The Box Tree Moth: An Invasive Species Severely Threatening Buxus Natural Formation in NW Italy

Abstract

(1) The box tree moth (BTM), Cydalima perspectalis Walker, represents one of the recent examples of exotic insect pests native to Asia accidentally introduced in Europe by the nursery trade. In Europe, BTM develops on Buxus sempervirens L., causing significant damage to ornamental and natural plants. (2) Basic aspects of BTM biology were investigated at three sites in the NW Alps, where B. sempervirens occurs on rocky slopes, forming a protected habitat. In 2019–2021, we evaluated: (i) the seasonal flight activity with sex pheromone traps, (ii) the fecundity and the effects of food on the egg load, (iii) the potential adaptation of BTM on native secondary host plants, and (iv) the recruitment of natural enemies. (3) Our results revealed the presence of two generations per year. The number of mature eggs increased in fed adults and was higher in females of the first generation. No evidence of BTM shift on secondary plants was found in either laboratory or natural conditions, and no significant occurrence of natural enemies was recorded, except for one pupa of the tachinid Pseudoperichaeta nigrolineata. (4) Our findings provide valuable information to address and timely plan management strategies to preserve B. sempervirens as an essential component of rare forest ecosystems.

An Environmentally Friendly Method to Protect Box Trees (Buxus spp.) from Attacks by the Invasive Moth Cydalima perspectalis

“…Since then, the non-native moth has spread across Europe, causing devastating damage to ornamental box trees (Buxus spp.) in private gardens, cemeteries, and urban and historical parks [3,4] and also affecting natural boxwood stands (Buxus sempervirens L.) in southern and western Europe [5][6][7][8]. More recently, C. perspectalis has been recorded in North America (first reported in Toronto, Canada, in 2018 [9]) and in Africa (first detected in Constantine, Algeria, in 2018 [10]).…”

The fast invasion of Europe by the box tree moth: an additional example coupling multiple introduction events, bridgehead effects and admixture events

“…The fast invasion of Europe by the box tree moth: an additional example coupling multiple… has been recorded only on Buxus species (Wan et al 2014;Matošević et al 2017;Ferracini et al 2022). In its native range, the insect has been reported to develop on several Buxus species, and three other host plants (Ilex purpurea, Euonymus alatus and E. japonicus) (Wan et al 2014).…”

“…However, the use of these three plants as host by BTM has recently been debated. Several performance experiments done with invasive populations showed that BTM larvae were only able to develop on Buxus species, suggesting that the moth is an herbivorous specialist of this plant genus (Brua 2014;Matošević et al 2017;Ferracini et al 2022). In Asia, approximately 40 native species of Buxus occur, among which at least 15 species are found in China (Kohler and Brückner 1989;Fang et al 2011).…”

“…In the years that followed, the moth appeared in central and southeastern Europe (e.g., Croatia [Koren & Crne, 2012]; Hungary [Sáfián & Horváth, 2011]; and Greece [Strachinis et al 2015]) as well as in Turkey [Hizal et al 2012]; southern Russia [Gninenko et al 2014]; Georgia [Matsiakh et al 2018] and Iran (Ahangaran 2016). At present, BTM has invaded more than 30 Eurasian countries (Bras et al 2019), where it is threatening several Buxus species (Mitchell et al 2018) both in urban and forest stands (Ferracini et al 2022). It has been observed for the first time in 2018 in Canada (Frank 2019) and was also intercepted several time in the USA on nursery plants shipped from Canada in 2020 and 2021 (USDA-APHIS 2021).…”

Survey of Natural Enemies of the Invasive Boxwood Moth Cydalima perspectalis in Southwestern Mediterranean Europe and Biocontrol Potential of a Native Beauveria bassiana (Bals.-Criv.) Vuill. Strain

“…Fewer works have also been carried out to detect possible native biotic factors of mortality (predators, parasitoids, entomopathogenic microorganisms and nematodes) capable of attacking or infecting the pest in Europe; Oltean et al [16] summarized data from the literature. The Diptera Compsilura concinnata (Meigen, 1824) was found to parasitize C. perspectalis larvae at a low rate in France [18]; Ferracini et al [19] found another tachinid, Pseudoperichaeta nigrolineata (Walker, 1853), in Italy; and a sirphid species, Xanthandrus comtus (Harris, 1780), was found by Las Heras et al [20] predating the larvae in Catalonia. Bird et al [21] reported, for the first time in Britain, the parasitism of the boxwood moth by P. nigrolineata and by a pteromalid, Stenomalina cf.…”