二點葉�@與神澤葉�@種間交尾及繁殖隔離機制之研究

Abstract

二點葉(Tetranychus urticae Koch)與神澤葉 ( T. kanzawai Kishida)之雄於無選擇條件下對同種及異種靜止期之雌後若( teleiochrysalis)之護雌率間無顯著差異；在選擇之條件下則偏好同種之 護雌。二種靜止期之雌後若及處女雌均能誘引該二種雄，但雄在 二擇一之機會下則顯著選擇同種。二者之種間護雌有敵對取代( agonistic and replacing)及保衛(defending)行為，並以二點葉較具 優勢，因此二點葉之種內及種間護雌競爭力導致選汰適合度高於神澤葉 。接觸護雌位之雄為交尾之第一優先個體，種內之護雌親和力( affinity)高於種間。於接觸護雌之雄神澤葉易放棄其種內及種間之護 雌率為66%及72.2%，而先與接近之一日齡處女雌交尾，二點葉則 有47.8%及28.6%之放棄護雌率。無選擇下二者之種間交尾機率高達96% 以 上，但無雌性子代產生，故種間交尾應無精子之傳遞，該雌與同種之二 次交尾依舊為有效交尾。該二種雄對彼此之處女雌分辨能力甚弱。種 間交尾中之配對其雄受同種雄取代率較高。二點葉子代性比(雌/ 雌+雄)會因交尾時間之延長而增加，但神澤葉則否。二種1∼8日齡之未 交尾雄對處女雌的有效交尾能力並不因日齡而有顯著差異。二種雌 於種內或種間交尾後之受精囊解剖切片顯示種間交尾無精子之傳遞。隔離 機制存在於交尾前之護雌行為，但該行為之專一性似嫌不足。總之，該二 葉之種間交尾為無效交尾，但其交尾後之真正隔離機制應為機械隔離。

Tetranychus urticae and T. kanzawai showed non- erence in guarding female teleiochrysalis toother in a non-choice test, but showederence in guarding to the same species in achoice test. The positive responses of malesoth female teleiochrysalis and virgin femaleshe same or different species were not signifi- ly different inthe non-choice test. The maleed strong perference in intraspecific responsehe two-choice test. Pheromone and emittedtances produced by females seem to be one ofreproductive isolation mechanisms to determineguarding and mating behavior of these twoies before copulation.Interspecific guardingetition showed on agonistic and replacing, andnding behaviour, T. urticae had dominant selec-fitness. Contact- guarding male got the first-ng-advantage position. T. kanzawai was moreency to copulate with virgin female while itding on female teleiochrysalis. Mating successnot relate to the species related responses;interspecific copulation was often interruptedaturely showed a shorter copulation intervalintraspecific copulation. Interspecific matinghese two species resulted in all-male produc-, neverthless, the consecutive and the secondaryaspecific mating was effective. The spermatophore-sfer mechanism between these two species aremed to be varied according to their differentelation between the copulation duration andnt of transferred spermatophores. At the pre-es of both female species, mating abilities,the number of mating and copulation, weren'tcted by the age of chaste male according to theility rate of progeny. The confirmable repro- ive isolation mechanism between T. urticae andnzawai wasthe mechanical isolation.