I HAVE READ Suzanne Griffith’s articles on agriculture and horticulture from time to time and have found them to be mostly accurate.
However, I have some difficulty with her Working With Whiteflies article published in the DAILY NATION of August 19.
She mentions the planting of companion plants which can act as natural repellents.
I wish to point out that based on my research work as an entomologist, none of the species mentioned have any major repellent properties against whiteflies.
As a matter of fact they all serve as whitefly hosts. On the issue of the so-called natural pesticides, in my research I have compared the efficacy of “natural pesticides” with “chemical pesticides” against whiteflies in statistically designed experiments and the natural pesticides have proven to be virtually useless in controlling even small whitefly populations.
Again in her piece she refers to the three life stages of the whitefly as “larvae or eggs, crawler and finally feeder”.
In the case of the whitefly there are six stages; the egg, the crawler, two nymphal stages, the pupa and adult.
She is correct in recommending that a small area of the plant (especially ornamentals) should be treated first, however in most cases the “burning” she refers to is not sunburn but chemical burning.
Just thought I would clear up these areas.
LENNOX CHANDLER
