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Stitchwort leafroll aphidOn this page: Identification & Distribution Other aphids on the same host
Identification & Distribution
Brachycolus stellariae lives on the upper side of the leaves of stitchworts (Stellaria spp.), especially Stellaria holostea (see uninfested plant in first picture below). The leaves are rolled into oblong pseudogalls (see second and third pictures below).
First two images above copyright Peter O'Connor and John Lyden, both under a Creative Commons License.
Adult apterae of Brachycolus stellariae (see two pictures below) are pale green, and covered with white wax powder. The head, antennae, and legs are brown, the siphunculi are pale and the cauda is dusky. Antennae are quite short, about 0.48-0.65 the body length, with the terminal process 2.4-3.6 times the base of antennal segment VI. The hairs on antennal segment III are about 0.6-0.8 times the basal diameter of that segment. The apical rostral segment is 0.55-0.72 times the second hind tarsal segment. The siphunculi are very small, flangeless, conical or barrel-shaped, with no polygonal reticulation, and less than 0.20-0.25 times the cauda (cf. Macrosiphum euphorbiae and Macrosiphum stellariae, which have long tubular siphunculi with subapical polygonal reticulation). The cauda is oblong, triangular, much shorter than the terminal process, and with 5-6 hairs (cf. Brachycolus brachysiphon in Canada, which has the cauda elongate, longer than the terminal process). Abdominal tergite VII has no supracaudal process. Body length of the adult Brachycolus stellariae aptera is 1.1-2.0 mm.
First image above, copyright AC Grosscurt, all rights reserved.
Alate Brachycolus stellariae (see picture below) have paired small faint sclerites on tergites I-III, and small crossbars on VII & VIII. Antennae are about 0.75 times body length, and bear 4-9 secondary rhinaria on antennal segment III, and 0-1 on segment IV. The cauda is rather slender and pointed.
Image above by permission of Roger Blackman, copyright AWP all rights reserved.
Brachycolus stellariae is monoecious on stitchwort (Stellaria species), rolling the leaves into pseudogalls. It has also been recorded on a species of another genus in the Caryophyllaceae, namely Moehringia trinervia. Brachycolus stellariae is holocyclic, producing oviparae and very small apterous males in September. Brachycolus stellariae is found through most of Europe, excluding Norway.
Other aphids on the same host
Brachycolus stellariae has been recorded on 3 stitchwort species (Stellaria graminea, Stellaria holostea, Stellaria nemorum).