INSECTICIDAL EFFECTS OF SELECTED SOAPS, OILS AND DETERGENTS ON THE SWEET-POTATO WHITEFLY - (HOMOPTERA, ALEYRODIDAE)

Efficacy against the sweetpotato whitefly (SPWF) Bemisia tabaci (Gennadius) of an insecticidal soap, two horticultural oils (one vegetable and the other petroleum based) and 15 detergents was evaluated under greenhouse conditions. Applications were directed to the underside of infested zucchini squash, tomato, or poinsettia leaves. Live nymphs were distinguished by their ability to deposit honeydew on water-sensitive paper held in contact. With the exception of 3 detergents, all materials evaluated at 1% concentration caused greater than 85% mortality of SPWF nymphs compared to applications of water. Similar results with 2 detergents and an insecticidal soap were obtained on infested cucumber leaves treated in the field in Florida. Saf-T-Side (mineral) Oil(TM), Natur'l(TM) (vegetable) oil, New Day(TM) liquid detergent or M-Pede(TM) applied with a mist blower reduced numbers of SPWF adults in heavily infested cucumber plots, although only Saf-T-Side Oil resulted in a significant reduction of nymphs.