The wing morphology of limnephilid caddisflies in relation to their habitat preferences

Abstract

Summary The aerial dispersal of merolimnic insects is a prerequisite for maintaining metapopulations and for colonising new habitats. Flight morphology, as one determinant of dispersal capacity, may be related to the distribution patterns and ecological preferences of aquatic insects, but empirical data for Trichoptera are scarce. This study aimed to provide flight morphological data for common European Trichoptera species in relation to their ecological preferences. We measured the flight morphology of 26 Central European species of Limnephilidae (Trichoptera) including wing length, wing width, wing area, relative wing length and the aspect ratio of the fore and hind wings (combined). There were strong relationships between forewing length and body length (r² = 0.884), wing width (r² = 0.960) and wing area (r² = 0.93) in the untransformed data. Species of the same genus may differ strongly in wing length, wing width and wing area; however, when the wing area is considered on the size‐independent scale of relative wing length, species of the same genus are more similar. Sexual dimorphism was species specific. Male wing dimensions exceeded those of females in all species that displayed significant differences between the sexes except in Parachiona picicornis. For aerodynamic indices such as aspect ratio, only 28 % of the studied species show sexual dimorphism; in Limnephilus fuscicornis and Potamophylax luctuosus, males exceed females, and in Drusus annulatus, Drusus discolor and Potamophylax cingulatus, females exceeded males. On the basis of our data, we conclude that females may be the primary dispersers in four of the 18 species for which sufficient data were available, whereas in two species males appear to be stronger dispersers. We found three different morphological blueprints in forewing length and wing width: Group 1 encompassed crenal‐inhabiting species with a distinct habitat preference for mineral habitats (low aspect ratio, small wings; e.g. D. discolor); group 2 comprised rhithral species without a distinct habitat preference (high aspect ratio, large wings; e.g. P. cingulatus); and group 3 encompassed species inhabiting lentic waters and preferring organic habitats (high aspect ratio, medium‐sized wings; e.g. Anabolia nervosa).

Description of two new filtering carnivore Drusus species (Limnephilidae, Drusinae) from the Western Balkans

“…The intriguing distribution patterns exhibited by some groups of species potentially result from the geological history of the region and historic and present-day climate conditions. Small-scale speciation of Drusinae presumably is facilitated by intrinsic traits of the subfamily, such as their occurrence at higher elevations (Pauls et al 2006, 2009), a putatively low long-distance dispersal potential (Müller-Peddinghaus 2011, Geismar et al 2015), and might be further enhanced by habitat fragmentation, e.g., by regional karstification. Occurrence of Drusinae could therefore serve as proxy to occurrence of other aquatic invertebrate taxa, particularly to crenobiont taxa exhibiting the same or similar traits.…”

Does wing morphology affect recolonization of restored farmland by ground‐dwelling beetles?

“…Examining the dispersal traits of insects in relation to habitats can reveal factors affecting colonization and composition of assemblages (Cole et al ; Gibb et al ; Muller‐Peddinghaus & Hering ). This is because differences in dispersal traits might be expected to influence whether species are able to reach different parts of a landscape, and thus inform us about the success or effectiveness of vegetation plantings in attracting and supporting biodiversity.…”

Environmental factors prevail over dispersal constraints in determining the distribution and assembly of Trichoptera species in mountain lakes

“…1996) according to the respective flight morphology (Hoffsten 2004; Müller-Peddinghaus 2011; Müller-Peddinghaus and Hering 2013). However, it is unclear whether widespread species are also those that disperse the best.…”

“…For example, the apparently low dispersal capacity of P. flavomaculatus does not preclude a widespread distribution of the species across Europe (Illies 1978), although there is a higher genetic differentiation of P. flavomaculatus among populations (Wilcock et al. 2007) than for species of higher dispersal capacity such as Plectrocnemia conspersa (Curtis), of the same family but with larger wings and body (Müller-Peddinghaus 2011). The relationship between the size of the distribution range of the species and their dispersal capacity requires more investigation as both features do not necessarily indicate the same.…”