PEST MANAGEMENT
caterpillars soon emerge . These caterpillars will feed on the leaf tissue just above the thatch layer .
Depending on your location , there may be different sod webworm species present and , thus , variation in developmental periods . The caterpillars are active at night and early morning prior to dawn , so this makes detecting them difficult . Symptoms include webbed tunnels in the thatch and green pellets ( frass ). Other symptoms include yellow / brown patches where the caterpillars have fed on the leaf blades . The preferred host is Kentucky bluegrass . Chlorantraniliprole and spinosad provide biorational control options for sod webworms . Pyrethroids such as bifenthrin , cyfluthrin and lambda cyhalothrin would be options for rescue treatments of these insects .
Cutworms are typically more of an issue on very low-cut turf such as golf course putting greens , but may occasionally affect sports fields . There are a few different species of cutworms ( actually caterpillars ) that can affect turf , but the common species include black , variegated and bronze cutworm . These caterpillars have a “ pebbly ” textured skin , and the black cutworm has a brown-earthen color tone , while the others are lighter in color . Black cutworms feed at night and burrow in the soil profile during the day . The presence of birds digging can be an indicator of cutworm presence . The most effective monitoring technique is a soap flush .
Damage includes clipping ( cutting ) turfgrass leaves off directly above the ground surface . Cultural control includes a few options . Females lay eggs on the tip of turfgrass leaves , so collecting these clippings and disposing of them far away from the field can help to reduce insect pressure . Biorational products for control include chlorantraniliprole ( which also provides season-long grub control ) and spinosad . Pyrethroids provide curative , contact-based control .
FALL ARMYWORMS Fall armyworms are generally a relatively minor pest on cool-season sports fields in the northeast and mid- to upper Midwest . Depending on the year , they have the potential to cause more damage for cool-season grasses in the transition zone east of the Rockies . The adults of the fall armyworms ( which are in the same Noctuidae family as cutworms ) overwinter in southern Texas and Florida and are blown northward over the course of the growing season by storms and wind currents from the south . Although typically not in large enough numbers to cause widespread damage to turfgrasses , in 2021 high overwintering populations and strong summer wind currents brought them north toward the end of the summer . Widespread damage occurred over areas that had never experienced that level of damage in decades . As a tropical insect , their life cycle slows dramatically with cooler nighttime temperatures in September .
Managing sports fields for reduced insect damage can be accomplished by optimizing IPM techniques . Selecting turfgrasses that have improved insect resistance and implementing proper primary cultural programs — such as mowing , fertilization and irrigation — are the cornerstones of IPM programs . Using control products based on threshold levels , and that have minimal impact on beneficial insects , will provide a high-quality sports turf with fewer insecticide applications . SFM
Geoffrey Rinehart is lecturer , turfgrass management , Institute of Applied Agriculture , University of Maryland .
The author would like to acknowledge Dr . Kevin Mathias for his contributions to this article .
References McGraw , Ben ; and Kline , Danny , Chinch Bugs , Penn State Extension
Fact Sheet , 2022
Fall armyworm damage to a tall fescue field without the endophyte ( right ) and a tall fescue field with endophyte ( left ). Photo by Dr . Kevin Mathias .
Smitley , David ; Rogers , Trey ; and Steinke , Kurt , Cultural Practices to Prevent Grub and European Crane Fly Damage to Lawns and Sports Fields ; Michigan State Lawncare , Athletic Fields , and Commercial Turf Field Day . 2012 , p . 9-12
Potter , Daniel A ., Conserve Beneficial Insects on Your Golf Course : Natural Enemies Buffer Turf Against Pest Outbreaks , USGA Green Section Record , November / December , 2001 , 39 ( 6 ): p . 8-10
Shetlar , David ; and Andon , Jennifer , Identification of White Grubs in Turfgrass , Ohio State University Extension Fact Sheet , 2012
Vittum , Pat , Sod Webworms , University of Massachusetts Extension Fact Sheet , 2011
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