Fu Shu, Huang Lili, He Haimin, Tang Jianjun, Wu Shaohui, Xue Fangsen
College of Oceanology and Food Science, Quanzhou Normal University, Quanzhou 362000, China.
Institute of Entomology, Jiangxi Agricultural University, Nanchang 330045, China.
Insects. 2022 Nov 6;13(11):1026. doi: 10.3390/insects13111026.
Individual insects often exhibit two alternative pathways of non-diapausing and diapausing developments. Yet, most studies have focused on the latitudinal variation in life-history traits for non-diapausing individuals. No study has examined the differences in life history traits between non-diapausing and diapausing individuals along a latitudinal gradient. We used six different geographical populations of to examine the latitudinal variation in life-history traits between non-diapausing and diapausing individuals in terms of their sex ratio, larval and pupal developmental times, pupal weight, growth rate, adult weight and weight loss, and sexual size dimorphism. The results showed that latitudinal variation in life-history traits for both non-diapausing and diapausing individuals exhibited a sawtooth pattern, but the life-history pattern of the two alternative developmental pathways was significantly different between the high and low latitudes. For the non-diapausing pathway, the high-latitudinal populations showed a significantly shorter larval developmental time, higher growth rate and greater body weight than the low-latitudinal populations, suggesting countergradient variation. Conversely, in the diapausing pathway, the high-latitudinal populations had longer larval developmental times, lower growth rates and relatively smaller body weights than the low-latitudinal populations, suggesting cogradient variation. We also found that in the high-latitudinal populations, larvae in the non-diapausing pathway had shorter developmental time and higher body weight, whereas larval developmental time of the low-latitudinal populations was longer and the body weight was smaller. The relationship between larval developmental time and pupal weight was also different between the two developmental pathways. These results provide new insights into the evolution of life-history traits in this moth.
单个昆虫通常表现出非滞育和滞育发育的两种交替途径。然而，大多数研究都集中在非滞育个体生活史特征的纬度变化上。尚无研究考察非滞育和滞育个体沿纬度梯度在生活史特征上的差异。我们使用了六个不同地理种群的[昆虫名称未给出]，从性别比例、幼虫和蛹的发育时间、蛹重、生长率、成虫体重和体重损失以及性大小二态性方面，研究非滞育和滞育个体生活史特征的纬度变化。结果表明，非滞育和滞育个体的生活史特征纬度变化均呈现锯齿模式，但两种交替发育途径的生活史模式在高纬度和低纬度之间存在显著差异。对于非滞育途径，高纬度种群的幼虫发育时间显著短于低纬度种群，生长率更高，体重更大，这表明存在逆梯度变化。相反，在滞育途径中，高纬度种群的幼虫发育时间更长，生长率更低，体重相对更小，这表明存在共梯度变化。我们还发现，在高纬度种群中，非滞育途径的幼虫发育时间较短，体重较高，而低纬度种群的幼虫发育时间较长，体重较小。两种发育途径中幼虫发育时间与蛹重之间的关系也不同。这些结果为这种蛾类生活史特征的进化提供了新的见解。
