Journal of Agriculture
and Environmental Sciences

The Paper wasp Polistes olivaceus (Hymenoptera: Vespidae) as an Important Predator of Beet Armyworm in Vietnam
Takatoshi Ueno

Abstract
Beet armyworm Spodoptera exigua is known as a pest of Welsh onion or green bunching onion in many Asian countries. Control of the armyworm solely by insecticides is often difficult. In the present study, a field survey was conducted to search natural enemies of the armyworm in the onion fields in Vietnam. Macao paper wasp Polistes olivaceus was found to be the most prevalent predator attacking the beet armyworm in summer. The wasp was detected rarely during early mornings but the number of wasps flying into onion fields increased during the daytime; they actively searched and predated the armyworm. The wasp was more abundant in onion fields with later plant growth stages where more armyworms were present. Conservation biological control together with other IPM practices may be useful in beet armyworm management.

Full Text: PDF     DOI: 10.15640/jaes.v4n2a6