Hu R, Hyland K E
Department of Biological Sciences, University of Rhode Island, Kingston 02881, USA.
J Med Entomol. 1998 Nov;35(6):1050-3. doi: 10.1093/jmedent/35.6.1050.
The chalcid wasp Ixodiphagus hookeri (Howard) is a parasitoid of several ixodid ticks including the blacklegged tick, Ixodes scapularis Say. We evaluated effects of the feeding process of nymphal I. scapularis on the embryonic development of I. hookeri. Potentially wasp-parasitized nymphal I. scapularis were collected on Prudence Island, RI. Subsamples of the questing nymph cohort were allowed to feed on laboratory white mice. Both the body length and the scutal length of ticks were measured individually for questing nymphs and for feeding nymphs that were removed from hosts at time intervals of 12, 24, 36, 48, and 72 h after attachment. The diameters of wasp eggs they contained were also measured for each designated time interval. There was a positive relationship between the mean scutal index (ratio between body length and scutal length) of ticks and the mean diameter of wasp eggs during 72 h of tick feeding (P < 0.05). Moreover, it appeared that within 24 h of tick attachment, the scutal index of ticks remained unchanged. However, after that period, the scutal index increased significantly (P < 0.05). Diameters of wasp eggs increased continuously during tick feeding and at 72 h after attachment, enclosed eggs and completely formed larvae were found in several ticks. We conclude that factors related to the feeding process of nymphal I. scapularis are necessary to initiate the embryonic development of wasps.
黄蜂类蜱虱啮小蜂（Ixodiphagus hookeri (Howard)）是包括黑腿蜱（Ixodes scapularis Say）在内的几种硬蜱的寄生蜂。我们评估了肩突硬蜱若虫取食过程对蜱虱啮小蜂胚胎发育的影响。在罗德岛的普鲁登斯岛采集了可能被黄蜂寄生的肩突硬蜱若虫。将搜寻若虫群体的子样本放在实验室小白鼠身上取食。分别测量了搜寻若虫以及在附着后12、24、36、48和72小时从宿主身上取下的取食若虫的蜱体长和盾板长。还测量了每个指定时间间隔内它们所携带的黄蜂卵的直径。在蜱取食的72小时内，蜱的平均盾板指数（体长与盾板长之比）与黄蜂卵的平均直径之间存在正相关关系（P < 0.05）。此外，在蜱附着后的24小时内，蜱的盾板指数似乎保持不变。然而，在那段时间之后，盾板指数显著增加（P < 0.05）。在蜱取食期间，黄蜂卵的直径持续增加，在附着72小时后，在几只蜱中发现了封闭的卵和完全发育成形的幼虫。我们得出结论，与肩突硬蜱若虫取食过程相关的因素是启动黄蜂胚胎发育所必需的。
