Pest management in orchards

Using perfumes for control of Heliothis and related moth pests (part 3)

Pheromones are a special kind of perfume. The most well known are those produced by female moths to attract males.
Pheromones can work well as control agents against small moths where mated females don’t fly too far.

They are useless as control agents for large moths like Heliothis and armyworms that fly hundreds of kilometres in a night and mate outside any area treated with a pheromone disruption agent.
This is a tale of how certain floral perfumes have been developed for these long–distance fliers, some of which are important pests.
Does it work? (Continued from last issue)
The short answer is yes.
After application, moths can be seen flying across the top of the crop from a large distance away. When they arrive, they feed enthusiastically on the bait.
We found that we could kill large numbers of moths and about half of these were young females before they had laid eggs.
The populations of adult moths crashed to almost zero in one or two nights, followed by the newly laid eggs on the crop.
The insecticide usage was reduced by 99% compared with that required for a cover spray.
Providing a fast knockdown insecticide is used, dead moths are readily visible in the treated rows and the next two or three on each side.
Needless to say, a sprayable bait targeting adult moths coming into the crop needs to be applied at the beginning of flights or regularly at lower rates as a preventive measure.
Baits for adults are not useful when the crop is already loaded with eggs and larvae.
Non target insects
We protect bees by recommending that the product not be used where bees are active.
It is important to use a fast knockdown insecticide. In this way, scout bees will not get back to the hive to alert the colony and no slower acting insecticide will be brought back to the hive.
Some beneficials and flies are killed but as 99% of the crop is not treated, the impact is minimal compared with a conventional cover spray.
Commercial acceptance
With the advent of GM cotton, the largest market for this technology in Australia fell away, but one product remains on the market.
Ours is a good one and could be reintroduced to Australia at any time if there is demand. It is comprised entirely of approved food ingredients and does not require registration.
In North America, regulatory costs and constraints made the commercialization unattractive.
Our product is now in widespread use in South America for protection of tomatoes, legume crops and corn.
In China, it is used increasingly in bait stations to protect vegetables from a range of pests including Heliothis, cluster caterpillar and beet armyworm.

See this article in Tree Fruit March 2019

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