Impiego di semiochimici nel monitoraggio e nel controllo di Tomicus destruens (Woll.) (Coleoptera: Scolytidae) in Toscana e in Puglia

USE OF SEMIOCHEMICALS TO MONITOR AND CONTROL TOMICUS DESTUENS (WOLL.) (COLEOPTERA: SCOLYTIIDAE) IN THE REGIONS OF TUSCANY AND APULIA Herein are reported the results of experiments carried out in the coastal pine woods of the Tuscany and Apulia regions to control Tomicus destruens adults with attractive or repellent semiochemicals.(-)- a pinene and Ipm were the most attractive for T. destruens, especially in the coastal pine woods. The Pherotech traps caught more adults than did Theysohn traps, particularly in autumn. The repellents used to protect bait logs had a weak action. Key words: pine forests, monoterpenes, Witasek trap, Pherotech trap, Theysohn trap.  Sono riportati i risultati di prove, con semiochimici a potere attrattivo o repellente, per il controllo degli adulti dello scolitide Tomicus destruens in pinete litoranee e interne della Toscana e della Puglia. Le sostanze più attrattive nei riguardi di T. destruens sono state (-)-a- pinene e Ipm, soprattutto nelle pinete litoranee. Le trappole Pherotech hanno catturato un numero maggiore di adulti rispetto alle Theysohn principalmente in autunno. Le sostanze repellenti impiegate hanno evidenziato scarsa attività di protezione nei riguardi dei tronchetti esca Parole chiave: pinete, monoterpeni, trappola Witasek, trappola Pherotech, trappola Theysohn

Roe deer browsing effects on growth development of Turkey oak and chestnut coppices.

Over the last three decades wild ungulates populations in Italy increased to values ranging from 300% to 600%. As a consequence, in Italy as well as in other European countries, situations with high ungulate density and, then, negative effects on the stability and dynamics of ecosystems, are increasing frequently. Starting from these evidences we investigated the effects of roe deer population on the vegetative regeneration of two different broadleaved tree species: Turkey oak (Quercus cerris L.) and chestnut (Castanea sativa Mill.) coppice stands. In Alpe di Catenaia (Apennines – Central Italy), after coppicing in 2002, we chose six experimental areas where fenced (P) and non-fenced (NP) plots were established. Measurements were performed at the beginning of the study period and in winter 2008 in both P and NP plots. Diameter and    height of all sprouts were measured. Results showed a different impact of roe deer on the two species. After seven years chestnut did not show any significant browsing-related damage, while in Turkey oak heavy differences between protected and non-protected areas are present: in NP plots roe deer browsing has produced a significant reduction in basal area (58%) and volume (57%) compared to P plots. The results agree with previous studies and confirm: (a) a selective browsing pressure on Turkey oak; (b) the lasting effect of the early impact after clear cutting, visible even seven years after. Based on the findings, we discussed the need for an integrated management of forest vegetation and forest fauna which should define the density of ungulates not only according to the theoretical carrying capacity    of ecosystems, but also considering (i) the preservation of the ecosystem overall functionality, (ii) the forest structure development and (iii) the forest management type

Population Dynamics of Native Parasitoids Associated with the Asian Chestnut Gall Wasp (Dryocosmus kuriphilus)

Native parasitoids may play an important role in biological control. They may either support or hinder the effectiveness of introduced nonnative parasitoids released for pest control purposes. Results of a three-year survey (2011–2013) of the Asian chestnut gall wasp (ACGW) Dryocosmus kuriphilus Yasumatsu (Hymenoptera: Cynipidae) populations and on parasitism rates by native indigenous parasitoids (a complex of chalcidoid hymenopterans) in Italian chestnut forests are given. Changes in D. kuriphilus gall size and phenology were observed through the three years of study. A total of 13 species of native parasitoids were recorded, accounting for fluctuating parasitism rates. This variability in parasitism rates over the three years was mainly due to the effect of Torymus flavipes (Walker) (Hymenoptera: Torymidae), which in 2011 accounted for 75% of all parasitoid specimens yet decreased drastically in the following years. This strong fluctuation may be related to climatic conditions. Besides, our data verified that parasitoids do not choose host galls based on their size, though when they do parasitize smaller ones, they exploit them better. Consequently, ACGWs have higher chances of surviving parasitism if they are inside larger galls

Use of attractant and repellent substances to control Tomicus destruens (Coleoptera: Scolytidae) in Pinus pinea and P. pinaster pine forests of Tuscany

We report the results of a two-year study conducted in maritime pine and stone pine forests in Tuscany to test the efficacy of various substances in attracting or repelling adults of Tomicus destruens in the reproductive stage, i.e. while seeking trees or parts of trees suitable for reproduction. The attractants tested were: Tomowit, (-)- and (+)- a pinene, racemic b pinene, Mt-mix, trans-verbenole “Destruens” and “Ipm”. The repellents used were: Green leaf volatiles (Glv’s, jans-2-hexen-1-ol), octanol (octanol-1-octanol), verbenone, alcohols C6 and C8, benzyl alcohol, (-)-b-pinene and racemic limonene. The most effective attractant was (-)-a pinene, although bark-beetles were also caught with Tomowit and Ipm. As regards the repellents, logs protected with verbenone had the lowest level of attack, but this repellent lost its activity when combined with other substances. Key words: terpenes, monitoring, protection, Pinus spp., Scolytidae.  MPIEGO DI SOSTANZE ATTRATTIVE E REPELLENTI NEI CONFRONTI DI TOMICUS DESTRUENS (COLEOPTERA: SCOLYTIDAE) IN PINETE DI PINUS PINEA E P. PINASTER DELLA TOSCANASi riportano i risultati di indagini biennali condotte in pinete di pino marittimo e di pino domestico della Toscana, allo scopo di valutare l’efficacia di semiochimici nell’attrarre o respingere adulti di Tomicus destruens nella fase di ricerca delle piante o parti di esse idonee alla riproduzione. Come attrattivi sono stati utilizzati: Tomowit, (-) e (+)-a pinene, il racemo di a pinene, Mt-mix, trans-verbenolo, “Destruens” e “Ipm”; come repellenti sono stati sperimentati: Green leaf volatiles (Glv’s, jans-2-hexen-1-ol), octanolo (octanol-1- octanol), verbenone, gli alcoli C6, C8, l’alcool benzilico, (-)-b pinene e il racemo di limonene. Tra le diverse sostanze attrattive sperimentate, (-)-a pinene è risultato il più efficace; catture si sono ottenute anche con l’impiego di Tomowit e con un nuovo formulato denominato Ipm. Tra le sostanze ad effetto repellente provate, il verbenone, quando impiegato da solo, sembra avere una certa attività, mentre perde questa sua proprietà quando viene provato in combinazione con altre sostanze. Parole chiave: terpeni, monitoraggio, protezione, Pinus spp., Scolytidae.