Prediction of Larval Infestation in Pasture Grasses by Spodoptera frugiperda (Lepidoptera: Noctuidae from Estimates of Adult Abundance

The seasonal fluctuations of adult Spodoptera frugiperda (J. E. Smith) populations were monitored for a 75-week period in pastures on a cattle farm in French Guiana. Adults were monitored using blacklight traps and sticky traps baited with (Z)-9-dodecen-1-ol acetate, an attractant for S. frugiperda males. Larval populations were sampled weekly using sweep nets. Significant correlations were obtained between adult captures for both trapping methods used and relative larval abundance. The highest correlation coefficient was obtained between weekly captures of moths in sticky traps and relative larval abundance one week later. The highest populations of moths and larvae were observed during the rainy seasons, and the lowest during the dry seasons. Results obtained in these experiments demonstrate that it is possible to use sticky traps baited with (Z)-9-dodecen-1-ol acetate in a system to warn growers of possible significant infestations of S. frugiperda larvae in pastures in French Guiana.