A Simple Non-Powered Passive Trap for the Collection of Mosquitoes for Arbovirus Surveillance

Abstract

Mosquitoes often are collected as part of an arbovirus surveillance program. However, trapping and processing of mosquitoes for arbovirus detection is often costly and difficult in remote areas. Most traps, such as the gold standard Center for Disease control light trap, require batteries that must be charged and changed overnight. To overcome this issue we have developed several passive traps for collection of mosquitoes that have no power requirements. The passive traps capture mosquitoes as they follow a CO2 plume up a polyvinyl chloride pipe leading to a clear chamber consisting of a plastic crate. We believe the translucent, clear windows created by the crate inhibits escape. Once inside the crate mosquitoes readily feed on honey-treated Flinders Technology Associates cards that then can be processed by polymerase chain reaction for viral ribonucleic acid. Of the two designs tested, the box or crate-based passive trap (passive box trap, PBT) generally caught more mosquitoes than the cylinder trap. In Latin square field trials in Cairns and Florida, PBTs collected mosquitoes at rates of 50 to 200% of Center for Disease Control model 512 light traps. Mosquito collections by PBTs can be increased by splitting the CO2 gas line so it services two traps, or by placing an octenol lure to the outside of the box. Very large collections can lead to crowding at honey-treated cards, reducing feeding rates. Addition of fipronil to the honey killed mosquitoes and did not impact feeding rates nor the ability to detect Kunjin viral ribonucleic acid by polymerase chain reaction; this could be used to minimize crowding affects on feeding caused by large collections. The passive traps we developed are made from inexpensive, commonly available materials. Passive traps may thus be suitable for collection of mosquitoes and potentially other hematophagous dipterans for pathogen surveillance.

Land Use Influences Mosquito Communities and Disease Risk on Remote Tropical Islands: A Case Study Using a Novel Sampling Technique

“…We think the efficacy of the passive trap used in this study could be further enhanced by the addition of secondary attractants, such as octenol, ammonia, or lactic acid because they are effective for some species and are easily transported. 13,59,60 These secondary attractants may yield higher collection totals and could be used to target more species-specific captures. In addition, we concede that there is always mosquito sampling bias depending on the type of traps used.…”

“…Field work was conducted during the wet seasons of 2013 and 2014. Adult mosquitoes were collected using nonpowered PBT (full description in Ritchie and others) 13 with the following modification: the entry bowl was painted black, which is attractive to many mosquito species. 24,25 The traps were baited with CO 2 (derived from sugar and yeast fermentation) from 15-L water bags (containing 4 L of water, 1 kg of sugar, and 40 g of yeast), which produced~120 mL CO 2 /minute.…”

“…Hence, there is a desperate need to develop and try new vector sampling methods that can be built and monitored within remote communities. Powerless traps, like our homemade passive box trap (PBT) (see full description in Ritchie and others) 13 have been used successfully in several cities in Australia with CO 2 obtained from pressurized gas cylinders or dry ice. 13,14 As these CO 2 attractants are difficult to transport to remote localities, we have also successfully trialed a novel method of producing CO 2 from sugar, yeast, and water.…”

“…Powerless traps, like our homemade passive box trap (PBT) (see full description in Ritchie and others) 13 have been used successfully in several cities in Australia with CO 2 obtained from pressurized gas cylinders or dry ice. 13,14 As these CO 2 attractants are difficult to transport to remote localities, we have also successfully trialed a novel method of producing CO 2 from sugar, yeast, and water. [15][16][17] In a recent study, we compared mosquito captures from standard traps (Center for Disease Control light trap model 512, John W. Hock Co., Gainesville, FL) baited with dry ice versus our sugar, yeast, and water method and found that while dry ice resulted in greater overall captures, mosquito species composition was similar between the two methods.…”

Culex interrogator(Diptera: Culicidae), a mosquito species new to Florida

“…In the southern part of the county, near the edge of a pasture, several Cx. interrogator were captured in a dry-ice baited CDC miniature light trap and a passive box trap (Ritchie et al 2013). Many more were taken in early morning collections of resting adults made with a battery powered aspirator (Table 1).…”