Useful biometric variables in Iberian exuviae of Boyeria irene (Fonscolombe, 1838) (Odonata: Aeshnidae)

Abstract

In species of similar shape and size, biometric analyses make it possible to establish differences. Within one species, biometrics can help researchers to detect differences between populations and analyze their adaptations to environmental conditions. Until now little was known about the biometrics of the Iberian populations of Boyeria irene (Odonata: Aeshnidae), a large species living mainly in southern Europe. Eight biometric variables were studied in male and female exuviae of B. irene collected in three rivers of the Iberian Peninsula, with the objective of ascertaining which are the most suitable populations of this species to study. An analysis of principal components (PCA) shows that lengths of the epiproct, paraproct and prementum are the most influential in each of the three populations. The other variables (head width, body length, length of the gonapophyses, maximum and minimum width of the prementum) proved not to be relevant in this context.

Biometric differences across three populations of Boyeria irene from the southern Iberian Peninsula (Odonata: Aeshnidae)

“…Our data are consistent with other studies in that females are larger than males ( Nunes et al . 2021a; Casanueva et al 2022).…”

“…2000; Goretti et al 2001; Wildermuth 2005). No attempt was made to measure the length of the cerci because B. irene has two morphs: brachycerca (short cerci) and typica (long cerci) ( Wenger 1959), which are much more frequently observed in females ( Nunes et al . 2021b).…”

“…However, head width has been used in recent studies on Cordulegaster boltonii (Donovan, 1807) and B. irene exuviae (Casanueva et al . 2020; Nunes et al 2021a; Hernández et al 2022).…”

“…In the literature, there is information about egg development, foraging, and reproductive behaviour in southern France and north-eastern Spain (Wenger 1955(Wenger , 1963Jurzitza 1967;Miller & Miller 1985;Wildermuth 2000). However, in the Iberian Peninsula very little is known about the larval development of this species (Nunes et al 2021a).…”

Geographical variation of prementum size in Iberian Cordulegaster boltonii (Odonata: Cordulegastridae) populations

“…Prementum length is a trait used in Odonata larvae and exuviae taxonomy (e.g., Conesa, 2021;Doucet, 2010;Tennessen, 2019), as well as populational analyses (Nunes et al, 2021). Present work confirms that it is also a valid trait to use in the analysis of variations between Iberian populations of C. boltonii using exuviae.…”