Extração de alimento por Cosmoclopius nigroannulatus Stål (Hemiptera: Reduviidae) de ninfas de Spartocera dentiventris (Berg) (Hemiptera: Coreidae)

Abstract

The food extraction by Cosmoclopius nigroannulatus Stål from first-instar nymphs of Spartocera dentiventris (Berg) was evaluated. The experiment was conducted in laboratory. Ten newly emerged and individualized adults of each sex were used, for each of the five quantities of prey tested (5.1; 14.7; 29.8; 36.6; 44.8 mg, for males and 5.5; 14.7; 31.1; 37.4; 48.5 mg for females). During five days, the weight of the adults, the total amount of nymphs consumed and the weight of the remaining nymphs, the time spent to ingest the food, estimating the amount and the proportion of food extracted from each nymph, the amount extracted per minute, the remaining food, and the relative consumption rate were measured every 24h. For both sexes, there was an increase in the total consumption of nymphs, in the mean weight of the predator, in the remaining food and in the relative consumption rate, with increase of the amount of food and a decrease in the proportion of total consumption, the food quantity, the proportion extracted per prey and the amount of food extracted per minute. The total consumption and food quantity extracted per prey were 29.8 mg and e 31.1 mg, respectively, for males and for females. There was no correlation between time of ingestion and number of nymphs. Females consumed and gained more weight than males, ingesting more quickly. Our findings suggest that the feeding behavior of predator is directly related to the quantity of prey available.