Are Botanical Biopesticides Safe for Bees (Hymenoptera, Apoidea)?

The recent global decline in insect populations is of particular concern for pollinators. Wild and managed bees (Hymenoptera, Apoidea) are of primary environmental and economic importance because of their role in pollinating cultivated and wild plants, and synthetic pesticides are among the major factors contributing to their decline. Botanical biopesticides may be a viable alternative to synthetic pesticides in plant defence due to their high selectivity and short environmental persistence. In recent years, scientific progress has been made to improve the development and effectiveness of these products. However, knowledge regarding their adverse effects on the environment and non-target species is still scarce, especially when compared to that of synthetic products. Here, we summarize the studies concerning the toxicity of botanical biopesticides on the different groups of social and solitary bees. We highlight the lethal and sublethal effects of these products on bees, the lack of a uniform protocol to assess the risks of biopesticides on pollinators, and the scarcity of studies on specific groups of bees, such as the large and diverse group of solitary bees. Results show that botanical biopesticides cause lethal effects and a large number of sublethal effects on bees. However, the toxicity is limited when comparing the effects of these compounds with those of synthetic compounds.

Impact of Super-High Density Olive Orchard Management System on Soil Free-Living and Plant-Parasitic Nematodes in Central and South Italy.

The soil nematode community plays an important role in ecosystem services. The objective of this study was to assess the effect of Super-high density (SHD) olive orchards on the nematode community in five sites with different soils, climates, and cultivars. At each site, the SHD management system was compared to the adjacent olive orchard traditional (TRAD) system, in which the same soil management and phytosanitary measures were applied. Soil management was assessed by total organic carbon content (TOC), while the soil nematode community was evaluated using the nematode taxa abundances and soil nematode indicators. TOC was significantly decreased in the SHD olive orchard system compared to TRAD in the sites characterized by conventional tillage and mineral fertilization. The two-way ANOSIM analysis on nematode abundance showed no difference between the two olive management methods, instead showing only a significant difference per site mainly due to variabilities in plant-parasitic nematode assemblage. However, a negative impact of SHD management was evident in environments stressed by summer droughts and conventional tillage: the ratio of obligate plant-parasites to bacterivores and fungivores (Pp/(B+F)) was significantly higher in SHD than in the TRAD olive orchard system, and the prey-to-predator θ mass ratio showed the lowest values in the sites under organic fertilization or green manure. The canonical correspondence analysis showed that the free-living nematodes were only slightly affected by SHD olive orchards; instead, the presence of plant-parasitic nematodes families such as Telotylenchidae, Paratylenchidae, Meloidogynidae, and Criconematidae was favored, in comparison to Longidoridae, Heteroderidae, and Pratylenchidae.

The Cotton Mealybug Is Spreading along the Mediterranean: First Pest Detection in Italian Tomatoes.

The cotton mealybug Phenacoccus solenopsis Tinsley (Hemiptera: Pseudococcidae) is an extremely polyphagous invasive pest that can cause serious damages to cultivated plants. The pest is native to America but invaded Asian and Mediterranean countries during the last decades. Tomato (Lycopersicon esculentum Mill., Solanaceae) is an economic relevant crop worldwide and its production can be threatened by numerous insect pests including P. solenopsis. We recorded for the first time P. solenopsis in association with tomato in greenhouse crops and urban landscapes in Sicily (Italy) during the fall season in 2020. The species was identified as P. solenopsis based on the morphological characters and DNA amplification of an ≈800 bp portion of mitochondrial cytochrome oxidase subunit I (mtCOI) gene. The phylogenetic analysis among the obtained P. solenopsis mtCOI sequences with those already available in GenBank suggests Asian countries as a potential source of new introduction. This is the first record of P. solenopsis attacking tomato plants in Italy and may represent a potential threat for tomato production in Europe and nearby countries. For this reason, actions should be taken to avoid the uncontrolled spread of this alien species.

Description of Diaspidiotus aetnensis sp. n. (Hemiptera: Coccomorpha:Diaspididae) living on endemic birch in Sicily (Italy), with a key to Diaspidiotus species recorded on Betulaceae.

The adult female of a new species of armoured scale insect, Diaspidiotus aetnensis Nucifora, Watson and Mazzeo sp. n. (Hemiptera: Coccomorpha: Diaspididae), is described and illustrated. It was collected in Sicily on the endemic birch, Betula aetnensis Raf. (Betulaceae). We provide supplementary notes on Diaspidiotus alni (Marchal), D. wuenni (Lindinger) and D. lenticularis (Lindinger), and a key to the Diaspidiotus species recorded on Betulaceae worldwide.

Paracoccus leucadendri Mazzeo & Franco in Mazzeo, Franco & Russo, 2009, a junior synonym of Paracoccus hakeae (Williams, 1985) comb. nov. (Coccomorpha: Pseudococcidae).

Two mealybug species (Hemiptera: Coccomorpha: Pseudococcidae) feeding on Proteaceae in U.S.A. (California), Portugal and Australia were studied: Paracoccus leucadendri Mazzeo & Franco in Mazzeo, Franco & Russo, 2009, described from Portugal, and Phenacoccus hakeae Williams, 1985, described from Australia. A comparative morphological analysis was made of relevant paratypes and additional specimens from Australia, California and Portugal, and the variability of the morphological characters in the populations in each country was documented. Molecular analysis of the COI gene of specimens from Australia and California showed them to be identical, and comparative morphological analysis among specimens from Australia, California and Portugal revealed no differences either; therefore Paracoccus leucadendri is placed as a junior synonym of Phenacoccus hakeae. A comparison of the COI sequences with those of species of Paracoccus, Phenacoccus and other mealybug genera revealed that Phenacoccus hakeae does not belong in Phenacoccus. Even though its COI shows no close match to any other species its morphology fits within the generic concept of Paracoccus, and we transfer it to that genus under the new combination Paracoccus hakeae (Williams, 1985) as a holding option until a comprehensive phylogenetic analysis of the group is carried out.

The scale insects (Hemiptera: Coccoidea) of the Maltese Archipelago.

Past works on scale insects (Hemiptera: Coccoidea) from the Maltese Archipelago are reviewed. Based on the literature and contemporary collections, a total of 93 species of scale insects belonging to 12 scale insect families are here reported (Aclerdidae 1 species; Asterolecaniidae 4; Coccidae 17; Diaspididae 46; Eriococcidae 5; Kermesidae 1; Margarodidae 1; Micrococcidae 1; Monophlebidae 2; Pseudoccocidae 11; Putoidae 2 and Rhizoecidae 2). Of these, 17 species represent new distribution records. Ten species are excluded from the scale insect fauna of the Maltese Islands. Of the 93 species present, only 29 (31.18%) are probably indigenous and the rest (68.82%) represent established introductions from elsewhere. More than 65% of the indigenous species are typical Mediterranean in distribution, with a few species having a mainly European chorotype. A quarter of the established aliens originate from Eurasia, followed by an East Asian/ Oriental component (20.31%); European (14.06%); Neotropical (14.06%); cryptogenic (14.06%); African (7.81%) and Australasian (4.70%). Movement of live fruit trees and ornamental plants into the Maltese Archipelago from nearby countries is probably the main route for entry of alien scale insects into the country. Some possible future introductions are discussed.