Managing Whitefly on Soybean

Abstract

The whitefly Bemisia tabaci (Gennadius, 1889) is a major pest species in soybean, leading to severe economic losses on this crop due to the difficulties involved on its management. Previously restricted to the Middle-west and Southeast regions of Brazil, whitefly infestations have steadily increased in the Southern state of Rio Grande do Sul, the third biggest soybean growing region of the country. Control failures and scarcity of updated information have led Brazilian soybean growers to raise excessively the number of sprays per crop season, increasing control costs and jeopardizing the long-term sustainbility of this strategy due to selection of resistant strains and potential harmful effects on the environment. The aim of this work was to evaluate the performance of different chemical insecticides in the control of B. tabaci nymphs and adults on soybean crops in two different sites, under the field conditions faced by the growers in the state of Rio Grande do Sul. The most efficient treatment for the control of B. tabaci adults was cyantraniliprole + lambda-cyhalothrin, at the doses of 100 + 7.5 g a.i. ha-1, which provided 65% of average control efficiency. As for nymph control, the most efficient treatment was acetamiprid + pyriproxyfen, at the doses of 60 + 30 g a.i. ha-1, which resulted in 67% of whitefly control in average. Two sequential sprays beginning at the infestation onset are recommended in order to enhance control efficiency.

Detection of Bemisia tabaci Mediterranean cryptic species on soybean in São Paulo and Paraná States (Brazil) and interaction of cowpea mild mottle virus with whiteflies

“…March (Conab, 2020;IBGE, 2020). This corresponds to the summer been well documented on soybean since the early 2000s (Arnemann et al, 2019), as well as the occurrence of the whitefly-transmitted CPMMV (Almeida et al, 2005;Zanardo & Carvalho, 2017).…”

“…This corresponds to the summer season, when environmental conditions (temperature and humidity) favour insect multiplication. Frequent outbreaks of whitefly have been well documented on soybean since the early 2000s (Arnemann et al, 2019), as well as the occurrence of the whitefly‐transmitted CPMMV (Almeida et al, 2005; Zanardo & Carvalho, 2017).…”

“…However, soybean yield losses due to whitefly attack only became frequent and significant after the introduction of the MEAM1 species in the early 1990s, currently the predominant species in Brazil (Moraes et al, 2018). Since then, an intense increase in soybean areas associated with the abusive use of nonselective insecticides has contributed to the occurrence of B. tabaci on soybean fields (Arnemann et al, 2019). B. tabaci MED was detected in the southernmost regions of Brazil in 2014 and since then, multiple detections of the MED species have been reported in the south, south-east, and mid-west regions of the country associated with ornamental plants and vegetable crops (Bello et al, 2020;Moraes et al, 2017Moraes et al, , 2018Krause-Sakate et al, 2020).…”

“…Since then, an intense increase in soybean areas associated with the abusive use of nonselective insecticides has contributed to the occurrence of B . tabaci on soybean fields (Arnemann et al, 2019).…”

Fatores ambientais e tempo de degradação foliar de neonicotinóides no controle químico de insetos sugadores em soja

“…A mosca-branca (Bemisia tabaci (Gennadius, 1889)) é uma das principais espécies de pragas da soja, levando a graves perdas econômicas devido às dificuldades envolvidas em seu manejo (ARNEMANN et al, 2019). O ciclo de vida curto (16-25 dias) (SOTTORIVA, 2010) e as altas taxas de oviposição (160 ovos por fêmea) (MALUMPHY et al, 2017) permitem que a mosca-branca complete de 11 a 15 gerações por ano com populações atingindo seu pico durante o estágio de floração das plantas de soja (MARABI et al, 2017).…”