Control of cattle grubs with fenthion pour-on and trichlorfon spot-on in Germany

Field tests in northern Germany showed that fenthion pour-on and trichlorfon spot-on are suitable for the control of cattle grubs. The advantage of these two methods of application compared with other methods is the exact, easy, and time-saving applicationField tests indicate that fenthion (Tiguvon) pour-on is highly effective againsts the migrating first instar and the second and third instars. Trichlorfon (Neguvon) spot-on was also highly effective against the migrating first instar but showed a lower efficacy against the second and third instars. It is suggested that the second and third instars are killed more reliably by direct contact with the compound. This contact is easier to achieve by the pour-on than by the spot-on method.Under German conditions, the following treatment plan is suggested: application of fenthion pour-on or trichlorfon spot-on in the autumn and, if required, fenthion pour-on in the spring. Since cattle eliminate trichlorfon faster than fenthion, application of the former may be preferable in certain cases.