Carabid Predators of the Wheat Midge (Diptera: Cecidomyiidae) in Saskatchewan

Reverting Conservation Reserve Program Lands to Wheat and Livestock Production: Effects on Ground Beetle (Coleoptera: Carabidae) Assemblages

“…Mention of a proprietary product does not consitute an endorsement or a recommendation by the USDA for its use. erman 1980, Scheller 1984, Floate et al 1990, Winder 1990, Ekbom et al 1992, Holopainen and Helenius 1992, Sunderland et al 1995. If Conservation Reserve Program lands revert to pasture for grazing livestock, an increased level of disturbance to the vegetation and soil may occur and may significantly alter assemblages of ground beetles.…”

Background and Current Status

“…Research initially focused on assessing the impact of wheat midge damage on yield, grade and milling quality 2,7,8,9 ; developing methods to monitor midge populations in commercial fields 10,11,9 ; evaluating the role of parasitic wasps and ground beetles as biological control agents 12,13 ; identifying alternate crops that could be grown with little or no risk of midge damage 14 ; and developing methods to improve the timing, placement and efficacy of insecticides applied by aircraft or high clearance ground sprayers 8,9.15,16 . During outbreaks in the 1990s, insecticidal sprays were applied to 300,000-500,000 ha of wheat annually to minimize midge damage 5 .…”

“…Other natural enemies 13 -Floate et al (1990) identified 14 carabid species (Coleoptera: Carabidae) that fed on wheat midge larvae in the field. Estimates of predation in the field ranged from <1 to 86 midge larvae/m 2 .…”

Impact of predatory carabids on below- and above-ground pests and yield in strawberry

“…Two carabid species have been shown to substantially remove sentinel weed seeds buried 0.5 or 1.0 cm below in greenhouse experiments (White et al 2007). DNA analysis of adult carabids collected from citrus orchards (Monzó et al 2011), and immuno-analysis of carabids from wheat fields (Floate et al 1990) indicated that carabids were consuming a fruit fly and midge pest, respectively. When carabids were excluded from oilseed rape plots, the number of emerging adult weevils from the soil was higher than from plots accessible to carabids (Zaller et al 2009).…”

“…Conversely, when carabids were augmented to plots, the number of emerging adult pollen beetles from the soil was marginally reduced (Zaller et al 2009). It is important to consider that the examples cited (Floate et al 1990, Zaller et al 2009, Monzó et al 2011) may also reflect carabids encountering pest larvae at the soil surface as the pest moves from the plant into the soil to pupate.…”