n African Entomology - The biology of Amphicallia pactolicus (Butler) (Lepidoptera : Arctiidae), a defoliator of Crotalaria species
|Article Title||The biology of Amphicallia pactolicus (Butler) (Lepidoptera : Arctiidae), a defoliator of Crotalaria species|
|© Publisher:||Entomological Society of South Africa (ESSA)|
|Author||H. Girma, M.R. Rao, R. Day, C.K.P.O. Ogol and B.A. Jama|
|Publication Date||Sep 2006|
|Pages||329 - 336|
|Keyword(s)||Amphicallia pactolicus, Cover crop, Crotalaria, Fallows, Host suitability and Soil fertility|
Crotalaria grahamiana (Wight & Arn.) (Leguminosae) is an exotic shrub widely used as a short-rotation cover crop or planted fallow in eastern and southern Africa. Recently, Amphicallia pactolicus (Butler) (Lepidoptera: Arctiidae), an indigenous insect, has become a major defoliator of the shrub in eastern and southern Africa. We studied the feeding habits of A. pactolicus and evaluated the suitability of different species of Crotalaria for its development. The life cycle of A. pactolicus is described for the first time. The larval stage of A. pactolicus passed through six instars. Larvae that fed on flowers and pods, gained body mass faster and had shorter larval duration compared to those that fed on leaves. Out of the eight Crotalaria species tested (C. agatiflora Schweinf., C. grahamiana Wight & Arn., C. laburnifolia L., C. ochroleuca G. Don., C. paulina Schrank, C. pycnostachya Benth., C. striata DC. Benth and C. incana L.), only C. incana was rejected by the larvae. A significant proportion of the food ingested was recycled back to the soil in the form of droppings. The nitrogen, phosphorus and potassium concentrations of the faeces were similar to those of the plant material ingested. Reproductive tissues of the plant are most affected, thus indicating greater risk for seed multiplication and less danger to short-duration (6-8 months) fallow planted for soil fertility benefits. Early infestation allows more generations of A. pactolicus to develop and has the potential to cause a significant biomass yield loss.
Article metrics loading...