''Melaphis rhois'' is an

aphid Aphids are small sap-sucking insects and members of the superfamily Aphidoidea. Common names include greenfly and blackfly, although individuals within a species can vary widely in color. The group includes the fluffy white woolly aphids. A t ...

species first identified by

Asa Fitch Asa Fitch (February 24, 1809 – April 8, 1879) was a natural historian and entomologist from Salem, New York. His early studies were of both natural history and medicine, which he studied at the newly formed Rensselaer Polytechnic Institute, g ...

in 1866. Known as the staghorn sumac aphid, it is the only species in the genus ''Melaphis''. It is a type of

woolly aphid Woolly aphids (subfamily: Eriosomatinae) are sap-sucking insects that produce a filamentous waxy white covering which resembles cotton or wool. The adults are winged and move to new locations where they lay egg masses. The nymphs often form l ...

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 Anacardiaceae, native to eastern North America. It is primarily found in southeastern Canada, the northeastern and midwestern United States, and the Appalachian M ...

''), 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 species of sumac in the family Anacardiaceae, native to North America, from southern Quebec west to southern British Columbia in Canada, and so ...

)''. 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 grc, παρθένος, translit=parthénos, lit=virgin, label=none + grc, γένεσις, translit=génesis, lit=creation, label=none) is a natural form of asexual reproduction in which growth and development ...

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. Staghorn Sumac (Rhus typhina) Gall

References

External links

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