Studies on the Harm, Flight Ability and Host Selection of <i>Sirex noctilio</i>

Abstract

In order to determine the damaging characteristics of Sirex noctililo, we used five-point sampling mode to conduct a survey, investigating the number, characteristics, and vertical distribution of the emergence holes. We also studied the damaging characteristics of the larva in the forest farm where the pest naturally occurs. By conducting host preference research in a laboratory environment, we predicted the potential hosts of Sirex noctililo and observed the ovipositional behavior of female adults. The flight capacity of the adult Sirex noctililo of 1-7 days of age was tested for 24 hours in a Jiaduo flight mill system. Total flight distance, total flight duration, and average flight speed were recorded. According to the results, the emergence holes of Sirex noctililo were positively circular, and the diameter was about 2.10 - 7.00 mm and distributed in the trunk height of 0 - 4. 20 m, having distinct difference with that of the emergence holes of other species of borer pests. he larvae's tunnels displayed circular cross-sections and were filled with feces and xylem-colored bore dust. Additionally, unlike some borers, the S. noctilio larvae's tunnels lacked fras holes. Sirex noctililo had a distinct preference for Pinus tabuliformi Carr. and Pinus massoniana Lamb. The one-day-old adults had maximized flight capacity, relying on which Sirex noctililo could spread 18.71 km annually. The study provides a reliable reference point for identifying and monitoring Sirex noctililo in the field in China. Moreover, the study preliminarily assesses the risk of Sirex noctililo continuing to spread.