Inventaire des Plantes-Hôtes de Maruca Testulalis (Geyer) (Lepidoptera: Pyralidae) en République du Bénin

Résumé

Les plantes-hôtes de la pyrale foreuse de fleurs et de gousses, Maruca testulalis (Geyer), ont été inventoriées dans le Sud, le Centre et le Nord du Bénin, pendant la saison sèche; ces plantes permettent la survie du ravageur jusqu'à la saison des pluies. Au total, 22 plantes-hôtes ont été recensées; elles se répartissent dans huit familles botaniques de Légumineuses, dont celle, majoritaire, des Papilionaceae.

Abstract

Record of host-plants of Maruca testulalis (Geyer) (Lepidoptera: Pyralidae) in Republic of Benin. — Host-plants which are used as refuge by the legume flower and pod borer, Maruca testulalis (Geyer), during the dry season in the South, Centre and North of Benin and therefore permit its survival until the rainy season have been taken stock. On the whole, 22 host-plants distributed in eight families: Papilionaceae, Caesalpiniaceae, Mimosaceae, Annonaceae, Malvaceae, Euphorbiaceae, Rubiaceae and Moraceae, have been recorded. In number of these plants which 77% are Leguminous, 18 species are newly reported while four ones were previously revealed. Among these Leguminous which 82% were from Papilionaceae family, Cajanus cajan (L.) Millsp., Vigna unguiculata (L.) Walp, Phaseolus lunatus L. and Pueraria phaseoloides (Roxb.) Benth, have been more often recorded than the other species. Amid those which were less often infested by M. testulalis larva, Crotalaria retusa Linn, appears to be singular as host-plant. It is favourable for the oviposition of the moths but noxious for the development of the larvae. Indeed, the most number of M. testulalis eggs counted during the survey has been laid on C. cajan whereas only one larva of aged instar (4th instar) was found in its flower after almost 1000 specimens of this species collected and dissected. In consideration of all host-plants of M. testulalis hitherto recorded through the world with addition to many others mentioned in the present study, the authors have come to the conclusion that M. testulalis is an essentially polyphagous borer. The efficiency of such a survey to reinforce Vigna spp. protection against this borer is discussed.