Temperature alters the interaction between a herbivore and a resistant host plant

Abstract

Temperature and other environmental factors can strongly influence arthropods and their interactions with host plants. However, such effects are usually studied while keeping the suitability of host plants as constant as possible, thereby removing the possibility of interactions between temperature and host plant resistance. We performed experiments to determine whether temperature interacts with plant resistance to alter the density, movement, and distribution of wingless soybean aphids on resistant and susceptible soybeans. In individual plant tests, temperature influenced aphids differently depending on the plant they were on; aphids in the warmer temperature did better than aphids in the cooler temperature when on susceptible plants, but when on resistant plants aphids did worse in the warmer temperature. This pattern was, in part, due to markedly increased aphid fecundity on susceptible plants in warmer temperatures which was not the case on resistant plants. A follow-up experiment showed that higher temperature meant lower adult survival for aphids on a nutrient-poor diet, further suggesting how higher temperatures may be difficult for aphids when on resistant host plants. We also saw that both higher temperature and resistance increased within-plant movement in an additive fashion. Altering temperature and host plant resistance can each influence the demographic and movement responses of herbivores; however, this study indicates that the two factors may interact to influence herbivores in potentially unexpected ways.

Reduced Fitness of Virulent Aphis glycines (Hemiptera: Aphididae) Biotypes May Influence the Longevity of Resistance Genes in Soybean

“…The variation among temperatures used for these experiments could be a possible explanation for the differences in results. Furthermore, there may be interactions between abiotic factors, like temperature, on the impact of Rag genes [ 37 , 38 ]. However, the extent that the protection from all Rag genes is influenced by temperature is unknown [ 39 ].…”

Sources of Soybean Aphid Resistance in Early‐Maturing Soybean Germplasm

“…Other lines can have variable susceptibility depending on temperature (Richardson 2012). Whalen and Harmon (2015) also demonstrated that overall soybean aphid population growth increases as temperature increases on susceptible plants, but decreases as temperature increases on resistant plants. In addition, Brunner et al (2014) found an inverse relationship between soybean aphid number and the number of root nodules, which can affect the amount of nodule‐colonizing bacteria and thereby affect N availability.…”

Effect of temperature on host plant‐specific leaf‐ and root‐feeding performances: a comparison of grape phylloxera biotypes C and G

“…This is in line with a similar study on soybean aphids ( Aphis glycines Matsumura), where increased temperatures had a positive effect on their abundance on susceptible soybean [ Glycine max (L.) Merr.] varieties and a negative effect on their abundance on resistant ones (Whalen & Harmon, 2015). These findings were partly attributed to the accelerating effect of a higher temperature on infestation parameters (i.e., soybean aphids would die either way on resistant soybeans, but this process is accelerated for high temperatures).…”