Study on host selectivity of Liriomyza sativae to different cultivars of cucumber.
Choice and no-choice tests were conducted in the field and laboratory in Wuhan, Hubei, China, to study the host selectivity of L. sativae to 10 different cucumber cultivars (Jinza 2, Jinza 4, Jinyou 1, Jinchun 2, Jinchun 4, Huazao 1, Zhongnong 5, Zaofeng 1, Jinyan 4 and Baisitiao). Significant differences in feeding-spots/cm2 and eggs/cm2 were found among these cucumber cultivars, whereas no significant differences in hatching rate, pupation rate and eclosion rate. The feeding-spots/cm2 and eggs/cm2 of Jinchun 4 were highest, whereas those of Jinza 4 were lowest. The feeding-spots/cm2 and eggs/cm2 of Jinchun 4 were 2 and 2.4 times higher than those of Jinza 4 in the field test, and 1.7 and 1.9 times higher in the laboratory test. The selectivity of L. sativae to the 10 cultivars was ranked as Jinza 4<Jinza2 and Baisitiao<Huazao 1 and Jinyou 1<Jinchun 2, Zhongnong 5, Jinyan 4 and Zaofeng 1<Jinchun 4. The glandular trichome density and length of cucumber leaf had negative correlations with selectivity of L. sativae. The glandular trichome density and length of leaf of Jinza 4 were 2 and 3 times higher than those of Jinchun 4.