Predatory activity of chlamydospores of the fungus Pochonia chlamydosporia on Toxocara canis eggs under laboratory conditions Atividade predatória de clamidósporos do fungo Pochonia chlamydosporia sobre ovos de Toxocara canis em condições laboratoriais

The objective of this study was to use chlamydospores of the fungus Pochonia chlamydosporia (isolates VC1 and VC4) against Toxocara canis eggs in a 15-day in vitro assay. One thousand T. canis eggs were placed in Petri dishes containing 2% water agar medium with different concentrations of chlamydospores (1,000, 10,000 or 100,000) of each fungal isolate of P. chlamydosporia (treated groups) and 1,000 eggs in Petri dishes without fungus (control group). Egg counts were performed to determine the ovicidal activity, which was classified as three effect levels: type 1, type 2 and type 3. Significant differences (P < 0.01) in egg destruction were found in comparison with the control group. The highest percentage of egg destruction was found in plates containing 100,000 chlamydospores (68.5% for VC1 and 70.5% for VC4). Chlamydospores of P. chlamydosporia were effective in destroying T. canis eggs and may contribute in the future towards combating the eggs of this parasite.<br>O objetivo do trabalho foi utilizar clamid&#243;sporos do fungo Pochonia chlamydosporia (isolados VC1 e VC4) na destrui&#231;&#227;o de ovos de Toxocara canis, num ensaio in vitro, realizado no intervalo de 15 dias. Em cada placa de Petri com &#225;gar-&#225;gua 2% foram vertidos 1.000 ovos de T. canis em 1.000, 10.000 ou 100.000 clamid&#243;sporos de cada isolado do fungo (grupos tratados). Foram realizadas as contagens para verificar a atividade ovicida, classificada em tr&#234;s n&#237;veis de efeito: tipo 1, tipo 2 e tipo 3. Os resultados demonstraram que houve diferen&#231;a significativa (P < 0,01) na destrui&#231;&#227;o dos ovos em rela&#231;&#227;o aos ovos observados nas placas do grupo controle. O maior percentual de ovos destru&#237;dos foi observado nas placas contendo 100.000 clamid&#243;sporos (68,5% para VC1 e 70,5% para VC4). Clamid&#243;sporos do fungo P. chlamydosporia foram efetivos na destrui&#231;&#227;o dos ovos de T. canis podendo contribuir no futuro para o combate aos ovos deste parasito.