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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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Aphis folsomiiVirginia Creeper AphidOn this page: Identification & Distribution Biology & Ecology Other aphids on the same host Damage & ControlIdentification & DistributionAdult apterae of Aphis folsomii are dark reddish brown, with dark or dusky siphunculi (see first picture below). Their antennal tubercles are weakly developed. The antennae of apterae are pale, apart from segment VI which is dark. The longest hairs on the third antennal segment are less than 3.5 times the basal diameter of the base of antennal segment III. The apical rostral segment (RIV+V) has 8-10 accessory hairs (cf. Aphis illinoisensis and Aphis fabae, which each have only 2 accessory hairs on RIV+V). Abdominal tergites 1 and 7 always have marginal tubercles. Their legs are dark apart from the apical parts of the tibiae. The cauda is short and broad, about as long as its basal width, with more than 20 hairs (cf. Aphis illinoisensis and Aphis fabae, which each have the cauda much longer than its basal width, with 7-19 hairs). The body length of adult apterae is 1.6-1.8 mm. Immature Aphis folsomii are light reddish brown with pale siphunculi.
Images above by permission, copyright Claude Pilon, all rights reserved. Alate Aphis folsomii (see second picture above) are reddish brown with a black head, thorax, antennae and legs and siphunculi (see Boudreaux, 1947). The antennal segments III, IV and V of alatae are all about the same length (cf. Aphis illinoisensis, which has antennal segment III much longer than IV or V). Aphis folsomii feeds on Parthenocissus species such as Virginia Creeper (Parthenocissus quinquefolia) and Boston Ivy (Parthenocissus tricuspidata). They form dense clusters along the midribs of leaflets and petioles, where they are attended by ants (see third picture above). The ant Crematogaster ashmeadi has been recorded as attending Aphis folsomii on Parthenocissus quinquefolia (Nielsson et al., 1971). Hottes & Frison (1931) reported this aphid species is never abundant enough to be conspicuous, and is not likely to become of economic importance. Davis (1908) has described the sexual as well as the viviparous forms. The Virginia Creeper Aphid is widely distributed in the USA east of the Rocky Mountains. Other aphids on the same hostAphis folsomii has been recorded from 3 Parthenocissus species (Parthenocissus inserta, Parthenocissus quinquefolia, Parthenocissus tricuspidata). Blackman & Eastop list 10 species of aphid as feeding on Parthenocissus worldwide, and provide formal identification keys (Show World list). Of those aphid species, Baker (2015) lists 3 as occurring in Britain (Show British list).
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