Intersexual Differences in Behaviour and Resource Use of Specialist Phengaris teleius Butterflies

Abstract

Although the behaviour of the Large Blue butterflies of the genus Phengaris (= Maculinea) is relatively well studied, most empirical data come from investigations of their dispersal and oviposition. Here, we assessed overall intersexual differences in resource use by tracking Phengaris teleius (Bergsträsser, 1779) individuals and recording the duration of their behaviours. Females were characterised by frequent, short flights, and devoted more time to resting and oviposition. Males engaged in numerous, but usually short interactions, and spent most of the time in flight exploring their surroundings for receptive females. Their average flight time was significantly longer compared to females. Average feeding time did not differ between the sexes but was shorter when butterflies were feeding on Sanguisorba officinalis L. Intraspecific interactions within P. teleius were three times longer than those with other insect species, and interactions between sexes were particularly long lasting. Significantly shorter interspecific interactions imply that butterflies can easily recognise conspecifics and differentiate between sexes, which offers obvious fitness benefits. Both sexes, but especially females, showed strong association with their larval host plant, and less so with other flowers of similar colour and shape. Females predominantly used their host plant for feeding, which possibly indicates neuro-sensory constraints towards this resource.

Phenotypic senescence in a natural insect population

“…Resource allocation can be different between the sexes, e.g., females may use more nutrients from muscle breakdown for reproduction than males, therefore experiencing a steeper decline (Stjernholm et al, 2005 ), but males may also invest into reproduction through the spermatophore, and in the case of the Clouded Apollo, through the sphragis (Vlašánek & Konvička, 2009 ). Flying is energetically costly (Dudley, 2002 ) and male butterflies often fly more than females (Popović et al, 2022 ). According to our field observations, Clouded Apollo males spend a lot of time patrolling to find mating partners, hence they possibly lose more water and reserves from their bodies than females.…”

Movements of a Specialist Butterfly in Relation to Mowing Management of Its Habitat Patches

“…Males of P. teleius tend to form small home ranges, while females travel longer distances to find new host plants for oviposition and are more likely to disperse to new habitats. From a behavioural perspective, females of P. teleius perform short-duration but frequent flights and devote more time to rest and oviposition, while males spend more time flying to explore their surroundings for receptive females [ 73 ]. Accordingly, male dispersal is typically promoted by the scarcity of females, while female dispersal is promoted by the lack of resources for oviposition [ 74 ].…”