Integrated Management of Tomato Whitefly Under Greenhouse Conditions

Abstract

The whitefly Bemisia tabaci (Gennadius, 1889) is a major pest species in many agricultural crops worldwide. Growers from the Vale do Caí region, in Southern Brazil (Rio Grande do Sul state) have been facing severe economic losses due to the increasing damages caused by this sucking insect in their horticultural crops. Small-scale farming in the Vale do Caí region relies heavily on horticulture, with many families involved in the activity and a consumer market spread throughout the whole state. Virus transmission and other damages inflicted by B. tabaci are especially harmful to tomato plants, and the managing of the pest currently demands two thirds of all chemical insecticides used in the region. While chemical control remains the main strategy for whitefly management on tomato crops, control failures and lack of updated information have led tomato growers to raise the number of sprays per crop cycle, with selection of resistant populations and harmful effects on the environment as consequent risks. The aim of this work was to evaluate chemical compounds and bioinsecticides in the control of B. tabaci nymphs and adults on tomato plants grown in two different greenhouses and under natural infestation conditions. The most efficient treatment for the control of B. tabaci adults was cyantraniliprole + lambda-cyhalothrin (50+30 g a.i. ha-1) with 64% of average control efficiency. As for nymph control, the most efficient treatment was the Embrapa formula, a bioinsecticide composed of 0.5% flaxseed oil + 0.5% neutral detergent + 0.3% sodium bicarbonate, which resulted in 72% of whitefly control in average.

Managing Whitefly on Soybean

“…Most researches on B. tabaci control are carried out in the Middle-west (Silva et al, 2003;Garcia et al, 2005;Silva et al, 2012) and Southeast (Alves et al, 2001;Valle, Lourenção, & Novo, 2002;Bacci et al, 2007) regions of Brazil, whereas whitefly infestations have been steadily increasing in the Southern states (Bernardi, 2016) and demanding up to 67% of all chemical insecticides sprayed on horticulture crops (Rosa, 2017). Satisfactory control efficiencies (≥ 80%) of B. tabaci are obtained only with highly specific and costly active ingredients, such as spiromesifene in cotton crops (Netto & Barros, 2016) and cyantraniliprole + lambda-cyhalothrin in tomato crops (Arnemann et al, 2019). In addition, while some sampling methods have been proposed (Czepak et al, 2018), a standardized method for monitoring and control decision remains absent due to the lack of a defined economic injury level for B. tabaci on soybean crops.…”

Validation of a sampling method: using one square centimeter for sampling the immature stages of Bemisia tabaci in soybean

“…The favorable geographic and climatic conditions of crops in the country allow the insect to occur throughout the crop cycle, increasing its damage potential and making it difficult to control (Arnemann et al, 2019). Therefore, many researchers have investigated management strategies to suppress the pest in soybean, especially in the Central‐Western and Southeastern regions of Brazil (Arnemann et al, 2019).…”

“…Whitefly is currently considered a key pest for soybean, Glycine max (L.) Merr. (Fabaceae), crops in Brazil, where crops have recently suffered from high numbers of this pest, especially in the reproductive period of the plant (Czepak et al, 2018). The favorable geographic and climatic conditions of crops in the country allow the insect to occur throughout the crop cycle, increasing its damage potential and making it difficult to control (Arnemann et al, 2019). Therefore, many researchers have investigated management strategies to suppress the pest in soybean, especially in the Central‐Western and Southeastern regions of Brazil (Arnemann et al, 2019).…”

Efficacy of Insecticides Against Whitefly Bemisia tabaci (Genn.) in Potato

“…have a significant influence on potato yield (Bhatnagar, 2007). Bemisia tabaci not only causes damage directly from sap sucking and toxin injection, and indirectly from virus transmission and honey dew secretion (Arnemann et al, 2019). Thus, it is among the most serious pests in cultivation of potatoes, since it has a significant influence on yield (Bhatnagar, 2007).…”