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■Bio-mathematics, Statistics and Nano-Technologies: Mosquito Control Strategies

• September 8 - 10, 2019

In all, the state treated parts of 21 communities over three nights, from September

8 to 10, with a pesticide formulated to kill adult mosquitos. The flight crew used

the pesticide, called Anvil 10 + 10, at an extremely low concentration, dispersing

a total of 556 gallons across 115,179 total acres – meaning that 6/10 of an ounce,

aerosolized, was used to treat an acre. That’s the equivalent of slightly less than

four teaspoons per acre. In Figure 8.1 notes that Regions 1 and 2 are nearly convex,

whereas Regions 3 and 4 are not.

• Wednesday, September 25, 2019

A second aerial spraying application was held on September 25 to control adult

mosquitos in two areas of Rhode Island assessed at a critical risk for the EEE virus.

The areas were identified using several factors, including information about new

human cases of EEE, cases of EEE in non-human mammals, positive mosquito sam-

ples in Rhode Island and in neighboring states, and information about the habitats in

which mosquitos most readily breed.

In Figure 8.2, the top region is nearly convex while the bottom region is quite non-convex.

It is likely the re-spraying occurred because of this, as not all areas were treated. Parts of

12 communities were aerially treated with mosquito pesticide. The spray area surrounding

West Warwick included all West Warwick and parts of Cranston, Warwick, East Green-

wich, West Greenwich, Coventry, and Scituate. Some of this area was previously sprayed

on September 9, but officials expanded this zone westward to Route 102 in Coventry and

both westward and southward in West Greenwich. The southwest area included much of

Westerly and parts of Hopkinton and Charlestown that were already sprayed on September

10. This expanded area of critical risk encompassed new swaths of Hopkinton, Richmond,

and Charlestown as well as the southwestern section of South Kingstown.

8.2.2

Winnipeg, Canada [4]

The fogging program (Figure 8.3) meandered throughout the city, a clear indication of

non-convexity.

8.3

FLIGHT DISTANCES, PATTERNS AND TIMES OF VARIED MOSQUITOS

AND DISEASE AGENTS

The flight distance data in Table 8.1 below comes from [5] and only includes a few

mosquito species that can spread the diseases mentioned above. Nonetheless, the ranges

vary from less than half a mile up to 40 miles (there are a few examples of longer flights).

The flight patterns are largely downwind, but wind directions are quite variable from day to

day. Female mosquitos (the ones that bite) fly from 1 to 1.5 miles per hour and in a zig-zag

pattern when they detect the presence of a likely target [6]. Note that there is no constraint

on the direction of flight. Hence the convex set of all possible routes is possible.