Elm Cockscomb Gall Aphid – Colopha ulmicola

Elm Cockscomb Gall Aphid (Colopha ulmicola)


Latin Name: Colopha ulmicola

Common Name: Elm Cockscomb Gall Aphid


  • Colopha compressa lives in cockscomb-shaped galls on the upper surface of American and red elm leaves that are crushed laterally.
  • When the galls are first developed, they are scarlet, but later in the season, they turn brown.
  • By early summer, aphids have developed a slit on the underside of the galls and are flying to the roots of grasses.

Hosts plants:

American elm (Ulmus Americana L.) primary whereas sedges (Carex spp.) and cottongrass (Eriophorum spp.) are secondary hosts plants

Damage caused by Colopha ulmicola:

Due to the appearance of two types of aphid galls on native elm leaves at this time of year, they might appear a little scraggly. Fortunately, none of these galls does considerable damage to the elm tree’s general health. These strange-looking plant structures might ruin the beauty of their deep green elm leaf platforms.

Description about Flower, Fruit, and seed feeder’s insects:

Lygus bugs, also known as tarnished plant bugs (Lygus lineolaris (Palisot)) and western plant bugs (Lygus Hesperus Knight), feed on a wide variety of broadleaf plants

Lygus bugs are frequent and widespread generalist flower and seed eaters that can reduce seed output dramatically. They eat flower buds and growing fruits at all phases of development, causing them to die. In Colorado and Oregon, a little seed beetle (Acanthoscelides sp.) was discovered in globe mallow seed-producing farms. The beetles are little and black, measuring around 5 mm (0.2 in) in length. Legless larvae with a black head capsule are white to cream in hue. Damage appears to be caused by larval feeding on the seeds themselves. Keep an eye out for this insect while sampling globe mallow seed crops.

Life History and Habits: 

The elm cockscomb gall aphid is only one of several aphid species with complicated lifestyles. These little sapsuckers have been living underground for much of the summer, sucking sap from the roots of grasses in my lawn. These grass feeders create a generation of vagabonds that take to the air searching for their winter home, which is my elm tree when the weather cools and the days become shorter. Females of the sexual generation migrate to the tree after consummating a male relationship and depositing a single big egg in their winter hideaway behind a bark flap. The egg survives the harsh winter in this haven.