Evaluating the presence of larvae of Lobesia botrana (Denis & Schiffermüller) developing on olive trees in some central-southern Italian regions

Autor: Pasquale Calabrese, Andrea Sciarretta, Pasquale Trematerra
Rok vydání: 2020
Předmět:
Zdroj: Phytoparasitica. 49:13-20
ISSN: 1876-7184
0334-2123
Popis: The present study was conducted in four central-southern Italian regions (Abruzzo, Campania, Molise, Puglia) in the years 2008 and 2016–2018, with the aim to verify in hilly areas characterized by the coexistence of vineyards and olive groves, the presence, frequency and density on olive trees of the larval instars of the European grapevine moth, Lobesia botrana on olive tree flowers, and to compare these parameters with those of other lepidopteran species as well. The sampling collection was conducted on the selected plots twice in each spring, during the phenological phase of flowering. The Lepidoptera larvae found in flower buds were identified through a chaetotaxy analysis. During samplings, 384 larvae belonging to three families (Geometridae, Tortricidae, and Praydidae) were found. The olive moth, Prays oleae, was by far the most abundant species (89.8% of the total collections) and was found in all samplings. L. botrana represented 8.2% of collected specimens and was found in all sampled fields, except in Molise during 2017. Prays oleae populations were significantly more abundant compared to L. botrana populations in all cases, except in Campania during 2017. The largest L. botrana populations were found in 2008 in Abruzzo olive groves, with 0.3 larvae per inflorescence, whereas in the other years and experimental fields the densities ranged between 0 and 0.14 larvae per inflorescence, from 3 to 24 times lower compared to P. oleae. At similar levels of infestation, L. botrana did not represent a harmful pest for olive trees; however, its presence cannot be considered occasional, as it has been found constantly, year after year, even on different olive cultivars. Kruscal-Wallis results showed significant differences among the olive orchards differently related with vineyards and suggests a direct link of L.botrana populations in olive groves and neighbouring vineyards. Olive trees located near vineyards can thus represent an important infestation focus and an insect reservoir, from which the first annual generation of L. botrana adult moths easily move and colonise the surrounding areas, including the neighbouring vineyards. Our results should be considered in IPM programmes for the control of L. botrana in those territories where vineyards and olive trees are closely cultivated.
Databáze: OpenAIRE
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