A method of field application of strontium chloride (SrCl2) and the assessment of local dispersal of marked Helicoverpa armigera moths in a mark-capture experiment in southern India are described. A 1.7 ha field of pigeonpea sustaining a population of approximately 400,000 larvae was treated with a single application of SrCl2 plus surfactant at 10 kg/ha, using a motorised high volume sprayer. An estimated 50,400 moths emerging over a 20 day period were unequivocally marked with Sr at a marking efficiency of 55%. Catches of moths in an array of 14 battery operated light traps and 29 pheromone traps, up to 3.5 km distant were analysed by atomic absorption spectrophotometry. Low recaptures of marked moths (7 %) in the treated field suggested the rapid exodus of emergent moths, even while the crop remained attractive, and their dilution or replacement by immigrants. The distribution of marked moths in light and pheromone traps is consistent with a predominantly downwind dispersal close to the ground during the early part of the night and more random movement later on.
King, A.B.S.; Armes, N.J.; Pedgley, D.E. A mark-capture study of Helicoverpa armigera dispersal from pigeonpea in southern India. Entomologia Experimentalis et Applicata (1990) 55 (3) 257-266. [DOI: 10.1111/j.1570-7458.1990.tb01370.x]