These factors include predation, parasitism, disease, weather and others. Predation is a relatively minor component in boll weevil population dynamics compared with other insect pests. Because most of the life cycle is spent inside the square, weevils tend to be safe from predators. However, studies have shown that some ants, especially fire ants, are effective predators of boll weevils. A number of insects, spiders, birds and other animals eat adult boll weevils, but these predators only have a minor effect on infestations.
Parasites also have little effect on boll weevil populations.
Several native parasitic wasps do attack weevil larvae but rarely in numbers high enough to reduce populations. An exotic parasitic wasp, Catolaccus grandis, is effective, but it cannot overwinter at these latitudes. It may be useful in release programs, though. Disease organisms do kill some boll weevils, but again, normally not at levels that will control infestations. Suicidal emergence can be a significant factor.