Cereal leaf beetle (Oulema melanopus) - Model output indicates that CLB oviposition has begun in many locations, and that larvae may begin to appear in the next 7-10 days. As of May 13th, CLB model runs indicated that oviposition was similar Lethbridge, Swift Current, Saskatoon and Brandon (Fig. 1).
Lifecycle and Damage:
|Figure 2. Adult Oulema melanopus measure 4.4-5.5 mm long (Photo: M. Dolinski).|
Egg: Eggs are laid approximately 14 days following the emergence of the adults. Eggs are laid singly or in pairs along the mid vein on the upper side of the leaf and are cylindrical, measuring 0.9 mm by 0.4 mm, and yellowish in colour. Eggs darken to black just before hatching.
Larva: The larvae hatch in about 5 days and feed for about 3 weeks, passing through 4 growth stages (instars). The head and legs are brownish-black; the body is yellowish. Larvae are usually covered with a secretion of mucus and fecal material, giving them a shiny black, wet appearance (Fig. 3). When the larva completes its growth, it drops to the ground and pupates in the soil.
|Figure 3. Larval stage of Oulema melanopus with characteristic feeding |
damage visible on leaf (Photo: M. Dolinski).