Search research reports:
The Effect of an Aphid Bacterial Symbiont on Interactions Among Soybean Aphid, Resistant Soybean, and Parasitoids
J. A. White
Department of Entomology
Soybean aphid is an invasive insect that is native to Asia. It was first discovered in North America in 2000 and is currently the major insect pest of soybean in North America. To reduce use of insecticides, researchers have used traditional breeding to create soybean varieties that are more resistant to soybean aphid. Most soybean aphids do not survive and reproduce on these new plant varieties, which are just reaching commercial availability.
However, some soybean aphid "biotypes" develop perfectly well on resistant soybean varieties. It is not known why some soybean aphids perform well and some perform poorly on resistant soybean, but it is important to understand the biological basis for this variation in the aphid, so that we can use the best strategies for deploying resistant soybean and preserving its usefulness.
In this grant, we are investigating the hypothesis that a bacterial symbiont in the aphid, known as Arsenophonus, might affect the aphid's ability to use resistant soy. Many insects have bacteria living inside of them that perform a wide variety of functions, and can affect ecological factors such as host plant usage and interaction with parasitoids (insects that attack and consume other insects). The function of Arsenophonus in soybean aphid is unknown, but preliminary tests suggest that aphids with this bacteria perform differently on resistant soy than aphids without it.
For this grant, we will cure multiple aphid biotypes using antibiotics, and then compare the performance of aphids with and without the symbiont on resistant soy. We will also test whether the symbiont affects the susceptibility of the aphid to introduced parasitoids that are being used for biological control of the aphid population.
This seed grant will therefore
1) generate differentially-infected aphid lines that can be used in this and future grants to understand the biology of the aphid and the bacteria,
2) indicate whether the bacterial symbiont affects soybean aphid ability to use resistant soy plants, and
3) test whether the bacterial symbiont affects soybean aphid susceptibility to biological control.