Appendix D. Relationships between beetle abundance and biomass.

Relationships between beetle abundance and biomass

Appendix E. Nonmetric multidimensional scaling analysis of beetle assemblages among the 10 different samples micro-habitats.

Nonmetric multidimensional scaling analysis of beetle assemblages among the 10 different samples micro-habitats

Map of the study area indicating the location of the quadrat, digital representation of cultivated areas [crops], and natural vegetation [forest or shrub]) and an overlay of the road and house locations.

<p>Insert indicates the location of the study area within the political map of Ecuador.</p

Flow velocity upstream of running spiders.

<p>The observed speeds (mean and standard deviation; dots and error bars, respectively), and the fit of the statistical function (Eq. 2) are represented.</p

Appendix F. Statistics of the power functions.

Statistics of the power functions

Vertical flow field and close-up view of the flow around a running spider.

<p>The sequence in (A) highlights the high air-flow velocity above the spider's body. The time delay between two images is 500 µs; the spider was running at a speed of 3.7 cm/s. An overlay of two images (first image in white, second image in grey) of a moving spider, separated by 500 µs, is shown in (B). The horizontal component of the air flow in the near vicinity of the legs is always directed forward, as front legs do not move back and forth (see cartoon in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0002116#pone-0002116-g002" target="_blank">Figure 2</a>). The running speed was 21 cm/s.</p

Appendix A. Frequency distribution of monthly rainfall at Yasuni Research Station.

Frequency distribution of monthly rainfall at Yasuni Research Station

Digital particle image velocity (DPIV) measurements of a running spider.

<p>In the horizontal position, the laser light sheet is focussed 3 mm above the floor, at mid-height of the spider, just below the bottom eye row level. The yellow portion represents the camera's field of view. Spiders were gently triggered to run using a stick inserted through a small hole at the entrance of the wind tunnel.</p

Spider's attack speed and cricket escape time.

<p>The potential escape time for a cricket (red line) is expressed as a function of the spider's attack speed. At slow attack speeds, the distance at which crickets can perceive spiders is limiting (ambush strategy), whereas at high hunting speeds, the escape time becomes limiting (cruising strategy). The potential escape time is defined as the time interval between predator perception by a cricket and hit by a spider running at a given speed. It is based on the distance, for a given speed, at which the threshold of 30 µm/s for danger perception is attained <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0002116#pone.0002116-Shimozawa2" target="_blank">[13]</a>. The minimal recorded escape time for crickets is around 0.2 ms (horizontal bar, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0002116#pone.0002116-Tauber1" target="_blank">[26]</a>). The distribution of observed attack speeds and the five successful attacks (stars) were obtained from observations of real attacks, at constant speeds, during cricket-spider interactions <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0002116#pone.0002116-Dangles1" target="_blank">[10]</a>.</p

Canonical ordination of the environmental variables associated with the presence of <i>T. cruzi</i>-infected triatomines for the different sampling dates between June 2009 and June 2010.

<p>Polygons represent the “environmental spaces” (see main text) of infected triatomines at each date. The first canonical axis explains 64.7% of the variation among groups.</p