Invasive pests are considered a major threat to biodiversity, conservation and agriculture. The Italian peninsula is a major site of intensive commercial exchange and transport of plants and goods, being consequently one of the European countries most invaded by alien insects. Hemiptera Coccomorpha are the largest group of non-native species recorded in Europe. For example, in the last 70 years more than 50 scale insect species have been accidentally introduced into Italy, 50% of which are now well established. This study was conducted to investigate the biology and the damage of the non-native pine tortoise scale Toumeyella parvicornis Cockerell (Hemiptera: Coccidae) accidentally introduced a few years ago into southern Italy. T. parvicornis is multivoltine in the invaded territories, being able to complete at least three generations per year, overwintering in the adult female stage. Oviposition periods during 2015-2017 surveys occurred from late April to end of May, from July to first half of August, and from mid-September to November. Fecundity was positively correlated to body size of gravid females and varied among the generations. Investigations on natural control by autochthonous species showed a seasonal activity of Metaphycus flavus (Hymenoptera: Encyrtidae), parasitizing mainly immature male individuals. The morpho-molecular approach confirms the hypothesis of an ongoing shift of parasitoid populations from other indigenous soft scales to the invasive one. Unfortunately, the low level of natural control was ineffective in hampering the spread of T. parvicornis, and preventing the dieback of local pine species, Pinus pinea, as observed in all invaded areas.

After the first record in 2008 in Southeast Italy, the alien invasive and quarantine pest Aleurocanthus spiniferus (orange spiny whitefly—OSW) has gradually spread throughout Europe, infesting several new host plants in addition to the known hosts. Molecular characterization of some Italian populations and a newly found Albanian population highlighted two different haplotypes invading Europe, belonging to one of the haplogroups previously recorded in China. A predator was recorded for the first time in several fields in Italy in association with OSW and other whitefly species. It was successively identified through a morpho-molecular characterization as a Nearctic member of the tribe Serangiini, the ladybird beetle, Delphastus catalinae. This predator represents a promising biocontrol agent to manage A. spiniferus outbreaks in Italy and other invaded countries.

The mite Varroa destructor Anderson and Trueman (Mesostigmata: Varroidae) has a dramatic impact on beekeeping and is one of the main causes of honey bee colony losses. This ectoparasite feeds on honey bees' liquid tissues, through a wound created on the host integument, determining weight loss and a reduction of lifespan, as well as the transmission of viral pathogens. However, despite its importance, the mite feeding strategy and the host regulation role by the salivary secretions have been poorly explored. Here, we contribute to fill this gap by identifying the salivary components of V. destructor , to study their functional importance for mite feeding and survival. The differential expression analysis identified 30 salivary gland genes encoding putatively secreted proteins, among which only 15 were found to be functionally annotated. These latter include proteins with putative anti‐bacterial, anti‐fungal, cytolytic, digestive and immunosuppressive function. The three most highly transcribed genes, coding for a chitin‐binding domain protein, a Kazal domain serine protease inhibitor and a papain‐like cysteine protease were selected to study their functional importance by reverse genetics. Knockdown (90%–99%) by RNA interference (RNAi) of the transcript of a chitin‐binding domain protein, likely interfering with the immune reaction to facilitate mite feeding, was associated with a 40%–50% decrease of mite survival. This work expands our knowledge of the host regulation and nutritional exploitation strategies adopted by ectoparasites of arthropods and allows the identification of potential targets for RNAi, paving the way towards the development of new strategies for Varroa mite control.

Endosymbiosis is very common between bacteria and insects, and it has been deeply studied for over a century on model insects such as Bactrocera oleae, the key pest of the olives. It was demonstrated that “Candidatus Erwinia dacicola” is the main component of its midgut bacterial communities, acting a fundamental role in the fly’s nutrition process and thus on its fitness. In this study, Trichoderma secondary metabolites have been used to treat olive fruit fly in order to alter the “Ca. Erwinia dacicola” titer and to assess the subsequent effects on its host. The selected metabolites, 6-pentyl-α-pyrone and harzianic acid, directly affect the insect’s fitness also on the subsequent generation, but not always in a concentration-dependent manner. Aside from the direct effects, the treatments also showed a modification of the bacterial titer. Therefore, real-time qPCRs were carried out on wild individual flies highlighting natural variations of the symbiont presence and activity during the seasons. The data obtained suggest that bioactive fungal metabolites can be formulated for direct or indirect control strategies of B. oleae in integrated pest management programs.

Bactrocera oleae is the key pest of olive production. Several attempts have been carried out over time to control it using biological solutions but with results rarely comparable to those obtained with chemical applications. The purpose of this work was to identify and test new compounds from samples of various Smoke Waters (SWs) for their effect on the fly, and given their low impact on the environment. SWs obtained from different feedstocks were used in in vitro and open field applications. SWs were shown to alter B. oleae fitness, acting on its microbiome, particularly on the presence and activity of the primary endosymbiont “Ca. Erwinia dacicola”, and also to affect the behavior of the adult flies, altering the attractiveness of the drupes susceptible to attack. The effects recorded were concentration-dependent and varied among repulsion, up to 87% towards females, indecision, up to 70% towards males, and attraction, comparable to fresh green olives, based on the starting materials. These responses were confirmed in electroantennography trials and during two-years of field trials carried out in South and Central Italy. Gas Chromatography–Mass Spectrometry highlighted the presence of compounds such as guaiacol and hydroquinone as potentially important for the observed activity. Principal Component Analyses confirmed the proximity among SWs obtained from similar feedstocks. In controlled conditions, females appear to be more sensitive to the SW treatments. Field trials have shown how the effects of SWs can lead depression of infestation levels obtainable with other well-known compounds, such as kaolin clay and isopropyl-myristate (repulsive), or pheromones (attractive).