Monitoring the activity of cabbage, seed corn and onion maggots on an organic farm

Information on the basic biology of insect pests is extremely helpful in planning control strategies for insect pests. Part of the problem with the maggot complex of insects is that they are poorly understood in California conditions. In addition, it is not readily apparent to growers when the flies are active because they are nondescript and easily confused with many other types of flies that are active and in great abundance. Monitoring for their eggs is also tedious and time consuming. This study was designed to provide information on the activity of adult the complex of cabbage, seed corn and onion maggots in the Santa Anna Valley of San Benito County. The following are the objectives and supporting justifications for the project:

1. Monitor the population of adult maggots and quantify their numbers on a weekly basis in the growers field and use this data to establish the patterns of activity of the adult maggots that occur in the field. This activity was the heart of this research project.

2. Conduct these studies for one year and evaluate the usefulness of this data with regard to modifying planting schedules of onion and cole crops to avoid problems with these insect. This project in a sense was a rough cut exploration of the biology of the maggots. If the data that we obtained looked useful we would then decide if it warranted further research effort.