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Abstract

The reproductive capacities and development of the seed beetle Acanthoscelides macrophthalmus (Schaeffer) (Coleoptera: Bruchidae), found in Togo, were determined under natural conditions in a Guinean zone for its use as a substitute host for the mass rearing of the parasitoid Dinarmus basalis Rond (Hymenoptera: Pteromalidae), a biological agent for the control of beetles that are pests of cowpea, Vigna unguiculata (L.) Walpers (Fabales: Fabaceae). Population dynamics at the field level; and survival, fecundity and offspring production by A. macrophthalmus under laboratory conditions were measured when fed on its natural plant-host Leucaena leucocephala (Lamark) deWit (Fabales: Mimosaceae). The data resulting from the laboratory study were used to calculate the demographic parameters of A. macrophthalmus by establishing its fertility and life tables. Contrary to cultivated leguminous food plants, L. leucocephala is a perennial subspontaneous leguminous plant whose pods are available year round. Although A. macrophthalmus was present in nature throughout the year, its infestation rate of the pods fluctuated according to the phenology of the plant. The maximum infestation of L. leucocephala pods was observed between August and December. Four larval stages and one pupal stage of A. macrophthalmus were identified in the laboratory. The total mean development time varied on average 33.75 ± 2.87 days on the mature pods and 33.39 ± 2.02 days on seeds. The adult female lived from one to two weeks. During its life time, the female laid an average of 62.3 ± 19 and 43.1 ± 13 eggs on the mature pods and seeds respectively and produced an average of 36.7 ±11.3 offspring on the mature pods and 21.8 ± 8.4 offspring on seeds. On seeds, the net reproduction rate was 5.88 females per female and the intrinsic rate of population increase 0.051 per day. The generation time was 34.59 days and the doubling time 13.59 days. The demographic parameters of A. macrophthalmus in this study are close to those of Callobruchus maculatus F. (Bruchidae), the natural host of D. basalis in a previous study. A. macrophthalmus could therefore be used as substitute host for the mass rearing of D. basalis and subsequently its release in farmers’ storage containers. The data presented in this study provide some baseline information regarding the reproductive capacities of A. macrophthalmus that may be useful for its promotion as a substitute host for mass rearing of D. basalis.

Keywords: Infestation, survival, fecundity, demographic parameters, mass rearing, biological control
Abbreviation: R₀, net reproduction rate; G, generation time; r_m, intrinsic rate of population increase; DT, doubling time

Correspondence: ^aquashie78@yahoo.fr, ^b*kamevoin@tg.refer.org, ^cynuto@tg.refer.org, ^dmonedith14@yahoo.fr, ^eiglitho@tg.refer.org, *Corresponding author
Associate Editor: T. X. Liu was editor of this paper.

Received: 27 February 2009 | Accepted: 26 May 2009 | Published: 9 August 2010

Copyright: This is an open access paper. We use the Creative Commons Attribution 3.0 license that permits unrestricted use, provided that the paper is properly attributed.  

ISSN: 1536-2442 | Volume 10, Number 129

Effowe TQ, Amevoin K, Nuto Y, Mondedji D, Glitho IA. 2010. Reproductive capacities and development of a seed bruchid beetle, Acanthoscelides macrophthalmus, a potential host for the mass rearing of the parasitoid, Dinarmus basalis. Journal of Insect Science 10:129, available online: insectscience.org/10.129