BSM Monitoring Updates
Bermudagrass Fields 2014
Prior to the initiation of sampling in north Florida described below, we sampled Bermudagrass fields during February to April in Alachua, Marion, Levi and Lafayette counties to try to anticipate the outbreak of flies in north Florida. No flies were detected in these more southern areas presumably due to the very low temperatures that occurred over the winter and early spring. Since then we have been sampling bermudagrass fields weekly or bi-weekly in Jackson, Holmes and Washington Counties. Thanks to the collaborating hay producers, we have the opportunity to monitor the presence of the bermudagrass stem maggot (BSM) in fields with different cultivars of bermudagrass. We are sampling Alicia, Coastal, Common, Russell, Cheyenne and Tifton 85 bermudagrass. This range of cultivars will help us determine if the BSM has a preference for a specific cultivar. BSM seems to prefers cultivars with thinner stems.
The first cutting of the season for most of the hay producers occurred without the presence of the pest. Now the fields are regrowing, and a few maggots and flies have been collected in some fields, but we have not detected a major infestation. So far this season, the biggest problem facing producers has been the high population of armyworms.
End of Summer 2014
Now that we are approaching the end of the hay season, the big concern during this Summer for hay producers were the amount of weeds in the fields of bermudagrass and the armyworms. Few flies and larvae of bermudagrass stem maggot were collected in some fields in Jackson county, Holmes county and Washington county, but no major damage or large population of flies were reported. Most of the fields were sprayed with pyrethroids and the weather allowed producers to cut 3 or 4 times during this season.
BSM presence in early Fall 2014
After finding low numbers of bermudagrass stem maggots (BSM) during the summer of 2014 in Jackson, Holmes and Washington county, their populations increased in late September and early October. Most producers could make the last cut in their pastures before any significant damage developed. However, some spots in the pastures showed the frosted appearance characteristic of the BSM larvae feeding damage. In general, hay producers did not suffer severe losses due to BSM this past summer; however, a real concern that season was the incidence of armyworms, which can still found in the fields.
Bermudagrass fields May-June 2015
We started sampling bermudagrass fields in Holmes, Washington and Jackson counties this May. During the first week of June we are observing the presence of bermudagrass stem maggot. We noticed a few brown top leaves in some pastures and also collected a few flies, but not pasture damage was observed.
Bermudagrass fields July 2015
The number of flies collected in some fields in Holmes county and Washington county is increasing. The pastures overall are still looking green, not major damage has been reported and the producers are cutting in their regular schedule.
Bermudagrass fields August 2015
During this summer, some areas are experiencing very dry conditions. The frosting appearance in some pastures in Holmes, Washington and Jackson county has been notorious. Most producers sprayed their fields with pyrethroids and cut hay early. We also observed the presence of armyworms. The picture below shows the presence of armyworms in a Cheyenne bermudagrass pasture.
Bermudagrass fields September 2015
In the first week of September the dryer conditions are still present. A few pastures were recently cut and some pastures that are in a growing stage, show a significant damage due to the bermudagrass stem maggot. The picture below shows a bermudagrass stem maggot fly over a Russell pasture.
In the middle of September the presence of bermudagrass stem maggot flies in the fields is notorious. Some producers sprayed with Dimilin + Mustang and cut their fields, but the flies are still present in the pastures.
Bermudagrass fields October 2015
We sampled the fields until the second week of October. The presence of the bermudagrass stem maggot was notorious in most of the fields, even though some fields were recently cut for the end of the hay season. October was the month with the highest number of flies collected in the three counties and May the lowest month. We can report for this month in Jackson County, 23 flies per 0.25m2, Holmes County 43.3 flies per 0.25m2, and Washington County 14.6 flies per 0.25m2. There is not difference between the presence of female flies or males during the sample season, among May and October.