Technology used by spies is detecting pesky moths

billions of dollars of damage to crops every year, driving farmers to apply pesticides on an industrial scale, at huge expense and often with unwelcome ecological side-effects. They take this carpet-bombing approach because they lack information about where and when it is best to hit pests, and nobody wants to use too little pesticide and thus risk losing crops. Technologists at FarmSense, a firm in Riverside, California, hope to change that. The established approach to detecting insect pests, moths in particular, is to employ pheromone-baited sticky traps. Pheromones are chemicals which animals use to communicate—and especially to attract members of the opposite sex. An appropriately baited sticky trap gives a fair idea of the number and type of pests around, but not with sufficient detail for the precise application of pest control measures. Such traps have, however, changed little in decades, except that some now come with a digital camera which transmits a daily picture of the trapped insects. FarmSense’s researchers reckon they can do better.