ATTRIBUTES OF OVIPOSITION SUBSTRATES AFFECT FECUNDITY IN RHODNIUS-PROLIXUS

The effect of the oviposition substrate on the rate of egg laying was investigated in the haematophagous bug Rhodnius prolixus. Fresh or old hen feathers or corrugated cardboard were offered to ovipositing fema les. The insects showed significant differences in the number of eggs laid depending on the substrate. Egg laying was maximal on the fresh f eathers and minimal on the cardboard. The variations cannot be explain ed by differences in the amount of blood ingested nor by differences i n the mating frequency between treatments. The amount of blood necessa ry per laid egg exhibited an inverse relationship with the absolute fe cundity, The dynamics of-mating and egg-laying for groups having two d ifferent substrates (corrugated cardboard and hen feather) and differe nt nutritional states (previously starved vs previously fed) was estab lished throughout one month. After a single meal, previously starved i nsects having feathers as a substrate laid their eggs and reached an o viposition peak sooner (6 days) than previously starved insects on the cardboard substrate. For both nutritional states the lack of feathers decreased the cumulative number of eggs laid by one third. Results ar e discussed in relation to the mechanisms of ovarian regulation known at present. Copyright (C) 1996 Elsevier Science Ltd