POTENTIAL OF HOST-SWITCHING IN NEZARA-VIRIDULA (HEMIPTERA, PENTATOMIDAE) TO ENHANCE SURVIVAL AND REPRODUCTION

The ability of Nezara viridula L. nymphs and adults to make up a suitable diet from several poor host plant species was studied. The ability of adult bugs to recover from poor nutrition experienced early in life (nymphal stage or prereproductive adult stage) when fed an optimal food plant was also investigated. Survival and development of nymphs, and reproductive performance of adults fed on a combined diet of poor host plant species, was inferior in comparison with individuals fed an optimal diet. There were indications that adults can partially recover from poor nutrition experienced early in adulthood, but their overall performance was still inferior to bugs fed an optimal diet. The adverse effects of poor nutrition were more dramatic when bugs experienced this condition throughout their nymphal development. It is suggested that, under some environmental conditions, there may be some advantages in periodic host switching by individual bugs, although they are limited in extent; e.g., some adults can survive and still reproduce when fed a combination of poor host plant species. These findings are discussed in relation to the seasonal patterns of abundance and pest status of N. viridula in SE Queensland and its adaptations to its host plants.