赣南花绒寄甲松树林间自然寄生率调查研究

Investigation on natural parasitic rates of Dastarcus helophoroides in Gannan pine forest

花绒寄甲Dastarcus helophoroides(Fairmaire)是松褐天牛Monochamus alternatus的有效寄生性天敌,为了解花绒寄甲在江西赣南苏区对松褐天牛种群数量的控制作用,开展了花绒寄甲在赣南松树林内自然分布、寄生率及松褐天牛种群情况的调查。结果表明,花绒寄甲在赣南松树林内分布广泛,对松褐天牛的自然寄生率为2.56%-22.41%,平均寄生率为11.74%,其中马尾松纯林的寄生率最高(14.81%),其次马尾松混交林(10.95%),湿地松纯林寄生率最低(2.56%),前两项差异不显著,后者与前两者均差异显著(P<0.05);花绒寄甲的种群数量动态与其寄主松褐天牛的种群数量动态是一致的,呈正相关关系(R2=0.8399),花绒寄甲在野外主要以1-2头幼虫寄生1头松褐天牛幼虫的寄生方式营寄生生活(占79.10%)。因此在赣南松林中,花绒寄甲种群数量较低,必须大量补充人工繁育的寄甲,才能达到控制松褐天牛防治松材线虫病的目的。

Dastarcus helophoroides is an effective parasitoid of Monochamus alternatus. In order to understand D. helophoroides in control population quantities of M. alternatus in Jiangxi Gannan Soviet Area,a survey carried out the natural distribution,parasitic rate of D. helophoroides and population of M. alternatus in pine forests in Jiangxi Gannan Soviet Area,the results show that D. helophoroides is widely distributed in Gannan,pine forest,but the natural parasitic rate of D. helophoroides parasitic on M. alternatus was 2. 56%- 22. 41%,the average parasitic rate was 11. 74%. The parasitic rate was the highest in the pure forest of Pinus massoniana（ 14. 81%）,secondly,mixed forest of P. massoniana,and it was the lowest in the pure forest of P. elliottii,the difference between the former both was not significant,the latter with the former two were significant differences. It is consistent with population quantity dynamics of D. helophoroides and its host population quantity dynamics,M. alternatus,and it is positive correlation（ R2= 0. 8399）. D. helophoroides is parasitic life mainly in 1- 2 larvae parasiticing 1larvae of M. alternatus in field forest（ accounted for 79. 10%）. The population quantity of D.helophoroides is lower in Gannan,pine forest,it must be supplement a large number of artificial breeding D. helophoroides only in this way, to achieve control objective of controlling M. alternatus and Bursaphelenchus xylophilus.