Occurrence of <i>Aromia bungii</i> in Osaka Prefecture

Abstract

The red necked longhorn beetle (Aromia bungii), globally known as an insect pest damaging Rosaceae, was found in Osaka Prefecture in 2015. The occurrence pattern was examined of the species on their host trees (Rosaceae) in Osaka Prefecture between 2015 and 2017. The number of damaged trees increased over years and some trees seemed to have died due to the feeding of the long horn beetles. More damages were observed in ornamental cherry trees with larger trunk (in perimeters at the root). When compared among similarly damaged trees of different size, larger trees were found less vulnerable and smaller ones tended to wither easily.The highest damage position of each tree was measured, and in most trees, the positions were lower than 2 m above the ground. Also, they were higher in those trees with longer period of damage.

Comparison of the Ecological Traits and Boring Densities of Aromia bungii (Faldermann, 1835) (Coleoptera: Cerambycidae) in Two Host Tree Species

“…Aromia bungii oviposits in cracks and crevices in the rough outer bark of trunks and large limbs. Thus, oviposition tends to be concentrated toward the lower portions of the tree in all host tree species [6,7,10,11,20,31]. This tendency is particularly strong in C. × yedoensis and young trees, which have a smooth trunk with few cracks, that are less susceptible to A. bungii.…”

Characteristics of Trees Infested by the Invasive Primary Wood-Borer Aromia bungii (Coleoptera: Cerambycidae)

“…The host trees were planted in areas such as public parks, streets, personal residential properties; in these regions, the host trees were mainly ornamental cherry trees (Cerasus spp. ), and small orchards (mainly P. mume) [24]. In our study, 49 public parks in the area were chosen as study sites; these parks each had four or more ornamental cherry trees (Figure 1).…”

“…The larvae of a new generation, hatched from eggs laid by adults, will start to develop inside the host tree. During the hatching year, it is usually difficult to identify the infestation via larval frass ejection [28], which has been used as an indicator of infestation in field studies [24,25,27], because annual larvae discharge tunneling frass at an undetectably small size and low volume. After the first overwintering inside the trees, A. bungii larvae resume feeding on the hosts and ejecting more visible frass.…”

“…Secondly, from September to October 2017, three characteristics were noted in the monitoring trees in the same study location: (1) bark roughness, (2) tree size, and (3) tree vigor. Bark roughness on tree trunks at a height of less than 2 m from the ground, where most ornamental cherry trees were damaged [24], was classified into three categories based on the degree of unevenness and cracking of the surface bark, according to visual inspection: (1) smooth, (2) intermediate, or (3) rough (Figure 2). Tree size was measured as the diameter (cm) of tree trunks at about 10 cm in height from the ground.…”

“…In relation to tree-boring cerambycid beetle infestations, previous studies have focused on tree characteristics, such as tree size [13][14][15], tree species [16], tree vigor [17][18][19], bark roughness [20,21], and micro-climate [22]. Recent observational reports have suggested that host trees that are larger in size [23][24][25], more mature [3], more stressed [3], and with rolled up or cracked bark [26] are more prone to being attacked by A. bungii; however, the factor and/or combinations of factors that decisively affect infestation in the field are unclear. Moreover, previous research on A. bungii have referred to tree conditions after damage by A. bungii having been found; in these studies, there is no denying the possibility that the condition of the infested trees was a result of the damage caused by the beetles [2].…”