| |
|||
![]() |
![]() |
![]() |
![]() |
Importation Project |
Assessing impacts on non-target aphids
When introducing new natural enemies for long-term (permanent) biological control, it is essential to minimize potential unwanted affects. As part of the NCSRP Soybean Aphid Biological Control Project, we have been assessing the potential for negative impacts of those Asian natural enemies that we are considering for release to control the aphid.
Filter A – Aphid phylogeny. We have focused on aphids most closely related to the soybean aphid. Other aphids, more distantly related, are found in places we felt soybean aphid natural enemies would not be typically searching for hosts to attack. This left about 300 aphid species.
By applying the filters, we arrived at 84 aphid species on 32 plant taxa. Most plants are found in prairies, grasslands or old fields. Others are wetland plants or are found in wooded areas.
Host specificity testing Host specificity testing of Binodoxys communis strains from both China and Japan indicate an intermediate level of host specificity. Soybean aphid is the most suitable host, with Aphis monardae showing slightly lower suitability on vegetative growth of the native prairie plant Monarda fistulosa.
Seven other species of aphids showed low suitability and a further 6 species were not used by B. communis at all. Aphis monardae is a native non-pest aphid that inhabits native prairie habitats and is therefore a non-target species that may be at risk if B. communis is released.
To evaluate this risk further, we have made observation of A. monardae in native prairie settings throughout Southern Minnesota. We found it abundant in both undisturbed prairie remnants and parkland meadows. During these observations, we also noticed that (i) this aphid tends to cluster in flower heads of its host plant, and that (ii) many of these aphid colonies are tended by ants (Lasius sp.). Both of these factors may decrease the risk of introduced B. communis to the native A. monardae. Results of this work were recently published as Physical and ant-mediated refuges from parasitism: implications for non-target effects in biological control. Wyckhuys, K. A. G., R. L. Koch, and G. E. Heimpel. 2007. Biological Control 40: 306-313. Read abstract»
2007/2008 Update
As in 2006, our survey efforts were focused on prairie habitats. A majority of native aphids species in the genus Aphis, the genus which contains the soybean aphid, are found on prairie plants. In 2007, we monitored 26 prairie sites in central Iowa, 6 sites in IN, and 4 sites in WI. Monitoring of aphids was conducted by visually inspecting plants along three 25 by 2 m transects per sampling date.
Parasitoid wasps of the aphids were reared from collected aphid colonies. We also used sweep net sampling to survey additional natural enemies adjacent to each transect. All aphids, their host plants and parasitoids are in the process of being identified to species, and predators are being identified to at least the family level.
K. Wyckhuys traveled to Lang Fang China in summer 2007 to begin experiments and supervise studies on habitat specialization of B. communis. Aphids were collected from over 30 host plants and examined for parasitism to determine whether B. communis was attacking aphids other than soybean aphids and cotton aphids (two primary known hosts). Data are still being analyzed from the 2007 field study, but analysis from a similar study in 2006 revealed that B. communis was attacking only cotton and soybean aphids.
North Central Regional Soybean Aphid Suction Trap Network
Of particular interest are the Aphis species because they are the non-target aphids that are most likely subject to parasitism by natural enemies released for control of the soybean aphid. An online key to the genus is being developed.
Publications Wyckhuys, K. A. G., R. L. Koch, and G. E. Heimpel. 2007. Physical and ant-mediated refuges from parasitism: implications for non-target effects in biological control. Biological Control 40: 306-313. Read abstract»
Wyckhuys, K. A. G., and G. E. Heimpel. 2007. Response of the soybean aphid parasitoid Binodoxys communis to olfactory cues from target and non-target host-plant complexes. Entomologia Experimentalis et Applicata
Chacon, J. M., D. A. Landis, and G. E. Heimpel. 2008. Biotic interference of a classical biological control agent of the soybean aphid. Biological Control 46: 216-225. Read abstract»
|
|
|
|||||
![]() |
![]() |
|
|
![]() |
|
This website is supported by a grant from the North Central Soybean Research Program and is compiled and hosted by the Department of Entomology, University of Wisconsin – Madison . |
|||||