Myzocallis bella Myzocallis bellus (Eastern dark-legged oak aphid) identification, images, ecology, control

Myzocallis bella is a member of the black-bordered oak aphid group (subgenus Lineomyzocallis), characterized by the costal margin of the forewing usually having a characteristic continuous band of black pigment extending beyond the pterostigma to the wing tip.

All adult viviparae of Myzocallis bella are alate. These alatae (see two pictures of presumed Myzocallis bella below) have the body colour yellow, apart from conspicuous dark longitudinal stripes, running on each side from behind the eye to the base of the forewing. On the prothorax the interposed yellow space between the two stripes is longer than broad (cf. Myzocallis melanocera & Myzocallis neoboralis which have the interposed yellow space broader than long). The legs are black, with only the extreme bases of the femora, trochanters and coxae pale (cf. Myzocallis granovskyi, which has the femora black on the distal third). The antennae have segments I & II pale or dark, and segments III through VI pale, with a dark tip. Antennal tubercles are poorly developed. Antennal segment III has 4-6 round secondary rhinaria. The rostrum reaches to just beyond the front coxae. Siphunculi are smooth without an apical flange. The anal plate is much less deeply indented than the basal width of the lobe of the anal plate, and the neck of the cauda is short.

Note: We cannot be 100% certain that the specimens shown are indeed Myzocallis bella, rather than Myzocallis neoborealis (formerly called the northern form of Myzocallis melanocera), given that summer viviviparae of the two species are almost identical in appearance (see Boudreaux & Tissot, 1961 & Quednau, 1999), and they share several of the same hosts. The interposed yellow space on the prothorax of the specimen shown here appears to be almost square - hence it is difficult to discriminate the two species.

Myzocallis bella (eastern dark-legged oak aphid) alate vivipara lateral view found on Quercus rubra (northern red oak) in Groton, Massachusetts, USA on 23 Sep 2021; Tom Murray

Both images above copyright Tom Murray under a Creative Commons Attribution License.

Immature Myzocallis bella (see picture below) are yellow, with legs yellow, except for the black tarsi. They have 5 pairs of large, distinct quadrate dorsal abdominal patches together forming an oval shape, bearing slender blunt hairs, and usually only one submarginal hair per segment. The alatoid nymphs tend to be more heavily pigmented than those of Myzocallis melanocera, which have a variable number of dorsal patches (this discriminant may not apply for Myzocallis neoboralis).

Myzocallis bella (eastern dark-legged oak aphid) colony at Reveler Conservation Area Stormont, Dundas and Glengarry United Counties, Ontario, Canada on 29 Aug 2017; Christine 123

Image above copyright Christine 123 under a Creative Commons Attribution License.

Myzocallis bella is monoecious on various red oaks (see below). They are holocyclic, with sexuales occurring in October-December. The species is widespread in eastern North America where it appears to coexist with several, closely related, similar species.

Other aphids on the same host

Myzocallis bella has been recorded on 7 species of oak (Quercus alba, Quercus coccinea, Quercus ilicifolia, Quercus macrocarpa, Quercus robur, Quercus rubra, Quercus velutina).

Blackman & Eastop list 19 species of aphid as feeding on white oak (Quercus alba) worldwide, and provide formal identification keys (Show World list). Of those aphid species, Baker (2015) lists 2 as occurring in Britain (Show British list).
Blackman & Eastop list 12 species of aphid as feeding on bur oak (Quercus macrocarpa) worldwide, and provide formal identification keys (Show World list). Of those aphid species, Baker (2015) lists none occurring in Britain (Show British list).
Blackman & Eastop list 18 species of aphid as feeding on northern red oak (Quercus rubra) worldwide, and provide formal identification keys (Show World list). Of those aphid species, Baker (2015) lists 4 as occurring in Britain (Show British list).
Blackman & Eastop list 14 species of aphid as feeding on black oak (=quercitron oak, Quercus velutina) worldwide, and provide formal identification keys (Show World list). Of those aphid species, Baker (2015) lists none as occurring in Britain (Show British list).

Acknowledgements

We are grateful to Tom Murray and Christine for making their images available under a creative commons license.
Identification was made by Natalie Hernandez (Bugguide) and by us from the photos of living specimens. We have used the keys and species accounts of Boudreaux & Tissot (1962), Richards (1965) and Quednau (1999), together with information from Roger Blackman & Victor Eastop in Aphids on Worlds Plants. We fully acknowledge these authors and those listed in the reference sections as the source for the (summarized) taxonomic information we have presented. Any errors in identification or information are ours alone, and we would be very grateful for any corrections. For assistance on the terms used for aphid morphology we suggest the figure provided by Blackman & Eastop (2006).

Useful weblinks

References

Boudreaux, H.B. & Tissot, A.N. (1962). The black-bordered species of Myzocallis of oaks (Homoptera, Aphidae). Miscellaneous Publications of the Entomological Society of America 3, 121-144.
Quednau, F.W. (1999). Atlas of the Drepanosiphine aphids of the World. Part I: Panaphidini - Myzocallidinae. Contrib. Am. ent. Inst 31, 1-281.
Richards, W.R. (1968). A synopsis of the world fauna of Myzocallis (Homoptera: Aphididae). Memoirs of the Entomological Society of Canada, Ottawa 100 Supplement S57, 3-76. Abstract

Myzocallis bella (= Myzocallis bellus)

Eastern dark-legged oak aphid

Identification & Distribution

Other aphids on the same host

Acknowledgements

Useful weblinks

References