The influence of three specialized tansy aphids on some biological parameters and survival of seven-spotted ladybird and green lacewing

Some predators have a broad prey range, but not all preys are equally suitable for a predator. We testedthe suitability of three specialized tansy (Tanacetum vulgare) aphids, Macrosiphoniella tanacetaria,Metopeurum fuscoviride and Uroleucon tanaceti, on biological parameters of their major predators,Coccinella septempunctata and Chrysoperla carnea. In the laboratory four different diet treatmentsconsisting of either each aphid species alone, or a mixed diet of all the three aphid species, was fed daily topredator larvae. Seventeen biological parameters of predators were measured. M. tanacetaria was the mostsuitable prey for C. septempunctata resulting in the shortest total developmental time, largest fresh and dryweight and largest growth rate while M. fuscoviride was the most profitable for C. carnea according to thesame parameters and also the shortest larval developmental time and lowest larval mortality. Larvae of bothpredator species that were fed on U. tanaceti had low survival and none of them developed to third instar.The mixed diet was worse than the best single-aphid diet for both predators. Thus, the predators did notbenefit from a mixed diet and this may be due to interference of ingested U. tanaceti with the utilization ofthe other two higher quality aphid species. Thorough information on the food suitability of insect predatorscould not only elucidate their nutritional ecology but also help to shed light on their functional role in aphidcommunities.

کلیدواژه ها:

Aphid ، predator ، food suitability ، ladybird ، green lacewing