Forest Pest Insects in North America: a Photographic Guide

Linden aphid

Eucallipterus tiliae (L.) (Hemiptera Aphididae)

Orientation to pest

Linden aphid, Eucallipterus tiliae (L.), is invasive in the United States. It is native to the Eurasia, but now occurs worldwide, wherever species of native or introduced linden trees (Tilia) occur. The winged adults are easily recognized by the black stripe along the body and the cloudy-black at the wing edge. Trees planted along streets and by parking areas are frequently attacked, and the honeydew produced by the aphid makes walkways and cars parked beneath them sticky. Sooty mold growing on honeydew blackens the leaves. Progeny are produced continuously during the growing season. It is attacked by several genera of parasitoids as well as lady beetles and other generalist predators.

Hosts commonly attacked

Basswood, also called American linden, (Tilia americana L.) and its variety, white basswood (T. americana var. heterophylla) are North American trees that are fed on by this aphid. However, damage to these plants is rarely serious because they are less susceptible to this aphid than are the introduced species of Tilia commonly planted in urban landscapes. Damage to such introduced species is the main focus of concern with this aphid.

Distribution

This aphid is found widely in eastern North America on basswood and on exotic species of Tilia in landscape plantings. California, especially, has problems with this aphid on exotic Tilia and has introduced parasitoids for its biological control.

Images of linden aphid

Winged adult linden aphid Bob Gaia 768x512
Nymph of linden aphid Bob Gaia 768x512
Group of winged adult linden aphids on underside of leaf Whitney Cranshaw, Colorado State University, Bugwood.org 768x512 / 1536x1024
Figure 1. Winged adult linden aphid Figure 2. Nymph of linden aphid Figure 3. Group of winged adult linden aphids on underside of Tilia leaf
Honeydew and sooty mold on linden, typical signs of linden aphid Whitney Cranshaw, Colorado State University, Bugwood.org 768x512 / 1536x1024
Dark discoloration on cement caused by sooty mold growing on honeydew dripping from linden tree infested by linden aphid Whitney Cranshaw, Colorado State University, Bugwood.org 768x512 / 1536x1024
Figure 4. Honeydew and sooty mold on linden, typical signs of linden aphid Figure 5. Dark discoloration on cement caused by sooty mold growing on honeydew dripping from linden tree infested by linden aphid

Important biological control agents related to this pest species

In California, where this is an invasive aphid on exotic street trees, a species of European parasitoid, Trioxys curvicaudus Mackauer, was introduced and anecdotal information suggests this introduction lowered density of aphids on street lindens. In Europe, parasitoids seem not to be the primary regulator of linden aphid numbers, and generalist predators and density-dependent feedback from the tree are believed to be important. This aphid and seven related species occur in northern China and the Russian Far East; hence, this area may be a good source of natural enemies. There are ten parasitoid species in the superfamily Ichneumonoidea and nine in the Chalcidoidea recorded from aphids in the genus Eucallipterus.

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