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"It has long been an axiom of mine that the little things are infinitely the most important" |
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Myzocallis granovskyiLongtailed oak aphidOn this page: Identification & Distribution Other aphids on the same hostIdentification & DistributionAll 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 hostMyzocallis granovskyi has been recorded on 6 species of oak (Quercus laurifolia, Quercus nigra, Quercus palustris, Quercus rubra, Quercus shumardi, Quercus velutina).
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