Rain makes grain but it apparently doesn’t make bugs. Alberta Agriculture pest specialist Scott Meers in his latest Call of the Land interview says abundant moisture is keeping a lid on several pest populations.
Diamondback moths were a concern early in the season, but "Now we’re having trouble finding very many of them in any numbers. We think it’s probably related to all the rain we’ve had," Meers said.
Despite high forecast numbers, there have been "no calls about grasshoppers to this point," Meers said, and "We’re just not seeing very many lygus at all."
He said lygus numbers could remain low if moisture continues, but said that if not, it only takes a few lygus adults to cause trouble later in the season.
Meers said wheat midge could start emerging in the next week to 10 days. Wheat coming into head is susceptible and producers in areas where high numbers have been forecast should be scouting their fields. Weatherfarm wheat midge development maps are now available.
Bertha armyworm trap numbers are up in some areas, Meers said. "It looks like we are going to have some bertha issues in some parts of the province."
Cereal leaf beetle numbers have been reported at near-threshold levels in southern Alberta. Meers said the natural predator numbers are also at good levels so producers should avoid spraying unless absolutely necessary.
Alberta’s Bugs.R.Us monitoring network also reported the following this week:
Byron Puchalski, AAFC-Lethbridge, reports that some wheat fields in the Fort McLeod, Granum, Claresholm and Vulcan areas now have stripe rust and should now be included in the stripe rust alert zone. Areas previously identified on alert should remain on alert as the spring wheat is coming into a stage where infection is more likely. Active scouting is essential and fungicide applications, if necessary, should be made. The Burdett-Grassy Lake area, where stripe rust has been most severe, has been aggressively sprayed and movement of rust out of this area has been slow.
Puchalski’s survey has not detected stripe rust in commercial wheat fields north of Highway #1. Additionally, Bassano, Brooks, Tilley and Medicine Hat have surveyed clean. However, Dr. Kequan Xi, ARD-Lacombe reported that stripe rust pustules were found on winter wheat in the Lacombe breeding plots on June 26 and had moved up the canopy last week. Pustules were also observed in a spring wheat differential plot at Olds. Therefore, producers north of Highway #1 should actively scout their cereal fields for stripe rust.
It appears that overwintering of stripe rust has been negligible and stripe rust losses should be less than those seen in 2011, due to the slower start of the disease.