Using Parasitoids in an Integrated Pest Management Approach to Control Flies on Dairy Farms

Using Parasitoids in an Integrated Pest Management Approach to Control Flies on Dairy Farms

Summary

The overall purpose of this three year project is to develop a biologically based IPM program to manage house and stable flies on small and medium sized dairies. Initial studies during the first year will delineate species composition and seasonal occurrence of naturally occurring pteromalid wasps on Arkansas, Mississippi and North Carolina dairies. Pteromalid wasps are parasitoids of both house and stable flies and prevent parasitized pupae from emerging as adult flies. The project involves other IPM techniques such as manure management and judicious use of insecticides that are compatible with natural enemies such as pteromalid wasps.

Pteromalid parasitoid species composition data gathered from year 1 and 2 will be used to determine both release rates and release timing of commercially available pteromalid wasps during later stages of the project. The overall IPM concept will be incorporated with commercial wasp releases. These IPM techniques include population monitoring of fly pest species, establishment and use of treatment thresholds, limited use of insecticides that are compatible with natural enemies and effective manure and waste management. Most of the outreach components of the project will be conducted during the later stages of the project when firm release rate recommendations will be available.

During 2004 cooperating dairies were selected in Arkansas (4), Mississippi (2) and North Carolina (6). Initial data collection was delayed in 2004 due to the late award notification and issuing of contracts. Cooperating institutions were hesitant in expending funds on the project until contracts were in place and awards were assured. Once funding contracts were in place in July, preliminary baseline data gathering began. The collection of baseline data will be repeated and/or initiated in the 2005 so that an entire fly season can be included in the data set.

Studies with the red-eyed mutant strain of Muscidifurax raptor in North Carolina were conducted in 2004. In addition, collection of wild house and stable fly pupae and use of sentinel bags containing house fly pupae were initiated in Arkansas and North Carolina. Results from 2004 indicated that these methods will prove fruitful in collecting naturally occurring pteromalid wasps.

Principal investigators from Mississippi, North Carolina and Arkansas met twice to coordinate and standardize methods used in data collection and analysis. Both meetings provided a valuable forum to initiate a successful project. In addition, one meeting with county agents and specialists was conducted to establish focus groups and select dairy producers to serve on this focus team. The next focus team meeting is scheduled for June 1, 2004. During the initial meeting the committee decided that a dairy producer survey is needed to determine what the most common fly IPM system is on dairies in the south. The team will begin developing the survey at the June meeting.

Objectives/Performance Targets

The major objective for year one of this project was to establish the study location and initiate the study. The study locations were established during the summer of 2005. Baseline data collection to determine species composition and seasonal abundance of pteromalid wasps will be repeated and/or initiated in 2005. This part of the project was not initiated until about 2 months into the fly season because of the late arrival of contracts and notification. Another component of the timetable for year one was the establishment of focus teams which has been accomplished. Studies in North Carolina using the red-eyed Muscidifurax raptor mutant were also conducted.

Accomplishments/Milestones

Preliminary field and laboratory work in 2004 was successful. This work has enabled investigators to determine the best methods to use with available resources resulting in more efficient data collection in 2005.

Impacts and Contributions/Outcomes

Numerous dairies were visited in 2004 to select dairies to use in the initial studies and potential dairies to use for demonstrations in the latter stager of the project. One of these dairies had a significant house fly problem. After further investigation we determined that a scheduled use of pyrethroid fogging in the calf barn had led to a resistance problem resulting in less than adequate fly control. We recommended an improved sanitation and monitoring program with the use of fly baits and other IPM tactics. These recommendations resulted in adequate fly control at a reduced cost.

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