Laboratory efficacy of the entomopathogenic fungi, Paecilomyces carneus and P. farinosus, was assessed against the first larval instars of Pteroma pendula, using conidia generated on solid fermentation media. Three isolates of P. carneus and three isolates of P. farinosus were infective on the first larval instars of P. pendula. Most of the Paecilomyces spp. caused a significant increase in mortality between seven days after treatment (DAT) and 11 DAT. However, a dramatic increase in mortality was recorded with isolate PC2 of P. carneus whose effectiveness increased nearly three-fold over this period. The highest corrected mortality after 11 DAT varied from 75% for P. farinosus to 93.8% for P. carneus. Among the tested isolates, P. carneus caused the highest corrected mortality of 93.8% at 11 DAT, while a corrected mortality of only 75% was induced by P. carneus isolated from the soil. The most successful isolate was of P. carneus which controlled over 80% of the first larval instars of the P. pendula population at 11 DAT. This indicates that the efficacy of P. carneus is superior to that of P. farinosus against the first larval instars of P. pendula, and can be exploited as biological control agents of the oil palm pest bagworm.