广东松材线虫病发生规律研究

 室内试验和林间调查、监测结果表明,广东省松材线虫病的疫区范围1988年在深圳市沙头角一带,1997年扩大到深圳市大部分地区及惠州市、东莞市的局部地区,疫区面积由1988年的1.13万hm²增大到 1997年的1.67万hm²,病树累计449286棵.发病树种为马尾松;发病率与树龄有关,同一病点内,成林松林平均发病率为17.8%,而幼林仅为0.3%;每年发病时间为 5～12月,7月和11月为病树发生高峰期,与松褐天牛的年发生世代及生活史相吻合;病害靠自然传播和人为传播扩散;病害主要向西北方向扩展,其次为西南和东北方向,年均扩展距离774.4(0～1500)m,扩展方向与风向有关;降水量对发病有一定的影响,降水量大,当年发生面积小;一般南坡松林发病早且重,北坡松林发病迟且轻.

The Occurrence and Development of Pine Wilt Disease, Bursaphelenchus xylophilus , in Guangdong Province

A series laboratory experiments and field survey shown that pine wilt disease, Bursaphelenchus xylophilus, was first found in Shatoujiao area, Shenzhen, Guangdong province in 1988 and dispersed to most part of Shenzhen municipality and some part of Huizhou and Dongguang municipality.The epidemic zone expanded from 11300 hm² in 1988 to 16700 hm² in 1997 with totally 449286 dead infested trees.The massonian pine, Pinus massoniana, is the susceptible species.Susceptibility seemed change with tree ages, 17.8% mature trees were infested while 0.3% young trees were in a some epidemic site.Dead infested trees appeared from May to December with peaks in July and November that tallied with the history and generations of long corn beetle, Monochamus alternatus. The disease transmitted by man and vector insects.The disease dispersed to the northwest faster than to the southwest and northeast with a yearly average dispersal distance of 774.4(0～1500) m.Dispersal directions were some related to wind directions.Precipitation affected the occurrence of disease to some degree, the larger the precipitation, the smaller the infested area, Generally trees on south slopes were infested earlier and more serious than those on north slopes.