Adaptations of Coccinella magnifica Redtenbacher, a myrmecophilous coccinellid, to aggression by wood ants (Formica rufa group). I. Adult behavioral adaptation, its ecological context and evolution

Coccinella magnifica is an obligate associate of Formica rufa-group ants. T he congener Coccinella septempunctata can serve as a model for its nonmyrme cophilous ancestor. Formica rufa behavior toward these two ladybirds, and t heir behavior was compared, Although C. magnifica was rarely attacked on an t trails, it was usually attacked on tended aphid colonies. Coccinella sept empunctata was more readily attacked. The two ladybirds' behavior was simil ar on trails, but C, magnifica used more defense and C. septempunctata more rapid escape behavior on aphid colonies. Only C. magnifica fed upon tended aphids. Chemical adaptation to overcome ant aggression probably exists in C. magnifica, but it possesses almost no novel behaviors to counter ant agg ression. Instead, modifications have occurred in the expression of behavior s present in C. septempunctata.