Sclerobia tritalis (Couch grass Webworm)

Family: - Pyralidae

Order: - Lepidoptera



Colour - Grey to brown.

Body - Small. Stout with long hair scales. 10mm 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. 15mm 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:



Caterpillars cut grass plants 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:



Collated by HerbiGuide. Phone 08 98444064 for more information.