Sex-dependent seasonal feeding activity variations among two species of Nymphalidae (Lepidoptera) in the Mexican tropical dry forest

Abstract

Tropical dry forest, such as that found in Mexico, is a biome where very few alimentary resources are available during 6 months of the year. Within some families of Lepidoptera such as Nymphalidae, some species are known to survive the dry season as adults using the few decayed pulp fruits available as a food source. We compared the temporal abundance and sex ratio of two model species, one belonging to the subfamily Charaxinae, found world-wide, and one belonging to the subfamily Biblidinae, endemic to the Americas. We used baited traps to measure feeding frequency of both species to asses monthly temporal resource use curves. The butterfl y frequency of feeding drops dramatically in the dry season for all species-gender, except for females of the Biblidinae species. There are few differences between the sexes in the relative feeding frequency, assimilated to activity pattern, of Charaxinae between the dry and rainy seasons, while the activity pattern of Biblidinae is very different depending on the sex. These results suggest differential consequences on mate choice competition for both species. Females of the Charaxine species showed a use curve nested on the male curve, while for all other pair-wise comparisons between gender-species, the use curves were signifi cantly different. These differences in the temporal foraging pattern could explain at least in part, the coexistence between both sympatric species in the stressful season.Resumé. Activité saisonnière de nourrissage dépendante du sexe chez deux espèces de Nymphalidae (Lepidoptera) de la forêt tropicale sêche Mexicaine. La forêt tropicale sèche, comme celle que l'on trouve au Mexique, est un biome où très peu de ressources alimentaires sont disponibles durant 6 mois de l'année. Au sein d'une famille de lépidoptères ; les Nymphalidae, certaines espèces dépassent la saison sèche comme imagos en utilisant les rares fruits à pulpe disponible comme nourriture. Nous avons comparé les ressources temporelles et l'abondance de deux espèces modèles, une appartenant à la sous-famille des Charaxinae, qui est distribuée dans tous les continents, et une appartenant à la sous-famille des Biblidinae, restreinte à l'Amérique tropicale. Nos résultats montrent qu'il y a peu de différences d'activité de vol entre sexes chez les Charaxinae entre la saison des pluies et la saison sèche alors que des différences importantes s'observent pour les Biblidinae. Ces résultats suggèrent des stratégies différentes de concurrence pour l'accouplement. La coexistence entre les deux espèces pourrait s'expliquer, au moins en partie, par des différences dans la structure temporelle de la recherche de la nourriture.

Rainfall as a significant contributing factor to butterfly seasonality along a climatic gradient in the neotropics

“…The pattern of butterfly abundance peaking through the wet season found here is concordant with the majority of studies into temporal dynamics of tropical insects (Wolda 1978, Novotny & Basset 1998, Grimbacher et al 2009, for a review Kishimoto-Yamada & Itioka 2015), and particularly with studies focused on butterfly communities distributed in Neotropical dry forests (Shahabuddin et al 1999, Pozo et al 2008, Torres et al 2009, Checa et al 2010, Checa 2014.…”

“…Species detection probability or detectability may additionally bias the observed seasonal patterns. For example, sunny days enhance butterfly activity, hence increasing probability of trap captures, and the level of bait attractiveness may differ over seasons (Torres et al 2009, Ribeiro et al 2015. Although these factors can certainly explain some variation, the bias produced is likely to be negligible in this study since butterfly abundance peaks were detected during the wettest part of the year (the dry season encompasses a larger number of sunny days which increases the probability of both trap captures and scheduling sampling during warmer days), and differences in abundance among years and seasons were relatively large (see Checa et al 2014).…”

“…Butterfly data apparently support these results at regional scales. In Neotropical dry forests, butterfly abundance peaks during the months with highest precipitation and relative humidity in Mexico (Pozo et al 2008, Torres et al 2009), Venezuela (Shahabuddin & Terborgh 1999), and western Ecuador with relative humidity, but not temperature as a significant associated factor with this temporal abundance variation (Checa 2010, Checa et al 2014. In contrast, butterfly communities of relatively aseasonal or rainforests in the Neotropics may show decreased species richness and abundance during the wet season but peaks through the transitional months (see DeVries & Walla 2001, Checa et al 2009, Grøtan et al 2012, Valtonen et al 2013, Grøtan et al 2014 or warmest part of the year (Ribeiro et al 2010).…”

Relative contribution of neutral and deterministic processes in shaping fruit‐feeding butterfly assemblages in Afrotropical forests

“…Adult fruit-feeding butterflies seem to compete for the same resources (e.g., fallen fruits), but there may be some specializations based on proboscis morphology (Molleman, Krenin, et al, 2005). Furthermore, species may differ in competitive ability leading to dominance hierarchies at fruit items (Torres, Osorio-Beristain, Mariano, & Legal, 2009). During the larval stage, competition among species depends on host-plant overlap.…”

Quantifying the effects of species traits on predation risk in nature: A comparative study of butterfly wing damage

“…Notably, the sexes may differ in their responses to trap height and their tendency to remain trapped after entering a trap (Alexander & DeVries, ); therefore, we excluded species known to show marked sexual differences in flight altitude from the analyses, reducing the sample size for this analysis to 31 species. It is also possible that within butterfly species, males and females differ in their seasonal foraging activity, as previously shown in a Mexican dry forest (Torres, Osorio‐Beristain, Mariano, & Legal, ). Nevertheless, this effect is likely offset by the long duration of our study (1–6 years) and may not be as pronounced given the moderate seasonality of the butterfly community at our study site (Valtonen et al, ).…”