Daily and Seasonal Foraging Activity of the Oriental Non-army Ant Doryline Cerapachys sulcinodis Species Complex (Hymenoptera: Formicidae)

Abstract

The ant subfamily Dorylinae contains the true army ant genera, the species of which are dominant predators, as well as non-army ants. Some of the non-army ant genera are closely related to true army ants, so they could be an important key in understanding the evolution of the army ant adaptive syndrome. Nevertheless, there has been little field research on the non-army ant doryline species because many of them are very rare. Cerapachys is one of the genera closely related to the Old-World army ants. We found some species of Cerapachys are commonly distributed in northern Thailand, so we investigated the daily and seasonal foraging activities of a non-army doryline ant of Cerapachys sulcinodis species complex in the seasonal tropical area of northern Thailand. Workers of the C. sulcinodis complex were diurnal and actively foraged during the rainy season, and their reproduction and foraging activity paused during the dry season. This report is the first on the foraging activity of non-army doryline ants under field conditions.

The Leptogenys Roger, 1861 (Formicidae, Ponerinae) of Hong Kong SAR with additional records from Guangdong, China

“…Based on a molecular phylogenetic study ( Schmidt 2013 ), the genus is hypothesised to have an Old World origin and to confirm this, a broader understanding of its taxonomic and ecological diversity is paramount. Leptogenys species are highly predatory, with epigaeic and leaf-litter foragers that predominantly hunt upon isopods, diplopods, earthworms, termites, earwigs, and other leaf litter invertebrates ( Maschwitz et al 1979 ; Steghaus-Kovac and Maschwitz 1993 , Dejean and Evraerts 1997 ; Schmidt and Shattuck 2014 ; Peeters and De Greef 2015 ; Mizuno et al 2022 ). Predatory behaviours range from solitarily foraging, to mass raiding reminiscent of doryline army ants, with a continuum of foraging and recruitment modes between both extremes ( Maschwitz et al 1989 ; Duncan and Crewe 1994 ; Janssen et al 1997 ; Schmidt and Shattuck 2014 ; Mizuno et al 2022 ).…”

“… Leptogenys species are highly predatory, with epigaeic and leaf-litter foragers that predominantly hunt upon isopods, diplopods, earthworms, termites, earwigs, and other leaf litter invertebrates ( Maschwitz et al 1979 ; Steghaus-Kovac and Maschwitz 1993 , Dejean and Evraerts 1997 ; Schmidt and Shattuck 2014 ; Peeters and De Greef 2015 ; Mizuno et al 2022 ). Predatory behaviours range from solitarily foraging, to mass raiding reminiscent of doryline army ants, with a continuum of foraging and recruitment modes between both extremes ( Maschwitz et al 1989 ; Duncan and Crewe 1994 ; Janssen et al 1997 ; Schmidt and Shattuck 2014 ; Mizuno et al 2022 ). Nests are often ephemeral and typically found within soil, dead wood, or leaf litter, with the whole colony moving to new nest sites frequently ( Maschwitz and Mühlenberg 1975 ; Schmidt and Shattuck 2014 ), with species of the processionalis group even forming temporary bivouacs ( Maschwitz et al 1989 ).…”