RESUMO
Generalist predators and parasitoids are considered to be important regulators of aphids. The former not only feed on these pests, but might also consume parasitoids at all stages of development. This direct or coincidental interference affects the natural control of aphids, the scale of which is largely unknown, and it has rarely been examined under natural conditions. Here, molecular diagnostics were used to track trophic interactions in an aphid-parasitoid-generalist predator community during the build-up of a cereal aphid population. We found that generalist predators, principally carabid and staphylinid beetles as well as linyphiid spiders, had strong trophic links to both parasitoids and aphids. Remarkably, more than 50% of the parasitoid DNA detected in predators stems from direct predation on adult parasitoids. The data also suggest that coincidental intraguild predation is common too. Generalist predators, hence, disrupt parasitoid aphid control, although the levels at which the predators feed on pests and parasitoids seem to vary significantly between predator taxa. Our results suggest that taxon-specific trophic interactions between natural enemies need to be considered to obtain a more complete understanding of the route to effective conservation biological control.
Assuntos
Besouros/fisiologia , Cadeia Alimentar , Comportamento Predatório , Aranhas/fisiologia , Animais , Afídeos/classificação , Afídeos/genética , Afídeos/parasitologia , Besouros/genética , Complexo IV da Cadeia de Transporte de Elétrons/genética , Inglaterra , Himenópteros/genética , Himenópteros/fisiologia , Proteínas de Insetos/genética , Controle Biológico de Vetores , Reação em Cadeia da Polimerase , Crescimento Demográfico , Aranhas/genéticaRESUMO
We report the case of a patients with a metachronous cystic pancreatic metastasis from an undifferentiated large cell lung carcinoma two years after the primary tumor had been surgically removed. Clinically, he presented with epigastric pain, fever, weakness and anorexia. The patient was operated and a palliative cystogastrostomy was performed after an intraoperative biopsy had been informed as positive for carcinoma. Six months later the patient died. Pancreatic metastases from lung carcinoma are found in approximately 7-9% of patients deceased of this neoplasm. Clinical and radiological findings simulate primary pancreatic tumors, being epigastric pain, jaundice and upper digestive bleeding the most frequent symptoms. They represent stages of advanced systemic disseminated tumoral disease, and because of this reason total or partial surgical curative resections will only be performed in a few cases of patients with isolated metastasis, criteria of resectability and without evidence of extended disease to other organs or systems. In the most of the cases, the treatment will only be palliative, even medical or surgical.
