Observations of Predators of European Corn Borer Eggs

It is generally agreed that the proportion of European corn borer eggs which hatch and reach the adult stage is very small. The mortality often reaches 80 to 95 percent, which means that somewhere during the life cycle there are high losses. Relatively little specific information on the causes of this mortality occurs in literature. Field work during the 1949 season presented an opportunity to obtain notes on the fate of individual corn borer egg masses. Since it was not always possible to tell whether a given egg mass had been hatched or eaten, it is possible that many more masses were recorded as hatched which actually had been destroyed by predators. Even so, about one-third of the egg masses checked daily had been eaten, at least in part. Of the 447 masses checked daily, 152 showed positive evidence of predation and in 51 cases the predator was actually seen at work