Spermatophore production and egg-laying behaviour in Rhodnius prolixus Stal. (Hemiptera; Reduviidae)

Abstract

1. Spermatophore production in Rhodnius and Triatoma is a structural adaptation for copulation and sperm delivery.2. In Rhodnius a certain amount of sperm is stored in the spermathecae while the remainder is ejected with the collapsed spermatophore about 12 hr. after copulation. Hypergamesis never occurs.3. The secretion in the male accessory glands was found to disappear if males were kept unfed for about 60 days. Such males were unable to copulate.4. An average of ninety-eight fertilized eggs was produced as a result of one insemination by a young male. Four such inseminations at intervals of 45 days are, therefore, necessary to secure fertilized eggs throughout the entire life of the female. In nature repeated copulation is the rule.5. The first spermatophore produced by males starved for 21–28 days was found to be as efficient as that produced by recently emerging well-fed males.6. A male is capable of producing a great number of spermatophores; as many as fifty were obtained. Probably spermatophores produced by old males, although they contain a great number of sperm, lack sufficient of some substance necessary for fertilizing the eggs.