Amiota, Loew, 1862

Jones, Lance E. & Grimaldi, David A., 2022, Revision Of The Nearctic Species Of The Genus Amiota Loew (Diptera: Drosophilidae), Bulletin of the American Museum of Natural History 2022 (458), pp. 1-181 : 4-6

DIVERSITY OF AMIOTA

The genus consists of 154 species found worldwide ( Bächli, 2020; Wang et al., 2020), but the greatest number is found primarily in the northern temperate areas of the world comprising the Nearctic and Palaearctic Region. Southwestern China, especially the Hengduan Mountains, is home to an exceptionally rich fauna ( Chen et al., 2005; Zhang and Chen, 2006; Cao et al., 2008). With a large number of species waiting to be described from Nearctic, four times the number previously known from the region, this area is now another center of species diversity for this genus.

Diversity of Amiota seems much lower outside of the temperate zones. They appear to be relatively absent from low tropical islands like those of the Caribbean, where just one species is known to us (an undescribed one from Jamaica in the collections of the AMNH). In their treatment of the drosophilids of Micronesia, Wheeler and Takada recorded no species of Amiota (1964) . Few species have been described from the Paleotropics, and only one has been described from the mainland Neotropics, A. steganoptera Malloch , although many undescribed species do occur there based on museum collections (L.E.J., personal obs.).

Prior authors have attempted to delineate lineages within the genus and as the genus became more narrowly defined. At times, Amiota has contained nearly six subgenera, including: Amiota s.str., Phortica Schiner , Erima Kertesz , Apsiphortica Okada , Paraphortica Duda, and Sinophthalmus Coquillett ( Máca, 2003) . Of all the subgenera, only Amiota s.str. seems to be worldwide, and only three of the subgenera are known from the Nearctic: Amiota , Phortica , and Sinophthalmus (Marshall, 1965), the last of which is now considered a synonym of Phortica . According to Máca (2003), Amiota now contains no subgenera; these subgenera were reinstated at the genus level or transferred to other genera.

Although the study of this worldwide genus may have begun with a study of American species, during the last 70 years most descriptive work has been conducted on the Palaearctic species. Some important works include Okada (1956, 1960, 1971). These works primarily centered on the Japanese fauna but are notable in their foresight of including descriptions and figures of the male genitalia, which has aided in the understanding of Nearctic species. The European fauna was initially revised by Duda (1934) and later by Máca (1980). A third revision, including the East Asian species, was conducted by Chen and Toda (2001). Bächli et al. (2004) provided a key, descriptions, and illustrations of most known species in western Palaearctic. Most descriptive work in the genus, however, has been in South and southwestern China, especially the Hengduan Mountains, by Chen and colleagues ( Chen et al. 2005; Zhang and Chen, 2006; Cao et al. 2008; Wang et al., 2020; and others). The region of high diversity has been hypothesized to be the center of origin for the genus ( Chen et al., 2005; Wang et al., 2020), but this has never been tested with a global phylogenetic analysis.

Compared with well-known animals such as birds, insects are vastly understudied. Unlike birds, where features such as geographic ranges, diets, plumage variation, female morphology, calls, nesting preferences, and behavior is well documented for most species, essentially nothing is known about the biology of most invertebrate species. In fact, many insect species are known only from their holotype or from a small number of specimens ( Bickel, 2009; Deng et al., 2019). The difficulty of studying insects is probably due to many factors, including the immense number of invertebrate taxa, the low number of working specialists relative to species richness, lack of collection effort for certain taxa, high rates of endemism, diverse life histories that make collection difficult or require specialized protocols, and a lack of literature for identification in most groups.

For these reasons and others, the study of Amiota is still at an exploratory stage. This stage is essentially defined by taxonomic descriptions and the gradual fleshing out of regions of diversity with every new record acquired. Scant is known of how they live. What little is known about their biology is scattered and anecdotal in the literature, primarily concerning the Palaearctic fauna. Indeed, as Steyskal found, Amiota has been ripe for revision for decades.