To refer to this article use this url: http://www.zoologischemededelingen.nl/83/nr03/a18
Species groups within Diopsis Linnaeus, 1775
Diopsis remained the sole diopsid genus till Say (1828) erected Sphyracephala. Until Rondani (1875) described two more genera, all newly described diopsids were placed in Diopsis, except for two more Sphyracephala. As a result, many species were subsequently referred to later described genera. To some extent, Diopsis remained a default genus and a thorough revision of the genus is overdue. After Linnaeus’ description “Capite bicorni, oculis terminalibus,” the genus has never been redescribed. So far, only some partial keys were produced. Séguy (1955) produced two keys, one for Diopsis with a black or brown abdomen and the other for Diopsis with an abdomen that is largely or completely red. Lindner (1962) gave a key for Diopsis with a red abdomen. Feijen (1978) gave keys for Diopsis with a large apical wing spot and for dark Diopsis with banded wings. Feijen (1984b) briefly reviewed black Diopsis with irregularly infuscated wings. Below, a provisional subdivision of Diopsis is given. This subdivision is intended as a first guide only into the genus. Subsequent subdivisions need to be based on descriptions of male and female genitalia and DNA analyses. For future species descriptions, the importance of pollinosity patterns on the dorsal thorax has to be stressed. The greater number of Diopsis species remains to be described, while many of the existing species need to be redescribed.
- The circularis Macquart group: dark Diopsis with banded wings. This is the easiest group to recognise with a mainly dark grey to black colour, though some parts can be reddish brown. The wing has dominant dark bands; the most central one of these dark bands is almost round. Feijen (1978) gave a key for this group and proposed a number of synonymies. However, Feijen (1984a) reconsidered some of these synonymies. In any case, the group comprises circularis Macquart, 1835, ornata Westwood, 1837, pollinosa Adams, 1903 and munroi Curran, 1929. Proposed junior synonymies of the first three species will have to be reviewed. This concerns macquartii Guérin-Méneville, 1837-1844, curva Bertoloni, 1861, aries Hendel, 1923, conspicua Eggers, 1925 and globosa Curran, 1931.
-
The carbonaria Hendel and gnu Hendel groups: Blackish Diopsis with irregularly infuscated wings. Feijen (1984b) divided the eleven black species into two groups. The first group was referred to as the carbonaria-groupand is characterised by tiny IVB and OVB and strongly incrassate front femora. It includes
carbonaria Hendel, 1923, melania Eggers, 1925, aterrima Brunetti, 1926, diversipes Curran, 1928, baigumensis Séguy, 1955, nitela Séguy, 1955 and, probably, nigrasplendens Feijen, 1984. The second group was referred to as the gnu-groupand is characterised by the presence of inner and outer spines on the stalks (replacing IVB and OVB) and hardly incrassate front femora. It includesgnu Hendel, 1923, acanthophthalma Eggers, 1925, angustifemur Brunetti, 1926, anthracina Brunetti, 1928 and orizae Séguy, 1955. - The apicalis Dalman group: Diopsis with brown head, thorax without cross-like pattern of pollinosity and almost always a large apical wing spot, living in open habitat (savannah, swamps). This is, no doubt, the largest group of Diopsis with many undescribed species (Feijen, 1987). It includes apicalis Dalman, 1817 (= tenuipes Westwood, 1837) and lindneri Feijen, 1978, but also the well-known rice diopsid longicornis Macquart, 1835 (= thoracica Westwood, 1837 and phlogodes Hendel, 1923), which has only some apical infuscation on the wing. The apicalis group is more closely related to the cruciata and fumipennis groups than to the other groups.
-
The cruciata Curran group: Diopsis with brown head, thorax with cross-like pollinosity pattern and a large apical wing spot. The species in this group are (rain) forest dwellers. This group is superficially very similar to the apicalis group and its species are often found under ‘apicalis’labels in museum collections. So far, it only includes
cruciata Curran, 1934, though another 15 species await description. This group might also include eisentrauti Lindner, 1962, but its thoracic cross is not complete and it has wrinkled, sausage-shaped spermathecae instead of the usual round spermathecae. - The fumipennis Westwood group: Diopsis with black head and a large apical wing spot. Pollinosity pattern on the thorax is variable; usually no cross-like pattern, but fumipennis itself has a cross. Species can occur in savannah habitat or forest habitat. The group includes fumipennis Westwood, 1837, punctiger Westwood, 1837, (= trentepohlii Westwood, 1837), atricapillus Guérin-Méneville, 1837-1844, fascifera Eggers, 1925 and many undescribed species.
- The indica Westwood group: Asian Diopsis with an apical wing spot, abdomen with black base or tip and sometimes completely black. The relation between the Asian Diopsis and the African Diopsis requires study. For the moment, the systematics of this group is complicated given summary original descriptions and questionable origins. As this group is considerably larger than earlier anticipated, it appears better to disregard, for the moment, earlier proposed synonymies. Next to indica Westwood, 1837, the group then includes graminicola Doleschall, 1857 and westwoodii Westwood, 1848. It is not unlikely that abdominalis Westwood, 1837, and assimilis Westwood, 1837 are of Asian origin and would also belong to this group. A recent addition was chinica Yang & Chen, 1996.
- The ichneumonea Linnaeus group: Diopsis with a distinctive preapical wing spot. This group might have to be split into two groups: slender forest Diopsis and more broadly built savannah Diopsis. This group is large and contains already quite some described species: ichneumonea Linnaeus, 1775, arabica Westwood, 1837, basalis Brunetti, 1926, collaris Westwood, 1837, dimidiata Curran, 1929, erythrocephala Westwood, 1837, hoplophora Hendel, 1923, macromacula Brunetti, 1926, nigriceps Eggers, 1925, pallida Westwood, 1837, planidorsum Hendel, 1923, praeapicalis Speiser, 1910, rubriceps Eggers, 1925 and somaliensis Johnson, 1898 (= lunaris Hendel, 1923).
- The ichneumonea Linnaeus group: Diopsis with a distinctive preapical wing spot. This group might have to be split into two groups: slender forest Diopsis and more broadly built savannah Diopsis. This group is large and contains already quite some described species: ichneumonea Linnaeus, 1775, arabica Westwood, 1837, basalis Brunetti, 1926, collaris Westwood, 1837, dimidiata Curran, 1929, erythrocephala Westwood, 1837, hoplophora Hendel, 1923, macromacula Brunetti, 1926, nigriceps Eggers, 1925, pallida Westwood, 1837, planidorsum Hendel, 1923, praeapicalis Speiser, 1910, rubriceps Eggers, 1925 and somaliensis Johnson, 1898 (= lunaris Hendel, 1923).
- The servillei Macquart group: clear winged Diopsis. This is a not so well-defined group of rather dissimilar species. The colour varies from the common brown head, black thorax, brown abdomen to almost completely black. It includes servillei Macquart, 1843, affinis Adams, 1903, diversipes Curran, 1928, flavoscutellata Brunetti, 1928, sulcifrons Bezzi, 1908 (= maculithorax Brunetti, 1928) and a few undescribed species. Most species are savannah-dwelling.
- The absens Brunetti group: slender forest diopsids with no or minor wing markings, brown head, black thorax and brown abdomen with often black base. It includes absens Brunetti, 1926, finitima Eggers, 1916, micronotata, malawiensis spec. nov. and vanbruggeni spec. nov.