Argentine Stem Weevil: Identification, Risk Window, and Control Strategies
Argentine Stem Weevil (ASW) can be devastating to cool-season turf through dry, warmer months. Activity typically ramps up as temperatures rise and conditions dry out, with damage possible from October through May (timing varies by region and season). Multiple, overlapping generations are common when warm weather persists, so early detection and rapid response are critical.
How ASW Damages Turf
Monitoring: Catch It Early
Routinely inspect known “hot spots” such as collars, walk-offs, edges and dry slopes each week through spring–summer, and use pyrethrum flushing to confirm presence and pressure so you can treat at the first signs and prevent population blow-outs. Keep simple records (dates, counts and weather), so you can spot patterns and anticipate the next wave, noting that generations often overlap.
Treatment Principles
Start with adults, then protect crowns from larvae.
Early adulticides can suppress population build-up; follow with larvicide coverage to protect stems/crowns as eggs hatch.
Match product to objective and timing.
Longevity and speed of kill differ across chemistries; the right choice depends on pest stage, pressure and weather.
Nail the application details.
Nozzle, carrier volume, overlap and post-application irrigation (or not) are make-or-break for performance. When in doubt, call your Living Turf Tech Rep for a tailored program.
Product Guidance
√ Tempo Xtra® & Sentinel® (adulticides): Apply with Brushwet® and leave on the leaf for optimal adult knockdown. Best used at the first sign of adult activity to reduce egg-laying.
√ Quali-Pro® Twister (eggs, larvae and adults): A newer option that uniquely impacts eggs as well as larvae, helping to break the cycle when generations overlap.
√ Spinner® (systemic larvicide): Slower acting but concentrates in the crown, providing longer-term larval control and protection of growing points.
√ Tetrino® (faster larval action): Delivers quicker knockdown on larvae—an important role with the unavailability of organophosphates.
√ MP Reinforce™ (supporting plant defence): Toughens plant tissue (more abrasive, harder to consume) and has been observed to reduce egg-laying, complementing chemical control.
Irrigation notes: Follow label guidance precisely. Some adulticides perform best when not watered in for a set interval; many larvicides require light irrigation post-spray to move actives to the feeding zone. Small deviations can halve performance.
Cultural Practices That Help
√ Maintain even moisture (avoid dry-down on collars and high spots).
√ Reduce plant stress (shade/airflow/traffic) so turf tolerates feeding better and recovers faster.
√ Document what worked (dates, weather, counts, photos) so next summer’s plan starts smarter.
Need a site-specific ASW plan?
Contact your Living Turf Tech Rep for a tailored monitoring and treatment schedule, including nozzle selection, irrigation set-ups and rotation to suit your turf species and microclimate.