Paper, begone! Larvaciding field supervisor Rod Hale (left) no longer sorts through hundreds of maps to develop application schedules or determine treatment efficacy. Instead, he queries a database that's updated daily with information gathered by field crew members, like Tony Parent, who tap in data on a touchscreen PDA. Photo: Ada County Mosquito Abatement District

It took five years for the West Nile virus to travel four-fifths of a continent from metropolitan New York, where it was first detected in 1999, to Idaho; but once it invaded, it took hold with a vengeance. Two years after its arrival, the nation's 39th-largest state had the highest incidence of illness, such as meningitis and encephalitis, related to the mosquito-borne virus.

Global warming proponents attribute the virus' advance to an increase in floods and droughts, which help disease carriers survive warmer winters and spread to new territories. Although Idaho's climate is generally dry, pockets of ponds that fill up after rains make the state an ideal breeding ground for virus-laden mosquitoes.

In late 2005 testing at one of the Ada County Mosquito Abatement District's 20 insect trap sites revealed infected mosquitoes. Founded in 1974, the district treats more than 2000 bodies of standing water and fog-sprays more than 1500 miles of transects annually, all spread out over 406 square miles that include the state capital of Boise. Crews start work in April or May, and continue until the weather gets cold, usually September or October.

Realizing their crews needed more powerful tools than magic markers and unwieldy maps to thwart a potentially deadly outbreak, field operations manager Jack Bennett seized the opportunity to update surveillance, larvaciding, and adulticiding procedures. In addition to hiring a full-time ecologist to oversee its long-term integrated pest management program, the district added 20 more test sites and, most significantly, began a multiyear journey to gather and manage data electronically.

GPS + GIS = Data Integrity

For this particular challenge, the district retained Electronic Data Solutions, a consulting firm in Jerome, Idaho, that's designed technology-based field data collection programs for the district since the 1980s. Among other initiatives, the firm helped Ada County electronically map roadside herbicide applications to track where, how much, and what kinds of chemicals are applied.

To make the transition from manual to automatic as easy as possible for field crews who gather the data that drives the district's decision making, the firm recommended an all-in-one package of software and hardware that combines GPS and GIS into a single application.

Like everything related to maintaining public infrastructure, the cost of preventing disease is far less than the cost of controlling it after an epidemic begins. Thus, the district focuses most of its budget and energy on eliminating mosquito larvae.

The district bought each of its five larvaciders a handheld personal computer, the Archer from Juniper Systems Inc., which runs Redlands, Calif.-based ESRI's ArcPad mobile GIS software and includes a Trimble Pathfinder XB GPS receiver. In the field, crew members enter information by tapping on the unit's screen with a stylus. The touchscreen technology eliminated the need to invest in more expensive ruggedized laptop computers with full keyboards.

The software guides users through a series of predefined questions, ensuring that all inspection, treatment, and inventory information is reported consistently regardless of who's entering it. Depending on site conditions, crew members make anywhere from two screen taps up to filling out four form pages.

If they're at a pond, larvaciders follow this step-by-step process to map a site, record an inspection, view a past inspection, or record application and efficacy dates of previous larvacide applications.