Adaptations of Coccinella magnifica, a myrmecophilous coccinellid to aggression by wood ants (Formica rufa group). II. Larval behaviour, and ladybird oviposition location1

Abstract

Abstract. Like adults, larvae of the myrmecophilous ladybird Coccinella magnifica are rarely attacked by Formica rufa ants on for aging trails, but more often attacked on ant-tended aphid colonies. Larvae of the non-myrmecophile Coccinella septempunctata, to which C. magnifica was compared, were more readily attacked by ants in both situations. To avoid or counter ant aggression when foraging for aphids, C. magnifica larvae exhibit three main tactics: they may feed on un-or non-tended aphids; when feeding on tended colonies they often carry prey away, minimising time spent there; and if attacked, they use limited chemical defence. No novel behaviours were found in C. magnifica larvae, not occurring to some extent in C. septempunctata. Coccinella magnifica eggs were laid distant to ant-tended aphids, although closer to un-or non-tended aphids.

The ant-associations and diet of the ladybird Coccinella magnifica (Coleoptera: Coccinellidae)

“…Published work supports the view that C. magnifica adults and larvae are less vigorously attacked by F. rufa than are other ladybirds, notably C. septempunctata (Donisthorpe, 1919(Donisthorpe, -1920Majerus, 1989;Sloggett et al, 1998). The adults also use physical defence on colonies of F. rufa-tended aphids, where the probability of ant attack is much greater .…”

“…Coc cinella magnifica's chemical counter to ant-aggression probably involves chemical repellence rather than chemical mimicry (Sloggett, 1998;Sloggett, unpub. data), and C. magnifica defence behaviour is, like its probable chemical adaptation, effective against most ant species (Arnold and others in Majerus, 1994, p.151;Sloggett et al, 1998). Coccinella magni fica may thus be potentially able to coexist with a wide variety of ant species, both typical and accidental associates, without suffering high ant aggression.…”

Evolutionary Perspectives on Myrmecophily in Ladybirds

“…In myrmecophilous species, the larvae tend to move slowly and inconspicuously, as has been observed for Coccinella magnifica (Redtenbacher), P. luteorubra, and B. quadripunctata [33,40,42]. The comparison between the myrmecophilous species C. magnifica and its close nonmyrmecophilous relative C. septempunctata (Linnaeus) has shown that C. magnifica uses physical, behavioral, and chemical defenses adapted from the general defenses observed in Coccinellidae [42,43].…”

Ant-aphid interactions in multispecies ant communities: Some ecological and ethological aspects

“…It is well known that ladybirds eat aphids. Coccinella septempunctata, a good model of a potential predator, is readily attacked by Formica rufa (Sloggett et al, 1998). All the ants studied, except F. cunicularia and F. fusca, protect aphid colonies from this predator to some extent.…”