Mark–recapture estimates of recruitment, survivorship and population growth rate for the screwworm fly, Cochliomyia hominivorax

Abstract

Pradel model mark-release-recapture estimates of survivorship, phi, recruitment, f, and the rate of density-independent population growth, lambda, are presented for eight mark-recapture studies of the screwworm Cochliomyia hominivorax (Coquerel) (Diptera: Calliphoridae) from Costa Rica, totalling 19 573 released and 4476 recaptured flies. Corroborative estimates of survivorship and the rate of population growth based on an extensive review of the literature are also reported. Weighted-mean +/- standard error of the mean (SEM) mark-release-recapture estimates of survivorship, recruitment and the rate of population growth were phi = 0.798 +/- 0.008, f = 0.193 +/- 0.008 and lambda = 1.005 +/- 0.002, respectively. Population doubling time was estimated from lambda at 139 days. Estimates of phi and lambda from the literature both exceeded those calculated by mark-recapture methods and estimates of population doubling times were consequently shorter.