Chemical defense: Bestowal of a nuptial alkaloid garment by a male moth on its mate William E. Conner Ruth Boada.. Frank Schroeder, Andrés Gonzilez, Jerrold Meinwald\'. and Thomas and of Biology Wake Forest University. PO Box 732s Winston Salem. and Behavior, Cornell University. Ithaca, NY 14853 Contributed by errold Meinwald, October 2000 Males of the moth GArctidae) acquire pyrroli- zidine alkaloid by feeding on the excrescent fluids of certain plants (for instance, Eupatorium capillifolium). They incorporate the alkaloid have a pair and as a resultare protected against spiders. The males filaments, of abdominal pouches. densely packed with fine outiailar discharge which in allualoid-fed males are alkaloid laden. The males the filaments on the female in bursts during courtship, embellishing her with alkaloid as a result. The topical investiture the female against spiders. Alkaloid-free filaments, from males, convey no such protection. The males also transmit alkaloid to the female by seminal infusion. The systemic alkaloid thus received, which itself may contribute to the female\'s defense against spiders, is bestowed in part by the female the on paternal contribution to egg been demonstrated for several aretid moths, protective nuptial festooning of afemalebyits mate, such asispracticed by Cmyrodora, appears to be without parallel among insects. laboratories on their natural larval foodpla Pyrrolizidine alkaloid paternal investment Ipredation IArctidae. (Asteraceae), providing the bulk of indiv observations were made. ere we describe the behavior of a moth in which acquisition Flocoulent. The pouches in the male that of pyrrolizidine alkaloid (henceforth, for simplicity, some- are two invaginations of the ventral sul times called alkaloid) plays a crucial role in defense. We (spanning stemites II-IV), ordinarily con demonstrate that the alkaloid is initially procured by the male icy. The flocculent can be readily from plants, and that the male derives protection against spiders forceps (Fig 1D).For scanning electron I (Nephila clavipes) as a result. We demonstrate further that the flocculent were air dried and gold coatu male allocates some of the acquired alkaloid to a cottony mass of cuticular filaments that he keeps tucked away in the abdomen Plant Analyses. Air-dried powdered plan and that he discharges on the female in bursts during courtship. leaves (50 g or E. capillifolium roots We show that the alkaloid-laden filaments thus bestowed by the Soxhlet apparatus with methanol males protect the female against N clavipes, whereas alkaloid- the solvent was removed in vacuo, free filaments from control males that had no access to alkaloid partitioned between dichloromethane provide no such protection. We show further that the female The aqueous phase was separated, ba receives additional alkaloid from the male through seminal concentrated aqueous NH, and extra infusion, an endowment that can itself contribute to her defense ane. After evap.