Glossal morphology of the Colletidae and recognition of the Stenotritidae at the family level (Hymenoptera: Apoidea).

Abstract

The glossal morphology of the Colletidae is exam ined with light and electron microscopy. Colletids (excluding the Stenotritinae) are apparently monophyletic. Recognition of the Stenotritidae is proposed. Glossal morphology has figured prominently in the higher classification of bees. Kirby (1802) recognized two genera of apoids on the basis of glossal length. Melitta included those bees with relatively short glossae (present day Colletidae, Halictidae, Andrenidae, Melittidae) and Apis, those with elongate glossae (Megachilidae, Anthophoridae, Apidae). This division is informally maintained today with the terms short-tongued and long tongued bees (see Winston, 1979, for details of this distinction). Within Melitta, Kirby recognized five groups, referred to as families but not given formal names. Two of these groups, now known as Collet?s and Hylaeus, were recognized as being distinctive owing to their obtuse glossae (the glos sa being acute in other apoids). Kirby predicted that when the . . Hy menoptera comes to be more attentively studied and better understood, it may be found necessary to separate these two families from Melitta. His prediction has been realized with the present-day recognition of the Colle tidae. The Colletidae are of special interest to the systematist as they are usually thought to represent the most primitive group of extant bees (Malyshev, 1968; Michener, 1974). With the higher classification of bees currently undergoing extensive re-examination (Michener, work in progress), the cla distic basis of the Colletidae assumes fundamental importance. Information from adult and larval morphology and nesting biology has hitherto provided no convincing evidence for the monophyletic basis of the Colletidae. As reviewed above, the historical basis for this family is the possession of an obtuse glossa in adults. This is a feature shared with all non-apoid Hymenoptera, apparently a plesiomorphic apoid condition and therefore of no value in supporting colletid monophyly. A recent study of 1 Contribution number 1726 from the Department of Entomology, University of Kansas, Lawrence, Kansas 66045. 2 Present address: Museum of Comparative Zoology, Harvard University, Cambridge, Mas sachusetts 02138. Received for publication 2 August 1979. This content downloaded from 40.77.167.72 on Wed, 27 Jul 2016 04:15:45 UTC All use subject to http://about.jstor.org/terms 540 JOURNAL OF THE KANSAS ENTOMOLOGICAL SOCIETY