Comparative Host Suitability of SomeBrassicaCultivars for the Whitefly,Aleyrodes proletella(Homoptera: Aleyrodidae)

Abstract

Four cultivars of broccoli (Brassica oleracea L. variety ÔitalicaÕ), two cultivars of early caulißower (Brassica oleracea L. variety ÔbotrytisÕ), four cultivars of late caulißower, and one cultivar of red cabbage (Brassica oleracea L. variety ÔcapitataÕ) were screened to determine some reproductive parameters of Aleyrodes proletella L. in a no-choice assay. The highest and lowest oviposition rates and production of pupae and adults were obtained with late caulißower (cultivar Picasso) and red cabbage (cultivar Cabeza negra), respectively. The highest percentages of adult emergence (indicating survival from egg to adult) were obtained on broccoli (cultivar Chevalier) and late caulißower (cultivars Mayfair and Picasso), whereas the lowest was obtained on late caulißower (cultivar Arbon). In a choice experiment, A. proletella preferred late caulißower (cultivar Picasso) and broccoli (cultivar Agripa) to red cabbage (cultivar Cabeza negra). SigniÞcantly more adults per day, and more pupae and empty pupal cases per plant, were found on broccoli and caulißower cultivars than on red cabbage. In another no-choice assay at 22 Ϯ 1.5ЊC, A. proletella required signiÞcantly more days for development on red cabbage than on broccoli and caulißower cultivars. A. proletella developed signiÞcantly faster on broccoli cultivars Agripa and Chevalier and late caulißower cultivars Mayfair and Picasso. These results suggest that it is important to minimize the use of broccoli (cultivars Agripa and Chevalier) and late caulißower (cultivars Mayfair and Picasso) to avoid the risk of further expansion of whiteßy populations where these Brassica crops and A. proletella are present.

Host plant resistance towards the cabbage whitefly in Brassica oleracea and its wild relatives

“…The increasing resistance may be linked to the time of natural whitefly infestation in the field, suggesting that cabbage plants invest in direct defense responses against the cabbage whitefly when needed (Boege and Marquis 2005). Age dependent resistance was not recognized in earlier studies (Ramsey and Ellis 1996;Nebreda et al 2005). In those studies, experiments were performed at the six true leaf stage, which is comparable to our 6 week old plants stage.…”

Temperature-Dependent Development of <I>Aleyrodes proletella</I> (Homoptera: Aleyrodidae) on Two Cultivars of Broccoli Under Constant Temperatures

“…Several experiments were conducted to record insect development on the same cultivars of B. oleracea at eight constant temperatures: 16, 18, 20, 22, 24, 26, 28, and 30ЊC. Following the methodology of a previous study (Nebreda et al 2005), ten 7-d-old females, all from the same colony, were introduced into each of 10 clipcages (Muñ iz and Nombela, 2001) and attached to the under-surface of one leaf (one cage per plant; Þve plants per cultivar). The caged females were held in the climatic chamber for a 10-h oviposition period at the above-mentioned conditions and subsequently removed.…”

“…In a previous study with A. proletella (Nebreda et al 2005), it was observed that Marathon and Agripa, two of the most cultivated brassica crops in Navarra (Spain), were the less and the most affected cultivars, respectively. The main objective of this study was to contribute to clarify the variation in growth and development of A. proletella with regard to these cultivars, so that effective management strategies can be developed in those places where these plants and whiteßies are present.…”

“…Although insect developmental rates are mainly determined by temperature, other factors need to be considered. Variation in host plant may produce important reproductive variability of insect stages (Fan et al 1992, Muñ iz and Nebreda 2003, Nebreda et al 2005. Although the estimation of economic thresholds with great accuracy and the development of reliable sampling programs is important to effective pest management, accurate determination of developmental times and number of generations of an insect pest on a speciÞc crop cultivar would obviously beneÞt the application of control measures.…”

The Banker Plant Method in Biological Control

“…For example, the bird cherry-oat aphid, Rhopalosiphum padi (Linnaeus) (Homoptera: Aphididae), an important pest of cereals (Lowles, 1995), is used as alternative prey for aphid parasitoids for biological control in greenhouse vegetables (e.g., Neil et al, 1997;Hansen, 2000). Similarly cabbage whitefly, Aleyrodes proletella (L.) (Hemiptera: Aleyrodidae), a serious pest of cabbage (Nebreda et al, 2005), could be used as an alternative host for E. formosa for biological control of greenhouse whiteflies in greenhouse cucumber (Laska and Zelenkova 1988; van der Linden and van der Staaij, 2001).…”