''Melaphis rhois'' is an

aphid Aphids are small sap-sucking insects in the Taxonomic rank, family Aphididae. Common names include greenfly and blackfly, although individuals within a species can vary widely in color. The group includes the fluffy white Eriosomatinae, woolly ...

species first identified by

Asa Fitch Asa Fitch (February 24, 1809 – April 8, 1879) was a natural historian and entomologist from Salem, New York. Biography Asa Fitch was born at Fitch's Point, Salem, New York on February 24, 1809. His early studies were of both natural history ...

in 1866. Known as the staghorn sumac aphid, it is in the genus '' Melaphis''. It is a type of woolly aphid and one of the few aphids that induce the formation of galls.Paul D. N. Hebert, Terrie L. Finston and Robert Foottit
Patterns of genetic diversity in the sumac gall aphid, Melaphis rhois
1991. ''Genome'', 34: 757-762.

Ecology

The species produce galls on the staghorn sumac (''

Rhus typhina ''Rhus typhina'', the staghorn sumac, is a species of flowering plant in the family (biology), family Anacardiaceae, native plant, native to eastern North America. It is primarily found in southeastern Canada, the northeastern and midwestern Unit ...

''), an eastern North American variety of sumac, and they are also found on the smooth sumac (''

Rhus glabra ''Rhus glabra'', the smooth sumac, (also known as white sumac, upland sumac, or scarlet sumac) is a North American species of sumac in the family Anacardiaceae. Description Smooth sumac has a spreading, open habit, growing up to tall. The bar ...

)''. The gall is variously called "sumac leaf gall" and "red pouch gall" as it sometimes appears red. The galls occur when female aphids lay a single egg on the underside of the sumac leaf, inducing the leaf to form a sac over the egg. According to Hebert et al, the eggs "give rise to a series of

parthenogenetic Parthenogenesis (; from the Greek + ) is a natural form of asexual reproduction in which the embryo develops directly from an egg without need for fertilization. In animals, parthenogenesis means the development of an embryo from an unfertiliz ...

generations, which remain within the gall. Winged females leave the gall in late summer and fly to moss, where they establish asexually reproducing colonies. The colonies produce the males and sexual females responsible for recolonizing sumac each spring." In 1989, it was reported that the use of alternate plant hosts by the aphids dates from 48 million years before present. When identified, this was the oldest known documented insect-plant relationship; much older relationships have subsequently been discovered. See more at Paleoparasitology.

Relation to plant mortality

Though parasitic, the aphids are considered inconsequential to the health of the host plant.Tom Glasgow
Identify the problem before applying pesticide
New Bern Sun Journal (North Carolina), August 1, 2014 Accessed September 4, 2014 Unlike the Chinese gall, sumac leaf galls have no commercial value.

References

External links

Bibliography for Melaphis rhois (1866 - 1963)
Biodiversity Heritage Library {{Taxonbar, from=Q10580975 Aphididae Insects described in 1866 Taxa named by Asa Fitch Gall-inducing insects Hemiptera of North America