Dicyphini collected in horticultural areas of north-western Italy (Heteroptera Miridae)

Abstract

In the last years, some species of Dicyphini (Heteroptera Miridae)
have revealed to be efficient pest predators in horticultural crops of the
Mediterranean Basin; they may colonize vegetables when the pesticide pressure
is reduced. Thus, to improve the knowledge on these mirids, studies on their
distribution and host plants were carried out in horticultural areas of north-western
ltaly from 1990 to 1999. lnsects were collected on vegetables and wild plants
growing around the crops in severa! localities of Piedmont and Liguria. The main
vegetables checked were tornato, sweet pepper, eggplant and zucchini, either in
greenhouses or in the open air. During the surveys, eleven Dicyphini species were
found, but only four were sampled also in the crops: Dicyphus errans (Wolff,
1804), Macrolophus melanotoma (Costa, 1853) [= M. caliginosus Wagner, 1950],
M. pygmaeus (Rambur, 1839) [= M. nubilus (Herrich-Schaeffer, 1836)], and
Nesidiocoris tenuis (Rambur, 1895). For these species, tornato was the most
favourite crop, whereas Calendula officinalis L., Inula viscosa (L.) Aiton,
Parietaria officinalis L. and Solanum nigrum L. were the preferred wild plants.
The presence and abundance of the species were related to the area and the season.
Generally, in Piedmont D. errans was the predominant mirid, whereas
Macrolophus spp. prevailed in Liguria; N. tenuis was found only in Liguria, never
in Piedmont. Their distribution and alternative host plants are discussed.