Origin and transformation of the in‐flight wing‐coupling structure in Psocodea (Insecta: Paraneoptera)

Abstract

Many four-winged insects have mechanisms that unite the forewings and hindwings in a single plane. Such an in-flight wing coupling apparatus may improve flight performance in four-winged insects, but its structure is variable among different insect groups. The wings of bark lice (Insecta: Psocodea: "Psocoptera") also have an in-flight wing coupling apparatus, but to date, its morphology has not been studied in detail. In this study, we examined the wing-coupling structure in representative species of the three suborders of bark lice (Trogiomorpha, Troctomorpha, and Psocomorpha) and inferred its origin and transformation. We conclude that the main component of the psocodean wing coupling apparatus evolved once in the common ancestor via modification of cuticular structures at the apex of the forewing CuP vein. Morphological differences in components of the coupling structures are phylogenetically informative at the intraorder level and include an autapomorphy that characterizes Troctomorpha and a synapomorphy that supports a sister relationship between Troctomorpha and Psocomorpha.

Microsatellite markers developed using a next‐generation sequencing technique forNeotroglaspp. (Psocodea: Prionoglarididae), cave dwelling insects with sex‐reversed genitalia

“…). Thus, although results obtained by different sets of molecular markers cannot be simply compared, the observed genetic differentiation between the Neotrogla populations supports the hypothesis that the adults are poor fliers (Ogawa & Yoshizawa ) and migration between caves is limited. However, both caves (LI and GM) are located in a continuous limestone outcrop, and several shelters with suitable microclimate conditions certainly exist in between those caves.…”

“…Similarly, in the ant Formica exsecta Nylander (Hymenoptera: Formicidae), populations in Switzerland and the Ural Mountains, which are more than 3,000 km apart, show genetic differentiation measured as F ST = 0.043 (Goropashnaya et al 2007). Thus, although results obtained by different sets of molecular markers cannot be simply compared, the observed genetic differentiation between the Neotrogla populations supports the hypothesis that the adults are poor fliers (Ogawa & Yoshizawa 2018) and migration between caves is limited. However, both caves (LI and GM) are located in a continuous limestone outcrop, and several shelters with suitable microclimate conditions certainly exist in between those caves.…”

“…2016). However, their wing structures (and observation of living specimens) suggest that they are poor fliers (Ogawa & Yoshizawa 2018), and that migrations may occur only among nearby cave populations. The distributions of the four named species of this genus do not overlap (Lienhard et al 2010;Lienhard & Ferreira 2013), nor do those of populations that possibly represent undescribed species.…”

Cave insects with sex‐reversed genitalia had their most recent common ancestor in West Gondwana (Psocodea: Prionoglarididae: Speleketorinae)

“…Probably, the common ancestor of Sensitibillini also inhabited such environments and then the African and South American Sensitibillini changed their habitat to the carbonatic caves independently. This relatively recent change to the cave environment might also explain the preservation of well-developed eyes and flight ability (Ogawa & Yoshizawa 2018) in Sensitibillini. The female penis is thought to have evolved independently in Afrotrogla and Neotrogla (Yoshizawa et al 2018a), which could also be related to their independent habitat shifts to the dry and oligotrophic caves (the type locality cave of Sensitibilla strinatii is dry but is colonized by bats that produce lots of guano, a copious food resource for these psocids; R.L.…”

“…Probably, the common ancestor of Sensitibillini also inhabited such environments and then the African and South American Sensitibillini changed their habitat to the carbonatic caves independently. This relatively recent change to the cave environment might also explain the preservation of well‐developed eyes and flight ability (Ogawa & Yoshizawa ) in Sensitibillini. The female penis is thought to have evolved independently in Afrotrogla and Neotrogla (Yoshizawa et al .…”