Impoinvil Daniel E, Cardenas Gabriel A, Gihture John I, Mbogo Charles M, Beier John C
Global Public Health Research Group, University of Miami, South Campus, Building A, 12500 SW 152nd Street, Miami, FL 33177, USA.
J Am Mosq Control Assoc. 2007 Jun;23(2):124-30. doi: 10.2987/8756-971X(2007)23[124:CTATPE]2.0.CO;2.
Anopheles gambiae Giles sensu stricto (Diptera: Culicidae) egg development and its relation to environmental parameters is an understudied aspect of vector biology. Although several studies have illustrated the dramatic effects of temperature on egg development, egg hatching dynamics remain unclear. The objective of this study was to expose An. gambiae eggs to various temperatures for different lengths of time and determine the impact on egg development and hatching count. Batches of mosquito eggs (n = 30 eggs/replicate) were incubated under moist conditions at temperatures of 12, 22, 27, 33, and 42 degrees C for intervals of 1, 3, 7, and 10 days. After that, they were flooded with distilled water at 27 degrees C, and hatching counts were observed for up to 7 days. Mosquito eggs held at 22 and 27 degrees C had the highest overall mean hatching count. During early incubation periods, eggs held at 33 degrees C had hatching counts comparable to 22 and 27 degrees C, but counts decreased drastically during later incubation periods. Temperatures of 12 and 42 degrees C reduced mosquito egg viability, because few eggs hatched in these temperature regimes. Other experiments revealed that during early embryonic development, temperature had a major effect on the developing embryo, while later in embryonic development it had no dramatic effect. Microscopic observation of the An. gambiae embryo showed that extreme low and high temperatures affected the normal development of the embryo. A regression model was developed to describe the effect of incubation temperature and incubation period on egg hatching counts, which demonstrated that the optimum temperature for egg hatching ranges from 24 to 30 degrees C, irrespective of incubation period. The interaction between temperature and time period may have implications for dry-season survival and climate-based models of malaria risk.
冈比亚按蚊狭义种（双翅目：蚊科）的卵发育及其与环境参数的关系是媒介生物学中一个研究不足的方面。尽管多项研究已阐明温度对卵发育的显著影响，但卵孵化动态仍不清楚。本研究的目的是将冈比亚按蚊的卵置于不同温度下不同时长，以确定其对卵发育和孵化数量的影响。将成批的蚊卵（每组30枚卵）在潮湿条件下于12、22、27、33和42摄氏度的温度下分别孵育1、3、7和10天。之后，将其置于27摄氏度的蒸馏水中，观察长达7天的孵化数量。置于22和27摄氏度的蚊卵总体平均孵化数量最高。在孵育初期，置于33摄氏度的卵孵化数量与22和27摄氏度的相当，但在后期孵育阶段数量急剧下降。12和42摄氏度的温度降低了蚊卵的活力，因为在这些温度条件下很少有卵孵化。其他实验表明，在胚胎发育早期，温度对发育中的胚胎有重大影响，而在胚胎发育后期则没有显著影响。对冈比亚按蚊胚胎的显微镜观察表明，极低和极高温度会影响胚胎的正常发育。建立了一个回归模型来描述孵育温度和孵育期对卵孵化数量的影响，结果表明，无论孵育期如何，卵孵化的最佳温度范围为24至30摄氏度。温度与时间段之间的相互作用可能对旱季生存和基于气候的疟疾风险模型有影响。
