Recently, authors, including Safeguard partner Viktor Szigeti from the Centre for Ecological Research (OK), presented an article on the mate-guarding investment of Clouded Apollo (Parnassius mnemosyne) butterflies. This is the first quantitative study to investigate potential factors on which male investment in mate-guarding devices may depend, and how the variation in these devices impacts their persistence on females. The paper, published in the Ecology and Evolution journal, aims to shed light on the alternative mate-guarding devices’ (i.e. CAP, Copulatory opening APpendix) replacement dynamics within Clouded Apollo females during their lifetime. Furthermore, the study seeks to understand how male investment into these devices is (i) related to their persistence on the female, that is, securing paternity, (ii) associated with female quality, measured as size and (iii) with actual adult sex ratio.
The results of this study demonstrate that the larger mate-guarding devices (shields) are the most frequent ones and are more persistent than the smaller (small CAPs), often lasting for life, excluding future matings. Thus, most females bearing a large mate-guarding device are deprived of postcopulatory female choice, and the genetic variance in their offspring may be reduced.
The studied Clouded Apollo butterflies spend a lot of time foraging flowers in mountain meadows, where they play a crucial role in pollinating some wild and rare plant species. This species is Near Threatened and protected under the Habitats Directive of the European Union.
To safeguard this species, pollinators and their habitats, we need to reveal their detailed ecology by longitudinal, exploratory field work on their behaviour.
Read the full article here.
Photo: Figure 1 from the article: Female Copulatory opening APpendix (CAP) types (a–e) in Clouded Apollo butterflies. A mating pair with a shield being produced (f). The length measurement of the CAP-type shield (g). A female with a marked shield (h). The copulatory opening is free, no CAP can be observed in virgin or CAP-lost females (a). Small, thread-like filaments (b), small, compact stopples (c; b, c together is called a small CAP) or large shields (i.e. sphragides; d, e) may be produced by males during mating (f). All CAPs leave the ovipositor free (b–e). The shield is built over a large stopple, the stopple being fixed in the female copulatory opening (d). Colour dots on the male's forewing are individual markers. Note sexual dimorphism in body colouration and hairiness (f). Shield length was measured as the largest anterior–posterior distance with callipers (g). A feeding female's black dot on the shield's posterior shows that this shield had already been measured; the dot can be seen with binoculars from a distance (h). Views: posterior-ventral (a–c), posterior (d) and left lateral (e). Light grey arrowheads show the ovipositor (a–e), the magenta arrowheads indicate the clear copulatory opening (a) or the respective CAP (b, c, f) or the stopple on which the shield is built (d), or the black dot marker on the shield's posterior tip (h). All pictures were taken by JK; butterflies captured for a–e, g were later released.