Repelling whitefly (Bemisia tabaci) using limonene-scented kaolin: A novel pest management strategy

Despite intensive control efforts, whitefly Bemisia tabaci, remains a difficult pest to manage due to its wide host range and ability to easily switch feeding between crop hosts and surrounding weed hosts. To develop more economical management strategies, the combination of kaolin and limonene was tested as a natural organic repellent against whiteflies. Whitefly host selection was compared between kaolin and limonene-coated tomato and control plants using closed cage bioassays. Combining limonene and kaolin had an additive effect on repelling adult whiteflies compared with the control. Field trials were conducted during two fall seasons in Quincy, Florida. In the 2019 field trial, during dry conditions, tomatoes treated with kaolin + limonene (K + L) had a three to four-fold reduction in B. tabaci adult populations compared to controls and a two to three-fold reduction compared to kaolin-only and limonene-only treatments. In addition, infection with Tomato Yellow LeafCurlVirus (TYLCV) was at least two times lower on average in K + L treatments compared to the control. This translated to a two-fold increase in marketable yield of tomatoes harvested from K + L treatments. In fall 2020, due to wetter conditions we only observed a decrease in adult populations on plants in the K + L treatment compared to the control, yet no difference in TYLCV incidence between treatments. Limonene-scented kaolin's effectiveness as a whitefly repellent seems to depend largely on rainfall. In dry conditions, more effective control of whiteflies and of TYLCV was achieved. •Combination of kaolin and limonene to control whitefly in tomatoes was investigated.•Kaolin and limonene alone provided slight protection against whiteflies.•Combined, Kaolin and limonene had an additive effect.•The efficacy of limonene-scented kaolin was reduced following rain events.