Attractancy and ovipositional response of adult Bemisia argentifolii (Homoptera: Aleyrodidae) to type IV trichome density on leaves of Lycopersicon hirsutum grown in three day-length regimes

Clonal plants of six accessions of Lycopersicon hirsutum Humb. and Bonpl., a wild relative of tomato, were grown in three day-length regimes. Clones of an accession grown in different day-length regimes were genetically identical but differed in density of type IV and type VI trichomes on their leaves. Leaves on these plants were then evaluated for resistance to whiteflies (Bemisia argentifolii Bellows and Perring) in choice and non-choice bioassays. Plants grown under short days had elevated type IV density, reduced type VI trichome density, and were less attractive to whiteflies. Correlation and covariance analysis supported the hypothesis that high type IV trichome density resulted in reduced attractancy, especially on plants grown under short days.