Impact of Bemisia tabaci MEAM1 (Hemiptera: Aleyrodidae) on soybean yield and quality under field conditions

Authors: SCHUTZE, I.X - University Of São Paulo; Naranjo, Steven; YAMAMOTO, P.T. - University Of São Paulo

Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/20/2022
Publication Date: 3/22/2022
Citation: Schutze, I., Naranjo, S.E., Yamamoto, P. 2022. Impact of Bemisia tabaci MEAM1 (Hemiptera: Aleyrodidae) on soybean yield and quality under field conditions. Journal of Economic Entomology. 115(3):757-766. https://doi.org/10.1093/jee/toac026.
DOI: https://doi.org/10.1093/jee/toac026

Interpretive Summary: Whiteflies (Bemisia tabaci) have become more problematic in soybean production in Brazil in recent years. Little data is available on the relationship between insect pest density and crop yield and quality parameters. A two year controlled infestation study was conducted on caged soybean plants at two sites in Brazil. Temperature profiles differed greatly over the two years and led to different insect population growth rates. Higher temperatures promoted a shorter lifecycle and and nearly one more generation during the study period. Yield loss at the high pest infestation level varied from 500 to 1147 kg ha-1, the weight of thousand grains declined from 18-33 g. No significant differences were observed grain vigor quality, but protein content was reduced up to 440 kg ha-1 in at high infestation levels. Data on the relationship between yield and pest density was used to estimate the economic injury level (EIL) of the pest. This is the density at which the cost of control equals the loss of yield. EILs ranged from 2.5 – 25.67 nymphs per leaflet and 0.17 – 1.79 adults per leaflet over a range of control costs, soybean production values and control efficacies. These results should provide data useful towards development of pest management decision making tools for growers.

Technical Abstract: Bemisia tabaci MEAM1 (Hemiptera: Aleyrodidae) is a key insect pest in soybean fields in Brazil but data are lacking on the relationship between pest abundance and crop yield and quality. Controlled infestation studies were conducted on caged soybean plants in the field over a two year period at two sites in Brazil. Differences in temperature in the two years affected population growth of B. tabaci, reaching 413 nymphs per leaflet in the first year, and 179 the second year even when the average temperature was 3 ºC higher. Higher temperatures promoted a shorter lifecycle and nearly one more generation. Yield was affected with losses up to 500 kg ha-1 in 2017/2018 and 1,147 kg ha-1 in 2018/2019. A decrease in the weight of a thousand grains of 18 and 33 g was observed in the first and second year, respectively. No significant differences were observed in grain germination, but estimated losses in protein content were up to 440 kg ha-1 at the highest infestation level. Pest density and yield data were used to estimate economic injury levels (EILs). EILs ranged from 2.5 – 25.67 nymphs per leaflet and 0.17 – 1.79 adults per leaflet over a range of control costs, soybean production values and control efficacies. These results should provide data useful towards development of pest management decision making tools.