Leaf beetles are ant-nest beetles: the curious life of the juvenile stages of case-bearers (Coleoptera, Chrysomelidae, Cryptocephalinae)

Abstract

Although some species of Cryptocephalinae (Coleoptera: Chrysomelidae) have been documented with ants (Hymenoptera: Formicidae) for almost 200 years, information on this association is fragmentary. This contribution synthesizes extant literature and analysizes the data for biological patterns. Myrmecophily is more common in the tribe Clytrini than in Cryptocephalini, but not documented for Fulcidacini or the closely-related Lamprosomatinae. Myrmecophilous cryptocephalines (34 species in 14 genera) primarily live among formicine and myrmecines ants as hosts. These two ant lineages are putative sister-groups, with their root-node dated to between 77–90 mya. In the New World tropics, the relatively recent radiation of ants from moist forests to more xeric ecosystems might have propelled the association of cryptocephalines and ant nests. Literature records suggest that the defensive behavioral profile or chemical profile (or both) of these ants has been exploited by cryptocephalines. Another pattern appears to be that specialized natural enemies, especially parasitoid Hymenoptera, exploit cryptocephaline beetles inside the ant nests. With the extant data at hand, based on the minimum age of a fossil larva dated to 45 mya, we can infer that the origin of cryptocephaline myrmecophily could have arisen within the Upper Cretaceous or later. It remains unknown how many times myrmecophily has appeared, or how old is the behavior. This uncertainty is compounded by incongruent hypotheses about the origins of Chrysomelidae and angiosperm-associated lineages of cryptocephalines. Living with ants offers multiple advantages that might have aided the colonization of xeric environments by some cryptocephaline species.

A new ant-mimetic species of Metopiellus (Staphylinidae: Pselaphinae) from the Northern Colombian Amazon

“…Navarrete-Heredia (2001) reports ten Pselaphinae species associated with Atta and Acromyrmex, of which Attapsenius (Attapseniini) is an obligate guest of Atta sexdens fungus galleries (Park 1942). On the ant-camptosome associations' synthesis, Agrain et al 2015, report the genus Atta, specifically the species Atta texana (Buckley 1860) and Atta mexicana (Smith 1858), as ant-host of Cryptocephalinae beetles. These authors also noted that fungus-growing ants nests could provide food to their beetle guests.…”

Molecular systematics, higher‐rank classification and Gondwanan origins of Cryptocephalinae leaf beetles

“…On the one hand, they represent a time framework that postdates the supposed origin and diversification of angiosperms (Morris et al., 2018; Soltis & Soltis, 2004), which has been one of the driving factors considered for the evolution and radiation of phytophagous beetles, and on the other hand, it also postdates the origin of ants, in the Late Jurassic (Moreau et al., 2006). There is a strong possibility that the apomorphy of Camptosomata, the development of eggs and larvae within the protection offered by the scatoshell, is a protective device mainly against ants, with which lamprosomatines and cryptocephalines often interact (Agrain et al., 2015). The evolution of this highly adaptive trait is obviously expected to occur only when the evolutionary pressure was already in place.…”

First record of Pachybrachis Chevrolat, 1836 (Coleoptera: Chrysomelidae: Cryptocephalinae) on Spermacoce verticillata L. (Rubiaceae) and synthesis of its plant associations in Brazil

“…Because it is essentially phytophagous, it plays a big role in insect-plant interactions. Members of the subfamily Cryptocephalinae, represented in Brazil by 723 species in 37 genera (Chamorro et al 2021), feed on green leaves, decaying plant material, and girdle stems (Chamorro 2014); some are myrmecophilous (Agrain et al 2015). Members of the Cryptocephalini tribe are flower eaters and pollen eaters (Chamorro 2014).…”