Effect ofNiesthrea louisianicaSailer on reproduction of velvetleaf,Abutilon theophrastiMedicus, was determined by caging various numbers of the insects on single plants in the field. Number of seeds per plant ranged from 5,129 ± 1,761 with 0 insects to 1,366 ± 1,233 seeds with an original infestation of 100 first instars. A decrease in seed viability was inversely correlated with insect density from 74 ± 19% for the 0-insect treatment to 14 ± 30% for the 100 first-instar treatment.