干旱区拟步甲水分散失速率的特征

Water-loss Rate of Insect Tenebrionidae in Arid Region

不同时空分布的拟步甲(Teneberionidae)抗干旱能力存在着差异性,其抗干旱能力主要采用水分散失速率进行评价。在室内30℃恒温处理下,采用重量法测定了不同季节典型干旱环境下13种拟步甲水分散失速率,同时采用陷阱捕获法在野外调查了拟步甲种群动态,分析了不同时空拟步甲抗干旱能力。结果表明,夏季活动高峰种的拟步甲水分散失速率明显小于春季活动高峰种,但夏季活动高峰种致死中时间(LT50)与最大死亡时间(Tmax)比春季活动高峰种大;不同干旱环境下的拟步甲水分散失速率也存在差异性,表现为干旱绿洲区>干旱荒漠区>极度干旱区,而LT50与Tmax的大小顺序与水分散失速率相反,表明了夏季活动高峰种的拟步甲抗干旱能力大于春季活动高峰种,极度干旱地区的拟步甲更能忍耐干旱环境。

The drought resistance ability of insect Tenebrionidaes is different in space and time, and it can be assessed by water loss rate. The water loss rates of 13 kinds of Tenebrionidaes were evaluated by their weight loss at 30℃ in the laboratory, and the population dynamics of Tenebrionidaes were investigated by pitfall traps in field during 2008. The results indicated that summer＇s species of Tenebrionidaes had a lower water loss rate, a longer lethal time to 50% mortality（LT50 ） and a longer dead time to maximum（Tmax） than spring＇s species. The water loss rates of Tenebrionidaes were significantly different in different dry habitats, which showed a spatial sequence of arid oasis region〉arid desert region〉extremely drought region; while the spatial sequence of LT50 and Tmax was opposite. The conclusion suggested that the drought resistance ability of summer＇s species of Tenebrionidaes was stronger than that of spring＇s species, and Tenebrionidaes form extremely drought regions could endured drier environment than other Tenebrionidaes.