Ecology and life histories of two Alpine-Apenninic species of Velia (Hemiptera: Heteroptera: Veliidae)

Abstract

Abstract. Velia currens (Fabricius, 1794) and V. gridellii Tamanini, 1947 are two South European species of Veliidae, whose ecology and behaviour are poorly known. The aims of this study were to investigate their life histories, quantify occurrence of wing polymorphism and gather information on their degree of co-occurrence. Nine different populations were regularly surveyed from April to November 2010. Furthermore, a dataset containing information on the occurrence of the two species and the presence of winged morphs at 294 sites was compiled from museum collections, private collections and published literature. No evidence for multivoltinism was detected in either species. However, oviposition and and/or hatching were protracted in time so that early-instar nymphs and adults co-occurred up to midsummer. Although their distributional ranges completely overlap at a large spatial scale, the two species co-occurred only rarely at the same sites and the degree of co-occurrence was lower than expected by chance. Winged specimens were rarely recorded. At least in V. gridellii, the numbers of winged individuals were inversely related to the altitudes of the sites. During the summer, when some of the streams surveyed dried up, several specimens were found in an apparent state of lethargy, under stones. It is hypothesized that the ability to aestivate, coupled with the ability to walk from one site to another may reduce the advantage associated with producing winged forms and account for the low rate of occurrence of macropterism in these species.

Differences in prey capture in semiaquatic bugs (Heteroptera:Gerromorpha)

“…Velia caprai is univoltine or partly bivoltine prevalently with an apterous morph (Ditrich & Papáček 2009b). Velia gridellii is an Italian endemic species with very similar body dimensions, life history and habitat preferences as V. caprai (Cianferoni & Santini 2012, 2013.…”

Molecular phylogeny and biogeography of the West‐Palaearctic Velia (Heteroptera: Gerromorpha: Veliidae)

“…Temperate species can overwinter both as adults and eggs on river banks (Ditrich & Papáček, ; Ditrich & Koštál, ). In a similar way to other gerromorphans, most Velia species exhibit wing polymorphism by having long‐winged (macropterous) and short‐winged (brachypterous) or long‐winged and completely wingless (apterous) morphs (Andersen, ; Ditrich & Papáček, ), although the winged morph is very rare or unknown in some taxa (see Cianferoni & Santini, ; Berchi & Kment, ).…”

“…These include Veliidae, which has been more or less overlooked until recently (cf. Ditrich & Papáček, ,b, ; Ditrich & Koštál, ; Ditrich et al ., ; Cianferoni & Santini, ). Likewise, most of the available data on the ecology and biology of Velia refers to the few species from central and northern Europe, whereas a modest number of reports are available for the southern and eastern taxa (e.g.…”

“…Water crickets of the genus Velia Latreille (Hemiptera: Heteroptera: Gerromorpha: Veliidae) are common semiaquatic bugs from streams and rivers throughout the temperate and subtropical parts of the Palaearctic region (Andersen, ). Members of the genus Velia are gregarious insects, inhabiting shaded areas of streams where they feed on dead or drowning insects floating on the water surface (Poisson, ; Andersen, ; Cianferoni & Santini, ). Velia species possess tarsal adaptations that enable their movement on the water surface through a synchronous rowing of the intermediary legs (Andersen, ), and they move on land in a fashion similar to terrestrial bugs (Ditrich & Papáček, ).…”

“…Likewise, most of the available data on the ecology and biology of Velia refers to the few species from central and northern Europe, whereas a modest number of reports are available for the southern and eastern taxa (e.g. Cianferoni & Santini, , ). From a molecular phylogenetic perspective, only a handful of species have been analysed and only in a wider systematic context (e.g.…”