Climate change set to increase insect appetite

APHIDS will feed more to make up for the lowerquality plants that are expected to grow under predicted 2050 CO2 levels, new research has found.
New research has found increased carbon dioxide levels predicted for 2050 will cause aphids to feed more leading to greater plant damage in the future.
The study, published in Scientific Reports earlier this month, revealed the complex interactions between plants, insect pests and viruses under future climate conditions, with implications for plant disease severity and food crop production.
Agriculture Victoria research scientist Dr Piotr Trebicki, who led the study, said the research showed that when it comes to pests, diseases and food crops, the effect of future climate conditions is far from well understood.
“Food crops will be required to feed nine billion people in 30 years’ time and with grain a staple food across the world, this research will help ensure our growers and exporters are well equipped to meet increasing demand”, Dr Trebicki said. Dr Trebicki said the study investigated how increasing carbon dioxide (CO2) concentration affects wheat, a virus pathogen and the aphid vector spreading the virus.
The authors studied insect biology on wheat plants exposed to increased CO2 levels, predicted for 2050, in the presence and absence of the barley yellow dwarf virus.
Insect pests and plant diseases can decimate crop production when not treated and even with current control measures, which are costly and hazardous to the environment, yield losses are still substantial.
“In a not-too-distant future, atmospheric CO2 concentration will be double those from the preindustrial revolution.
“It will reach unprecedented levels, significantly affecting plants and other organisms, particularly pests and disease,” Dr Trebicki said. The researchers showed it is well documented that in plants grown under increased CO2 levels, nitrogen concentration is reduced and as a consequence, grain products are expected to have inferior nutritional quality.
Due to the reduced plant quality under elevated CO2, aphid offspring production decreased but to recompense the lower quality aphids are forced to feed more.
The increased feeding, on average will lead to greater plant damage.
“It is highly complex, on the one hand, less aphids is good news, but on the other, there will be more aphid damage, which is bad news.
“Virus infection can also change the proportion of infected aphids flying around, increasing virus incidence and disease severity,” Dr Trebicki said. The research was funded by Agriculture Victoria and the Grains Research Development Corporation.