Frommer Updraft Gravid Trap

The Frommer Updraft Gravid Trap Model 1719 operates in a fashion similar to the CDC Gravid Trap (Model 1712) by creating an upward current of air from within the confines of the oviposition pan, so that the mosquitoes are drawn into the unit during their pre-oviposition examination of the medium.

  • The chief advantage of the 1719 over the 1712 trap is that the Frommer version has a collection chamber below the fan and the adults are not exposed to the aspiration fan; the result is pristine specimens that are easy to identify.
  • A second important feature of the Frommer Updraft Trap is the inclusion of two complete collection chambers; this means once-a-day tending.   After collecting one night, visit the trap any time in the next day with the second collection chamber, remove the first chamber with last night’s catch, insert the second chamber and attach the battery.  Return to the lab with the first day’s catch/chamber and process.
  • This trap was developed and evaluated with the aid of Dr. Robert Frommer of the Manatee Mosquito Control District of Florida.

Frommer Updraft Gravid Trap


  • Improved design protects specimens from aspiration fan.
  • Specific for virus-positive mosquitoes.
  • Attracts mosquitoes with hay infusion in oviposition pan.
  • Updraft trap with fan to keep catch in the trap.
  • Unit is supplied complete with aspirator fan, cylinder, and rainshield, black bucket, support bench, battery cables, and two complete collection chambers permitting once-a-day tending.
  • Model 1719 Manual

Design Characteristics

Frommer Updraft Gravid Trap Diagram

Cross-sectional (left) and external view (right) of the Frommer Updraft Gravid Trap Model 1719

In these views you can see from top to bottom the rainshield with standoffs, the aspiration section with fan and motor, the collection chamber with screen disk at top and screen cone at bottom and finally below the collection chamber is the couple mounted to the base stand or bench. Not shown but included with the trap is the black oviposition media pan, an extra complete collection chamber, instructions, and the caps for covering the intake end of the collection chamber while in transit.

The aspirator and collection chamber assembly is mounted in a half couple that is permanently attached to the black powder-coated bench; the bench holds the bottom intake ca. 1″ above the hay-infusion wa­ter in a large black plastic pan (supplied). Immediately above the bench is the 6″ long collection cham­ber fitted with a non-removable inverted stainless screen cone in the bottom; attached to the top of the collection chamber is a couple with a stainless screen disk. This assembly is the collection chamber.

The trap comes supplied with two complete collection chambers permitting once-a-day tending. In the morning with the fan still running, the bottom thumbscrew is loosened and the collection chamber and upper fan are removed from the coupling attached to the base. A cap (supplied) is put on the bottom of the chamber and the fan is disconnected from the battery. The upper thumbscrew is now loosened and the fan housing and rainshield are removed. After the mosquitoes are knocked down with cold, the middle thumbscrew is loosened and the couple (with attached screen disk) is removed and the mosquitoes are easily removed by inverting the collection chamber over the sorting table.

Oviposition Attractant and Site Selection

The hay infusion is made by adding 1 lb (0.5 kg) of hay to 30 gal (114 liters) of tap water, and allowing the infu­sion to incubate for 5 or more days; see references for a slightly different Culex formulation. The trap is placed at the desired collection site at least one hour before sunset and the pan is filled to a depth of 1″ such that the level of infusion solution is near the 4 notches on the black powder coated base or bench. Captured mosquitoes are removed early the following morning to ensure maximum survival of the insects and any virus that may by present. New medium is used each night.

Included Items

The Frommer Updraft Gravid Trap Model 1719 includes:

  • Trap
  • Two Collection Chambers
  • Power Cable
  • Oviposition Pan
  • Instructions


  • The trap draw is 0.125 Amps/hour at 6 volts.
  • Requires a 6 volt, 12 amp DC battery; this size of battery would run the trap continuously for 72 hours. See the batteries and chargers product page for options.


NOTE: This collecting trap cannot be ordered with a PhotoSwitch and since this is an updraft trap, an Air-Actuated Gate is not necessary or useful.

P/N Description
1.5 4 D-cell External Battery Holder
2.3 Sealed, Gelled-Electrolyte Battery, 6 volt, 12 Amp Hours. (requires a charger).
4.10 Motor and Fan for Miniature Traps (6-volt)