Seasonal Prevalence of the Invasive Longhorn Beetle Aromia bungii in Osaka Prefecture, Japan

Abstract

A thorough understanding of the seasonal prevalence of invasive pests in newly invaded regions is key for establishing an appropriate and localized control plan for their successful eradication. In this study, we investigated the seasonal prevalence of the invasive longhorn beetle Aromia bungii (Coleoptera: Cerambycidae) in Osaka Prefecture, Japan. We determined the number of adult beetles sighted on host trees more than once a week from late May or early June to late August for 3 years at three study sites (one site from 2019-2021 and two sites from 2020-2021). The appearance period of A. bungii adults spanned over 2 months (June-August), and peak sighting in the field occurred in late June; the adults were more abundant in the early phase of their seasonal prevalence (around the peak dates) and almost disappeared by August. The number of adult beetles emerging from A. bungii-infested trees at one study site was surveyed daily in 2021. This survey showed a short-span adult emergence period: Approximately 1 month from the first emergence day, supporting the idea of the concentration of adult abundance in the early phase. These results will help to establish a timely pest-control plan for A. bungii in Osaka Prefecture.

Keywords: Aromia bungii; Cerambycidae; Rosaceae; body size; emergence; invasive species; longhorn beetle; seasonal prevalence; sex ratio; wood borer.

Figure 1

Three study sites (Habikino, Tondabayashi 1, and Tondabayashi 2) to determine the seasonal prevalence of Aromia bungii in the field in Osaka Prefecture, Japan. Shaded triangles denote the locations of the study sites. The numbers in parentheses represent the survey years. The map in the top right corner is a map of Japan’s prefectures. The red square represents the location of the study sites (Osaka Prefecture).

Figure 2

An emerged Aromia bungii adult captured in a fine-mesh net set over an emergence hole using push pins and staples on a tree stump on 14 June 2021.

Figure 3

Line charts of the number of adults sighted in the field (total, male, and female) for each survey year and study site. Open circles represent the number of sighted adults on each survey date.

Figure 4

Number of adults that emerged daily from each tree (A) and cumulative ratio of the number of emerged adults among the tree types (including all trees) per day (B). Numbers (1 to 9) on each graph represent tree numbers that were allocated arbitrarily.