No abstract

Integrative taxonomy is a recently developed approach that uses multiple lines of evidence such as molecular, morphological, ecological and geographical data to test species limits, and it stands as one of the most promising approaches to species delimitation in taxonomically difficult groups. The Pnigalio soemius complex (Hymenoptera: Eulophidae) represents an interesting taxonomical and ecological study case, as it is characterized by a lack of informative morphological characters, deep mitochondrial divergence, and is susceptible to infection by parthenogenesis-inducing Rickettsia. We tested the effectiveness of an integrative taxonomy approach in delimiting species within the P. soemius complex. We analysed two molecular markers (COI and ITS2) using different methods, performed multivariate analysis on morphometric data and exploited ecological data such as host-plant system associations, geographical separation, and the prevalence, type and effects of endosymbiont infection. The challenge of resolving different levels of resolution in the data was met by setting up a formal procedure of data integration within and between conflicting independent lines of evidence. An iterative corroboration process of multiple sources of data eventually indicated the existence of several cryptic species that can be treated as stable taxonomic hypotheses. Furthermore, the integrative approach confirmed a trend towards host specificity within the presumed polyphagous P. soemius and suggested that Rickettsia could have played a major role in the reproductive isolation and genetic diversification of at least two species.

Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) is a serious threat to tomato crops in So uth America. In Europe, after its first detection in Spain in 2006, it rapidly spread through the Mediterranean basin, reaching Italy two years later. The aim of our work was to find ind ige no us effective biological control agents and to evaluate their potential role in the control of larval populations of T. absoluta (tomato borer) in controlled conditions. Nine sp ec ies o f la r va l pa ras ito id s emerged from field-collected tomato leaves infested by T. absoluta. The most abundant, Necremnus nea r artynes (Walker) and N. nea r tidius (Walker) (Hymenoptera: Eulophidae), were tested in laboratory parasitism trials. Furthermore, since the species N. artynes a nd N. tidius are each reported in literature as a n ectoparasitoid of Cosmopterix pulchrimella Chambers (Lepidoptera: Cosmopterigidae) on upright pellitory plants, olfactometer bioassays were performed to assess the response of our parasitoids to the odors of tomato and pellitory leaves infested by T. absoluta a nd C. pulchrimella, respectively, compared with healthy ones. Both Necremnus species showed good adaptation to the invasive pest, and we observed a high larval mortality of T. absoluta due to host feeding and parasitism. Even olfactory responses highlighted a preference of both wasps for tomato plants infested by the exotic pest. These preliminary results demonstrated a high suitability of these ind ige no us na tura l e ne mies fo r controlling the tomato borer. Further investigations are therefore needed to confirm their role as potential biological agents in commercial tomato plantations. Ke ywo rds bio lo gic a l co ntro l, tomato borer, native natural enemy, exotic invasive pest, Necremnus spp.

We provide a karyological study of 12 species of the genus Pnigalio in an attempt to evaluate the taxonomic utility of karyotypes at the species level. For all species of Pnigalio examined the number of chromosome was 2n=12. Karyotype formulae presented mainly metacentric and submetacentric chromosomes, although a pair of acrocentrics or subtelocentrics, shorter than biarmed chromosomes, was present in some species. The analysis of karyotypes of Pnigalio showed frequent but not general interspecific variability of the chromosome traits. Although most of the studied species revealed concordance between morphological and karyological characters (centromeric index and relative length), two other categories have been identified: morphologically distinct species without reciprocal differences in karyotype structure, and morphologically similar species that strongly differ in chromosomal characters.

The European species of Diglyphus Walker are reviewed. Fifteen species are included. One of these, D. clematidis sp. n., is described as new, and one, D. anadolucus Doganlar, is recorded as new to Europe. Several of the species have their geographical distribution increased as many new country records are introduced. New host records and compilation of host records from the literature are presented in tables. To facilitate the identification of the species a key and numerous illustrations are included. The identity of one of the species described from Europe, D. phytomyzae Ruschka, is unclear. It has not been possible to locate the type material of this species and the original description is not detailed enough to make an unambiguous interpretation possible. Two species, D. scapus Yefremova from Iran and D. sensilis Yefremova from Turkey, are discussed as they occur in the vicinity of Europe.