The white marked tussock moth (Orgyia leucostigma) can cause considerable damage to shade trees in early summer with the larvae’s leaf consuming feeding habits.  Tree death is rare, but high populations have the potential to significantly reduce the aesthetic value of the tree by defoliating it.  Larvae may become a nuisance due to dropping excrement, and possess “nettling hairs", which may cause an allergic skin reaction when come into contact with.

The white marked tussock moth affects a wide variety of trees.  Some of the preferred hosts include basswood (Tilia), maple (Acer), sycamore (Platanus), poplar (Populus), apple (Malus), oak (Quercus), pear (Pyrus), plum (Prunus), willow (Salix), and elm (Ulmus).

Pest
Orgyia leucostigma

Symptoms
* Small holes in leaves in early summer
* Entire leaves may be consumed except for the veins and midribs by mid summer

Signs
* Larvae are 1 to 1 ½ inches (25-38mm) in length
* Larvae have a bright red head, yellowish body with a wide black stripe along the back and wider gray stripe down each side.  
* Also present on the body are a pair of black upright tufts of hair on the first segment of the thorax, a single black tuft of hair on the eighth abdominal segment, white to tan tufts on each of the first four abdominal segments, and red dots on the sixth and seventh segments.
* The adult male moth is gray brown with dark wavy bands on the forewing and a white spot.  Wingspan is about 1 ¼ inches.  Females are a grayish white and wingless.

Life Cycle
* Eggs hatch in early spring
* Larvae feed until early summer where pupation begins
* Larvae pupate in cocoons and emerge in about 2 weeks.
* Adult females emerge, mate, and lay eggs in a mass on her cocoon
* Overwintering is in the egg stage
* One generation in the North.  Three generations are possible in the South.

Distinguish from look-alikes
Proper identification of the host plant, timing of symptoms, and particular marking characteristics are key distinctions between caterpillars.

Distribution
The white marked tussock moth is found throughout the eastern United States and west to Texas and Colorado.

Though extensive damage is rare, control is sometimes needed when populations are high, especially when tussock moth feeding coincides with abiotic stress.  Chemical control is most effective on young larvae that are present in early summer. 

Properly timed soil applications will result in high levels of control and are a more feasible option than spraying on taller or difficult to spray trees.  Foliar spray applications can be successful if timed correctly, but proper coverage on larger trees becomes more difficult. 

Auburn University

U.S. Forest Service

Texas A&M