External Morphology of Immatures of Mischocyttarus nomurae Richards (Hymenoptera, Vespidae) during the Post-embryonic Development

Abstract

IntroductionThe species Mischocyttarus nomurae was described by Richards in 1978 from two females collected in Fortaleza, Ceará State (CE), Brazil; it was included in the Mischocyttarus cerberus group in a review published by Silveira (2004). The individuals are black, with many pale-yellowish gaster markings, with distinct stripes and frontal margin of the proepisternum distinctly elevated (Richards, 1978). The males of that species were described by Silveira (2004) from samples collected in Lençóis (Chapada Diamantina), Bahia State (BA), Brazil. Among other features, the clypeus is covered by dense recumbent hairs with silvery reflections; the antenna is spirally rolled at the apex, with the last three segments elongated. Souza et al. (2015) recently recorded the occurrence of specimens of M. nomurae in Montes Claros, Minas Gerais State (MG), Brazil, captured in traps using passion fruit bait. These are the only references to the species in the literature. AbstractWe describe here the immatures of Mischocyttarus nomurae Richards from twenty colonies collected in the municipality of Rio de Contas in the Chapada Diamantina, Bahia State, Brazil. We determined the number of larval instars in post-embryonic development and measured 145 eggs, 353 larvae, 12 prepupae, and 59 pupae. Egg lengths varied from 0.80 to 1.33 mm and their widths from 0.33 to 0.50 mm. The average rate of growth of the larvae was 1.48. Cephalic capsule widths varied from 0.20 -0.43 mm in the 1 st instar larvae, from 0.47 -0.63 mm in the 2 nd instar, 0.67 -0.83 mm in the 3 rd instar, 0.87 -1.20 mm in the 4 th instar, and 1.37 -1.73 mm in the 5 th instar larvae. The cephalic capsule of the 1 st instar larva was smaller than the width of the egg. The median widths of the 5 th instar larvae and the pre-pupae cephalic capsules did not differ significantly. The species has two abdominal lobes that are highly projected forward, and the diameter of first thoracic spiracle is 3.1 times greater than the second. M. nomurae shows development patterns typical of the genus.