Impact of flowers an the demography of western flower thrips Frankliniellaoccidentalis (Thysan., Thripidae)

The impact of flowers on the population growth of Frankliniella occidentali s was characterized on waxflower plants, Impatiens walleriana. In the prese nce of flowers, the populations grew exponentially while in their absence, the thrips populations only maintained themselves and showed no growth. The difference in number and in size of thrips reared in both conditions sugge sted that the flowers were essential for the success of thrips development. In the presence of flowers, the distribution of females between the leaves and the flowers varied strongly according to the availability of flowers. By contrast, the proportion of first larvae in the flowers increased up to the last day of the experiment.