Matteo Alessandro Saladini

Chalcid parasitoid community associated with the invading pest Dryocosmus kuriphilus in north-western Italy

Abstract.  1. Biological invasions of exotic species pose a major threat to native biodiversity. Invaders are known to have direct impacts on native species; however, less well studied are the indirect impacts mediated through the integration of invaders into trophically linked communities.

Impact of insecticide treatments on Ostrinia nubilalis (Hübner) (Lepidoptera: Crambidae) and their influence on the mycotoxin contamination of maize kernels.

BACKGROUND European corn borer (ECB), Ostrinia nubilalis (Hübner), is the main maize pest in Central and Southern Europe and promotes the infection of maize with Fusarium spp., which produce mycotoxins. The objective of this study was to determine the effect of insecticide treatments on ECB damage, Fusarium infection and mycotoxin contamination. The field experiments were performed from 2000 to 2006 in three locations in north-western Italy. At harvest, ears were rated for the incidence and severity of ECB damage and Fusarium ear rot symptoms, and the harvested kernels were analysed for fumonisins and zearalenone. RESULTS In all the years except 2003, the chemical treatment had a significant effect on ECB incidence and severity. The ear damage was reduced, on average, by 44.1%. Fusarium ear rot and fumonisin contamination were affected by ECB control. The occurrence of the mycotoxin was significantly reduced, on average by 68%. The differences between the treatments were less clear in the year with highest ECB pressure. No significant difference was observed between the different insecticide classes. No relations were detected between the ECB activity and the occurrence of zearalenone. CONCLUSION This research indicates that the production of kernels with low fumonisin content may be enhanced by an insecticide treatment against the second ECB generation.

Non-target host risk assessment for the parasitoid Torymus sinensis

Torymus sinensis Kamijo (Hymenoptera: Torymidae) has been released throughout Italy for biological control of the chestnut gall wasp. In response to concern about non-target impacts associated with the introduction of this exotic biological control agent, this study aimed at investigating T. sinensis’s host range. In total, 1371 non-target galls were collected in north-central Italy in a two-year period, representing nine different species. Collections were carried out on common oak, downy oak, sessile oak, Turkey oak, and wild rose. A total of five native torymid species were recorded from the non-target galls (Megastigmus dorsalis, Torymus affinis, T. auratus, T. flavipes, and T. geranii), and three ♂♂ T. sinensis individuals emerged from Biorhiza pallida galls collected in the field. Under controlled conditions, most of the non-target galls tested were not suitable hosts for oviposition. T. sinensis females only laid eggs on Andricus curvator. In olfactometer bioassays, higher numbers of T. sinensis females showed more interest to the chestnut galls compared to non-target hosts. This data highlights how T. sinensis has a broader ecological host range than reported in the literature and that it is attracted by non-target hosts other than D. kuriphilus.

Post-release evaluation of non-target effects of Torymus sinensis, the biological control agent of Dryocosmus kuriphilus in Italy

A post-release study was performed to assess the impact of Torymus sinensis (Hymenoptera: Torymidae), the biological control agent of Dryocosmus kuriphilus (Hymenoptera: Cynipidae), on native cynipid gall inducers in Italy. In total, 14,512 non-target galls were collected, corresponding to seven genera: Andricus, Aphelonyx, Biorhiza, Cynips, Diplolepis, Neuroterus, and Synophrus, and 8708 chalcid parasitoids were recorded. The Torymidae family accounted for about 30%, and Bootanomyia (=Megastigmus) dorsalis, Torymus affinis and T. flavipes were the most represented species. A total of 116 T. sinensis emerged from 15 different oak galls, mainly Andricus curvator and A. inflator. In controlled conditions, oviposition was recorded on A. cydoniae, A. grossulariae and A. lucidus, while no mating with native congeneric species occurred. This paper confirms the realised host-range expansion by T. sinensis. Even if it were extremely difficult to evaluate its magnitude, the impact appears minimal, and an occasional feeding with no changes in the distribution or abundance of non-target hosts is expected.

Environmental factors and agronomic practices associated with Savi’s pine vole abundance in Italian apple orchards

The development of an integrated rodent pest management strategy requires the adoption of protocols that should be based on a good knowledge of species–habitat relationships. Vole damage to orchards has increased in Italy in recent decades, as new cultivation practices have been introduced, despite the use of rodenticides. To improve our understanding of factors influencing Savi’s pine vole abundance in Italian apple orchards, we monitored the relationship between environmental and agronomic variables and population densities. Vole population sizes were influenced by the abundance of voles in the neighbouring fields and the presence of kiwifruit orchards, usually not treated with rodenticides, bordering on apple orchards. The type of irrigation system had the strongest influence on vole abundance and flood-irrigated fields had fewer voles than drip-irrigated fields. Apple-tree age and tilling practices also had an influence on vole abundance. Our research provides evidence that vole populations are influenced mostly by agronomic practices and type and extension of fruit orchards. An integrated management strategy in the apple orchard district should include coordination in chemical treatments between farmers and the experimentation of flood irrigation and regular soil tillage management as a possible cost-effective way to reduce vole populations.

Glue barriers reduce earwig damage on apricots in north-western Italy

ABSTRACT The European earwig, Forficula auricularia L. (Dermaptera: Forficulidae), is a well-known species that is cosmopolitan and present throughout Europe. Due to its omnivorous feeding behaviour, this species can act as a generalist predator, preying on several top fruit pests, but also as a pest causing shallow gouges or holes in stone and soft fruits such as apricots, strawberries, raspberries or blackberries. In Piedmont (NW Italy), significant fruit damage has been observed lately in apricot orchards where earwigs fed on ripening fruits and made a considerable part of the produce unmarketable. In this study, we sampled earwig populations in three apricot orchards in Piedmont and tested the effectiveness of glue barriers applied to the tree trunks in reducing both earwig density in the canopy and fruit damage. The arboreal glues Rampastop® and Vebicolla® were tested both in the field and laboratory trials. Glue barriers demonstrated to be effective control measures, significantly reducing earwig abundance in the canopy and fruit damage. Rampastop® gave better results on old trees with a very rough and cracked bark, since in that case Vebicolla® could not perfectly bond with the trunk.

Pyrethroid application timing to control European corn borer (Lepidoptera: Crambidae) and minimize fumonisin contamination in maize kernels.

Ostrinia nubilalis (Hubner) (European corn borer) is the main maize pest in Central and South Europe and it promotes Fusarium verticillioides infection on maize grains, which is able to produce fumonisins. The objective of this study was to determine the effect of the timing of pyrethroid treatments on European corn borer damage, fungal ear rot and fumonisin contamination. The field experiments were performed from 2005 to 2007 in NW Italy. Four application timings were compared to an untreated control. The insecticide treatments were applied at approximately 10 days intervals, starting from the end of flowering. The last treatment was performed approximately 15 days after the ECB flight peak. At harvest, the ears were rated for the incidence and severity of European corn borer damage and fungal ear rot symptoms, and the harvested kernels were analyzed for fumonisins B 1 +B 2 . In all the years, the treatments applied 7–10 days before the European corn borer adult flight peak showed the best efficacy to co...