OVIPOSITIONAL PREFERENCE AND NYMPHAL PERFORMANCE OF TRIALEURODES-VAPORARIORUM (HOMOPTERA, ALEYRODIDAE) ON DENDRANTHEMA-GRANDIFLORA UNDER DIFFERENT FERTILIZER REGIMES

Chrysanthemum plants, Dendranthema grandiflora, were treated with different concentrations of a complete fertilizer and exposed to the greenhouse whitefly, Trialeurodes vaporariorum (Westwood). In choice tests, the number of eggs laid and the number of reared adults increased in plants treated with high concentrations of fertilizer, and were correlated with nitrogen content of leaves. In no-choice tests, ovipositon increased only by doubling the fertilizer concentration. More adults were produced from plants that had been fertilized. However, neither adults produced nor oviposition was correlated with nitrogen content of leaves. In a choice test ovipositing females selected plants based on the plant's nutritional condition, as indicated by total leaf nitrogen content. In no-choice tests, however, other plant characteristics may have influenced the female's decision to oviposit, and the frequency of oviposition. Thus, plant selection and frequency of oviposition were correlated with the plant's suitability to support survival and development of whitefly progeny.