Host plant selection and oviposition behaviour of whitefly Bemisia tabaci (Gennadius) in a mono and simulated polyculture crop habitat

Abstract

The host plant selection, oviposition behaviour and survivorship of whitefly (Bemisia tabaci (Gennadius) was evaluated in green house. Three host plants cultivars namely: Brinjal (Solanum malagna), chilli (Capsicum annuum) and tomato (Solanum lycopersicum) were placed in a multiple crop habitat at 34 - 36°C, 70 - 80% relative humidity (RH) in a normal day light. There was a variation of morphological characteristic among host plants (smooth and thick trichome leaves) where all developmental stages of pest were given free choice of foraging. Although the host plants genus C. annum and S. lycopersicum were also the potential host of B. tabaci but in the presence of S. malagna, the attack rate remains minimum on both the host plants. The feeding and egg laying was significantly higher on S. malagna L. leaves as compare to other two host plants in the open arena. S malagna L. was also preferred when pest was tested in confined cages for free choice probing on capsicum and S. malagna L. There was no significant but a slight difference in survivorship of all developmental stages of whitefly when Brinjal and Chilli and then Brinjal and tomato from two different experimental arenas were compared. There was no host plant varietal effect on the overall developmental time from egg eclosion to the adult. The leaves of S. malagna with thick trichomes were chosen significantly more higher for egg laying compared to other host plants. The morphological characters and plant architecture contribute to higher densities of adult whitefly (wf) compared to new leaves. No symptoms of viral infection has been observed on the chilli with Brinjal, whereas, the same variety of chilli was reasonably infected with virus in chilli monocrop arena.

Key words: Multiple cropping, host plant selection, oviposition fecundity, intrinsic rate of increase.