Tree Fruit Research & Extension

New Options in Pest Control

Introduction

Today there are several options to consider for control of codling moth (CM) and leafrollers (LR). Following the passage of the Food Quality Protection Act of 1996 the fruit industry was greatly concerned that it would lose access to many frequently used insecticides or that the use of these products would be severely restricted. This has, in fact, occurred over the past 8 years with products like methyl-parathion (Penncap-M), which is no longer available; chlorpyrifos (Lorsban), which has been restricted to use during the prebloom period; and azinphosmethyl (Guthion), which now has restrictions on the amount used per application and per year along with an extended re-entry interval (14 days). Another concern of the fruit industry was that, while they were losing older insecticide products, new products would be very slow to become registered. The fear was that chemical control tools, especially for the most important pests, would decline to a very few. History has shown that the industry’s worst fears have not come to fruition. Today we have more insecticides registered for CM and LR control than we did prior to 1996. However, growers and crop consultants are now faced with deciding how best to choose from the available insecticides to achieve control of these pests.


Codling Moth Control Tactics:

Table 1 shows the products that are registered and useful for managing CM in apple orchards. The organophosphate (OP) insecticides have been used almost exclusively for CM control since the 1960s. These products have provided excellent crop protection at a reasonable cost. When conducting efficacy trials with new insecticides we include an untreated control and an industry standard, usually Guthion, as a comparison. We are therefore able to compare the level of crop protection provided by a new insecticide to a product such as Guthion for which we have years of experience. Fig. 1 summarizes the results of our efficacy evaluations of new insecticides over the last three years, 2002-2004. These data are presented as the percentage that each treatment reduced successful CM entries/fruit relative to an untreated control. For example, Guthion reduced CM entries/fruit (successful entry of a larva into the fruit) an average of 98%. That is, there were 98% fewer CM entries/fruit than observed in the untreated control. CM populations in our test plots are extremely high. We typically record 70% or more injured fruit at harvest in untreated controls with each fruit averaging about 2 entries. Under these conditions we can easily separate the most effective insecticides from those that are ineffective or those that could be acceptable under less pest pressure.

Table 1. Insecticides registered for codling moth control.

Traditional insecticides -- organophosphate and carbamate
Guthion, Imidan, Sevin

Pyrethroids
Danitol, Warrior, Asana
Neonicotinyl insecticides
Assail, Calypso
Biological insecticides
Mineral oil, CM viruses, Success (Entrust), Pheromones
Insect growth regulators
Intrepid, Esteem, Rimon
Other Insecticides
Avaunt, Proclaim*

* not yet registered for use on tree fruit crops.


From Fig. 1 it is clear that there are new insecticides that have very good efficacy against CM. Warrior, a relatively new pyrethroid, provides fruit protection nearly equal to that of Guthion. Success, or the organic formulation of this product, Entrust, also provides a high degree of fruit protection. Proclaim, a product not yet registered for use on apple, also provides excellent protection from entries but (data not shown) allows a high percentage of “stings.” Stings occur when the CM larva eats through the apple skin but dies soon thereafter. A scar is produced that can downgrade fruit. Rimon, a new insecticide that should be available for use on apple in 2005, provides excellent CM control. And finally, two of the neonicotinyl insecticides, Assail and Calypso, provide very good fruit protection. Clutch, in the same class as Assail and Calypso (neonicotinyl insecticides) has not proven to be a effective against CM. Other insecticides that do not provide a high degree of fruit protection, less than 90% suppression (e.g. Intrepid, oil, Cyd-X, Esteem - Fig. 1), can still be useful as part of a CM control program. These programs will be discussed later.

Fig. 1
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