Total sulphur contents over a three-year period in different organic vineyards of Apulia region, South-Eastern Italy

Sulphur (S) is one of the most important pillars of pest control in organic viticulture. In organic vineyards, sulphur is used mainly for the control of grapevine powdery mildew. Grapevine is widely grown organically in Apulian farms. The objective of the work was to evaluate total sulphur concentrations with ICP-OES in four Apulian organic vineyard over a three-year period. Total sulphur contents were determined also in other fields such as olive groves and a pasture where no sulphur had been used. The highest values were found in the organic vineyard where the smallest quantities of sulphur were used. No relationship was found between sulphur applications and its effective accumulations. A decrease of S concentrations was observed in the vineyard where the highest quantity of sulphur was used in 2005 and 2006 growing seasons whereas an increase was observed in the field where relatively low quantities had been applied. Furthermore, total S concentrations were higher in the control fields where no sulphur-based treatments had been performed. Results obtained indicated that many factors must be taken into account while considering sulphur turnover, the most important of which are soil management, climate and crop growth pattern. A positive correlation was found between total S concentrations and organic matter contents. Our results, although confined into a relatively short period of time, underlined the urgent need for further investigations to follow sulphur long-term dynamics in the Mediterranean soils

Attraction of Egg Parasitoids Trissolcus mitsukurii and Trissolcus japonicus to the Chemical Cues of Halyomorpha halys and Nezara viridula

9openInternationalItalian coauthor/editorTrissolcus mitsukurii and Trissolcus japonicus are two Asian egg parasitoids associated with different pentatomids such as Halyomorpha halys. Adventive populations of T. mitsukurii were found in Northern Italy, suggesting its employment as a biological control agent (BCA) against H. halys. Nevertheless, to reduce the latter’s population, T. japonicus was released in Italy. Releasing an exotic parasitoid requires investigating the interaction between the BCA and the environment to avoid negative impacts on the entomofauna of the new habitat. Trissolcus mitsukurii is mainly associated with Nezara viridula in its native area. Therefore, we investigated and compared the ability of female T. mitsukurii and T. japonicus to distinguish between naturally released cues of H. halys and N. viridula. A single parasitoid was exposed to contact kairomones of both pests to evaluate its modifications in orthokinetic and locomotory behaviour. The behaviour of female T. mitsukurii was also tested on synthetic compounds simulating the cues of the two pentatomids. When naturally released cues were used, T. japonicus preferred the traces of H. halys, while T. mitsukurii preferred N. viridula’s cues. Moreover, the attraction of T. mitsukurii to N. viridula’s cues was confirmed with synthetic cues. Additional studies are needed to judge if this parasitoid can be used as a BCA.openScala, M.; Fouani, J.; Zapponi, L.; Mazzoni, V.; Wells, K.E.; Biondi, A.; Baser, N.; Verrastro, V.; Anfora, GScala, M.; Fouani, J.; Zapponi, L.; Mazzoni, V.; Wells, K.E.; Biondi, A.; Baser, N.; Verrastro, V.; Anfora, G

Reduction of post-harvest injuries caused by Drosophila suzukii in some cultivars of sweet cherries using a high carbon dioxide level and cold storage

9openInternationalItalian coauthor/editorEfficient strategies are required in sweet cherry fruits to control the spotted wing drosophila (SWD), Drosophila suzukii, due to its adverse economic effect on farmers. Cold storage (CS) and storage with elevated carbon dioxide (CO2) are environmentally safe approaches for the pest control of stored fresh fruit. These strategies are effective in controlling a wide variety of insect species, without allowing toxic compounds to accumulate. The purpose of this study was to assess the effectiveness of a post-harvest application of CO2 treatment at 50%, cold treatment at 4 °C (CT), and a combination of both (CO2-CT) in controlling the early stages of SWD within four cultivars of freshly harvested cherry fruit, namely “Burlat-Bigarreau”, “Giorgia”, “Ferrovia”, and “Lapins”. In addition, an evaluation of the quality attributes of the cherries (skin firmness, berry firmness, strong soluble material, and titratable acidity) was carried out at harvest and after 10 and 20 days of storage. All treatments significantly reduced the rate of emergence of SWD when compared to the control (untreated cherry at 24 °C), and 100% SWD mortality was obtained in Burlat-Bigarreau (CO2-CT). In addition, over the entire storage time, the quality parameters were preserved in the samples stored at 4 °C and in the samples with combined treatments in comparison with the control.openMostafa, Manal; Ibn Amor, Abir; Admane, Naouel; Anfora, Gianfranco; Bubici, Giovanni; Verrastro, Vincenzo; Scarano, Luciano; El Moujabber, Maroun; Baser, NurayMostafa, M.; Ibn Amor, A.; Admane, N.; Anfora, G.; Bubici, G.; Verrastro, V.; Scarano, L.; El Moujabber, M.; Baser, N

Host stage preference, efficacy and fecundity of parasitoids attacking Drosophila suzukii in newly invaded areas

Drosophila suzukii (Matsumura) (Diptera: Drosophilidae) causes severe damage to certain fruit crops in both North America and Europe. This may be due, in part, to the absence of specialized natural enemies that suppress population outbreaks. We performed a series of experiments under controlled laboratory conditions in tandem with a field study to evaluate the presence and efficacy of natural enemies associated with this pest in Italian and western United States fruit production regions. Our study involved one larval parasitoid, Leptopilina heterotoma (Thomson) (Hymenoptera: Figitidae), and two pupal parasitoids, Pachycrepoideus vindemiae (Rondani) (Hymenoptera: Pteromalidae) and Trichopria drosophilae (Perkins) (Hymenoptera: Diapriidae). Three indices were used to describe host-parasitoid interactions: degree of infestation (DI), success rate of parasitism (SP) and total encapsulation rate (TER). Results confirmed that each of these parasitoid species can develop on certain populations of the pest. In addition, host stage preferences of the tested parasitoid populations, developmental parameters and lifetime fecundity of North American P. vindemiae are provided. Results are discussed with respect to differences in potential utilization of D. suzukii among the tested parasitoid species and regional populations.Keywords: Leptopilina heterotoma (Hymenoptera: Figitidae), Parasitoid, Trichopria drosophilae (Hymenoptera: Diapriidae), Biological control, Drosophila suzukii (Diptera: Drosophilidae), Pachycrepoideus vindemiae (Hymenoptera: Pteromalidae

Influence of Distance from the Host on Parasitisation by Psyttalia concolor (Szépligeti) (Hymenoptera: Braconidae)

The olive fruit fly, Bactrocera oleae, is considered the main olive pest worldwide, and has been the target of biological control programmes through the release of the braconid parasitoid Psyttalia concolor. Laboratory tests were performed to evaluate the influence of distance from the host on parasitisation, placing larvae of the substitute host Ceratitis capitata at seven distances (0, 0.5, 1, 1.5, 2, 2.5, 3 mm) and four different time periods (7, 15, 30, 60 min). Moreover, field collected olives of Ogliarola Barese cultivar infested by B. oleae were exposed to P. concolor females to confirm its ability to parasitise B. oleae in small olives. Psyttalia concolor oviposition was inhibited at 2.5 and 3 mm due to the ovipositor length of the parasitoid females (2.7 mm). Hosts were easily parasitised at distances between 0 and 1.5 mm. The thin fruit pulp (up to 3.5 mm) of field collected olives allowed the parasitisation to occur also in mature fruits. At the best combination distance/time (0 mm, 30 min), tests performed with different larvae/parasitoid female ratio showed an increasing emergence of P. concolor (from 20% to 57%) with larvae/parasitoid ratio increasing from 0.11 to 0.74. The results of the present study might optimise the mass rearing of P. concolor, through a proper setting of its parameters, such as the host/parasitoid ratio, exposure distances, and interaction time

Potential of entomopathogenic fungi and nematodes against Drosophila suzukiiin laboratory assays

Rec.: Audronė Bliujienė. Romėniškasis ir tautų kraustymosi laikotarpiai. – Lietuvos archeologija. III tomas, Klaipėda, 750 p

Total sulphur contents over a three-year period in different organic vineyards of Apulia region, South-Eastern Italy

Sulphur (S) is one of the most important pillars of pest control in organic viticulture. In organic vineyards, sulphur is used mainly for the control of grapevine powdery mildew. Grapevine is widely grown organically in Apulian farms. The objective of the work was to evaluate total sulphur concentrations with ICP-OES in four Apulian organic vineyard over a three-year period. Total sulphur contents were determined also in other fields such as olive groves and a pasture where no sulphur had been used. The highest values were found in the organic vineyard where the smallest quantities of sulphur were used. No relationship was found between sulphur applications and its effective accumulations. A decrease of S concentrations was observed in the vineyard where the highest quantity of sulphur was used in 2005 and 2006 growing seasons whereas an increase was observed in the field where relatively low quantities had been applied. Furthermore, total S concentrations were higher in the control fields where no sulphur-based treatments had been performed. Results obtained indicated that many factors must be taken into account while considering sulphur turnover, the most important of which are soil management, climate and crop growth pattern. A positive correlation was found between total S concentrations and organic matter contents. Our results, although confined into a relatively short period of time, underlined the urgent need for further investigations to follow sulphur long-term dynamics in the Mediterranean soils