Optimal trap for collecting <i>C. putoria</i>.

<p>Optimal trap for collecting <i>C. putoria</i>.</p

Experiments for developing a flytrap for collecting <i>C. putoria</i>.

a<p>Standard trap design consisted of 10 entrance holes, each 1.6 cm in diameter, in a white lid of a 3 L polypropylene box, with transparent sides. 50 g of raw fish was placed in a 9 cm diameter white pot, covered with cotton netting.</p

The scaling between egg-laying and productivity is only apparent after normalizing both productivity and egg laying by carrying capacity.

<p>In completely heterogeneous environments, there may be a poor correlation between <b>a</b>) carrying capacity and productivity; <b>b</b>) egg laying and productivity; and <b>c</b>) egg laying and carrying capacity. <b>d</b>) The crowding law governing density dependence is found by plotting the ratio of eggs laid to carrying capacity against the ratio of productivity to carrying capacity (i.e. ). The constant was used to scale the <i>x</i>-axis.</p

Understanding productivity (<i>i.e.</i>, the emergence rate of adults ) in heterogeneous habitats depends upon understanding the relationship between egg laying, carrying capacity (), and crowding.

<p><b>a</b>) The functional relationship between the rate of egg-laying and productivity depends on the functional response to crowding. In this model, the relationship is sensitive to the power-law scaling relationship ( blue; red; purple). Carrying capacity is given for a single value of egg laying rates, given at the steady state if that pool had existed in isolation. <b>b</b>) In a system with 2 pools linked by egg-laying, where the carrying capacity of pool 1 is approximately 90% of the total (dashed blue line) and pool 2 has the rest (dashed red line), the population totals overall (solid black) are generally below the maximum, unless egg laying is fine-tuned such that the proportion of eggs laid was equal to that pool’s proportion of carrying capacity (vertical grey). <b>c</b>) A comparison of productivity (red) and carrying capacity (black line) for a typical set of heterogeneous aquatic habitats. Productivity equals carrying capacity when the distribution of eggs laid is finely tuned to match the distribution of carrying capacities (i.e. ). <b>d</b>) The ratio of productivity to carrying capacity was computed for 100 sets of heterogeneous aquatic habitat. The green line plots the 1∶1 ratio, when productivity equals carrying capacity. These distributions, plotted here as the median (solid line) and the 10^th and 90^th quantiles (dashed lines), shows the robust pattern that the habitats with the lowest productivity tend to be under capacity and the few highly productive habitats tend to be over capacity.</p

The “effect size” of LSM in relation to coverage tend to be either linear or quadratic depending on whether eggs are laid in “treated” habitats and how well LSM is targeted.

<p><b>a</b>) Holding the total number of productive pools constant, adult mosquito population density declines as the number of unproductive pools increases and absorb eggs. <b>b</b>) The “egg sink” effect gives a non-linear effect to LSM if adult mosquitoes continue to lay eggs in the treated pools, so that treating 50% of the pools reduces adult density by 75%, and treating 75% of the pools reduces adult density by 95% (red). If adult mosquitoes do not lay eggs in the treated pools, however, then reductions in mosquito density are proportional to the % of habitat treated (blue). <b>c</b>) The change in adult mosquito density due to LSM in highly heterogeneous habitat as a function of the proportion of habitats treated depending on whether the adults lay eggs in treated pools (red) or avoid treated pools (blue), and depending on whether LSM was done in one particular random order (grey spikes), perfectly efficiently targeted (dashed lines), or perfectly inefficiently targeted (dotted lines). The black line represents a linear response with respect to coverage. <b>d</b>) For the same graphs as 3c, the effect sizes are plotted on a semi-log scale to highlight the benefits of LSM at high coverage. The best case for this system, with efficient targeting and egg-sink effects, predicts a hundred-fold (99%) reduction in mosquito density for 60% coverage. These benefits also get larger for higher coverage and show that there is enormous potential for LSM to reduce transmission through targeted repeated application of modern larvicides.</p

Mean <i>Anopheles gambiae s.s</i> catch sizes of CDC, Frommer updraft and Box gravid traps.

<p>Error bars equal the 95% confidence intervals; 200 gravid females were released in semi-field system per night for 12 nights.</p

Box gravid trap (A) and open pond (B) surrounded by a square of electrocuting nets.

<p>Box gravid trap (A) and open pond (B) surrounded by a square of electrocuting nets.</p

Set up of three gravid traps.

<p>(A) CDC gravid trap, (B) Frommer updraft gravid trap; (C) Box gravid trap. i) aluminium supports, ii) collection bag, iii) upright tube, iv) pan, v) rain shield, vi) base stand, vii) horizontal exhaust tube, viii) anti-spread bar; (D) Box gravid trap lowered into ground in semi-field system.</p

The OviART gravid trap set up.

<p>Trap was set by sinking the water-filled bucket into the ground so that the lip of the bucket was flush with the sand surface. The suction tube was buried in the sand leaving only the end with the fan exposed above the soil in order to let airflow freely.</p

Ovi-ART gravid trap prototype.

<p>(A) Trap parts: i) round black bucket, ii) suction tube prepared from collapsible plastic pipe, iii) collection chamber prepared from plastic bottle and fiber glass netting gauze, iv) fan (12V, 0.38A), v) electric cable, vi) 12V battery. (B) Collection chamber backside towards fan. (C) Collection chamber entry funnel.</p