Sanborn Allen F, Villet Martin H, Phillips Polly K
School of Natural and Health Sciences, Barry University, Miami Shores, FL, 33161-6695, USA.
Physiol Biochem Zool. 2004 Sep-Oct;77(5):816-23. doi: 10.1086/422226.
The platypleurine cicadas have a wide distribution across Africa and southern Asia. We investigate endothermy as a thermoregulatory strategy in 11 South African species from five genera, with comparisons to the lone ectothermic platypleurine we found, in an attempt to ascertain any influence that habitat and/or body size have on the expression of endothermy in the platypleurine cicadas. Field measurements of body temperature (T(b)) show that these animals regulate T(b) through endogenous heat production. Heat production in the laboratory elevated T(b) to the same range as in animals active in the field. Maximum T(b) measured during calling activity when there was no access to solar radiation ranged from 13.2 degrees to 22.3 degrees C above ambient temperature in the five species measured. The mean T(b) during activity without access to solar radiation did not differ from the mean T(b) during diurnal activity. All platypleurines exhibit a unique behavior for cicadas while warming endogenously, a temperature-dependent telescoping pulsation of the abdomen that probably functions in ventilation. Platypleurines generally call from trunks and branches within the canopy and appear to rely on endothermy even when the sun is available to elevate T(b), in contrast to the facultative endothermy exhibited by New World endothermic species. The two exceptions to this generalization we found within the platypleurines are Platypleura wahlbergi and Albanycada albigera, which were the smallest species studied. The small size of P. wahlbergi appears to have altered their thermoregulatory strategy to one of facultative endothermy, whereby they use the sun when it is available to facilitate increases in T(b). Albanycada albigera is the only ectothermic platypleurine we found. The habitat and host plant association of A. albigera appear to have influenced the choice of ectothermy as a thermoregulatory strategy, as the species possesses the metabolic machinery to elevate to the T(b) range observed in the endothermic species. Therefore, size and habitat appear to influence the expression of thermoregulatory strategies in African platypleurine cicadas.
扁侧蝉科蝉类广泛分布于非洲和亚洲南部。我们研究了来自五个属的11种南非扁侧蝉科蝉类的内温性作为一种体温调节策略，并与我们发现的唯一一种外温性扁侧蝉科蝉类进行了比较，试图确定栖息地和/或体型对扁侧蝉科蝉类内温性表达的任何影响。体温（T(b)）的野外测量表明，这些动物通过内源性产热来调节T(b)。实验室中的产热将T(b)提高到与野外活动的动物相同的范围。在五种被测物种中，在无法获得太阳辐射的鸣叫活动期间测得的最高T(b)比环境温度高出13.2摄氏度至22.3摄氏度。在无法获得太阳辐射的活动期间的平均T(b)与白天活动期间的平均T(b)没有差异。所有扁侧蝉科蝉类在通过内源性升温时都表现出一种对蝉来说独特的行为，即腹部随温度变化的伸缩脉动，这可能起到通风作用。扁侧蝉科蝉类通常在树冠层内的树干和树枝上鸣叫，即使有阳光可用来提高T(b)，它们似乎也依赖内温性，这与新大陆内温性物种表现出的兼性内温性不同。我们在扁侧蝉科蝉类中发现的这个普遍规律的两个例外是瓦尔伯格扁侧蝉（Platypleura wahlbergi）和阿尔巴尼扁侧蝉（Albanycada albigera），它们是所研究的体型最小的物种。瓦尔伯格扁侧蝉的小体型似乎使其体温调节策略转变为兼性内温性，即当有阳光时它们利用阳光来促进T(b)的升高。阿尔巴尼扁侧蝉是我们发现的唯一一种外温性扁侧蝉科蝉类。阿尔巴尼扁侧蝉的栖息地和寄主植物关联似乎影响了其选择外温性作为体温调节策略，因为该物种拥有将体温升高到在内温性物种中观察到的T(b)范围的代谢机制。因此，体型和栖息地似乎会影响非洲扁侧蝉科蝉类体温调节策略的表达。
