Identification of Major Pests and a Sampling Plan for Lepidoptera Larvae in Amaranthus Viridis (Callaloo) in Jamaica

Major species in the pest complex on callaloo are moth caterpillars (Lepidoptera) Spodoptera frugiperda. S. exlgua; Herpetogramma bipunctalis, Spoladea recurvalis, beetles (Coleoptera) Disonycha spp. Diabrotica baleteata., leafhoppers (Homoptera) Empoasca spp. and mites (Acarina) Tetranychus sp. Baseline surveys on 15 callaloo farms in the major callaloo producing area of Bushy Park, St Catherine indicated that of these pest species, the lepidoptera complex ranked highest in importance. Adult and larval populations ofthe five lepidoptera species on callaloo, were monitored over three cropping seasons between April 1997 and March 1998 at Bodies Experimental Station, St Catherine. There was significant correlation between moth flights and larval populations which suggests a potential for using adults as an early warning to intensify in-field scouting, The frequency distribution of the larval populations was determined and a sequential sampling plan developed for use by fanners in scouting. Comparison between a sequential sampling plan and a sampling plan based on a fixed sample size of 25 plants per fann showed the fanner to be 46% more efficient (mean 13.5 sample plants per farm) while giving the same pest management decision as the latter on 87.5% of the farms, Of the remaining 12.5% of farms in the validation exercise the sequential sampling plan recommended additional samples on 9.4% of them and only gave inaccurate decisions at 3.1% of the sites. This work will allow greater efficiency and structure for implementing scouting programmes in callaloo production systems.