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. 10mm long.
Wings - 2 Pairs. Membranous. Hairy. Wing span of 7mm.
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 - 10mm long, 2mm 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.