Garcia S L, Rodrigues V L, Garcia N L, Ferraz Filho A N, Mello M L
Departamento de Biologia Celular e Parasitologia, Instituto de Biologia, SP, Brasil.
Mem Inst Oswaldo Cruz. 1999 Jan-Feb;94(1):131-7. doi: 10.1590/s0074-02761999000100026.
Survival and molting incidence were studied after heat (40 degrees C) and cold (0 degree C) shocks in specimens of Panstrongylus megistus with the aim of establishing its response to temperature stress under laboratory rearing conditions and to understand occasional changes in the biological characteristics of specimens captured in nature. The response to the thermal shocks was found to vary as a function of the temperature and duration of the shock, developmental phase and sex of the specimens, and in certain cases, the insect habit and nourishment conditions. P. megistus specimens were found to be less resistant to the heat shock assay than Triatoma infestans, another reduviid species. The short cold shock affected survival of P. megistus more than did the heat shock, survival of fully-nourished specimens being preferential. The response of adults to the short cold shock was affected by sex, males being generally less resistant. The insect sylvatic habit was found to seldom affect the thermal shock response established for specimens with domestic habit. A decrease in molting frequency and sometimes a slowdown of the molting rate were found after the short heat and cold shocks, possibly promoted by change in hormonal balance, and differing from patterns reported for T. infestans. The results indicate that no generalization should be made for different reduviid species in terms of the effects of temperature shocks.
为了确定大锥猎蝽在实验室饲养条件下对温度胁迫的反应，并了解自然界捕获的样本生物特征的偶尔变化，研究了大锥猎蝽样本在热激（40摄氏度）和冷激（0摄氏度）后的存活率和蜕皮发生率。结果发现，对热激的反应会因激温度和持续时间、样本的发育阶段和性别而有所不同，在某些情况下，还会因昆虫习性和营养条件而有所不同。发现大锥猎蝽样本比另一种猎蝽科昆虫——骚扰锥猎蝽对热激试验的抵抗力更弱。短时间冷激对大锥猎蝽存活率的影响大于热激，营养充足的样本存活率更高。成虫对短时间冷激的反应受性别影响，雄性通常抵抗力较弱。发现昆虫的野生习性很少影响为具有家养习性的样本建立的热激反应。短时间热激和冷激后，蜕皮频率降低，有时蜕皮速率减慢，这可能是由激素平衡变化导致的，与骚扰锥猎蝽报道的模式不同。结果表明，对于不同的猎蝽科物种，不应就温度激的影响进行一概而论。
