Experimental intoxication by larvae of Perreyia flavipes Konow, 1899 (Hymenoptera: Pergidae) in pigs and some aspects on its biology

Abstract

Two pigs were dosed with 5 and 10g/kg bw of fresh Perreyiaflavipes larvae collected at the municipality of Pelotas. Two other pigs were dosed with 0.87 and 1.7g/kg of dry P. flavipes (equivalent to 5 and 10g/kg bw of fresh larvae). Another pig was dosed with 0.17g/kg of dry larvae, daily, during 20d. Forty-eight hours after the ingestion, all pigs that ingested single doses showed clinical signs and marked rise in serum aspartate aminotransferase. Alanine aminotransferase and gamma glutamiltransferase were also slightly increased. The pig dosed with 10g/kg of fresh larvae died in 96h. The others recovered in 4–5days after ingestion. No clinical signs were observed in the pigs dosed during 20d with 0.17g/kg of dry larvae. The main lesion observed in the pig dosed whit 10g/kg of fresh larvae was a centrilobular liver necrosis. These results confirmed the toxicity of P. flavipes for swine, demonstrated that the larvae maintain the toxicity after being dried, and suggest no cumulative effect in the larval toxicity. The larvae collected in the field were conditioned in boxes containing swards of native grasses and covered with gauze to prevent the escape of adults on emergence. The larvae pupated from August 11 to September 25. Emergency of adults occurred from February 10 to March 4. Adult females and males live only for 18–36 and 24–48h, respectively. The eggs had an incubation period of 26–33d. The larval period extend from March 1 to August 24.