ROTHERAY et al. 2007 (Article) phytotelmata

Neotropical Copestylum (Diptera, Syrphidae) breeding in bromeliads (Bromeliaceae) including 22 new species

Author(s):—G.E. Rotheray, E.G. Hancock & M.A. Marcos G.

Publication:—Zoological Journal of the Linnean Society 150(2): 267-317. (2007) — DOI

Abstract:—Twenty-three species of Copestylum (Diptera, Syrphidae) were reared from Bolivia, Costa Rica, Ecuador, Mexico, and Trinidad from 1998 to 2004. Twenty-two were new species. We describe these new species, their breeding sites, and the third stage larva and/or the puparium of all 23 species. Adults had species-specific head shapes and colour patterns, but similarities between 14 of the species enabled two groups and three subgroups to be recognized. Nonetheless, the high level of morphological disparity suggests independent colonizations of bromeliads. Adult colour patterns appear to be predominantly cryptic in function and based on reflectiveness derived from matt to shiny integumental ground colours, combined with overlying areas of variously coloured hairs, dust, and pruinosity. In addition, disruptive spots, bands, and vittae occur on the face, thoracic pleurites, and second tergite. Larvae were saprophagous in either live or dead bromeliads with no overlap between categories. A major factor explaining variation in larval morphology could be access to food. Larvae in live bromeliads are characterized by varying levels of dorso-ventral flattening, and modifications to the mouthparts and prothorax. These features appear to facilitate feeding in the narrow spaces between overlapping bromeliad leaves. Larvae exploiting dead bromeliads are characterized by varying levels of armature to the thorax, and extensions to the anal segment. Armature either consists of arrangements of sclerotized spicules distributed at various places on the thorax or large hooks on the lateral margins. Armoured thoraces facilitate burrowing through decaying tissue, and extended anal segments may reduce exposure during respiration.

Keywords:—crypsis, larva, phytotelmata, rearing, reflective colours