Rhagovelia species

Zettel, Herbert, Laciny, Alice & Freitag, Hendrik, 2020, Review of the genus Rhagovelia Mayr, 1865 (Insecta: Heteroptera: Veliidae) in the Palawan biogeographic region, the Philippines, Raffles Bulletin of Zoology 68, pp. 810-837 : 811

Treatment of Rhagovelia species groups and species in the Philippines. Adults of almost all Rhagovelia species are dimorphic, with an apterous (wingless) and a—usually rarer—macropterous (winged) morph. These two forms are structurally extremely different. Matsuda (1956) described the new subgenus Neorhagovelia Matsuda, 1956 , for those species which possess a short pronotum in the apterous morph. However, such splitting into two subgenera most likely does not reflect natural clades and was rejected by most of the subsequent authors. Instead, a group concept for the species of Rhagovelia in the Oriental, Malesian, and Australian Regions was established by Polhemus & Polhemus (1988), and later modified in several minor details by J.T. Polhemus (1990), D.A. Polhemus (1996), Nieser et al. (1997), and Zettel (2003a, 2006). A comparison of these species groups with those groups, which inhabit the New World, Africa, and Madagascar, is still lacking.

For the Philippines, a key to the species groups was presented by Zettel (1994b). Later, D.A. Polhemus (1996) discussed and confirmed the inclusion of R. werneri Hungerford & Matsuda, 1961 , in the R. novacaledonica group, but excluded R. hoogstraali Hungerford & Matsuda, 1961 , to form a group of its own. These two species are endemic to the mountains of Mindanao Island. Zettel (1999) recorded the R. borneensis group as new for the Philippines ( R. fischeri Zettel, 1999 , from North Luzon). Zettel (2003a) proposed that the R. caesia group (sensu Zettel, 1995a) is polyphyletic and based on convergences (characters related to a special mating behaviour with small “phoretic males”), and restricted it in a narrow sense to those species inhabiting New Guinea. The Philippine species formerly included in that group were then placed in new, separate clades, namely R. lansburyi Zettel, 1995 , which is an isolated species close to the R. borneensis group; and R. phoretica Polhemus, 1996 , and R. sallyae Zettel, 2003 , which form another Philippine-endemic group called the R. phoretica group (sensu Zettel, 2003a; not sensu Polhemus & Polhemus, 2011) and might be related to the R. orientalis group.

In the Palawan Region, only three species groups have been recorded so far. In the remaining Philippines, the R. papuensis and R. orientalis group are strongly dominating, while in Greater Palawan, the R. papuensis group is represented by only two widely distributed species ( R. kawakamii hoberlandti Hungerford & Matsuda, 1961 ; and R. gapudi , new species), and the R. orientalis group is replaced by the R. sarawakensis group. Field observations suggest that these two groups occupy similar ecological niches. Rhagovelia lansburyi from Central Palawan is a very peculiar species with unclear relationships (see above). Short diagnoses and a key to the three species groups are provided in the taxonomic part.