Treatment Guidelines for Cattle Grubs

Treatment Guidelines for Cattle Grubs

By Lee Townsend, Extension Entomologist

Cattle grub treatments must be properly timed in order to be effective and to minimize risk to animals. Make applications as soon as heel fly activity ceases, usually by the last week in July. Do not treat after October 31, preferably not after October 15. Cattle grub treatments applied as pour-ons, spot-ons, injections, or sprays are systemic insecticides which travel within the animal's bloodstream. Treatments applied too late may cause toxic reactions and must be avoided. When using Ivermectin in the fall worming, there is no need to use another insecticide for cattle grub control. Do not treat calves less than 3 months old or cattle under stress from illness, shipping, castration, dehorning, etc.

Spot-ons Spotton 20% OS can be used according to label directions. Apply to a single location on back midline; maximum dosage per animal 20 cc. 45 slaughter interval.

Injection Ivomec 1% or Ivomec F can be injected for cattle grub control. 49 day slaughter interval. Dectomax 1% Injectable has a 35 day slaughter interval.

Sprays (Amount / 100 gallons water) Co-Ral 25% WP - 12 to 16 lbs, Co-Ral 11.6% EC - 3 gal, GX118 11.6% EC - 2 gal When using systemic insecticide sprays for cattle grub control, it is necessary to use a high pressure sprayer to insure that the skin as well as the hair is thoroughly soaked. Sprayer pressures should be from 200 to 400 psi. Wet all animals thoroughly to insure that the insecticide is absorbed into the body (3-4 quarts of finished spray per animal).

Pour-ons Apply pour-on formulations along back line from shoulder to hip. Maximum dosage per animal: Co-Ral, Neguvon, Warbex- 4 oz; Prolate- 8 oz.

Grub Pour-on Insecticides Amt/hundred weight Days to Slaughter
Co-Ral 4% OS fl oz (4 oz maximum) 0
Cydectin Pour-On (moxidectin) See label 0
Dectomax Pour-On (doramectin) See label 45
Eprinex Pour On (eprinomectin) 1 ml / 22 lbs 0
Ivomec Pour On (ivomectin) 1 ml per 22 lbs 49
Neguvon 8% OS (trichlorfon) fl oz (4 oz maximum) 21
GX118 11.6% EC (phosmet) 1 fl oz of 1:2 water mixture 21
Tiguvon 3% OS (fenthion) fl oz 35
Warbex 13.2% OS (famphur) fl oz (4 oz maximum) 35