A column elutriator for extracting cyst nematodes and other small invertebrates from soil samples

Abstract

A column soil elutriator (the Wye Washer) for extracting cyst nematodes and other small invertebrates from soil samples is described. Laboratory tests have shown the new equipment to achieve extraction rates equal to or better than existing techniques and to offer operational advantages also. Soil in quantities of up to 1 kg may be processed without drying or subsampling, the equipment can be left unattended once set to work, and can be used to extract a range of target organisms. There is only one working part (a valve) and no electrical parts, but water use and price is high. The Wye Washer is now used in the advisory entomology laboratory at Wye as the standard equipment for extracting cysts of Heterodera and Globodera, for eggs of cabbage root fly (Delia radicum) and for cocoons of black currant leaf midge (Dasineura tetensi).

Comparison of the in-soil hatching responses of Globodera rostochiensis and G. pallida in the presence and absence of the host potato crop cv. British Queen

“…Each bulked, infested soil now contained mixed generations (a minimum of at least three generations) of either PCN species. Cysts of each species were extracted in January from the moist, bulked soil using a Wye Washer elutriator (Winfield et al, 1987) and collected on filter paper. The cysts were immediately picked off the filter paper and placed onto soil (collected from the field where the experiments were to be conducted) contained in a tissue-embedding cassette (dimensions 4 × 2.5 × 0.5 cm; Tissue Embedding Cassettes, Fisher Scientific UK Ltd, Loughborough, UK).…”

Effect of sample size on cyst recovery by flotation methods: Recommendations for sample processing during EU monitoring of potato cyst nematodes (Globodera spp.)

“…This study suggests that where samples are divided into portions, the portions should not exceed 500 mL. Other methods/equipment, including a recently scaled‐up Seinhorst elutriator and the Wye Washer will accommodate larger samples (Winfield et al ., 1987; Been et al ., 2007).…”

PM 7/119 (1) Nematode extraction

“…The Wye washer allows extraction of cysts from wet and dry soil. The apparatus is constructed of a 50 cm long, 15 cm diameter wide clear acrylic tube which, at its lower end, is held inside two tight‐fitting concentric PVC sleeves (Winfield et al ., ) (Fig. ).…”

“…For comparison of methods and extraction efficacy see D 'Errico & Brzeski (1975), M€ uller (1980, Clayden et al (1985), Winfield et al (1987), Riggs et al (1997), Tenente et al (2007) and Bellvert et al (2008a,b).…”