Sclerobia tritalis (Couch grass Webworm)

Family: Pyralidae

Order: Lepidoptera


Colour - Grey to brown.
Body - Small. Stout with long hair scales. 10 mm long.
Wings - 2 Pairs. Membranous. Hairy.
Mouthparts -
Antennae - 3 segments. Filiform (Finely hair like).
Legs - Broad overlapping scales. Feet (Tarsi) have 5 segments.
Head - Smooth. Broad overlapping scales. Large rounded compound eyes.
Thorax - Broad overlapping scales. 3 segments. Front segment much smaller. Hairy
Abdomen - Broad overlapping scales. 7-11 segments. Spiracles on segments 1-7. Hairy
Egg - Flat. Oval.
Habits - Can't fly when cold. Attracted to lights.
Caterpillar -
Colour - Translucent.
Body - Cylindrical. 15 mm long.
Mouthparts - Chewing.
Antennae - Short. 3 segments.
Legs - 5 segments. Single claw on end.
Head - Hard.
Thorax - 3 pairs of legs.
Abdomen - 10-11 segments. Spiracles on segments 1 to 8. Prolegs on segments 3, 6 and 10.
Habits - Herbivorous. Live in web shelters. Emerge when cool and damp - usually at night.


Life Cycle:

The moths lay eggs on grasses in the autumn. These hatch and the caterpillars burrow into the soil. They feed through out winter.


Origin and History:



The caterpillar cuts grass plants off at ground level. They are a pest of pastures and turf.

Management and Control:

Insecticides are used for control in turf and pastures.

Related Species:

Cabbage Centre Grub (Crocidolomia binotalis), Cucumber Moth (Diaphania indica), Wax moths (Galleria mellonella and Achroia grisella), Rice moth (Corcyra cephalonica), Meal moth (Pyralis farinalis)

Similar Species:



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