The GMPCC program focuses on controlling mosquitoes at the larval stage. This is recognized as the most efficient control strategy and is considered a very low risk-responsible approach from an environmental perspective. In order to determine the larvae densities, it is important to undertake a continued monitoring of the standing water to assess the presence of mosquito larvae.
Due to the specific nature of the larvicide (Bti) and its residual potent activity, it is critical to determine the initial development stages, as the larvicide is most effective during the first and second stages of larvae development. It is during this time that they are active feeders, which provides the optimum time for effective treatment. Once consumed, the larvicide Bti attacks the digestive system of the emerging larvae thus impedes their ability to continue feeding.
Larval densities within the marsh areas are based on the average amount of larvae present in a standard 250 ml sample. The dipper below demonstrates the densities levels, which can be encountered by the field crews primarily in May and June, however in 2018 similar densities were obtained in July and August.
Thousands of hectares of marshland need to be treated concurrently within a few days following the detection of larvae if we want to be successful in controlling the adult mosquitoes. It has become increasingly evident that, in order to control the emergent larvae population within an acceptable level, we need to rely heavily on the availability of our fleet of Argos as they enable us to cover large expanses of marsh area within a relatively short time. The Management Committee has adopted an equipment replacement program which will ensure that our argo fleet is capable of supporting the degree of control which is required to ensure that adult mosquito population are kept within acceptable limits.
As all of our Argos is equipped with rear-mounted spreader, we are able to have crews working in Riverview and Dieppe simultaneously. This enables us to cover all of the marshes within a 5 to 8 days rotation. The new Argos is also capable of towing the Buffalo turbine, which is capable of a providing larvicide to a greater portion off the marsh.
In addition to our fleet of Argos and the Buffalo turbine, we also depend on backpack applicators and hand applicators to achieve larval control within the small ponds and ditches. In many instances, particularly in mid-summer, it is necessary to proceed with hand applications and backpack applicators given that the marsh vegetation reduces the efficiency of the Argo.
The gator and backpacks are used to regularly apply larvicide to the trail system within Riverview, Dieppe and Moncton. Given the level of use of the trail system by the citizens of the three communities, we have designated the trail as priority areas and as such they are serviced on a continuous basis during the season.