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We present a synthetic review and expert consultation that assesses the actual risks posed by arthropod pests in four major crops, identifies targets for integrated pest management (IPM) in terms of cultivated land needing pest control and gauges the imple mentation “readiness” of non-chemical alternatives. Our assessment focuses on the world’s primary target pests for neonicotinoid-based management: western corn rootworm (WCR, Diabrotica virgifera virgifera) in maize; wireworms (Agriotes spp.) in maize and winter wheat; bird cherry-oat aphid (Rhopalosiphum padi) in winter wheat; brown planthopper (BPH, Nilaparvata lugens) in rice; cotton aphid (Aphis gossypii) and silver-leaf whitefly (SLW, Bemisia tabaci) in cotton. First, we queried scientific literature databases and consulted experts from different countries in Europe, North America, and Asia about available IPM tools for each crop-pest system. Next, using an online survey, we quantitatively assessed the economic relevance of target pests by compiling country-level records of crop damage, yield impacts, extent of insecticide usage, and “readiness” status of various pest management alternatives (i.e., research, plot-scale validation, grower-uptake). Biological control received considerable scientific attention, while agronomic strategies (e.g., crop rotation), insurance schemes, decision support systems (DSS), and innovative pesticide application modes were listed as key alternatives. Our study identifies oppor tunities to advance applied research, IPM technology validation, and grower education to halt or drastically reduce our over reliance on systemic insecticides globally.

Nella prima sezione della presente ricerca è stato studiato l'effetto di Infrastrutture Ecologiche a diverse scale spaziali su popolazioni di Imenotteri parassitoidi. Lo studio è stato condotto in vigneti situati nelle colline della provincia di Bologna, nel nord Italia. Infrastrutture ecologiche all'interno del vigneto come siepi di bordo e altre strutture perimetrali (micro scala) e reti ecologiche esterne (macro scala) sono state mappate e misurate dal GIS. La biodiversità dei parassitoidi è stata campionata utilizzando trappole Malaise nel periodo compreso tra giugno e ottobre 2016. Molte delle famiglie di imenotteri catturate hanno mostrato correlazioni positive con l'aumento dell'eterogeneità della componente vegetale degli habitat considerati. In un'altra sezione di questo lavoro, viene descritta una ricerca sull'uso di piante trappola poste vicino a pereti per il controllo dell'insetto esotico Halyomorpha halys (Stål, 1885). A tale scopo, sono state seminate quattro specie di piante trappola: favino, pisello, soia e fagiolino. Le dinamiche delle popolazioni di cimice in queste colture sono state valutate mediante conteggio visivo e, in alcune occasioni, con campionamenti con retino da sfalcio. Favino e soia hanno mostrato di avere una capacità attrattiva di gran lunga maggiore rispetto al pisello e al fagiolino. Un'ulteriore indagine riguardante H. Halys è stata condotta infestando in modo controllato alcuni grappoli d'uva (varietà Cabernet Franc) al fine di verificare la possibile influenza delle punture di alimentazione degli insetti sulle caratteristiche qualitative del mosto. In particolare, il trans-2-esen-1-olo e 1-hexanolo sono stati rilevati in quantità maggiori in mosti ottenuti da grappoli su cui la cimice non si era alimentata. In fine, nella primavera del 2018, è stata individuata l'opportunità di rilevare e monitorare la presenza del pentatomide nell'arcipelago maltese. Questa indagine è stata effettuata con l'uso di trappole a feromone d'aggreg, In this research the effect of ecological infrastructures at different spatial scales on parasitoids populations was been studied. The study was conducted in vineyards located in the hills in Bologna province, North Italy. Ecological infrastructures within the vineyard such as edge hedges and other perimeter structures and external ecological networks have been mapped and measured by GIS. Parasitoid biodiversity was sampled with Malaise traps between June and October 2016. Many of the hymenopteran families captured have shown positive correlations with the increase in the heterogeneity of the plant component of the habitats considered. Another section of this work describes a research on the use of traps crops placed near pear orchards for the control of the exotic insect Halyomorpha halys (Stål, 1885). For this purpose, four trap crop species were sowed: fava bean, pea, soybean and green pea. The dynamics of brown marmorated stink bug populations in such trap crop species were assessed by visual count and also by sweep net sampling. Fava bean and soybean proved to be markedly more successful than pea and green pea in attracting brown marmorated stink bugs. A further investigation concerning H. halys was carried out by infesting in a controlled manner some bunches of grapes (Cabernet Franc variety) in order to verify the possible influence of insect feeding bites on the qualitative characteristics of Must. In particular, the trans-2-esen-1-ol and 1-hexanol have been detected in larger quantities in musts obtained from clusters on which the bug has not been fed. In the end, in the spring of 2018 has been identified the opportunity to detect and monitor its presence in the Maltese archipelago. This survey was carried out with the use of pheromone traps of the glue type and allowed to ascertain the presence of the insect on the island of Malta.

The general aim of my PhD was focused on study the role of different agricultural systems in promoting functional biodiversity. In particular, the importance of habitat management techniques on natural enemy enhancement and conservation was considered at farm level with two-years samplings. Predation by polyphagous predators, which represents one of the most important ecosystem services in conservation biological control, was assessed using different approaches. In this context, molecular marker and artificial caterpillars (sentinel preys made by plasticine) were used to investigate the role of polyphagous predators in different cultivated systems. The hypothesis of my thesis is in agreement with the general assumption that diversified agro-ecosystems are more suitable for natural enemies than simplified ones. In vegetable system, natural enemies should be also favoured by the presence of Agro-ecological Service Crops by means of food supply, refuges and shelters. Moreover, we hypothesized that sustainable approaches such as green manure and roller crimper reduce soil disturbance and strengthen the ecosystem services, in comparison with conventional methods., Le attività di ricerca svolte durante il mio PhD sono state focalizzate allo studio dei metodi e delle tecniche per conservare e promuovere la biodiversità funzionale negli agro-ecosistemi. Campionamenti biennali, effettuati a livello di azienda, hanno permesso di valutare l’azione dei predatori polifagi nei confronti degli insetti dannosi utilizzando marker molecolari e bruchi artificiali di plastilina (dummy caterpillars). L’ipotesi della mia tesi è in accordo con il generale presupposto secondo cui i nemici naturali sono favoriti dai sistemi agricoli diversificati. A tal proposito, un punto chiave del dottorato ha riguardato l’influenza che le “Agro-ecological Service Crops (ASC)” hanno nei confronti degli insetti utili e dannosi in sistemi orticoli biologici. Difatti, è ben noto come le ASC avvantaggino i nemici naturali grazie a una maggiore disponibilità di cibo e di rifugi riducendo di conseguenza le infestazioni; sebbene tale affermazione debba essere valutata caso per caso. Inoltre, abbiamo ipotizzato che tecniche agronomiche quali il roller crimper e il sovescio riducano il disturbo del suolo rafforzando i servizi ecosistemici rispetto ai metodi convenzionali.

An experiment on life-table of the aphid on Bt-maize and isoline was performed. No significant differences were found between treatments. Differences in aphid performance were the lower adult and total longevity on the second generation, and the opposite trend of the pre-reproductive time that increased from the first to the second generation on isoline and decreased on Bt-maize. None of the demographic parameters analyzed showed significant differences. LTREs showed that this trend could be ascribed to a higher fecundity of young adult aphids of the second generation, probably connected to the lower pre-reproductive time. These differences could be the result of differences in chemical constituents. Analyses of secondary metabolites showed significant reduction of free polyphenols in Bt-maize. The experiment with the coccinellid H. variegata were performed evaluating the effects due to eating Cry1Ab toxin in maize pollen. No significant differences were found between GM and near-isogenic maize in all the parameter studied. Even if no significant, the reduced λ of H. variegata feeding on Bt-maize pollen, caused a population delay of 28 days. LTRE decomposition showed a lower egg and larval survival in the offspring of Bt pollen fed H. variegata, all contributing most on λ reduction. A bioassays were carried out in the greenhouse to assess the population-level responses of the coccinellid H. variegata, feeding on aphids reared on Bt-Maize and near-isogenic plants in a more realistic condition respect to laboratory trials. No differences in the mean number of eggs, larvae, pupae, and adults of H. variegata between Bt-maize and near-isogenic line. A higher number of pupae was found a week early in Bt-maize. No differences observed in H. variegata population growth rates between treatments. Using LTRE decomposition, the effect of Bt-maize exposition on λ have been decomposed into contributions arising from the effect on each stage-specific parameter.