Contribution to the bio-ecology of Acrobasis consociella (Hübner, 1813) (Pyralidae, Phycitinae) in Tunisia

Abstract

Q. coccifera is the characteristic species present in the north-eastern forest (Jebel Abderrahmane) and the north-western forest (Sejnane). At the end of April of 2005, a complete defoliation of more than 500 ha of evergreen shrubs of Jebel Abderrahmane caused by larvae of Orgyia trigotephras was observed. At the beginning of April 2010, a severe defoliation of a shrub-forest was noted in Sejnane, where about 2500 ha of the forest were defoliated by larvae of O. trigotephras. However, on defoliated Halimium halimifolium trees we found in addition to larvae and pupae of O. trigotephras, larvae and pupae of Anacampsis scintillella. In March 2012, pupae of Acrobasis consociella were observed on Q. coccifera in Jebel Abderrahmane and Sejnane to compete with O. trigotephras. Preliminary investigations of bioecology of A. consociella were carried out in the two forests. To estimate host plant infestations’, a direct counting was carried out on the host plant, yielding a mean number of shelters of 5.80 shelters for A. consociella and 0.24 for O. trigotephras at the two sites. About 30 shelters of A. consociella from Q. coccifera were collected to be analyzed in the lab. The mean number of larvae was 0.59 at Sejnane and 0.93 at Jebel Abderrahmane. Results show that the life cycle of A. consociella took 10 weeks. First instar larvae were observed in the beginning of February. Pupa was observed in mid-March, and it took about 3 weeks to become adult; the first adult was observed in the beginning of April. Life history of A. consociella was poorly studied, so far. In this paper, we present a contribution of its biological cycle, although further investigations must be done to deepen the knowledge of this pest.

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