de Oliveira Simone A, Souza Brígida, Auad Alexander M, da Silva Daniela M, Souza Lívia S, Carvalho Caio A
University Federal de Lavras, Department de Entomologia, MG.
Neotrop Entomol. 2009 May-Jun;38(3):311-6. doi: 10.1590/s1519-566x2009000300002.
The aphid Sipha flava (Forbes) is a pest on elephant grass, but little is known about its biology. The objective of this work was to evaluate the temperature effects on the development, survival and reproduction of S. flava fed on Pennisetum purpureum. Twelve-hour-old nymphs were individualized on sections of elephant grass blades and maintained at 12, 16, 20, 24, 28 and 32 degrees C+/-1 degrees C, UR 70+/-10% and 12 h photophase. A total of 150 nymphs were used per treatment divided in 30 replicates, using a totally random design. The lower threshold temperatures (LTT) for first, second, third and fourth instars were 0.83, 1.05, 3.01 and 4.98 degrees C, respectively, indicating a change in thermal requirements as the development progress. The LTT for the whole nymphal stage was 2.08 degrees C, pointing to the tolerance of this species to low temperatures. A significant reduction in survival was observed at high temperatures (28 and 32 degrees C). Although the reproductive periods were longer and insects lived longer at 12 degrees C as compared with those at higher temperatures, the total fecundity was substantially reduced. The overall life cycle duration was almost twice as long at 12 degrees C than at 24 degrees C. The greatest daily production of nymphs and greatest number of nymphs produced overall occurred at 24 degrees C. The temperatures of 20 degrees C and 24 degrees C were more suitable to S. flava development and reproduction.
甘蔗黄蚜（福布斯）是象草上的一种害虫，但对其生物学特性了解甚少。本研究的目的是评估温度对取食紫狼尾草的甘蔗黄蚜发育、存活和繁殖的影响。将12小时龄的若虫分别置于象草叶片切段上，在12、16、20、24、28和32摄氏度±1摄氏度、相对湿度70%±10%和12小时光照期的条件下饲养。每个处理共使用150只若虫，分为30个重复，采用完全随机设计。一龄、二龄、三龄和四龄若虫的下限温度分别为0.83、1.05、3.01和4.98摄氏度，表明随着发育进程热需求发生变化。若虫整个阶段的下限温度为2.08摄氏度，表明该物种对低温具有耐受性。在高温（28和32摄氏度）下观察到存活率显著降低。虽然与较高温度相比，在12摄氏度时繁殖期更长且昆虫寿命更长，但总繁殖力大幅降低。在12摄氏度时，整个生命周期几乎是24摄氏度时的两倍长。若虫的最大日产量和总体产生的若虫最大数量出现在24摄氏度时。20摄氏度和24摄氏度的温度更适合甘蔗黄蚜的发育和繁殖。
