Pear or Cherry Slug

Pear or Cherry Slug
Caliroa cerasi (Linnaeus, 1758)

Don Herbison-Evans
Stella Crossley

(updated 8 May 2010)

Caliroa cerasi
(Photo: courtesy of Merlin Crossley)

These are not true Caterpillars or slugs, but are the larvae of a Saw Fly (which is a Wasp, actually!). They are black with a white line, and with a yellow head and tail. They appear to have no legs, and slither about on their food plant, which can be many species from the plant family ROSACEAE :

  • Serviceberry ( Amelanchier species ),
  • Flowering Quince ( Chaenomeles species ), and
  • Cotoneaster ( Cotoneaster species ),
  • Hawthorn ( Crataegus species ),
  • Quince ( Cydonia oblonga ),
  • Cherry ( Prunus avium ),
  • Plum ( Prunus domestica ),
  • Pear ( Pyrus communis ), and
  • Mountain Ash ( Sorbus species ).

They grow to a length of about 1 cm. They pupate in a cell in the soil.

The adult is a little black wasp, with a wingspan of about 1 cm.

The female wasp slits the leaf of a host plant between the upper and lower surfaces and lays the eggs inside the leaf.

The species is found worldwide, for example :

  • Chile,
  • Canada,
  • Finland,
  • Germany,
  • Italy,
  • New Zealand,
  • Slovenia,
  • South Africa, and
  • USA,
    as well as in much of Australia, including:
  • Victoria.

Control has been attempted using :

Further reading :

C. French,
Handbook of the Destructive Insects of Victoria, Victorian Department of Agriculture, Melbourne, 1891, pl. XI, pp. 98-103.