raspberry sawfly
Beginner
Scientific Name: Monophadnoides geniculatus
Identification
- Belongs to the wasp family and is seldom a serious pest.
- Adults are inconspicuous, small (about 6 mm in length) and wasp-like with a thick, black body. Grown larvae are around 13 mm long, bright green and possess many bristle-like structures all over their body.
- Feed on leaf tissue, chewing elongated holes in the foliage.
Often Confused With
Japanese Beetle - damage
Rose Chafer - damage
Raspberry fruitworm - damage
Period of Activity
The raspberry sawfly has one generation per year. The larvae will actively feed on leaf tissue from mid-May to June. They overwinter in cocoons in the ground and emerge as adults the next year.
Scouting Notes
The colour of sawfly larvae is similar to that of the leaf tissue, making it hard to notice larvae in the field. They can be identified by their bright green colour and distinctive bristle-like structures on their bodies. Holes in leaves and feeding damage towards the tip of leaves indicate the presence of sawfly larvae. During the late morning and early afternoon, larvae are mainly found on the underside of the leaves to protect themselves from the sun. Turn over leaves with feeding damage to scout for larvae.
Thresholds
None established.
Advanced
Scientific Name: Monophadnoides geniculatus
Identification
Raspberry sawfly belongs to the wasp family and is seldom a serious pest. The adults are inconspicuous, small (about 6 mm in length) and wasp-like with a thick, black body. The grown larvae are around 13 mm long, bright green and possess many bristle-like structures all over their body. They feed on leaf tissue, chewing elongated holes in the foliage. Damage can be extensive and in heavier infestations only the large leaf veins may remain.
Often Confused With
Japanese Beetle and Rose Chafer
Raspberry sawfly larvae damage is restricted to the leaf tissue, while Japanese beetles and rose chafers will also feed on blossoms and buds. In addition, Japanese beetles can damage ripe fruit and beetles are generally easy to find.
Raspberry Fruitworm
Both raspberry fruitworm beetles and raspberry sawfly larvae feed on foliage. Feeding damage may look similar; however, sawfly larvae are easily spotted on the underside of damaged leaves or in newly developing leave whorls. Larvae of sawfly typically feed on primocane leaves while fruitworm beetles typically feed on buds and leaves on fruiting canes.
Biology
The raspberry sawfly has one generation per year. The adult sawfly lays its eggs onto young leaves in May and early June. The larvae feed on leaf tissue for approximately two weeks. After that they migrate to the ground where they build cocoons in which they overwinter to emerge as fully developed adults the next year.
Period of Activity
The larvae actively feed on leaf tissue from mid-May to June.
Scouting Notes
The colour of sawfly larvae is similar to that of the leaf tissue, making it hard to notice larvae in the field. They can be identified by their bright green colour and distinctive bristle-like structures on their bodies. Holes in leaves and feeding damage towards the tip of leaves indicate the presence of sawfly larvae. During the late morning and early afternoon, larvae are mainly found on the underside of the leaves to protect themselves from the sun. Turn over leaves with feeding damage to scout for larvae.
Thresholds
None established.
Management Notes
- Damage to foliage is seldom excessive and controls are rarely needed.
- Where there is a history of severe damage from this pest, apply a registered insecticide at the first signs of leaf chewing, usually prebloom.
- See OMAFRA Publication 360: Fruit Crop Protection Guide (Chapter 3: Berry Crops) for a list of registered insecticides.
