Isoe J, Millar J G
Department of Entomology, University of California, Riverside 92521, USA.
J Am Mosq Control Assoc. 1995 Mar;11(1):21-8.
Fermented infusions of organic matter were tested for their effects on Culex tarsalis oviposition. Bermuda grass infusion and polluted water collected from a natural oviposition site (La Brea tar pits, CA) enhanced oviposition rates, but an alfalfa infusion and water from a 2nd natural oviposition site (Prado Basin, CA) did not. Bermuda grass infusion was fractionated by dialysis and filter sterilization. Crude Bermuda grass infusion, and fractions of the infusion containing large molecules (> 12,000 daltons), particulates, and microorganisms significantly increased oviposition rates compared to distilled water controls. The fraction containing small molecules was no better than a distilled water control, suggesting that small molecules are not involved in oviposition stimulation in this species. However, using the egg raft counting bioassay, the possibility that the small molecules fraction contained oviposition attractants could not be ruled out. Overall, our experiments suggest that results obtained with the egg raft counting bioassay, which has been used frequently to screen for oviposition attractants, should be interpreted with caution. High oviposition rates in this bioassay may be due to responses to factors such as nonvolatile, contact oviposition stimulants rather than to volatile attractants.
对有机物的发酵浸液进行了测试，以研究其对致倦库蚊产卵的影响。百慕大草浸液和从一个天然产卵地（加利福尼亚州拉布雷亚沥青坑）采集的污水提高了产卵率，但苜蓿浸液和来自第二个天然产卵地（加利福尼亚州普拉多盆地）的水则没有。通过透析和过滤除菌对百慕大草浸液进行了分级分离。与蒸馏水对照相比，粗制百慕大草浸液以及含有大分子（> 12,000道尔顿）、颗粒和微生物的浸液级分显著提高了产卵率。含有小分子的级分并不比蒸馏水对照更好，这表明小分子不参与该物种的产卵刺激。然而，使用卵块计数生物测定法，不能排除小分子级分含有产卵引诱剂的可能性。总体而言，我们的实验表明，经常用于筛选产卵引诱剂的卵块计数生物测定法所获得的结果应谨慎解释。该生物测定法中的高产卵率可能是由于对非挥发性、接触性产卵刺激物等因素的反应，而非挥发性引诱剂。
