Cochliomyia hominivorax (Coquerel, 1858)

Szpila, K., Hall, M. J. R., Wardhana, A. H. & Pape, T., 2014, Morphology of the first instar larva of obligatory traumatic myiasis agents (Diptera: Calliphoridae, Sarcophagidae), Parasitology Research (1629) 113 (5), pp. 1629-1640 : 1631-1632

Cochliomyia hominivorax (Coquerel, 1858)

( Figs. 2a–h ; 3a–d ; 6c, d ; and 7b

Pseudocephalon: Antennal complex with slightly elongated dome, height of basal ring less than length of antennal dome ( Fig. 1c ); maxillary palpus with three sensilla coeloconica and three sensilla basiconica (sb1–sb3, sc1–sc3) clustered in the central part, sb3 not distinct ( Fig. 2d ), one or two additional small sensilla are situated close to sb1, two additional typical sensilla coeloconica (ns1–ns2) arranged laterodorsally on the surface of the maxillary palpus; labial lobe triangular ( Fig. 2e ); ventral organ small, situated lateral to the functional mouth opening and level with the adjacent integument ( Fig. 2e, f ); oral ridges terminate medio-laterally on pseudocephalon ( Fig. 2a, b ). Cephaloskeleton: mouthhooks strongly sclerotised in anterior and mid parts, mid part of mouthhooks bar-like, slightly curved and equally broad for the entire length, apical part with six to eight long, strongly sclerotised, pointed teeth arranged in a large cluster and with tips orientated ventrally, teeth with only slightly differentiated size, basal part of mouthhook slightly sclerotised with visible lateral arm ( Figs. 2b, e and 6c, d ); labrum long, with well differentiated narrower apical part, broad basal part of labrum 3× longer than short, narrow apical part ( Fig. 6c ); intermediate sclerite H-shaped in ventral view ( Fig. 6d ); parastomal bars broad and straight in lateral view; vertical plate very wide, about 3× as wide as widest part of dorsal cornua; dorsal cornua slightly longer than ventral cornua, ventral cornua with similar width to the dorsal cornua; dorsal bridge absent ( Fig. 6d ).

Thoracic segments: anterior spinose band on t1 broad, with spines arranged in 6–7 rows dorsally and 10–12 rows ventrally, spines large and elongated, size of spines decreasing gradually towards the posterior end of body, anterior-most spines of each segment very long and almost straight with only apical part curved ( Figs. 2a, b and 6c ); anterior spinose bands of t2 and t3 with homogeneous, strongly sclerotised, elongated spines. Abdominal segments: anterior spinose bands complete on a1– a5, interrupted dorsally by narrow break on a6, on a7 band incomplete being interrupted dorsally and laterally ( Fig. 7b ), spines on ventro-lateral surfaces of each segment larger than other spines, each anterior spinose band ventrally with a transverse lenticular gap without spines ( Fig. 3a ); all posterior spinose bands incomplete, spines present only as single row of spines on ventral surface with few additional spines on ventro-lateral surfaces ( Fig. 7b ); lateral creeping welts with strong spines directed posteriorly only the most posterior lateral creeping welt without spines. Anal division: Anal pads rounded, small and slightly protruding ( Fig. 3c ), anal tuft with few spines dorsally, readily apparent in light microscope; circle of hair-like spines around spiracular field entirely absent ( Fig. 3d ), several small conical spines present along ventral edge of spiracular field; posterior spiracles each with four peristigmatic tufts of differentiated size ( Fig. 3d ), dorso-lateral tuft narrower than others, other tufts broad and serrated to form three to six broad branches; anterior spinose band developed only ventrally and ventrolaterally ( Fig. 7b ); p1, p3 and p5 developed as small cones with a short sensillum on the extremity resembling a large sensillum coeloconica, p7 with sensillum on small protuberance, p2, p4 and p6 developed as sensilla situated level with adjacent integument.

Figures

Fig. 2 First instar of Cochliomyia hominivorax. a Anterior end of body, antero-lateral view. b Anterior end of body, ventral view. c Antennal complex. d Maxillary palpus. e Functional mouth opening. f Ventral organ. g Keilin’s organ. h First thoracic segment, spines

Fig. 3 First instar of Cochliomyia hominivorax. a Abdominal segments 1–3, ventral view. b Abdominal segment 2, spines. c Anal division, ventral view. d Anal division, posterior spiracles. Abbreviations: a1–a3 abdominal segments 1–3, ao anal opening, ap anal pad, asb anterior spinose band, at anal tuft, lcw lateral creeping welt, psb posterior spinose band, st peristigmatic tufts

Fig. 6 Cephaloskeleton of OTMA. a Chrysomya bezziana, lateral view. b Chrysomya bezziana, ventral view. c Cochliomyia hominivorax, lateral view. d Cochliomyia hominivorax, ventral view. e Wohlfahrtia magnifica, lateral view. f Wohlfahrtia magnifica, ventral view. Scale bar=0.1 mm. Abbreviations: a length of apical part of labrum, b length of basal part of labrum, db dorsal bridge, dc dorsal cornua, is intermediate sclerite, la lateral arm, lb labrum, mh mouthhook, pb parastomal bar, vc ventral cornua, vp vertical plate

Fig. 7 Habitus. a Chrysomya bezziana. b Cochliomyia hominivorax. c Wohlfahrtia magnifica. d Lucilia cuprina. Abbreviations: a1–a7 abdominal segments 1–7, ad anal division, pc pseudocephalon, t1–t3 thoracic segments 1–3. Scale bar=0.1 mm

Fig. 1 First instar of Chrysomya bezziana. a Anterior end of body, lateral view. b Functional mouth opening. c Antennal complex. d Maxillary palpus. e Ventral organ. f Third abdominal segment, ventral view, anterior spines. g Anal division, posterior view. Abbreviations: abr antennal basal ring, ad antennal dome, an antennal complex, ao anal opening, ap anal pad, cir cirri, mh mouthhooks, mp maxillary palpus, ll labial lobe, lo labial organ, ns1 first additional sensillum coeloconicum, ns2 second additional sensillum coeloconicum, or oral ridges, p1–p7 papillae 1–7 sb1–sb3 sensilla basiconica, sc1–sc3 sensilla coeloconica, sp posterior spiracle, vo ventral organ