The Third Trophic Leve L of Plant Defence: Neotropical Social Wasps' Use of Odours of Freshl Y Damaged Leaves When Hunting

An important aspect of the hunting strategy of neotropical social wasps (I-Iymenoplera: Vespidae) is where thcy hunt. Three species used two behavioural components in their se lection ofa place 10 search for prey. The wasps utili zed lhe odom of (j'eshly damaged leaves as cues (which could be synomones) to se lecl which leaves to inspect and also they remembered a place to which they were strongly attracted to hunt recenlly and relurned lhcre. Polybia igl10bilis (Haliday, 1836) and Polistes satan Bequaert, 1940 hunted on a lawn of Digitaria diversinervis Stapf immediately after iI was mown in signiticantly larger numbers than aI other times. P. ignobilis and Polistes versicolor (Olivier, 1791) hunted in significantly greater numbers on frcshly CUl leaves of passion vine (Passiflora edulis Sims) than on uncut leaves. Sometimes wasps inspected cards rubbed with freshly crushed leaves of P. edulis, bul not control cards. Preliminaty data suggest that severa 1 otherspecies ofsocial wasps around Brasíl ia hunt in a similar manncr on native and cxotic plants. Apparently the production of ephemeral odours by freshly cul leaves aUract generali sl insectivorous predators which perceive lhesc scents and lhe soc ial wasps investigated are members ofthe lhird trophic leveI of lhe plants' defence against attacks by herbivorcs. Available infOll11ation suggests a difference between lhe behaviour of generalists and that of specia li st al1hropod predators which are attracted to lhe odour emitted afier their pa l1icular prey havc damagcd the leaves.