Chrysomelidae Latreille, 1802

Berx, Peter, Bosmans, Bart, Dekoninck, Wouter, Janssen, Marc, Stassen, Eugène & Crevecoeur, Luc, 2023, Faunistic survey of myrmecophilous and other ant-associated beetles and spiders in the Belgian province of Limburg (Araneae, Coleoptera, Hymenoptera: Formicidae), Belgian Journal of Entomology 141, pp. 1-61 : 10-11

Chrysomelidae Latreille, 1802

Chrysomelidae or leaf beetles are phytophagous and can therefore become agricultural pests, but some species can be used to control invasive crops. A remarkable leaf beetle associated with ants is Clytra quadripunctata (7.0- 11 mm) ( Fig. 7 ). The known image of C. quadripunctata reproduction is that the female wraps an egg in a cocoon above the nest of RWA and drops this cocoon into the ant nest, where the protected larva is incorporated into the ant community. However, during a long-term investigation of the verges along the E314 highway in 1999, five cocoons containing a larva were found in pitfall traps at four different locations (observation by the first author - unpublished). This indicates that it is not self-evident that these cocoons can only be found in the anthills of RWA where the larvae continue their development undisturbed. Wood ants can remain at the same location for years, but changes in the environment in which they are situated can force a wood ant nest to relocate. Moreover, a colony of wood ants may split up due to an increase in population and the incorporation of more queens after the nuptial flight. These conditions are accompanied by a great deal of activity in the environment with nesting material and brood being transferred from one place to another. During these migrations, other invertebrates from the mother nest will also make the transfer, either on their own or carried by the workers of the wood ants ( PARMENTIER, 2019).

Phyllotreta undulata (2-2.5 mm) is a plant parasite of cabbage plants ( Brassicaceae ). The adult beetles lay up to 200 eggs at the base of cabbage plants, after which the larvae feed on the roots. A new generation of beetles feeds on the leaves of the crops in late summer and overwinters as adults. For this purpose, they seek refuge in leaf litter and wood dust under trees. This explains why they are sometimes found in the vicinity of saproxylic ants.

Figures

Fig.7. Clytra quadripunctata (Linnaeus, 1758) (range 7.0-11.0 mm). © U. Schmidt.