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Sapling sycamore aphidIdentification & Distribution Biology & Ecology Damage & Control
Identification & Distribution:All adult Drepanosiphum acerinum viviparae are alates. These alates are pale whitish-green to chrome yellow, with thoracic lobes darker. There are often one or two short brown bars on abdominal tergites 4-5 only, and usually a conspicuous brown-black spot in front of the base of each siphunculus. The siphunculi are only slightly swollen, and are either entirely or distally dark or black. The long antennae are pale but the segments have brownish tips. The Drepanosiphum acerinum body length is 2.1- 3.3 mm.
The first picture is a dorsal view of an alate vivipara of the sapling sycamore aphid on a sycamore leaf. Note the dark thoracic lobes and two dark abdominal cross bars. The second picture is a lateral view to show one of the brown-black spots in front of each siphunculus.
Drepanosiphum acerinum aphids live on sycamore (Acer pseudoplatanus) saplings in the shade. Sexual forms occur in September-October. The species is found throughout Europe, except the Baltic region.
Biology & Ecology:
In Britain Drepanosiphum acerinum is the least common of the four aphid species that live on sycamore - the others are Drepanosiphum platanoidis , Periphyllus acericola and Periphyllus testudinaceus . It is described by Stroyan (1977) as being local. It is the last of these species to hatch from the eggs, well after bud burst in late April when the leaves are nearly fully grown. The picture below shows an alatiform fourth instar nymph.
Unlike the common sycamore aphid, the sapling sycamore aphid reproduces all summer with no aestivation. Wellings (1981) has shown that at high temperatures the growth rate of the sapling sycamore aphid is significantly higher than that of the common sycamore aphid. Dixon & Hopkins (2010) comment that this seems to indicate that it is not poor nutrition but high temperatures that make sycamore a poor host for some other aphid species in mid-summer leading them to aestivate.
This shows a Drepanosiphum acerinum extruding a drop of honeydew. Unlike Periphyllus testudinaceus, this species is not ant attended and indeed probably falls prey to ants attending other species on sycamore.
Damage and control
This a relatively rare species so control is not normally an issue. However, there is evidence that it is a vector of Maple Leaf perforation virus (Sutakova, 1984 ) which could be a problem for ornamental varieties.