Beginner

Scientific Name
            Janetiella brevicauda

Identification
Larvae

• Orange
• 3.0 mm
• No legs

Pupae

• 1.5 mm long, 0.8 mm wide
• Vary in colour from pale to dark orange

Adults

• Fragile flies with plume-like antennae
• Dark brown to reddish
• About 2.5 mm long
• One pair of wings

Damage:

• Small (3-6.5 mm), smooth red or green galls on leaves, shoots and/or fruit

Often Confused With
Phylloxera- green or red flesh galls, 6-20 mm in diameter on undersurface of leaves or tendrils

Period of Activity
Spring to late summer.

Scouting Notes
Look for reddish  galls on young leaves, petioles, shoots and flower clusters.

Threshold
 None.

Advanced

Scientific Name
            Janetiella brevicauda

Identification
Eggs

• pale to bright orange
• microscopic (0.25 mm)
• laid in masses of more than 200 eggs

Larvae

• Orange
• 3.0 mm
• lack appendages

Pupae

• 1.5 mm long, 0.8 mm wide
• vary in colour from pale to dark orange

Adults

• fragile flies with plume-like antennae
• dark brown to reddish
• about 2.5 mm long
• one pair of wings

Damage:

• Small (3-6.5 mm), smooth red or green galls on leaves, shoots and/or fruit

Often Confused With
Phylloxera- green or red flesh galls, 6-20 mm in diameter on undersurface of leaves or tendrils

Biology
Grape tumid gallmaker has one to three generations per year depending on weather conditions and the location of the vineyard. Adults developing from the overwintered larvae emerge in the spring through to late summer. Emergence does not occur if the air temperature is below 19ºC.  Adults lay eggs within unfolding leaves or shoot tips. Maggot-like larvae hatch from these eggs and enter the shoot or leaf tissue. As the larvae feed, galls develop in the leaf tissue around them.
When the larvae have fully developed, they leave the gall and drop to the soil. There they form a cocoon for pupation within 2.5 to 5 cm of the soil surface. Depending on the time of year, the larvae either pupate and produce emerging midges within two to three weeks, or they overwinter as cocoons in the soil.

Period of Activity
Spring to late summer.

Scouting Notes
Look for reddish  galls on young leaves, petioles, shoots and flower clusters.

Threshold
None.

Management Notes 
Grape Tumid Gallmaker larvae rarely occur in large enough numbers in commercial vineyards to justify control measures.