Articles
CONTROL OF THE GREATER PEACH TREE BORER (SYNANTHEDON EXITIOSA) (LEPIDOPTERA: SESIIDAE) IN SMALL-SCALE ORGANIC ORCHARDS
Article number
1001_10
Pages
111 – 114
Language
English
Abstract
In conventional orchards, the greater peach tree borer (Synanthedon exitiosa) is controlled by broad-spectrum residual insecticides applied to the trunk of the host tree to kill newly-hatched larvae before they enter the wood.
However, the lack of organically-approved insecticides with prolonged residual activity makes this a challenging pest for organic growers to manage.
To address this issue, we conducted three years of field trials at two sites in New Mexico using two different approaches: soil and trunk applications of entomophagous nematodes (Steinernema feltiae and Heterorhabditis bacteriophora) and mating disruption with a commercial pheromone product (Isomate®-PTB Dual). Three trials were conducted with the two nematode species, applied at a rate of approx. 300,000 per tree, either once in late-summer or three times during the growing season.
The nematodes were applied as a soil drench to an area approx. 15 cm wide adjacent to the base of the trunk.
An additional 30,000 nematodes per tree were applied as a trunk spray.
In none of the trials was there a significant effect on S. exitiosa infestations.
The pheromone product is not normally recommended for very small-scale orchards such as those typical of New Mexico.
However, we tested it in a very small peach block (approx. 0.08 ha) from 2010-2012. The dispensers (plastic twist-ties) were deployed in May 2010 and May 2011 at a rate of approx. 500 per ha.
After 1 year, the summer S. exitiosa infestation rate in the block had declined from an historic average of 40-50% to 13%, and to 8.4% the following spring.
While this level of control is not adequate alone, it may provide the basis of an integrated pest management strategy.
However, the lack of organically-approved insecticides with prolonged residual activity makes this a challenging pest for organic growers to manage.
To address this issue, we conducted three years of field trials at two sites in New Mexico using two different approaches: soil and trunk applications of entomophagous nematodes (Steinernema feltiae and Heterorhabditis bacteriophora) and mating disruption with a commercial pheromone product (Isomate®-PTB Dual). Three trials were conducted with the two nematode species, applied at a rate of approx. 300,000 per tree, either once in late-summer or three times during the growing season.
The nematodes were applied as a soil drench to an area approx. 15 cm wide adjacent to the base of the trunk.
An additional 30,000 nematodes per tree were applied as a trunk spray.
In none of the trials was there a significant effect on S. exitiosa infestations.
The pheromone product is not normally recommended for very small-scale orchards such as those typical of New Mexico.
However, we tested it in a very small peach block (approx. 0.08 ha) from 2010-2012. The dispensers (plastic twist-ties) were deployed in May 2010 and May 2011 at a rate of approx. 500 per ha.
After 1 year, the summer S. exitiosa infestation rate in the block had declined from an historic average of 40-50% to 13%, and to 8.4% the following spring.
While this level of control is not adequate alone, it may provide the basis of an integrated pest management strategy.
Publication
Authors
T.R. Grasswitz, Shengrui Yao
Keywords
Steinernema feltiae, Heterorhabditis bacteriophora, Prunus persica, pheromone, mating disruption
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