Multidecadal, continent-level analysis indicates agricultural practices impact wheat aphid loads more than climate change

Abstract

Temperature has a large influence on insect abundances, thus under climate change, identifying major drivers affecting pest insect populations is critical to world food security and agricultural ecosystem health. Here, we conducted a meta-analysis with data obtained from 120 studies across China and Europe from 1970 to 2017 to reveal how climate and agricultural practices affect populations of wheat aphids. Here we showed that aphid loads on wheat had distinct patterns between these two regions, with a significant increase in China but a decrease in Europe over this time period. Although temperature increased over this period in both regions, we found no evidence showing climate warming affected aphid loads. Rather, differences in pesticide use, fertilization, land use, and natural enemies between China and Europe may be key factors accounting for differences in aphid pest populations. These long-term data suggest that agricultural practices impact wheat aphid loads more than climate warming.

Long-term expansion of cereal crops promotes regional population increase of polyphagous Helicoverpa armigera

“…On the other hand, weather characteristics are also important drivers of regional pest population dynamics across years. However, the co-occurrence of land-use and climatic changes makes it di cult to separate the effects of these factors through using historical time-series data that lack independent gradients for land-use and climate elements, and this problem may cause different results to be obtained at different spatiotemporal scales (Forister et al, 2010;Lawton et al, 2022;Sun et al, 2022). We linked long-term monitoring data on H. armigera adult population to changes in the acreage of main cereal crops and climate factors that corresponded in time to development of speci c stages of particular pest generations.…”

“…Changes in land use and climate are widely viewed as the two main drivers of pest population dynamics; however, the latter factor has rarely been taken account in landscape level studies, which are often restricted by limited climate gradients (Courson et al, 2022;Kammerer et al, 2021;Newbold, 2018;Sun et al, 2022). In such cases, landscape level results may not accurately predict trends in a pest's regional population dynamics at a broad temporal scale because the impact of land use changes on pest population may be contingent on climate changes (Ganuza et al, 2022;Oliver and Morecroft, 2014).…”

Polygenic adaptation of a cosmopolitan pest to a novel thermal environment

“…The prediction is that global climate change will escalate the occurrence of extreme events, including heatwaves (Bauerfeind & Fischer, 2014). Temperature is known to be one of the most important abiotic factors affecting phenotype (Sun et al, 2022). Insects can robustly adapt to temperature variations, attributed to their short life cycle and significant population variability across different spatial and temporal scales (Bale et al, 2002).…”

Efficacy of Imidacloprid Seed Treatments against Four Wheat Aphids under Laboratory and Field Conditions

“…Throughout its development, wheat is subject to various forms of damage by insect pests, including wheat aphids, wheat midges, and soil pests, which threaten wheat yield and quality. In China, aphids were not the main insect pests of wheat before the 1970s [ 1 , 2 ], but with changes in tillage [ 3 , 4 , 5 ], farming systems, and variety replacement [ 6 ], wheat aphids have become the most important insect pests, with a total acreage of up to 14 million ha in 2018 [ 7 , 8 ]. Wheat aphids feed on the functional blades and spikes from the booting stage to the milk development stage.…”