Manganese and zinc in the ovipositors and mandibles of hymenopterous insects

X-ray microanalysis of the ovipositor and mandibles of various hymenopterou s insects has revealed the presence in many species of up to 10% wt/wt of e ither zinc or manganese in the cuticle. These metals appear to be involved in cuticular hardening, so helping to reduce abrasive wear. Zinc is found i n the ovipositors of most Siricidae, Stephanoidea, and Chalcidoidea. In Ich neumonoidea and Cynipoidea, the metal involved is manganese. Megalyroidea a re unique in the Hymenoptera in having both zinc and manganese in their ovi positors, though in different locations. Except for Bethylidae, no metals w ere detected in the ovipositors or stings of species that penetrate soft su bstrates or do not make holes at all. The cutting edge of the mandibles of many insects that chew their way through hard substrates during egress from their pupation sites almost invariably contain high concentrations of zinc , and this is present in many that lack metals in their ovipositor. The phy logenetic and ecological implications of metal occurrence are discussed. (C ) 1998 The Linnean Society of London.