Yellow Sugarcane Aphids in a CO₂-Enriched and Warmer World

In the words of Auad et al. (2012), the yellow sugarcane aphid - first called Chaitophorus flavus, but later changed to Sipha flava - "has an extensive geographic range that includes all the Americas and Hawaii," noting that it "is not only a serious pest of sugarcane, but it infests corn, sorghum, wheat, and several other grasses," while explaining that "plant injury caused by this aphid is often severe and is associated with the release of an unidentified toxin followed by leaf chlorosis (Breen and Teetes, 1986; Webster, 1990)." And in Brazil, where Auad et al. reside, the four scientists report that elephant grass (Pennisetum purpureum) - which is one of the most widely used grasses for dairy cattle forage - "is being compromised by S. flava attack."

Very briefly, in the present study the four Brazilian researchers set out to investigate the "effects of elevated CO₂ alone and in combination with elevated temperature on the interactions of S. flava and one of its hosts," choosing, not surprisingly, P. purpureum as the guinea pig of their study. So what did the results reveal?

Auad et al. discovered that "the combination of elevated CO₂ and high temperature significantly decreased the duration of nymphal stadia," as well as "the longevity and reproductive success of S. flava," such that "adults produced fewer nymphs in an environment with elevated CO₂ and high temperature than an environment with elevated CO₂ and lower fluctuating temperatures."

The four researchers conclude by stating that based on their observations, "S. flava populations will significantly decrease under future climatic conditions when both the concentration of atmospheric CO₂ and temperature are projected to increase."

Additional References
Breen, J.P. and Teets, G.L. 1986. Relationships of the yellow sugarcane aphid (Homoptera: Aphididae) density to sorghum damage. Journal of Economic Entomology 79: 1106-1110.

Webster, J.A. 1990. Yellow sugarcane aphid (Homoptera: Aphididae): detection and mechanisms of resistance among Ethiopian sorghum lines. Journal of Economic Entomology 83: 1053-1057.