Populational fluctuation and spatial distribution of Alphitobius diaperinus (Panzer) (Coleoptera; Tenebrionidae) in a poultry house, Cascavel, Parana state, Brazil.

Knowledge of the population fluctuation and spatial distribution of pests is fundamental for establishing an appropriate control method. The population fluctuation and spatial distribution of the Alphitobius diaperinus in a poultry house in Cascavel, in the state of Parana, Brazil, was studied between October, 2001 and October 2002. Larvae and adults of the lesser mealworm were sampled weekly using Arends tube traps (n = 22) for six consecutive flock grow-outs. The temperature of the litter and of the poultry house was measured at the same locations of the tube traps. Beetle numbers increased continuously throughout all the sampling dates (average 5,137 in the first week and 18,494 insects on the sixth week). Significantly greater numbers of larvae were collected than adults (1 to 20 times in 95% of the sampling points). There was no correlation between temperature and the number of larvae and adults collected, therefore no fluctuation was observed during the sampling period. The population growth was correlated to litter re-use. The highest temperatures were observed in deep litter. The spatial distribution of larvae and adults in the poultry house was heterogeneous during the whole period of evaluation. Results suggest that monitoring in poultry houses is necessary prior to adopting and evaluating control measures due to the great variability of the insect distribution in the poultry house.

Populational fluctuation and spatial distribution of Alphitobius diaperinus (Panzer) (Coleoptera; Tenebrionidae) in a poultry house, Cascavel, Parana state, Brazil

Knowledge of the population fluctuation and spatial distribution of pests is fundamental for establishing an appropriate control method. The population fluctuation and spatial distribution of the Alphitobius diaperinus in a poultry house in Cascavel, in the state of Parana, Brazil, was studied between October, 2001 and October 2002. Larvae and adults of the lesser mealworm were sampled weekly using Arends tube traps (n = 22) for six consecutive flock grow-outs. The temperature of the litter and of the poultry house was measured at the same locations of the tube traps. Beetle numbers increased continuously throughout all the sampling dates (average 5,137 in the first week and 18,494 insects on the sixth week). Significantly greater numbers of larvae were collected than adults (1 to 20 times in 95 percent of the sampling points). There was no correlation between temperature and the number of larvae and adults collected, therefore no fluctuation was observed during the sampling period. The population growth was correlated to litter re-use. The highest temperatures were observed in deep litter. The spatial distribution of larvae and adults in the poultry house was heterogeneous during the whole period of evaluation. Results suggest that monitoring in poultry houses is necessary prior to adopting and evaluating control measures due to the great variability of the insect distribution in the poultry house.

O conhecimento da flutuação populacional e distribuição espacial de pragas são fundamentais para o estabelecimento de uma metodologia de controle adequada. A flutuação populacional e distribuição espacial de Alphitobius -diaperinus em aviário de corte, localizado em Cascavel, Paraná foi avaliada no período entre outubro/2001 e Outubro/2002. Larvas e adultos do cascudinho foram coletados semanalmente com armadilhas de Arends (n = 22) em seis lotes de frangos, consecutivamente. A temperatura da cama foi medida nos locais onde as armadilhas foram expostas, bem como a temperatura no interior do galpão do aviário. O número de besouros aumentou continuamente em todas as áreas do aviário no decorrer das semanas de coleta (média de 5.137, na primeira semana, e de 18.494 insetos, na sexta semana). O número de larvas coletadas foi significantemente maior que o número de adultos (de 1 a 20 vezes em 95 por cento do total de coletas realizadas). Não houve correlação entre as variações de temperatura do galpão e da cama e o número de insetos coletados, não sendo, portanto, observada flutuação populacional ao longo do período de avaliação. O crescimento da população esteve relacionado ao acúmulo de camas, observando-se temperaturas mais altas em locais onde a cama era mais profunda. A distribuição espacial de larvas e adultos no galpão foi desuniforme com relação aos locais de coleta. Com base nos resultados obtidos, sugere-se que há necessidade de monitoramento dos aviários individualmente antes do emprego de qualquer medida de controle, devido à grande variabilidade na distribuição dos insetos em um único galpão de criação.