Again, at each location, bromegrass panicles were beginning to emerge. Most of the sawflies were males. They appear a few days earlier than female wasps. Sawflies were also beginning to emerge from infested stubble from last year, and were flying to nearby wheat crops. Winter wheat stems were elongating and were vulnerable to infestation.
Sawflies lay eggs in plant stems.
Some spring wheat fields were still in the seedling stage, and probably will escape attack. The sawfly emergence and egg laying period will last several weeks, and is extended by cool. Sawfly development also can be determined by examining the overwintering sites in the wheat stubs. The larvae, or worms, go through a brief pupal stage during transformation into wasps. Young pupae are white, but are yellow and black colors when wasps are ready to emerge.