Pine tortoise scale

Pine tortoise scale - Long, narrow, flat, white shields protecting the males
  • Latin name: Toumeyella parvicornis (Cockerell)
  • French name: Cochenille-tortue du pin
  • Order: Homoptera
  • Family: Coccidae
  • Synonym(s): Toumeyella numismaticum (Pettit & McDaniel)
Description

Distribution

Prairie Provinces, Eastern Canada

Micro-habitat(s)

Twig, Annual shoot, Branch

Damage, symptoms and biology

Pine tortoise scale larvae cause yellowing of the needles, and reddening and mortality of the twigs. The honeydew and frass left by the female on the twigs are eventually covered by sooty mold (black fungus), giving the branches a blackish appearance.

The newly hatched larvae begin feeding on young shoots, sucking the sap from the twigs. They produce a waxy protective substance. Adult females can be detected in groups on twigs by the presence of their brick-red, hard, shell-like covers. In the spring, the eggs are laid and develop beneath this cover.

Although pine tortoise scale prefers small trees, it sometimes feeds on larger pines. A severe infestation can result in branch mortality and even the death of the entire tree.

In pine tortoise scale, only the young larvae, or crawlers, are mobile. They eventually become fixed to feeding sites on annual shoots, after which they are no longer mobile. Male and female scales develop differently: the cover of the male is long and whitish in colour. They have a pupal stage and the adults are winged. The cover of the females is rounded and brick-red in colour. Immature females mate, continue their development until late fall and overwinter at this stage. The pine tortoise scale has one generation per year.

Life cycle (East of the Rockies)

Life cycle (East of the Rockies)
Stage/Month J F M A M J J A S O N D
Egg
 
Larva
 
Pupa
 
Adult
 
 

Other information

Pine tortoise scale was first reported in 1920 in the state of Wisconsin, in the United States. Since then, it has also been reported in Canada. Infestations of this insect are generally localized, but can be severe.

To limit damage, it is recommended that the affected part of the host tree be pruned out and destroyed. The presence of predatory larvae of the lady beetle family contributes to controlling pine tortoise scale invasions.

Canadian Forest Service Publications

Pine tortoise scale

Diet and feeding behaviour

  • Sap-feeding : Feeds on plant sap.
    • Piercing-sucking: Has specialized mouthparts for sucking the fluids from plants, thereby causing deformities or killing the affected plant sections.
Information on host(s)

Main host(s)

Jack pine, scots pine

Photos
  • Pine tortoise scale Young nymphs at the base of a jack pine twig
  • Pine tortoise scale Long, narrow, flat, white shields protecting the males
  • Pine tortoise scale Old damage
  • Pine tortoise scale Black mushroom developing on female sweet secretions
  • Pine tortoise scale Close-up of damaged twig
  • Pine tortoise scale Young jack pine seriously affected
  • Pine tortoise scale Old damage
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