Natural enemies ofAcraea terpsicore [Lep.: Nymphalidae] in ghana, with particular reference to the parasiteCharops diversipes [Hym.: Ichneumonidae]

Abstract

The arthropod parasites and predators ofAcraea terpsicore (L.) were determined in the forest zone of Ghana. An unidentified mite was predatory on the very young larvae. The pentatomidsPlatynopus rostratus Dru. andMacrorhaphis acuta (Dall.) were also predatory on the larvae.Telenomus sp. parasitized the eggs. The tachinidCarcelia normula (Curran) and the ichneumonidCharops diversipes Roman were parasitic on the larvae.C. diversipes was hyperparasitized by the chalcididBrachymeria feae Masi and the eulophidPediobius taylori Kerrich. Laboratory tests showed that parasitism ofA. terpsicore byC. diversipes was significantly highest in the 1st instar, followed by the 2nd, 3rd and 4th. The 5th instar was not parasitized. These results seemed to reflect both host susceptibility and parasite preference. Only a singleC. diversipes larva developed in a host. The developmental period of the parasite egg and larva varied inversely with the age of the host at which it was parasitized. A femaleC. diversipes could oviposit immediately after emergence.

Résumé

Les arthropodes parasites et prédateurs deAcraea terpsicore (L.) ont été déterminés dans la zone forestière au Ghana. Les très jeunes larves sont la proi d'un acarien indéterminé. Les pentatomidesPlatynopus rostratus Dru etMacroraphis acuta Dall. sont aussi des prédateurs des larves.Telenomus spp. parasite les œufs. Le tachinideCarcelia normula Curran et l'ichneumonideCharops diversipes Roman parasitent les larves.C. diversipes est parasité par le chalcidienBrachymeria feae Nasi et l'eulophidePediobius taylori Kerreich. Des essais en laboratoire montrent que la parasitisme deA. terpsicore parC. diversipes est significantivement plus élevé au ler stade, suivi par les 2ème, 3ème et 4ème stades. Le 5ème stade n'est pas attaqué. Une seule larve deC. diversipes se développe dans un hôte, selon un délai qui varie en raison inverse de l'âge de l'hôte au moment du parasitisme. La femelle deC. diversipes peut pondre dès l'émergence.