The term Sod Webworm is used to denote the species that includes Eudonia spp., Orocrambus spp. and Scoparia spp. The adults emerge as moths from September through until December. These adult moths feed on clover and the flowers of native plants. Egg laying continues until late February. The resultant caterpillars live in shallow burrows in the ground and emerge to eat the foliage of surrounding grass plants. Damage is known to occur from January until as late as October however typically the majority of the damage is seen occurring during the period February – June. The caterpillars range from 10 – 20mm in size and are generally green with dark green spots located in lines down the length of the body. Because they live in shallow burrows, heavy rain on flat ground is known to reduce numbers through drowning of the caterpillars. No pesticides are registered specifically for sod webworm control after cultivation, however, any products containing chlorpyriphos or pyrethroid should provide effective control if applied in autumn when their activity is at a peak.
- Apply Pyriphos granules at label rates from late March to June. Ensure that at least 25mm of water is applied within 7 days of application.