Assessing the suitability of noncultivated plants and associated insect prey as food sources for the omnivorous predator Macrolophus pygmaeus (Hemiptera: Miridae)

The suitability of noncultivated plants Solanum nigrum and Dittrichia viscosa, with or without the nonpest prey Aphis fabae solanella and Capitophorus inulae, respectively, as food sources for the polyphagous predator Macrolophus pygmaeus was investigated. A. f. solanella supported the development and longevity of M. pygmaeus on S. nigrum. However, the fecundity and rate of population increase of the predator fed A. f. solanella were reduced compared with those of other aphid species. M. pygmaeus completed its development feeding solely on S. nigrum and adults survived similarly for a period while feeding on A. f. solanella. The results show that M. pygmaeus can increase in numbers on S. nigrum, suggesting that this plant can support the maintenance of predators in the field. On the other hand, M. pygmaeus performed poorly on D. viscosa. Although it completed its development while feeding on D. viscosa and the aphid C. inulae, females laid only a few eggs; the predator was unable to complete development while feeding on this plant alone. The widespread noncultivated plant S. nigrum may contribute to the conservation of M. pygmaeus in the open field, mostly through supporting its survival and, at a lower rate, its reproduction. The same cannot be said for D. viscosa.