Day‐flying moths are smaller: evidence for ecological costs of being large

Abstract

Research on evolutionary forces determining optimal body sizes has primarily relied on experimental evaluation of respective selective pressures. Accounting for among-species variation through application of phylogenetic comparative methods is a complementary although little used approach. It enables the direct association of body size values with particular environments. Using phylogenetically explicit comparative analyses, we show that small body size is associated with diurnal (rather than nocturnal) activity of adults among temperate species of the moth family Geometridae. The association of an exclusively adult trait with species-specific body size suggests that optimal body sizes are at least partly determined by the costs being a large adult, as opposed to the more frequently considered costs of attaining large size. It appears likely that size-selective predation by insectivorous birds is the primary factor responsible for selection against large body size in day-flying moths.

Directional selection on body size but no apparent survival cost to being large in wild New Zealand giraffe weevils

“…; Ercit and Gwynne ; Tammaru et al. ) or parasite loads (Zhang ; Kotiaho and Simmons ). Individuals who live longer are likely to experience more mating opportunities, and therefore benefit from a higher lifetime fitness.…”

“…; Tammaru et al. ). For example, wider heads and smaller legs in male tree crickets ( Oecanthus nigricornis ) are more attractive to females and increase mating success, but negatively impact their ability to avoid predators, with narrower heads and longer legs conferring higher survival (Ercit and Gwynne ).…”

No Indication of High Host-Plant Specificity in Afrotropical Geometrid Moths

“…The phylogenetic tree of geometrid moths was constructed on the basis of both data submitted to GenBank by earlier researchers (Wahlberg et al 2005, 2010; Snäll et al 2007; Viidalepp et al 2007; Õunap et al 2008, 2011, 2016; Wahlberg et al 2013; Mutanen et al 2010; Strutzenberger et al 2010; Hausmann et al 2011; Sihvonen et al 2011; Huemer et al 2014; Holm et al 2016, 2018; Tammaru et al 2018; Zrzavá et al 2018) and original sequences of both Ugandan and Estonian species, which were obtained following reaction protocols described in Õunap et al (2016). The final data matrix comprised 373 taxa and 6543 base pairs from eight markers that have repeatedly been used for phylogenetic inference in geometrid moths.…”

A comparative morphometric study of sensory capacity in geometrid moths

“…Females of geometrid moths are typically slow fliers, predominantly active at twilight, though there are some diurnal species (Tammaru, Johansson, Õunap, & Davis, ). Locating larval host plants appears to be predominantly the responsibility of ovipositing females, though experimental studies on oviposition behaviour in these moths are rather scarce and mainly restricted to pest species (but see, e.g.…”