral surface. First segment with spiracles on tentacle-like anterior respiratory processes. Anterior respiratory processes porrect, each tapering to blunt apex, constricted slightly subapically. Segments 2–10 with paired tubercles on tips of lateral processes; segments 2–10 dorsally each with three welt-like swellings: one medial bearing two small tubercles, one each admedianly bearing single small tubercle. Ventrally, segments 2–10 each with medial patch of dense microspicules ( Fig. 5 ). Last segment with posterior spiracles borne on paired respiratory processes. Each process small and tapered to apex. Posterior spiracles each with three oval-shaped openings surrounded by a ridge.

Remarks. Adults have not been associated with the larvae, but the porrect anterior respiratory processes ( Figs. 1 , 3 ) (directed caudally or decumbent in other Batrachomyia species, cf. Figs. 2 , 4 ) the distinctive triangular shape (when viewed dorsally) of the lateral portions of the abdominal segments with the presence of tubercles laterally on each segment (absent in Australian Batrachomyia species), and the ventromedial patches of dense microspicules ( Fig. 5 ) (these segments each with single row of small blunt spinules in Batrachomyia , cf. Fig. 6 ) are unlike any other described species known and give me no hesitation in describing this species as new. Its large size (largest specimen 16.9 mm) is larger than the recorded larval length in other described Batrachomyia species but I have seen larval specimens of an undescribed species from Australia in AMS with specimens of a similar size, so this in itself may not be of any significance.

It is hoped that future collections can be made in the same general area to search specifically for adults but it is highly improbable that this specific area will be searched again for many years due to logistical difficulties. The frog species ( Rana supragrisea ) is fairly widespread on Fergusson Island but parasitized specimens were found only in the one specific area given above. A total of 16 frog specimens (7 males and 9 females) were found by Kraus to be parasitized. Only 3 of the frogs were dissected to obtain larvae for the type series. The rest of the parasites remain in situ. All larval parasites were found on the sides of the frogs in front of the hind legs.

Etymology. The specific epithet honors the primary collector of the species, Dr. E. Frederick Kraus. It has been pointed out to me that it is extremely unlikely that he will ever get something named after him, so I might as well do it now.

Distribution: Known only from Fergusson Island, Papua New Guinea.

Figures

FIGURES 5 – 6. Batrachomyia last instar, ventral view. Detail of anterior portion of larva. 5. B. krausi, sp. nov., showing medial patches of microspicules on segments. 6. B. nigritarsis, showing medial row of small spinules on segments.

FIGURES 1 – 2. Batrachomyia, third (last) instar larval habitus, dorsal view. 1. B. krausi, sp. nov. 2. B. nigritarsis Skuse (Royal National Park, NSW; AMS specimen). Abbreviations; ar = anterior respiratory process; t = lateral tubercle; pr = posterior respiratory process.

FIGURES 3 – 4. Batrachomyia last instar, dorsal view. Detail of anterior portion of larva. 3. B. krausi, sp. nov. 4. B. nigritarsis. Abbreviations. ar = anterior respiratory process; t = tubercle; dw = dorsal welts.