关键词: 松树蜂, 繁殖行为, 信息素, 植物挥发物, 共生真菌, 化学生态

Abstract:

The European woodwasp (Sirex noctilio) (Hymenoptera:Siricidae), originated from Europe, Asia (Republic of Georgia, and Mongolia) and North Africa, is a major forestry invasive pest in the world. It has been introduced to many countries, causing great economic losses to their pine resources. In 2013, it was first found that the woodwasp invaded China and settled in northeast of China on Pinus sylvestris var. mongolica. Therefore the monitoring techniques are urgently needed to monitor the population transmission situation, in order to control the invasive pest. In this paper, we summarize the reproductive behavior and chemical ecology regulation in S. noctilio. As to reproductive behavior, males emerge a few days to weeks earlier than females and male's population is more abundant than female's. Its eclosion is affected by climate and the height of the eclosion hole on the trunk. Males aggregate in the upper tree branches for brighter light there. Courtship behavior is regulated by physical factors (light and sound) and chemical factors (host plant volatiles and pheromone). Sirex adults are sexually mature at emergence. Both parthenogenesis and hermaphroditism can be carried out in this insect. If females are parthenogenetic, unmated females oviposit only unfertilized eggs, which develop into males. Once mating happen, mated females can oviposit both fertilized and unfertilized eggs, fertilized eggs develop into females, while unfertilized eggs develop into males. The female can lay eggs after eclosion, and some of them can lay eggs after mating. The amount of laying eggs is affected by temperature and humidity, the shape of female and the symbiotic fungus in the trunk. As to chemical ecological regulation, pheromones from female's cuticle are attractive to males, while pheromones released by males are attractive to either males or virgin females. The release of pheromone is consistent with the mating rhythm. Health and damaged host plant volatile, physiologically stressed trees (pesticide injection and circumcision) in particular, are attractive to S. noctilio, including monoterpenes, sesquiterpenes, aromatic compounds, green leaf volatiles, carbohydrates and so on. There is a dynamic releasing rhythm in volatiles from physiologically stressed hosts. The wasp can carry symbiotic fungus. Volatiles of fungi are composed of monoterpenes, aldehydes, esters and ketones, which can trigger behavioral responses of both wasps and their parasitoids. It is indicated that parasitoids locate the larvae and eggs by symbiotic fungi volatiles. Finally, forest structure improvement, natural enemies and nematode control, satellite remote sensing monitoring, inspection and quarantine are commonly used for monitoring and controlling S. noctilio in forests.

Key words: Sirex noctilio, reproductive behavior, pheromone, plant volatile, symbiotic fungus, chemical ecology