Chrysomya bezziana Villeneuve, 1914

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

Chrysomya bezziana Villeneuve, 1914

( Figs. 1a–g ; 6a, b ; and 7a )

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 (sc1–sc3, sb1–sb3) clustered in the central part, sb3 not distinct ( Fig. 1d ), one or two additional, small sensilla are situated close to sb1, two additional sensilla coeloconica (ns1, ns2) of typical appearance are arranged laterodorsally on the surface of the maxillary palpus, central cluster of sensilla surrounded by several crescent-shaped protuberances; labial lobe narrow and elongated, almost parallel-sided ( Fig. 1b ); ventral organ small, situated lateral to the functional mouth opening and level with the adjacent integument ( Fig. 1b, e ); oral ridges terminate medio-laterally on pseudocephalon ( Fig. 1 a ). Cephaloskeleton: mouthhooks large, strongly sclerotised and equally broad for the entire length ( Fig. 6a ), apical part with numerous (10–13), long, strongly sclerotised, pointed teeth arranged in a large cluster and with tips orientated ventrally, three to fourth teeth of each mouthhook larger than others ( Figs. 1a, b and 6a, b ); labrum long, with well differentiated narrower apical part, broad basal part of labrum at most 1.5× as long as narrow apical part ( Fig. 6a ); intermediate sclerite Hshaped in ventral view ( Fig. 6b ); parastomal bars broad and straight in lateral view ( Fig. 6a, b ); vertical plate very wide, about three times wider than greatest width of dorsal cornua; dorsal cornua slightly longer than ventral cornua, ventral cornua at widest point 1.5× as wide as dorsal cornua ( Fig. 6a ); dorsal bridge present ( Fig. 6b ). Thoracic segments: anterior spinose band on t1 broad, with spines arranged in 7–8 rows dorsally and 12–14 rows ventrally ( Figs. 1a and 6a ), spines large and slightly flattened, with broad triangular base and slender, curved, hook-like tip, size of spines decreasing gradually towards the posterior end of the body ( Fig. 1a ); anterior spinose bands of t2–t3 with homogeneous, strongly sclerotised, slightly flattened spines, tip of spines curved. Abdominal segments: anterior spinose bands complete on a1–a5, narrowly interrupted dorsally on a6, on a7 the band is incomplete being interrupted dorsally and laterally ( Fig. 7a ), 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. 1f ); posterior spinose band absent on a1, on a2–a4 band present as a single row of ventral spines with few additional spines ventrolaterally, on a5 spines present as a single ventral row with an additional small group of spines laterally, a6 with posterior band interrupted dorsally and laterally, band on a7 complete with a single row of spines laterally and with 2–3 rows ventrally and dorsally ( Fig. 7a ). Anal division: Anal pads rounded, slightly protruding ( Fig. 1g ), anal tuft with several spines dorsally, readily apparent in light microscope; hair-like spines around spiracular field entirely absent ( Fig. 1g ), several conical spines present along ventral edge of spiracular field; posterior spiracles each with four peristigmatic tufts of similar size, tufts broad with distal margin shallowly serrated to form four to seven irregular branches; anterior spinose band developed only ventrally and ventrolaterally ( Fig. 1g ); p1, p3 and p5 developed as cones with a long 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 ( Fig. 1g ).

Figures

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

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