Description
ORIGIN AND GEOGRAPHICAL DISTRIBUTION. The species originates from south-east Asia. In Europe it has only been reported in Germany (Bavaria 2011, 2016, 2017, 2019) and in Italy there are two outbreaks in the province of Naples (since 2012) and in the province of Milan (since 2013). In Trentino it is not present.
HOST PLANTS. Aromia bungii attacks both healthy and stressed plants, almost exclusively of species belonging to the genus Prunus, including: Apricot tree(Prunus armeniaca), Cherry tree(Prunus avium, Prunus cerasus), Peach tree(Prunus persica), Plum tree (Prunusdomestica), Almond tree(Prunus dulcis) and ornamental flowering Prunus. Apple trees(Malus domestica) and pear trees(Pyrus communis) may also be affected, but less frequently.
BIOLOGY. The females lay their eggs in cracks in the bark and on the main branches. The larvae first feed on the subcortical tissues and then penetrate deeper into the wood. From egg hatching to adult emergence, 2 to 4 years may pass depending on climatic conditions, host quality and latitude. It overwinters at the larva stage. Adults emerge from host plants from late spring, with a peak of activity concentrated in the summer months.
Morphology of the adult insect. Adults of A. bungii measure 28 to 35 mm in length and are shiny black, with a characteristic orange-red pronotum (also known as the neck); however, completely black specimens do exist. In males, the antennae are much longer than the body, while in females they are as long as the body.
The larvae live inside the affected plants and measure 2-2.5 mm in length at hatching, but reach 50 mm in length at maturity; they are whitish in colour and have an elongated shape.
SYMPTOMS AND DAMAGE The first symptoms that can be observed are the expulsion of abundant sawdust from the woody parts of the plant and oval flickering holes (2-3 mm in diameter). Direct damage is caused by the trophic activity of the larvae that feed on the woody part of the plant, forming galleries that damage the sap cycle. In addition, secondary pathogens may settle in the plant from the flicker holes produced by the adults through their mandibles. As a result, dry branches and general decay of the plant can be observed, up to death in the most serious cases.
PATHWAYS OF SPREAD. Introduction into the territory can occur through the transport or import of the following materials
- raw wood for packaging, crates, pallets and supports of goods from areas where the presence of A. bungii is confirmed, as if not carefully controlled it may harbour eggs, larvae and pupae of A. bungii;
- wood and plants belonging to the genus Prunus infested with eggs, larvae or adults.
In the event of an incursion, the spread in the wild in our territory should be rather slow according to studies carried out on outbreaks already present in Italy; in fact, A. bungii was found to have a spread rate of around 2 km in 6 years in Lombardy and 5 km in 6 years in Campania.
CONTROL AND PHYTOSANITARY MEASURES. In infested areas, control is based on the felling and destruction of affected plants. It is important that the wood and roots of infested plants are chipped and burnt as the insect is able to complete its development cycle even in a single portion of wood. If action is taken promptly, the pathogen can be eradicated.
In the areas considered to be free of the pathogen, including Trentino, a surveillance activity is carried out by the Provincial Phytosanitary Service as provided for by the protocols (Official Technical Document - DTU no. 37 - of the National Phytosanitary Service), which consists of visual monitoring of the host plants. In addition, with the dissemination of information material, the participation of individual citizens and professionals in reporting any suspicious findings is hoped for. The aim is to intercept the pathogen early if it is introduced in our territory.
REPORTING. To provide reports and receive information, contact the Provincial Phytosanitary Service (tel. 0461/495660; e-mail: serv.agricoltura@provincia.tn.it; pec: serv.agricoltura@pec.provincia.tn.it)
REFERENCE LEGISLATION. Regulation (EU) 2016/ 2031; Implementing Regulation (EU) 2019/2072; Legislative Decree No. 19/2021; Commission Implementing Decision (EU) 2018/1503 of 8 October 2018 laying down measures to prevent the introduction into and spread within the Union ofAromia bungii (Faldermann).