Age- and sex-related variation in defensive secretions of adult Chlaenius cordicollis and evidence for their role in sexual communication

Pygidial Glands in Carabidae, an Overview of Morphology and Chemical Secretion

“…In Oodes americanus, defensive secretion shows qualitative differences in males and females [89]. The sexual dimorphism of carboxylic acids found in the defensive secretion of Chlaenius cordicollis depends on the reproductive status and age of both sexes and provides a means of chemical communication between the sexes [89,90]. Sex-specific variation likely protects mates during copulation, and the flower number of compounds in female secretions saves females the cost of synthesising them [90].…”

“…The sexual dimorphism of carboxylic acids found in the defensive secretion of Chlaenius cordicollis depends on the reproductive status and age of both sexes and provides a means of chemical communication between the sexes [89,90]. Sex-specific variation likely protects mates during copulation, and the flower number of compounds in female secretions saves females the cost of synthesising them [90]. Although compounds that act as pheromones, such as pentacosadiene, 7-hexyldocosane, 9-methyltetracosane, have been detected in Laemostenus punctatus, Trachypachus gibbsi, and Helluomorphoides clairvillei, studies on their role in alarm or sex-aggregation reproductive behaviour are limited [27].…”

The chemical composition of the secretions, their antibacterial activity, and the pygidial gland morphology of selected European Carabini ground beetles (Coleoptera: Carabidae)

“…In other groups of insects, it was noted that the secretions with a dominant allomonic role often have the simultaneous function of an intraspecific signal -an alarm pheromone (Vesović, 2019). Future studies on the components of the pygidial gland secretions of Carabini will reveal their role and clarify whether they are allomonic compounds, solvents/carriers, with a role in sexual communications (Holliday et al, 2016) or perhaps it is a combination of these functions.…”

“…Considering other groups of insects, it is known that the discharge of defensive compounds leads to an overall more successful response to predatory attack (alarm pheromone function) among conspecifics (Pasteels et al, 1983;Blum, 1996). Although several studies on the dual function (intraspecific and interspecific chemical communication) of ground beetles' defensive substances have been carried out (Attygalle et al, 1991;Bonacci et al, 2011;Holliday et al, 2016), no generalised conclusions have been drawn. The occurrence of multi-compound defensive secretions creates the possibility of variations.…”

“…The occurrence of multi-compound defensive secretions creates the possibility of variations. To date, a limited number of studies indicate the existence of alterations to defensive secretions caused by various ecological factors (Wheeler et al, 1970;Holliday et al, 2012Holliday et al, , 2016Vesović et al, 2022).…”