1 - Phytosanitary Resources

Control Procedures
Managing Insecticide Resistance
The non-judicious application of insecticides can lead to the development of
resistance. In Bolivia and Chile, Tuta absoluta was reported to be resistant to
organophosphates in the early- to mid-1980’s. More recently, laboratory
studies of resistance in field strains of T. absoluta in Argentina revealed
reduced efficacy of deltamethrin and abamectin (Lietti et al., 2005). Resistance
to cartap, abamectin, permethrin and methamidophos (Siqueira et al., 2000a,
2000b), and acephate and deltamethrin (Branco et al., 2001), has been reported
in Brazil.
The newer insecticide classes have provided good activity against the tomato
leafminer (IRAC, 2009a). However, the modes of action need to be conserved
by implementing resistance management. In practice, alternation, sequence, or
rotation of compounds with different modes of action, usually provides a
sustainable and effective approach to managing insecticide resistance (IRAC,
2009c).
Insecticides have been organized into mode of action (MOA) groups based on
how they work to kill insects.
Procedure
One of the key steps in resistance management is to minimize the continuous
use of pesticides with the same MOA classification. This classification system
makes it easy for farmers and farm advisors to understand which pesticides
share the same MOA without having to know the biochemical basis. The MOA
classification thus provides growers, advisors, extension staff, consultants and
crop protection professionals with a simple guide to the selection of
insecticides for use in an effective and sustainable insecticide resistance
management strategy.
6/2011 Tomato Leafminer 6-7
Emergency and Domestic Programs