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Common American birch aphidOn this page: Identification & Distribution Other aphids on the same host
Identification & Distribution
All adult viviparae of Calaphis betulaecolens are alate. Their immatures (see first picture below) are apterous, yellowish and have long near-capitate pleural hairs. The alatae (see second picture below) are bright lemon yellow without dorsal markings. The antennae of the alate have segment III dark, segments IV & V with the basal portions light and the apical portions dark, and segment VI with just the apex of the base dark. Antennal segment III has twelve to eighteen oval secondary rhinaria. The apical rostral segment (R IV+V) is usually more than 0.14 mm long, as long as or a little longer than second hind tarsal segment (HT II) (cf. Calaphis leonardi, Calaphis viridipallida and Calaphis flava, whose R IV+V is usually less than 0.14 mm long and shorter than HT II). The forewing veins are heavily bordered with fuscous and the tibiae are dark. The siphunculi are entirely pale (cf. Calaphis betulicola, which has the siphunculi with the apical halves dark brown to black.) The body length of Calaphis betulaecolens alatae is 3.0-3.5 mm.
Both images above by permission, copyright Claude Pilon, all rights reserved.
The micrographs below are of Calaphis betulaecolens: immature and adult alate.
Images above copyright CBG Photography Group under a Creative Commons License.
Calaphis betulaecolens is mostly found on the leaves of yellow birch (Betula alleghaniensis =Betula lutea) and paper birch (Betula papyrifera); also occasionally on silver birch (Betula pendula) and gray birch (Betula populifolia). Hottes & Frison (1960) reported it as common in the northern part of Illinois, where the paper birch is native, and likely to be found wherever there are trees of that species. At times Calaphis betulaecolens was abundant and the eggs formed regular masses on the low branches and watersprouts of its host. Sexuales (apterous oviparae and alate males) occur in autumn. Calaphis betulaecolens is widely distributed in North America.
Other aphids on the same host
Calaphis betulaecolens occurs on 4 Betula species (Betula alleghaniensis, Betula papyrifera, Betula pendula, Betula populifolia).