FIELD INFESTATION OF CARYEDON SERRATUS OLIVIER [COLEOPTERA: BRUCHIDAE] ON THE PODS AND SEEDS OF ACACIA NILOTICA IN THE THAR DESERT OF INDIA

Abstract

Caryedon serratus Olivier has been recorded as a serious pest on pods and seeds of Acacia nilotica in the Thar desert of India. Pest infestation on developing pods and its relationship with morphological traits is reported. Bruchid infestation was recorded in April and the insect continued to multiply in the field as the pods remained on the tree when ripe. Infestation of pods varied from 10 to 30 % with 1.2 to 1.8 % infestation of seeds. Insect infestation resulted in a loss of 22.51% in seed weight and 1.18% loss in seed biomass of the tree. Infestation of pods was directly related to infestation of seed (r = 0.81"). Infestation of seed was directly correlated with loss in seed weight (r = 0.83") and loss in seed biomass from the tree (r = 0.76"). The insect remained in the field during the hottest months of May and June and was also reported to infest pods and seeds of Prosopis cineraria and P. juliflara. These trees thus act as the secondary host, for population buildup of C. serratus, from where it spreads to its primary host, the groundnut, Arachis hypogea, which is becoming a common crop of this region with the introduction of the Indira Gandhi Canal in the Thar desert.