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

Abstract

Specificity is one of the fundamental concepts in ecology. Host specificity of phytophagous insects has been of particular interest because of its crucial role in diversification and life-history evolution. However, the majority of tropical insects remain insufficiently explored with respect to their host-plant relations. A lack of respective data is also hindering the debate over whether higher levels of host-plant specificity prevail in tropical insects compared to temperate ones. We investigated host-plant specificity of forest geometrid moths (Lepidoptera: Geometridae) in equatorial Africa using host-plant acceptability trials with neonate larvae, with the addition of field observations. We compare our experimental data to the (well-known) host-specificity patterns of closely related temperate (hemiboreal) species. Similarly to the temperate region, there were broadly polyphagous tropical species in several clades of Geometridae utilizing hosts belonging to different plant families. Phylogenetic comparative analysis returned no significant differences in host specificity between the two regions. Our study contributes to the evidence that host-plant specificity of herbivores is not necessarily substantially higher in tropical than temperate regions.

Size‐related life‐history traits in geometrid moths: a comparison of a temperate and a tropical community

“…The phylogenetic tree of Geometridae was constructed on the basis of nucleotide sequences of eight gene fragments (see Appendices S1, S2, and Holm et al, 2018Holm et al, , 2019 for details and references). Four subfamily-specific ultrametric trees were created using beast v.1.8.1 (Drummond et al, 2012) on the CIPRES Science Gateway (Miller et al, 2010).…”

“…1; Table 1). The world may not be so different for a tropical and a temperate moth after all (for a similar conclusion relying on the study of oviposition behaviour, see Holm et al, 2018Holm et al, , 2019, although a much broader sample of sites is needed to confirm any systematic differences between the moths representing tropical and temperate habitats.…”

“…The study area represents species-rich, medium-altitude, moist, evergreen tropical forest (Struhsaker, 1997). The insects were fed the host plants they were found on, or plants that were identified as suitable hosts in pilot experiments with neonate larvae (Holm et al, 2019). The larvae were reared individually in 50-ml plastic vials under ambient conditions at Kibale.…”

“…The larvae were reared individually in 50-ml plastic vials under ambient conditions at Kibale. The insects were fed the host plants they were found on, or plants that were identified as suitable hosts in pilot experiments with neonate larvae (Holm et al, 2019). The sample of studied temperate moths is the same as that used in Davis et al (2012Davis et al ( , 2016, based on laboratory-reared moths of Estonian origin, representing the north European hemiboreal region.…”

Light environment drives evolution of color vision genes in butterflies and moths

“…LW sensitivity is useful for oviposition behavior in butterflies 67 and their high recovery and strong purifying selection in nocturnal species could be a signature of their role in oviposition. Butterflies display strong host plant specificity compared to moths, [68][69][70]…”