LFICD Spring Field Report 2019
June 27, 2019
Earlier this spring, thousands of migrating waterfowl staged on the flooded Lemon Fair river feeding on the first spring hatch of mosquito larvae. Not only does this feeding help with mosquito control but it provides these long distant migrants with food on their long journey to Canada. Extremely high water and sustained flooding from snow melt and frequent rains in April and May made it difficult to dip and evaluate the consistency of mosquitoes hatching throughout the valley. We chased new high-water lines and found no larval activity. When water levels receded to “mean” flood levels, larvae began to show up. Concentrations of larvae were isolated in pockets along the flood plain in places we expect to see them. And other expected sites were void of any larval activity. There were no new recognized sites.
Early June larval sampling continued and showed no new hatches. This early June sampling provided us with benchmark data for the next flood and potential hatch. This next potential hatch is important, because it may produce enough nuisance mosquitoes for aerial treatment.
Beginning on June 10, we began setting up Light Traps to identify adult mosquitoes. Many of the adult species from the Light Traps were common in upland pools (saturated swales that puddle water), ditches and artificial containers.
On June 20, we received our next flood event with 2.5” to 3” of rain which brought the Lemon Fair River significantly out of its banks. It usually takes a 4” rain event to do that. However, the soils were still saturated from the April and May flooding and there was no place for the water to go. Surprisingly, there has been little mosquito larvae. In fact, three large Lemon Fair River sites in Weybridge, Bridport and Cornwall yielded no new larval activity. As water levels continue to recede, we are witnessing dead larvae on blades of grass in the receding water line. So far, there has been no need to conduct an aerial treatment. We will continue to be vigilant in observing conditions and at the very least perform hand treatments if necessary.
In the meantime, protect yourself from mosquitoes and ticks by using insect repellent wisely, avoid being outside at dusk and dawn when certain mosquitoes are most active. Check the screens in your house to make sure there are no holes or gaps. Don’t leave containers on your property to collect water, i.e.: buckets, tarps, clogged gutters, wheelbarrows, flowerpots with water catchers under them. Empty and clean bird baths twice a week. Walk around your property and look for anything that collects and puddles water and remove it if possible or drain frequently.
Have a safe and enjoyable Summer. And note that the Lemon Fair Insect Control District will be holding its annual Open House at their lab/office in Weybridge behind the Congregational Church, Saturday, July 27 from 10:00 AM to 2:00 PM. Check out our web page, www.lficd.org .
If you are experiencing mosquito “distress” (you not the mosquitoes), please call our hotline at 802-349-5407.
Regards, Craig Zondag ~ LFICD Field Coordinator/Biologist