Local dispersal of palaearctic Culicoides biting midges estimated by mark-release-recapture

Parasites & Vectors

Table 2 Determining the expected numbers of traps in each concentric ring of a mark-release-recapture experiment

Radius of concentric ring (km)	Area of circle (km ² ) ^Aft	Area of concentric ring (km ² ) ^As	Actual number of traps	Expected number of traps
0 - 0.5	0.79	0.79	0	0.28
0.5 - 1.0	3.14	2.36	1	0.84
1.0 - 1.5	7.07	3.93	3	1.41
1.5 - 2.0	12.57	5.50	2	1.97
2.0 - 2.5	19.63	7.07	4	2.53
2.5 - 3.0	28.27	8.64	3	3.09
3.0 - 3.5	38.48	10.21	2	3.66
3.5 - 4.0	50.27	11.78	3	4.22
Total	160.22	50.27 ^At	18 ^Tt	18

Area of circle is the area of the circle contained within the outer limit of the concentric ring. Area of concentric ring (A _s ) is the area within the inner and outer limits of the ring. Actual number of traps is the number of traps within each concentric ring. Expected number of traps, A_s / A_t × T_t, is the number of traps required in each concentric ring to achieve equal density in all rings; where T _t is the total number of traps and A _t is the total trapping area.

ISSN: 1756-3305