Cryptic species diversity and character congruence: review of the tribe Anthracini (Diptera : Bombyliidae) in Australia

The Australian Anthracini are revised. In all, 28 new species are described , bringing the total fauna to 34 species. The previously described species of Anthrax Scopoli - A. maculatus Macquart, A. incomptus Walker, A. conflue nsis Roberts, A. lepidiotus Roberts and A, proconcisus Hardy - are diagnose d and the following eight new species of Anthrax are described: A. argentia , A. asciculus, A. clinatus, A. crenatus, A. dolabratus, A. funestus, A. op acus and A, torulus. This taxonomic study reveals a group of at least 20 cr yptic species previously included in collections under the name Anthrax ang ularis Thomson. A new genus, Thraxan, is erected to contain this cryptic gr oup of species and the following 20 new species are described: T. acutus, T . abditus, T. caligneus, T. cinctus, T. cornuatus, T. depressus, T, echinat us, T, ebenus, T. emicatus, T. hamulus, T. luteus, T. misatulus, T, nodus, T. norrisi, T. obstipus, T. patielus, T. planus, T. prolatus, T. simulatus and T. spiculus. Many of these cryptic species have been collected sympatri cally, hill topping together in eastern Australia. A key is provided to the species of Anthrax and Thraxan, genitalia drawings are presented for most species and distribution maps of all species are presented. A cladistic ana lysis of the species of Anthrax and Thraxan is also presented. A total of 2 6 of the species is compared for 125 synapomorphies in 39 adult morphologic al characters. Three species-groups were found: Thraxan, and two species-gr oups within Anthrax, the A, proconcisus species-group and the A. maculatus species-group. Previous authors divided Anthrax into species-groups on the basis of wing p atterns, but found that these species-groups were not confirmed when other characters were taken into consideration. We studied the congruence of seve n different character sets within the clade comprising Anthrax and Thraxan - antennae, venation, wing patterns, vestiture, genitalia, male genitalia a nd female genitalia - using several incongruence indices. Significance of i ncongruence was measured using a randomisation procedure. Results of these studies indicate that the wing-pattern character set is significantly incon gruent with the other morphological data. These quantitative cladistic resu lts explain the difficulty previous authors experienced in finding suites o f characters to support species-groups in Anthrax on the basis of wing patt erns. A relationship is found between the level of incongruence and the dis tance over which mate-recognition signals operate.