Day J F, Curtis G A, Edman J D
Institute of Food and Agricultural Sciences, University of Florida, Vero Beach 32962.
J Med Entomol. 1990 Jan;27(1):43-50. doi: 10.1093/jmedent/27.1.43.
Resting Culex nigripalpus Theobald were collected with a ground aspirator three times a week in Indian River County, Fla., from January 1985 through December 1987. The number of green (newly emerged), empty, blood-fed, and gravid females in each collection was counted; up to 100 empty females were dissected to estimate the abundance of empty, parous females in the population. In general, this species was uncommon during the dry season from January through June but increased during the wet season in July and remained abundant through early winter. During the wet season, green, parous, and gravid females were periodically abundant. Time series analysis demonstrated that green and parous mosquitoes were positively associated through time and that gravid females were associated negatively with daily rainfall. The strongest correlations were recorded in 1985, a year during which St. Louis encephalitis virus was detected with increased frequency in Indian River County. Laboratory experiments in a large outdoor wind tunnel confirmed that high relative humidity was important for the initiation and successful completion of oviposition by gravid, field-collected Cx. nigripalpus mosquitoes. Thus, intermittent rainfall during autumn may serve to delay oviposition, increase longevity, synchronize blood feeding, and enhance transmission of St. Louis encephalitis virus by infected mosquitoes in the field.
1985年1月至1987年12月期间，每周三次使用地面吸气器在佛罗里达州印第安河县采集静止的黑须库蚊（Culex nigripalpus Theobald）。统计每次采集的绿色（新羽化）、空的、吸血的和孕蚊的数量；解剖多达100只空蚊以估计种群中空的、已产卵雌蚊的数量。一般来说，该物种在1月至6月的旱季不常见，但在7月的雨季数量增加，并在初冬一直保持丰富。在雨季，绿色、已产卵和孕蚊会周期性地大量出现。时间序列分析表明，绿色和已产卵的蚊子随时间呈正相关，而孕蚊与每日降雨量呈负相关。最强的相关性记录在1985年，当年在印第安河县检测到圣路易斯脑炎病毒的频率增加。在一个大型户外风洞中进行的实验室实验证实，高相对湿度对于野外采集的孕性黑须库蚊产卵的开始和成功完成至关重要。因此，秋季的间歇性降雨可能有助于延迟产卵、延长寿命、同步吸血，并增强野外受感染蚊子传播圣路易斯脑炎病毒的能力。
