Lucerne Leafroller

Merophyas divulsana

Family: Tortricidae

Order: Lepidoptera

Description:

Adult

Colour - Light brown and yellow with darker markings.

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

Wings - 2 Pairs. Membranous. Hairy. Wing span of 7 mm.

Mouthparts - chewing.

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. Pale yellow.

Habits - Can't fly when cold.

Caterpillar -

Colour - Green.

Body - 10 mm long, 2 mm wide.

Mouthparts - Chewing.

Antennae - Short. 3 segments.

Legs - 5 segments. Single claw on end.

Head - Hard.

Thorax - 3 pair of legs.

Abdomen - 10-11 segments. Spiracles on segments 1 to 8. Prolegs on segments 3, 6 and 10.

Habits - Herbivorous. Wriggle from their shelters when disturbed.

Biology:

Life Cycle:

Eggs laid on the upper side of leaves at any time of the year. There may be many generations per year. Most damage occurs just before flowering.

Habitats:

Origin and History:

Distribution:

Significance:

Caterpillars feed on lucerne leaves and can completely defoliate a stand in a month. Leaves and tips are rolled over and joined with silk to form a shelter for the caterpillar.

Management and Control:

Spraying is usually not required unless numbers build up and seed production is threatened.

The first spray is normally applied when 30% of Lucerne terminals are rolled.

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:

References:

CSIRO. The Insects of Australia. Melbourne University Press. (1991) p873.

WADA. Insects and Allied Pests of Extensive Farming. Department of Agriculture - Western Australia Bulletin No. 4185. p56.

Acknowledgments:

Collated by HerbiGuide. Phone 08 98444064 or www.herbiguide.com.au for more information.