潮州单丛茶树天牛种群动态、空间分布型及成虫交配和产卵行为研究

Population dynamics,spatial distribution pattern,mating and spawning behavior of Fenghuang Dancong tea tree longhorn beetle in Chaozhou

【目的】明确广东省潮州市凤凰山单丛茶树天牛的发生规律及成虫交配和产卵行为,为潮州凤凰单丛茶树天牛的预测预报及有效防治提供科学依据。【方法】2020年1月—2021年8月,在广东省潮州市凤凰山单丛茶区选取5块样地(大庵村古茶园、大庵村新茶园、山外山新茶园、竹留村新茶园和深垭村新茶园),采用调查田间区块天牛排粪的方法研究天牛幼虫发生动态,根据种群聚集度指标法计算天牛幼虫的空间分布,利用性信息素诱捕法调查天牛成虫种群动态,通过室内观察的方法对天牛成虫交配和产卵行为进行研究。【结果】天牛幼虫种群动态监测结果表明,2020年天牛幼虫在3个样地均有发生,高峰期为8—11月,其中大庵村古茶园有虫株率明显高于大庵村新茶园和山外山新茶园,并具有2个明显的发生高峰期(2020年8月中旬—9月中旬和2020年10月中旬—11月中旬),有虫株率分别为12.7%和12.6%;有虫株率随着海拔的升高呈增加趋势,其中大庵村新茶园(海拔1100 m)和山外山新茶园(海拔1200m)9月有虫株率分别为9.3%和8.1%,二者差异不显著(P>0.05);应用聚集度指标测定结果表明,天牛幼虫在各样地均为聚集分布。天牛成虫种群动态监测结果表明,大庵村古茶园诱捕到的茶树天牛成虫为四脊茶天牛(Trachylophus sinensis Gahan),其羽化期于5月中旬—下旬开始,而后诱捕数量逐渐增加,7月中旬—下旬单个诱捕器的诱捕量为11.67±2.62头,形成一个明显的发生高峰,高峰期雄雌比率为1∶1.92;7月下旬—8月上旬结束羽化,诱捕数量逐渐下降。室内观察发现,雌雄成虫可多次交配,雄虫有假交配现象。雌虫多数喜将卵产在枝干上,是茶叶上产卵量的5.42倍;雌虫可多次产卵,交配后第5 d产卵数量最多,达9.00±5.10粒/雌,随后产卵量随产卵次数增加而减少。【结论】危害潮州单丛茶园的茶树天牛幼虫高峰期在8—11月,田间呈聚集分布;四脊茶天牛成虫高峰期在7月中旬—下旬,雌虫喜将卵产在枝干上。根据潮州单丛茶树天牛的发生规律,在天牛发生高峰期前进行有效的物理、农业、生物和化学防治等,减少虫口基数,以达到更高、更生态友好的防效。

【Objective】To evaluate the occurrence regularity,mating and spawning behavior of Fenghuang Dancong tea tree Trachylophus sinensis(Gahan)in Chaozhou,so as to provide the scientific basis for prediction and control of longhorn beetle of Fenghuang Dancong tea tree in Chaozhou.【Method】The population dynamics of longhorn beetle larvae in Dancong tea area of Chaozhou was investigated by the fresh faeces at tea tree cavities in the field,and the spatial distribution of longhorn beetle larvae was calculated by population aggregation index method and the population dynamics of adult longhorn beetles were investigated by using sex pheromone trapping. The mating and oviposition behaviors of adult longhorn beetles were studied by indoor observation.【Result】The results of larvae population dynamics monitoring showed that longhorn beetles occurred in the three sample plots and the fastigium of population quantity was from August to November. The infestation rates of ancient tea garden in Da’an Village sample plot was higher than that of the new tea garden in Da’an Village and new tea garden in Shanwaishan Village. Two obvious fastigiums of infestation rates of longhorn beetles(from mid-August to mid-September and from mid-October to mid-November,2020)were observed and the infestation rates of the two fastigiums were 12.7% and 12.6%,respectively. The infestation rates showed a trend of increase with higher altitude. The infestation rates of new tea garden in Da’an Village(1100 m)and new tea garden in Shanwaishan Village(1200 m)in September were 9.3% and 8.1%,respectively,with no significant difference(P>0.05)appeared. The results of aggregation indices showed that the longhorn beetle larvae was clustered in various sample plots.The results of adult population dynamics monitoring showed that the tea adult longhorn beetles was T. sinensis(Gahan)in the ancient tea garden of Da’an Village. The emergence period of longhorn beetles starts from mid-May to late-May and the number of entrapment gradually increased. An obvious fastigium of population quantity of longhorn beetles was witnessed from mid-July to late-July,with the amount of a single trap number of(11.67±2.62)and the male-female ratio of1∶1.92. The emergence period ended from late July to early August,and the number of traps decreased gradually. The results of oviposition of T. sinensis showed that male and female adults could mate multiple times,with false mating common among males. Females tended to lay eggs on branches,which is 5.42 times more than that on tea leaves. Females could lay eggs repeatedly,and the largest number of eggs was(9.00±5.10)per female on the 5th day after mating,with fewer eggs being laid each time subsequently.【Conclusion】The fastigium of longicorn beetle larvae in Dancong tea tree garden is from August to November during which longhorn beetle larvae clustered in the field and a positive correlation is found between the infestation rates and altitude. A fastigium of T. sinensis population quantity is from mid-July to late July and the male and female T. sinensis adult could mate multiple times,with female adults lays eggs on branches. The occurrence regularity of Dancong tea tree longhorn beetles in Chaozhou provides reference for effective physical,agricultural,biological and chemical control before the fastigium,so as to reduce the population base and achieve better control effect.