Self-/conspecific discrimination and superparasitism strategy in the ovicidal parasitoid Echthrodelphax fairchildii （Hymenoptera： Dryinidae）

Superparasitism in solitary parasitoids results in fatal competition between the immature parasitoids, and consequently only one individual can emerge. In the semisoli- tary ovicidal parasitoid Echthrodelphaxfairchildii （Hymenoptera： Dryinidae）, 2 adults can emerge under superparasitism with a short interval （〈24 h） between the first and second ovipositions. We determined the female parasitoid＇s behavioral responses under self- and conspecific superparasitism bouts with first-to-second oviposition intervals of 〈2 h. The self- and conspecific superparasitizing frequencies increased up to an oviposition interval of 0.75 h, with the former remaining lower than the latter, particularly for oviposition intervals of _〈0.25 h, suggesting the existence of self-/conspecific discrimination. The superparasitizing frequency plateaued for oviposition intervals of _〉0.75 h, with no dif- ference between self- and conspecific superparasitism. The ovicidal-probing frequency did not differ under self- and conspecific superparasitism, and was usually 〈20%. The females exhibited no preference for the oviposition side （i.e., ovipositing on the side with or without the first progeny） and almost always laid female eggs for any oviposition in- terval under self- and conspecific superparasitism. The sex ratio was not affected by the type of superparasitism, oviposition sides, or the occurrence of ovicidal probing. These observed results about the oviposition side, ovicidal probing, and sex ratios differed from the predictions obtained assuming that the females behave optimally. Possible reasons for the discrepancies are discussed： likely candidates include the high cost of selecting oviposition sides and ovicidal probing, and, for the sex ratio, the low frequency of encountering suitable hosts before superparasitism bouts.     

"概率"与"比例"问题的辨析

首先看下面2个问题： [问题1]基因型为AaBbCc的雄性个体（Aa、Bb和Cc3对等位基因均独立遗传）所产生的精子中，基因型为ABC的精子所占的比例为____。     

Solazyme公司用藻类生产的喷气机燃料在直升机上试用成功

2011年6月20日，美国Solazyme公司宣布，美国海军用Solazyme公司生产的100％来自藻类的喷气机燃料“solajetHRJ-5”与用石油生产的喷气机燃料按1：1的比例混合，调制成混合燃料，使用这种混合燃料在MH-60SSeahawk型军用直升机上试飞成功。