Woolly birch aphid (also called witch hazel gall aphid) is easily recognized by a covering of wool-like strands. Next spring female aphids will hatch out of these eggs and begin feeding on newly-emerged Witch-hazel leaves. Dear Gene: River birches can be attacked by an insect known as the spiny witch hazel gall aphid. A. Kunkel, Ornamentals IPM Extension Specialist, University of Delaware Winged adult green peach aphid. Dark green foliage turns a beautiful buttery yellow in the fall. Witch-hazel (Hamamelis virginiana) leaf with Witch-hazel cone gall, caused by an aphid (Hormaphis hamamelidis) Both of these aphids spend part of their life cycle on birch trees. Overwintering eggs are laid on witch-hazel in June and July. Each year, this Aphid goes through seven generations between spring and fall and only a couple are actually found on Witch Hazel. Spray with horticultural oil for some control. However, the common pest on birch, particularly river birch right now, is the Spiny Witch-hazel Gall Aphid Hamamelistes spinosus. Witch hazel gall aphid on river birch. Infested leaves crinkle up and take on a corrugated appearance in response to the aphids' feeding. Damage to a tree from winter storms. In autumn a second winged generation develops and flies back to the witch-hazel where eggs are laid on the twigs to start the process again the following spring. Witch-hazel branches have been used as divining rods to find underground water sources, a practice sometimes referred to as ‘water witching’. Both this aphid and the previous one migrate to birch for part of their life cycle. This gall, rich in nutrients, provides both food and shelter for the female aphid. Photo found at: http://www.na.fs.fed.us/ra/annualreport/fy06/images/pic07.jpg It is "Systemic Insect Killer" by Ortho. In the spring, this aphid feeds on river birch leaves. While inside the gall, the female aphid will produce young that eventually emerge in two forms, with two destinies: A wingless form stays on the host plant; the winged form goes to live on Birch trees. Witch Hazel Gall Aphids. The specific type of aphid that feeds on river birch foliage is known as the spiny witch-hazel gall aphid. The best cultivar of river birch for the landscape is ‘Heritage’ which has a similar growth habit to white birch, but has exfoliating bark in colors ranging from beige to salmon. A. Kunkel, Ornamentals IPM Extension Specialist, University of Delaware Winged adult green peach aphid. Inside these structures in the witch hazel’s leaves, baby aphids grow to maturity and eventually create the next generation of aphids. It has a complicated life cycle in that it alternates between two hosts: birch (Betula) and witch hazel (Hamamelis spp.). It starts as a green and fleshy projection that hardens into a brown, spiky object by winter. Leaf Distortion Witch Hazel Gall Aphid Leaves develop “corrugations” or pockets Leaf Blister Reddish or yellow-green blisters ... suited to Maryland’s climate is the river birch, Betula nigra. During ‘Episode 10 - Witch Hazel Rising: An Explosive Late Bloomer’ we found a bunch of conical galls growing on the Witch-hazel leaves. River birch is a popular, fast-growing native tree for the home landscape. Photo by: B. It has a complicated life cycle in that it alternates between two hosts: birch (Betula) and witch hazel Hamamelis spp.) Eastern tent caterpillar feeds on Witch-Hazel leaves. The host plant is witchhazel (Hamamelis virginiana). Aphids. Witch-hazel (Hamamelis virginiana) leaf with Witch-hazel cone gall, caused by an aphid (Hormaphis hamamelidis) Both of these aphids spend part of their life cycle on birch trees. A. Kunkel, Ornamentals IPM Extension Specialist, University of Delaware Woolly beech aphids are active later in the spring. Every year without fail, some of the leaves on my River Birch change, becoming weirdly distorted and deformed. This insect is also sometimes called the witch hazel cone gall aphid. witch-hazel gall aphid (Hamamelistes spinosus), which lives in the concavities of the lower leaf surface covered with wax and silk substances (Figure 2). There are a number of species of aphids that feed on most species of birch trees, including river birch. The witch-hazel cone gall aphid (Hormaphis hamamelidis) is a minuscule insect, a member of the aphid superfamily, whose presence on a witch-hazel plant is easily recognizable by a conical gall structure, green at first, it turns bright red. The small whitish aphids cluster in colonies on the undersides of leaves. A. Kunkel, Ornamentals IPM Extension Specialist, University of Delaware Woolly beech aphids are active later in the spring. Witch-hazel Cone Gall Aphids Laying Eggs. Winged aphids develop inside the galls, then leave and fly to birch trees. This aphid is a common pest on birch, particularly river birch. Females spend the winter on river birch and move to expanding leaves at bud break where they deposit live young. These findings confirm the original published life cycle description for the same locality. This species of aphid feeds on witch hazel and birch trees. This is caused by an aphid with a peculiar name, the spiny witch-hazel gall aphid; so named because it spends part of its life on witch-hazel and part on birch. River Birch Leaves Turning Yellow : Dropping Off In Summer. Leaf Gall Aphids: The galls witch hazel plants often develop when they grow near birch trees are actually insect nurseries for the witch hazel leaf gall aphid. Identification & Distribution. The aphid’s offspring then develop inside the gall where they are protected from predators as they develop, getting the nutrients they need from the sap of the plant. This paper is a very thorough study of the witch hazel gall aphids: Lewis, I.F. This is not a disease but is caused by an insect called spiny witch hazel gall aphid. The spiny Witch-Hazel gall aphid causes galls 3/4-inch-long with long, coarse spines. These structures are created by Cone Gall Aphids (Hormaphis hamamelidis) and have a fascinating life. At this time of year there is a species of aphid, Hormaphis hamamelidis, that is laying eggs on Witch-hazel branches. At low elevation in northern Virginia, the aphid had seven distinct generations alternating between the primary host, witch-hazel (Hamamelis virginiana), and a secondary host, river birch (Betula nigra). In the spring, this aphid feeds on river birch leaves. Witch hazel gall aphid on river birch. Although there is no accepted common name for Hamamelistes spinosus, it could be called the spiny witch-hazel gall aphid or woolly birch aphid for its appearance on the hosts that it attacks.. On birch, this insect overwinters on the bark as a hibernating female, sometimes called a “pupa.” 1958. Spray with dormant oil before the plants begin to grow in the spring. I took a leaf to the nursery where I bought the tree and they sold me an insecticide to spray on it. Birch trees are susceptible to a variety of aphids, "sucking bugs" that feed on plant tissue fluid. Feeding by the small aphids gives leaves a corrugated appearance. Eastern tent caterpillar feeds on witch-hazel leaves. Both this aphid and the previous one migrate to birch for part of their life cycle. The galls are green tinged with red. Hamamelistes spinosus host alternates from its primary host, witch hazel (Hamamelis virginiana), where it lives in a gall, to its secondary host, birch (Betula species), where it lives in a pseudogall.Unusually for aphids, this cycle take two years to complete. Small yellowish insects on underside of leaf. witch-hazel leaf gall aphid, Hormaphis hamamelidis. When spiny witch-hazel gall aphids feed on river birch the leaves become crinkled and discolored, with pink corrugated ridges. These aphids can also be found on birch, where they are known as the River birch aphid.Aphids from birch trees migrate to witch-hazel to create the next generation of aphids that will emerge the next spring. There, they give birth to scale-like insects, which feed and induce the birch to form corrugated galls on the leaves. The aphids become active in the spring when the leaf buds are opening. Leaf spots, Blotches, Anthracnose. Secondary or lateral veins in the leaf often take on a yellow (chlorotic) appearance. The overwintering eggs on witch hazel hatch in the spring. As River Birch is a native tree as well as being fairly common in landscaping, it is likely this alternate host is close enough to this aphid colony to be supporting them. At low elevation in northern Virginia, the aphid had seven distinct generations alternating between the primary host, witchhazel (Hamamelis virginiana), and a secondary host, river birch (Betula nigra). and L. Walton. This “potato chip effect” is what you are seeing. These aphids cannot complete their life cycle on river birch alone, they have to migrate to witch-hazels (Hamamelis spp). Photo by: B. Woolly Birch Aphid; June 22, 2005: Woolly aphids are being found on river birch in northern Illinois. Your description of damage is typical of spiny witch-hazel gall aphid (Hamamelistes spinosus). Photo provided by: B. The spiny witch-hazel gall aphid causes galls 3/4 inch long with long, coarse spines. This leaf distortion is actually caused by aphids - Spiny Witch Hazel Gall Aphids , to be exact - which feed on birch leaves starting in the spring and then eventually move on to Witch Hazel trees for the second part of its life cycle. However, the common pest on birch, particularly river birch right now, is the Spiny Witch-hazel Gall Aphid Hamamelistes spinosus. The aphids that cause these galls (Hormaphis hamamelidis) have a very complicated life cycle, but part of it is spent on River Birch (Betula nigra). My river birch has an aphid and after doing some research, it is apparently Spiny Witch-hazel Gall Aphids. Photo provided by: B. In early summer it moves on to witch hazel foliage, but will not infest any other type of plant. Two divergent life cycles associated with different elevations and latitudes have been documented for the witch-hazel leaf gall aphid, Hormaphis hamamelidis. Witchhazel gall aphids cause conical protrusions on witchhazel leaves. Removing the nest by hand will control the infestation. This aphid species feeds by sucking sap from leaves, causing chlorosis, or necrosis when the damage is severe. Found in buds, the Spiny witch-hazel leaf gall houses developing aphids inside of it. Witch-hazel branches have been used as divining rods to find underground water sources, a practice sometimes referred to as ‘water witching’. The galls are green tinged with red. The specific type of aphid that feeds on river birch foliage is known as the spiny witch-hazel gall aphid.