By Scott Hartley, PAg, Provincial Specialist, Insect/Vertebrate Pest Management
The Ministry of Agriculture conducts and participates in several insect surveys annually to provide information on potential risk to producers and to estimate the current distribution of species moving into Saskatchewan.
Pea leaf weevil survey
A pea leaf weevil survey was conducted in late May to early June. This pest of pea and faba bean has been established in some locations in the southwest since 2007; it has gradually increased its range across the south and just north of the South Saskatchewan River in the West Central Region. During the 2016 survey, and from other reports, it appears the pea leaf weevil has a much wider distribution east and north than previously known. Damage to pea plants (notching) was noted southeast of Moose Jaw and, although some feeding was observed on pea outside in fields around Outlook, faba bean at the irrigation centre (CSIDC) showed potentially economic levels of damage. There was also a field with high levels of feeding near Kyle (RM 228).
Cabbage seedpod weevil survey
The cabbage seedpod weevil survey was conducted in late June into July. This survey is coordinated by Agriculture and Agri-Food Canada (Saskatoon) (AAFC). Sweep samples are collected from fields across southern Saskatchewan to the Manitoba border by AAFC, Saskatchewan Agriculture and private industry personnel. Results from the processed samples will be mapped later this year. Based on the 2015 survey, the cabbage seedpod weevil is established east of Regina nearing the Manitoba border and as far north as Outlook.
Grasshopper forecast survey
The annual grasshopper survey is conducted by Saskatchewan Crop Insurance Corporation field personnel. Timing is when the majority of grasshoppers in an area have reached the adult stage and are winged. The 2015 survey indicated low risk for grasshoppers this year; however, there have been reports of high numbers in some areas. Although crops can compensate for feeding in most cases, at this stage there can be problems with grasshopper body parts in commodities such as pea during harvest.
Wheat midge forecast survey
The wheat midge forecast is based on viable wheat midge cocoons in the soil in the fall. There were reports of high wheat midge populations in a number of areas, primarily in eastern regions in early July. Conventional wheat is only susceptible from when the boot splits and any part of the head is visible until flowering (more than 50 per cent of the head is showing anthers). After this stage, the wheat has resistance to the midge. The economic threshold for wheat midge in conventional wheat varieties is one midge per four to five wheat heads for yield consideration and one midge per eight to 10 wheat heads for optimum grade. There is no economic threshold with respect to wheat midge and midge tolerant wheat. To date, the extra cost of the seed and reduced damage to midge tolerant wheat has not warranted an insecticide application.
Bertha armyworm moth monitoring
Bertha armyworm moth monitoring is underway for 2016. Cooperators across the province check traps weekly from early June until August. A weekly moth count map is produced throughout the season and can be used as a warning of potential risk from the army worm larvae in July and August. The risk from bertha armyworm to Saskatchewan crops is expected to be low this year.
Diamondback moth monitoring
A sentinel trap system is used to monitor Diamondback moth numbers in the spring. Traps are set up from the time the snow is gone in the spring until near the end of June to monitor moth populations blowing in from southern regions. No large numbers of moths were recorded this spring.
For questions about our surveys please email firstname.lastname@example.org.