ABSTRACT The Paspalum genus includes several species that are important for livestock in Rio Grande do Sul, such as P. notatum and P. guenoarum, typical of native pastures of the Pampa biome. The aim of this study was to investigate forage production and chemical composition of four ecotypes of these species in relation to the cv. ‘Pensacola’ (P. notatum). Ecotypes of P. guenoarum (Azulão and Baio) and P. notatum (André da Rocha and Bagual) and the cv. ‘Pensacola’ were evaluated for two years, during which four cuts/year were made. The work was carried out under field conditions at the Agronomic Experimental Station of the Federal University of Rio Grande do Sul (30°05’S; 51°39’W), in a completely randomized design. P. guenoarum stood out for higher productivity and greater tolerance to cold; the Azulão ecotype showed more autumn production in relation to the other ecotypes. Crude protein content ranged from 14 (Baio) to 15% (‘Pensacola’); for neutral detergent fiber, the variation was 68 (Azulão) to 71% (‘Pensacola’) and for acid detergent fiber there was a variation of 38 (‘Pensacola’) to 43% (Baio). The data demonstrates the potential of native genotypes for use as cattle feeding in southern Brazil.

Avaliou-se a extração de alimento por Cosmoclopius nigroannulatus Stål, de ninfas de primeiro ínstar de Spartocera dentiventris (Berg). O experimento foi conduzido em laboratório, utilizando-se 10 adultos de cada sexo de C. nigroannulatus, recém-emergidos, em cada quantidade de ninfas de (5,1, 14,7, 29,8, 36,6 e 44,8 mg oferecidas aos machos e 5,5, 14,7, 31,1, 37,4 e 48,5 mg oferecidas às fêmeas). A cada 24h, por cinco dias, registrava-se o peso dos adultos, a quantidade total de ninfas consumidas, o peso das ninfas remanescentes, tempo gasto em ingerir o alimento, estimando-se a quantidade e o percentual de alimento extraído de cada ninfa, a quantidade extraída por minuto, as sobras e a taxa de consumo relativa. Em ambos os sexos, houve um aumento no consumo total de ninfas ingeridas, no ganho de peso, nas sobras de alimento e na taxa de consumo, com o aumento da quantidade de ninfas oferecidas e uma diminuição na taxa de consumo total, na quantidade e no percentual de alimento extraído e na quantidade extraída por minuto. O consumo total e a quantidade de alimento extraído por presa estabilizaram-se a cerca de 29,8 g e 31,1 mg, respectivamente para os machos e para as fêmeas, não sendo evidenciada correlação do tempo de ingestão com o número de ninfas. As fêmeas consumiram e ganharam mais peso que os machos, ingerindo o alimento mais rapidamente. Os resultados sugerem que o comportamento alimentar do predador está diretamente relacionado com a quantidade de presas disponíveis.

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.