Mosquito Survival Data

This data file includes in the "Survival Data" tab the daily mortality events for the associated infection experiments. We have recorded number of mosquitoes alive vs. dead each day post-infection with human malaria. We also followed a blood-fed, uninfected control group to determine if the effects of temperature and diurnal temperature range had a different impact on the daily probability of mosquito survival for P. falciparum infected mosquitoes. Finally, we also recorded the number of mosquitoes that were dissected for midguts and salivary glands to assess parasite infection so that these cases could be censored in the downstream survival analysis. The "Data Codes" tab has descriptors for the various column headings and data labels

Malaria parasite data for Anopheles stephensi

This data file includes data on malaria infection in individual mosquitoes. For each temperature treatment we dissected midguts (on day 7 post infection) or salivary glands (day 15 post infection) from 20 individual mosquitoes within each temperature treatment if numbers permitted. The "Oocyst_data" tab includes data on whether or not a mosquito had oocysts on its midgut and overall oocyst burden. The "Sporozoite_data" tab includes information on whether or not an individual mosquito had sporozoites in its salivary glands. The "Data codes" tab includes information describing each column and how it is coded across both the "Oocyst_data" and "Sporozoite_data" tabs

Malaria parasite data for Anopheles gambiae

This data file includes data on malaria infection in individual mosquitoes. For each temperature treatment we dissected midguts (on day 7 post infection) or salivary glands (day 15 post infection) from 20 individual mosquitoes within each temperature treatment if numbers permitted. The "Oocyst_data" tab includes data on whether or not a mosquito had oocysts on its midgut and overall oocyst burden. The "Sporozoite_data" tab includes information on whether or not an individual mosquito had sporozoites in its salivary glands. The "Data codes" tab includes information describing each column and how it is coded across both the "Oocyst_data" and "Sporozoite_data" tabs

Malaria Mosquitoes Host-Locate and Feed upon Caterpillars

<div><p>Adult female mosquitoes need blood to develop their eggs and both sexes use nectar and honeydew as carbohydrate resources for flight, survival and to enhance reproduction. However, there are also a few reports in the literature of mosquitoes feeding on haemolymph of soft-bodied insects such as caterpillars. The frequency and significance of this entomophagous behavior is not well understood, but is thought to be a vestige of ancestral feeding behavior or an opportunistic behavior that has evolved over time. In our current paper we investigated the extent to which the malaria mosquito, <i>Anopheles stephensi</i>, is attracted to, and can successfully feed on, larvae of two common moth species, <i>Manduca sexta</i> and <i>Heliothis subflexa</i>. Using y-tube olfactometer assays we found that female <i>An. stephensi</i> readily flew upwind to and landed on the caterpillars of both moth species. The nature of the volatile cues used in host location remains unclear but respirometer studies suggest a possible role of CO₂. Laboratory cage assays further showed that the female mosquitoes were able to actively feed on moth larvae and gain sufficient nutritional benefit to influence survival. The extent to which such an opportunistic behavior occurs in the field has yet to be explored but our results suggest that this haemolymph feeding behavior could play a role in malaria mosquito life history and could provide a novel mechanism for horizontal transmission of pathogens and other micro-organisms between hosts.</p></div

Y-tube olfactometer using live and dead caterpillars.

<p>The olfactometer is 70×35×6 cm with the two upwind arms being supplied with charcoal-purified air at a rate of 0.75 litre/sec.</p

Survival data

Survival data for each replicate cup in each temperature and experimental block

The effects of exposure history on survival after 24 hours.

<p>The 4 panels show the results of the permethrin exposures on days 4, 8, 12, or 16. In each panel, the cluster of bars on the left represent the proportion of insecticide-naïve females surviving 24 h after exposure. The bars on the right half show the corresponding results for previously-exposed females. In the day 12 panel, for example, multiple exposures had occurred at days 4, 8 and 12, whereas the single exposures occurred on day 12 only. All mosquitoes on day 4 were naïve (see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0024968#pone-0024968-g001" target="_blank">Fig. 1</a>).</p

Kaplan-Meier survival curves of mosquitoes exposed to permethrin in exposure-history experiment 1.

<p>Panels reflect different permethrin concentrations, as denoted. Red vertical lines show timing of exposures. Plotted data were from the total number of mosquitoes in the 3 replicate cups in each treatment group (see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0024968#s2" target="_blank">methods</a>), so that n = 60 at the start of each curve. Colors correspond to the timelines in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0024968#pone-0024968-g001" target="_blank">Fig. 1</a>.</p

Y-tube olfactometer assays of <i>An. stephensi</i> females that were given a choice between live vs. dead caterpillars of two moth species.

<p>The figure shows the percentage of female <i>An. stephensi</i> (±95% binomial confidence intervals (C.I.) that were attracted to live fourth instar larvae of <i>Heliothis subflexa</i> or <i>Manduca sexta</i> (black bars) versus dead caterpillars killed by freezing and then thawed back to room temperature (light bars). Asterisks denote significantly different levels of attraction (Chi-square 2×2 test of independence; *P<0.05; **P<0.01; ***P<0.001; N = 90).</p

Gonotrophic cycle length, feeding propensity and EIP across temperature.

<p>A–C: Length of the first and second gonotrophic (or feeding) cycle of <i>Anopheles stephensi</i>, D–F: Proportion of blood fed <i>An. stephensi</i> responding to feeding stimulus (on days 1–6), G–I: proportion of infectious mosquitoes over time, overlaid with mean length of the first (black line) and subsequent cycles (grey lines), derived from A–C, at 22, 24 and 26°C.</p