DOI: 10.5061/dryad.x95x69prh
title: Do it yourself: 3D-printed miniature CDC trap for adult mosquito (Diptera: Culicidae) surveillance

description: The central component of mosquito and vector surveillance programs
 globally is the adult mosquito trap, which is intended to collect
 host-seeking mosquitoes. The miniature CDC trap is a widely distributed
 trap style in part due to its relative affordability and compact nature.
 Despite already being a simple trap, in-house production methods, such as
 3D printing, could improve the accessibility of the CDC trap by
 eliminating some of the supply chain variables. We present here several
 trials with the Salt Lake City (SLC) trap, a three-dimensional (3D)
 printed trap design. Functional assessments were made on secondary
 components and found no statistically significant differences when
 comparing CO2 line height (above vs. below fan), battery types (sealed
 lead acid vs. USB battery pack), and trap body collection shape (funnel
 body vs. simple/straight body). The SLC trap was compared directly to a
 commercial equivalent, the ABC trap, with comparative assessment on
 species diversity and evenness in collections and found to be
 statistically equivalent on all metrics. Methods also detail an
 accompanying optional transport system for a pressurized CO2/regulator
 set-up, should a practitioner elect not to use dry ice. Our final design
 is presented here with the publicly published stereolithography (STL)
 files and a detailed outline of the transport container system.
 Alternative models are available for in-house manufacture of mosquito
 traps, and we contribute these designs in an effort to stimulate further
 growth in vector surveillance.
description: A prototype trap design, referred to as the SLC trap, was
 developed from a variety of exploratory model tests that are found in
 supplemental figures (Suppl. Fig. 1). Essentially, the prototype is a
 1-piece tubular trap body with a rain guard (Fig. 1A). A 6-volt variable
 speed motor (RF-500TB-14415-R-J/32, Nichibo Taiwan Corp., Taipei, Taiwan)
 was equipped with a 4-blade, 7.5-cm propeller (Item #3C078RSHC1, Thorgren
 Tool & Molding, Inc., Valparaiso, IN) and secured inside the trap
 body with #2 conduit hanger (#2 ACC Conduit Hanger, Halex/Scott Fetzer Co,
 Cleveland, OH). All trap models can be operated using 18-guage, Class 2
 copper wire (16-strand dual conductor/182C-200SR, MaxBrite LED Lighting
 Tech LLC, San Jose, CA). All 3D-printed components were fabricated from
 PLA plastic filament extruded through a 0.6 mm nozzle with set temperature
 at 210 °C (410 °F) and 58 °C (136 °F) bed temperature. The comparison
 model was the Clarke (or Pacific Biologics, AUS) branded ABC trap, with
 the light removed (Clarke Mosquito Control, St. Charles, IL), which is
 primarily composed of polyethylene and PVC plastics to make a trap body
 and rain guard (Fig. 1B). <strong>Trap Evaluation
 Scheme</strong> Field sites were selected from
 historical surveillance locations of the Salt Lake City Mosquito Abatement
 District (SLCMAD) in environments containing a mixture of wetlands and
 sagebrush. Site 1 was closest to the Great Salt Lake and was composed of
 muddy shores and salt playas (Fig. 2). Site 1 was furthest removed from
 human influence and in the heart of shorebird and waterfowl habitats in
 wildlife sanctuary lands. Site 2 (Fig. 2) was in the fringes of alkaline
 mudflats encroached by the Great Salt Lake and composed of a mix of
 palustrine flood plains and salt desert shrublands that were adjacent to
 animal agricultural lands. Site 3 was the furthest north location (Fig. 2)
 and was in the freshwater overflow for nearby reservoirs. Site 3 was
 characterized by saline meadow seeps and saline wetlands and was well
 outside any human occupied areas. The majority of mosquitoes historically
 occupying these environments was split between <em>Aedes
 dorsalis</em> (Meigen) and <em>Culex tarsalis</em>
 Coquillett. For SLCMAD, <em>Cx. tarsalis</em> is a priority
 vector of West Nile virus. Lights have been previously shown to confound
 vector <em>Culex</em> sp. collections the same general
 eco-region, in addition to increasing non-target insect numbers (15).
 Therefore, all trap nights, regardless of model, excluded the use of a
 light source. Surveillance was conducted with 1 kg dry
 ice according to Sriwichai et al. (5) for trials comparing the SLC trap to
 the commercial model ABC trap. For experiments that were done for
 comparing various trap modifications to the SLC trap, the
 CO<sub>2</sub> source was from a regulated compressed cylinder
 at the rate of 250 ml/min.  For all trials traps were set for 24 hrs and
 trap collections were counted and identified with a hybrid camera and
 microscopy set-up using ImageJ (16). Species identifications were keyed
 according to Darsie and Ward (17). Tests were conducted with different
 supplies and components to optimize the base model SLC trap. Pairwise
 comparisons were conducted for SLC trap modifications were conducted
 exclusively at site 1. Tests were conducted between:
 CO<sub>2</sub> dispensed high or low on the trap body (8
 replicates); 6-volt sealed lead-acid batteries (PS-6100 6v 12Ah, Power
 Sonic Co., San Diego, CA) and USB battery packs (PowerCore 20 100mAh,
 Anker Innovations Co., Ltd, Hunan, China) (10 replicates); a funneled
 housing option (Suppl. Fig. 2) (4 replicates). For comparison of the SLC
 trap to the commercial model ABC trap (positive control), tests were
 replicated 4 times each at sites 2 and 3 for a total of 8 comparison
 nights. Whether doing accessory tests or the positive control comparison,
 both traps were present at the same site but spaced at least 100 m apart.
 Additional minor tinkering was conducted for transport container types,
 comparing tool boxes, buckets, and metal ammo cans. These transport
 containers were investigated for optional use with a pressure regulated
 CO2 cylinder system (moot in the case of dry ice, which can be carried in
 a separate cooler). Transport containers were selected
 based on size, ruggedness and long-term service potential (Suppl. Fig. 2,
 Suppl. Fig. 3). Although it is suitable to embed the battery and
 CO<sub>2</sub> source in a toolbox or bucket (Suppl. Fig. 2),
 the desire for space efficiency and durability led to selection of a
 re-purposed metal ammunition can from military surplus (Fig. 3, Fig. 4)
 for operational use at SLCMAD. The resulting final surveillance trap and
 container design was specially built around using a pressure-regulated
 CO<sub>2 </sub>cylinder system. SLCMAD
 chose to adopt a pressure-regulated CO<sub>2</sub> cylinder
 system after the above trials were conducted on trap design. Cylinder
 regulators were modified with a complex series of small parts to feed the
 gas safely to a lower CO<sub>2</sub> line attachment (Fig. 3).
 A “¼ in to #10-32 reducer” (4CQF-ENP-PKG, Clippard Instrument Laboratory,
 Inc., Cincinnati, OH) was reinforced with PTFE tape and attached directly
 to the lower regulator. Short coupling O-rings (11999-PKG, Clippard
 Instrument Laboratory, Inc., Cincinnati, OH) were seated on both sets of
 threads of a “#10-32 connector” (11999-PKG, Clippard Instrument
 Laboratory, Inc., Cincinnati, OH), which was then screwed into the
 reducer. The reducer starts with a “0.0075 in diameter air choke” (CD-C,
 Clippard Instrument Laboratory, Inc., Cincinnati, OH) that is fitted with
 a choke disk inside the curved (non-faceted) end of the piece, then
 screwed onto the remaining threads of another “¼ in to #10-32 reducer”.
 The faceted end of the air choke is finished by screwing in a “#10-32 to ¼
 in ID hose fitting” (11752-1-PKG, Clippard Instrument Laboratory, Inc.,
 Cincinnati, OH) (Fig. 3). The CO<sub>2 </sub>line extends off
 the lower choke assembly (Fig. 3) and attaches to the underside of a PA70
 ammo can measuring 42 cm × 30.5 cm” × 15.9 cm (B643, 8-Cartridge, 60MM,
 HE, M888 for M224 Mortar, United States Military Surplus) with another
 brass “#10-32 to ¼ in ID hose fitting.” For the
 transport container itself, the top side of the ammo can lid was fitted
 with a female push-to-connect piece (Airbrush Quick Release Coupling ⅛-in
 BSP, Point Zero Ltd., China) that receives the male end (Fig. 4) when
 traps are deployed. To brace the CO<sub>2 </sub>cylinder
 inside the ammo can, 7-8 cm wide thermoforming plastic sheet (Sekisui
 Kydex, Bloomsburg, PA) was softened with a heat gun and then molded around
 the cylinder (Suppl. Fig. 3). After cooling to form, the sheet was riveted
 inside the ammo can to create a holster for the cylinder (Suppl. Fig. 3).
 The opposite end of the ammo can interior was then reinforced with
 padding, in this case with duct tape strips, so as to pad the batteries
 and prevent contact with the battery terminals. (Suppl. Fig. 3). Once
 complete, the transport containers receive a 6v battery, filled
 CO<sub>2</sub> cylinder, and associated trap with collection
 net (Fig. 4).
description: # 3D\_printed\_cdc\_trap\_validation
 A prototype 3D printed
 trap design, referred to as the SLC trap, was developed from a variety of
 exploratory model tests. Field sites were selected from historical
 surveillance locations of the Salt Lake City Mosquito Abatement District
 (SLCMAD) in environments containing a mixture of wetlands and sagebrush.
 Pairwise tests were conducted with different supplies and components to
 optimize the base model SLC trap. ## Description of the data and file
 structure Trap_Development_data_DRYAD.xlsx Airstone Height: Positioning of
 the airstone for CO2 dispersal either above or below the downdraft fan.
 Data as aggregate mosquito collections for a 24 hr trap night per
 replicate using 1kg dry ice in a transport cooler and dispersed with a
 line to the trap body. Standard error of the mean included. Paired t-test
 results included. Variables: Rep = replicate number; Airstone Height =
 height of airstone; Location = site ID for trap rotations; # Mosquitoes =
 pooled mosquito collection totals Battery Type: A 6v sealed lead acid
 battery vs. a multi-day lithium USB battery pack. Data as aggregate
 mosquito collections for a 24 hr trap night per replicate using 1kg dry
 ice in a transport cooler and dispersed with a line to the trap body.
 Standard error of the mean included. Paired t-test results included.
 Variables: Rep = replicate number; Battery = 6v sealed lead acid battery
 or USB lithium battery pack; Location = site ID for trap rotations; #
 Mosquitoes = pooled mosquito collection totals Funnel: SLC trap body
 printed as either a funneled entry or a straight sided piece (traditional
 design). Data as aggregate mosquito collections for a 24 hr trap night per
 replicate using 1kg dry ice in a transport cooler and dispersed with a
 line to the trap body. Standard error of the mean included. Paired t-test
 results included. Variables: Rep = replicate number; Trap Body = funneled
 collection body vs. simple/straight sided trap body; Location = site ID
 for trap rotations; # Mosquitoes = pooled mosquito collection totals ABC v
 SLC: Pilot version of SLC trap using high mounted airstone, 6v battery,
 and straight-sided trap body. Comparison to a commercial mimi-CDC trap
 model, the Clark Mosquito Control (Pacific Biologics) ABC trap. Data both
 as aggregate mosquito collections and species breakdown from 24 hr trap
 nights per replicate using 1kg dry ice in a transport cooler and dispersed
 with a line to the trap body. Standard error of the mean included.
 Variables: Trap = designation for either the SLC custom trap, or the
 commercially available ABC trap; Location = site ID for trap rotations; #
 Mosquitoes = pooled mosquito collection totals; species name (Cx. pipiens,
 Cx. tarsalis, etc.) = proportion of total collections from the given
 species. Supp Figs Preliminary Traps: Prototypical trap models preceding
 the SLC trap model used in the airstone, battery type, funnel, and ABC v.
 SLC trap comparisons. A 3-piece base design developed using an entry
 funnel mounted to a computer case fan, then stacked with a second funnel
 for connecting a catch net; used for 3 trap designs: a 12-volt case fan
 (Tornado TD8038H, Vantec Thermal Technologies, Fremont, CA) and measured
 at 20-kph suction. A 6-volt case fan (Multifan S1 80mm, AC Infinity, Inc.,
 City of Industry, CA) measuring at 12-kph suction was then used for two
 separate models: “Complex Airstone” containing a 5-mm mineral airstone
 (Jardin Stone, UXCell Co., Hong Kong, China) on the CO2 line (4-mm inner
 diameter standard aquarium tubing, Penn-Plax, inc., Hauppauge, NY) for
 dispersing a lure homogenously; and “Pore Dispersal” where the CO2 line
 was fitted directly to the fan. The Salt Lake City trap design as covered
 in the main manuscript. 3D-printed trap design shared by Mosquito
 Consulting Services based in New Zealand. Positive control of the ABC trap
 (Clarke Mosquito Control, St. Charles, IL). Comparison data with a minimum
 of 4 replicates each and using aggregate adult mosquito collections for a
 24 hr trap night per replicate using 1kg dry ice in a transport cooler and
 dispersed with a line to the trap body. Standard error of the mean
 included. Variables: Rep = replicate number; trap = designation for
 various prototypes as described above; Location = site ID for trap
 rotations; # Mosquitoes = pooled mosquito collection totals; species name
 (Cx. pipiens, Cx. tarsalis, etc.) = proportion of total collections from
 the given species. n/a values are those in which the total pooled mosquito
 collection was known, but the species identifications for that trap on
 that night were not carried out. These are absent values for the species
 data, but the aggregate/pooled totals are still valid for analysis that
 does not require the species breakdown.
 Trap_Development_supplement_DRYAD.xlsx Figures, pictures, and labels to
 show what the test groups an the aforementioned pages looked like and
 summarize how they were used. ## Sharing/Access information This is a
 section for linking to other ways to access the data, and for linking to
 sources the data is derived from, if any. Data was derived from the
 following sources: * \[PNTD-D-23-00712](DO IT YOURSELF: 3D-PRINTED
 MINIATURE CDC TRAP FOR ADULT MOSQUITO (DIPTERA: CULICIDAE) SURVEILLANCE)