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Myzocallis granovskyi

Longtailed oak aphid

On this page: Identification & Distribution Other aphids on the same host

Identification & Distribution

All adult viviparae of Myzocallis granovskyi are alate and coloured yellow to orange-yellow. The species 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. The thorax is rather pale, except that the lateral margins of the pronotum usually each have a conspicuous dark longitudinal stripe, continuing on the mesonotum to the base of the forewing. But note: spring generations of Myzocallis granovskyi can almost entirely lack pigmentation, except for dusky patches at tips of Rs and apical branch of medial wing veins. The antennae are shorter than body and are pale apart from black rings around the apices of segments III-VI. The pronotum has 2-3 marginal hairs on each side and 2 (rarely 1 on one side) anterior pleural hairs.

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

The femora are black on the distal third (cf. Myzocallis bella, Myzocallis melanocera and Myzocallis neoborealis, which all have the femora black over at least half the length; and cf. Myzocallis walshii, which has entirely pale femora). The tibiae of all legs are black (cf. Myzocallis ephemerata, Myzocallis exultans, Myzocallis multisetis, Myzocallis longirostris & Myzocallis walshii, which have only the fore-tibiae very dark or black, distinctly darker than the mid and hind tibiae). The lobes of the anal plate are longer than their basal width and the cauda (see clarified mount below) has an elongate "neck" (cf. all other Myzocallis on oak, none of which have these characteristics). The body length of alate Myzocallis granovskyi viviparae is 1.8-2.3 mm. Immature Myzocallis granovskyi (not pictured) are pale yellow with a grey waxy bloom, dark dorsal patches and dark tibiae.

The image below shows a clarified mount of an alate vivipara of Myzocallis granovskyi.

Image above copyright Smithsonian Institution, under a Creative Commons Attribution License.

Myzocallis granovskyi does not host alternate. It feeds only on a few oak (Quercus) species. Unlike most other species of Myzocallis on oak, it usually feeds on the upper sides of leaves. Sexual forms develop in October and the oviparae deposit overwintering eggs on oak. Myzocallis granovskyi is found throughout eastern USA, and has been collected once in the west (Oregon). It is also found in Ontario and Quebec in Canada.

 

Other aphids on the same host

Myzocallis granovskyi has been recorded on 6 species of oak (Quercus laurifolia, Quercus nigra, Quercus palustris, Quercus rubra, Quercus shumardi, Quercus velutina).

Acknowledgements

We have made provisional identifications from high resolution photos of living specimens, along with host plant identity. In the great majority of cases, identifications have been confirmed by microscopic examination of preserved specimens. We have used the keys and species accounts of Boudreaux & Tissot (1962) and Richards (1978) along with Blackman & Eastop (1994) and Blackman & Eastop (2006). We fully acknowledge these authors 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).

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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.

  • 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