By Ed Ricciuti
The age-old cartoon caricature that pokes fun at entomologists in the field – bespectacled, waving a long-handed sweeping net – may have had its day. Like so many other tasks performed by humans, collecting live insects from the field could soon be replaced by a drone.
An exaggeration, perhaps, but drones have shown they can do the hard work of sampling insects in agricultural fields. At least that’s what an article published this month in the Journal of Insect Science Explain. It describes how to build and operate a low-cost drone named “iDrone Bee” that can drag a sweeping net across an agricultural field to catch live insect pests so managers can determine how best to deal with them, if necessary. . The University of Idaho scientists who wrote the paper predict that drones like the one they describe could “benefit the Integrated Pest Management (IPM) community by minimizing time and effort” human workers in the field.
The study comes on the heels of others indicating that drones are feasible for monitoring pest populations. These studies were carried out with commercially available drones, which could lead to a problem in their real-world use. Foreign manufacturers, often based in China, make most of the drones sold in the United States, and various federal actions have been taken against some of these companies and their products over safety concerns. Two years ago, for example, the US Department of the Interior banned its personnel from using Chinese-made drones. By contrast, the iDrone Bee is homemade from open source blueprints, and additionally can be built with motors, controls, and other items available at big box stores, online retailers, and even some local hardware stores. .
For some time, drones have been flying over agricultural fields for several purposes, in particular to monitor crop stress from pressures such as drought, disease and insect pests. Their potential for use in insect monitoring, however, is so new that sampling protocols have not even been developed. Nevertheless, the authors predict that collecting by drone can be faster and less laborious than collecting by hand.
Profiling pest populations, the authors explain, is an essential first step in a robust IPM plan for a major farm operation. Insect populations should be monitored to identify pest species and determine how to time and style treatments to have the greatest impact. As soon as the crops emerge from the ground, growers should monitor the fields weekly to determine when the economic threshold for treatment has been reached. Sweeping vegetation with a net is an age-old method of insect survey.
Sweeping a field of alfalfa, to use an example featured in the article, is hard, sweaty work if exposed to the scorching sun, leaving workers vulnerable to stings and insect bites and even, the authors note , snake bites. Typically, samplers use a net with a diameter of 15 inches to make several 180 degree sweeps over different parts of the fields. The contents of the sweep net are then placed in a plastic bag or jar, and insect counts are taken.
The authors hung a similar net from the iDrone Bee and used it to sample the western tarnished plant bug (Lygus hesperus), a serious pest of alfalfa, in an alfalfa field. The drone crew consists of a pilot-in-command (PIC) who controls the aircraft and a visual observer (VO) who monitors potential safety hazards such as collisions with other aerial objects, whether feather dusters or hawks.
“The iDrone Bee procedure takes about 3-5 minutes to collect insect samples in flight, but it depends on the applications,” the researchers write. Protocols need to be developed to get the most out of the drone, they say, and other features such as autopilot capabilities could be added to improve the accuracy of counts, especially in difficult terrain.
Ed Ricciuti is a journalist, author and naturalist who has been writing for over half a century. His latest book is called Bears in the Backyard: Big Animals, Sprawling Suburbs, and the New Urban Jungle (Countryman Press, June 2014). His missions have taken him around the world. He specializes in nature, science, conservation issues and law enforcement. A former curator at the New York Zoological Society, and now the Wildlife Conservation Society, he may be the only man ever bitten by a coatimundi on Manhattan’s 57th Street.