Aphis glycinesMatsumura

First report in North America, on soybean in the central U.S.A.

IDENTITY
Click here for the enlargement of
this photo or for additional images
Photo


Nombre: Aphis glycines Matsumura
Posición taxonómica:
Animalia: Arthropoda: Insecta: Homoptera: Aphididae
Nombre común: soybean aphid

Importancia:
The soybean aphid is a major pest of soybean in Asia, and is now found in the central U.S.A.

Preocupación: Aphids found infesting Wisconsin soybeans in July 2000 were originally identified as cotton or melon aphids, Aphis gossypii, but were subsequently determined to be soybean aphids, A. glycines. The North American distribution was quickly determined to include Wisconsin, Michigan, Minnesota, and Illinois; and more recently Indiana, Iowa, Kentucky, Missouri, and Ohio. Reports from West Virginia will require further confirmation. The extent of this distribution suggests the pest may have been present at unobserved levels for two or more years. The highest densities have been observed in Illinois, Michigan, Minnesota, and Wisconsin.

Aphis glycines is considered a major pest of soybean in China (CABI CPC, 1999). Although this reputation results primarily from severe feeding damage, it also has the capacity for vectoring numerous plant viruses (see Vectors).

Hospedantes: Aphis glycines is heteroecious (host alternating), between soybean (Glycine max) and buckthorn (Rhamnus spp.), where the eggs overwinter. In Asia, the overwintering host is known to be R. davurica, which also occurs in several states in the U.S. (North and South Dakota, Nebraska, Iowa, Illinois, Michigan, and Ohio). The host status of other Rhamnus spp. is currently unknown, but soybean aphids in the sexual stage have been found on R. cathartica in Michigan and Illinois, which may indicate overwintering potential in the North-Central U.S. Overwintering host preference is an active area of current research focus.

Vector(es)/Dispersión: Although no viral transmissions have been documented in the U.S., soybean aphids in Asia are known to vector soybean mosaic potyvirus (SMV), abaca mosaic, beet mosaic, tobacco vein-banding mosaic virus, peanut stripe potyvirus, mungbean mosaic virus and bean yellow mosaic virus. The damage thus far observed in the U.S. is from feeding only.

Distribución:
Australia; China; Indonesia; Japan; Korea; Malaysia; Philippines; Russia; Thailand; U.S.A. (new); Vietnam

Estrategias de detección
The soybean aphid is one of only a few aphid species known to attack soybean as a primary host. Soybean stem apices and young leaves are colonized early in the season and adults occur on leaf undersides later in the season. Common symptoms of aphid feeding on soybeans include crinkled or cupped leaves that may turn yellow.

In the soybean aphid's native Asian distribution, alate (winged) adults fly to buckthorn (Rhamnus spp.) in the fall, where they reproduce sexually and deposit eggs for overwintering. The ecology of soybean aphid overwintering in its newly discovered North American range will require further study.

Other species of legume feeding aphids, with which A. glycines might be confused, are the cotton aphid (A. gossyppii) and the cowpea aphid (A. craccivora). It has been suggested that these species are easily distinguished based on morphological characters, but in practice it is recommended that identifications be confirmed by a specialist. Due to the small size of nymphs and adults relative to other aphis species, a handlens (min. 10X) will greatly facilitate observation. If available, alate specimens are preferable for identification purposes. Soybean aphids are pale yellow when alive, with black siphunculi and pale cauda.

Efforts are currently underway to develop a standardized sampling protocol for individual states, in order to better delimit the current distribution and density.

Otro tipo de información:
Useful Links:
National Plant Board Alert
Australian Agric Scientific Collections Unit Fact Sheet (Good Photos)
MSU Website
UWI Website
Another MSU Website (Good Links Section)
IA State Website

Documentos relacionados:
CABI Crop Protection Compendium Datasheet (1999)    aphisglycines.htm