Biology, images, analysis, design...
|"It has long been an axiom of mine that the little things are infinitely the most important" |
Norway Maple Periphyllus AphidIdentification & Distribution Biology & Ecology Damage & Control
Identification & Distribution:Apterae are yellowish with brown dorsal markings, usually comprising a broad spinal stripe on head and thorax and a large V-shaped mark on the dorsal abdomen. The cauda is tongue shaped, about as long as broad, and often with a slight constriction. The body length is 1.9-3.0 mm. Alatae have dark marginal sclerites, but other dorsal sclerotization is limited to the spinal area, not forming cross-bands.
The Norway maple periphyllus lives on the undersides of leaves of Norway Maple (Acer platanoides). They often form large colonies producing much honeydew and are visited by ants and other insects. This species does not produce aestivating nymphs. Oviparae and alate males are produced in October-November. The Norway maple periphyllus is native to Europe, but it was introduced on Norway maple to North America, where it is now also widespread.
This shows an aptera of the Norway Maple aphid along with a first instar nymph. Although they often form quite large compact colonies, this aptera was on her own with her nymphs.
Biology & Ecology:
The eggs hatch early in spring and the fundatrices develop and stay on the bark of one-year old branches. Their nymphs constitute the second generation and develop on the undersides of the leaves, as soon as the buds open.
There is then a third generation, some of which develop into alates which disperse to colonize other trees (Hill Ris Lambers, 1947 ). The picture below shows a developing fourth instar alatiform nymph (left) and an apterous adult (right) along with several young nymphs.
Subsequent generations are usually apterous, and live in small groups on the undersides of the leaves along the main veins. The apterae often collect at the same spot and sit with their heads almost touching, depositing their offspring. Hill Ris Lambers (1947) reports that the colonies are usually attended by ants (Lasius spp.) during the summer. Stroyan (1977) notes the species may be locally common but is little recorded.
In the autumn they produce oviparous females and alate males. After mating, the oviparae lay their eggs on the wood of the branches.
Damage and control
Unlike most Periphyllus species, this one causes marked leaf wrinkling at the site of the colony. Since it can be abundant, it is often considered a pest species both in America and in Europe (Ripka (1999)).