Problem Statement: In Santa Fe, Argentina, farmers often find soil-dwelling insect larvae while planting their cereal crops in winter and early spring. These larvae, or white grubs (gusanos blancos), are considered harmful to their harvest, and insecticides are often used indiscriminately as a preventive measure against the alleged pest. Yet, pesticide use is expensive, potentially harmful to people and the environment, and may also eradicate beneficial insect species.

Methods: A reference collection of arthropods (mainly insects) was established in 1997 at the Rafaela Experimental Station of the National Institute of Agricultural Technology (INTA) in Argentina. This collection was used as the basis for research into the distribution and life cycles of soil-dwelling insect larvae, and into the effectiveness of different pesticides and natural predators in eradicating crop pests during their larval stages.

Outcomes and Impacts: The larvae in the Santa Fe region were identified as nine different species of Coleoptera: Scarabaeidae. Only the larvae of one of these species, Diloboderus abderus, cause serious damage to crops. Research based on the correct insect larvae taxonomy, and using information on species distribution gathered from farmers, showed that only 10% of the cereal fields would need insecticide treatment to prevent crop damage. Also, natural predators of these larvae, parasitic wasps, were found to occur in the region. Research revealed that it was best to rely on these for biological control, rather than use pesticides, which may have adverse effects on their populations. The findings were made available to farmers in the form of accessible and simple species identification guides and educational articles on the INTA website, enabling them to target and reduce their use of pesticides, reducing costs, and lessening environmental contamination.

Lessons: Biological reference collections are needed to support the development of agricultural practices that minimise costs and impacts on the environment and human health.  Online dissemination of easy-to-use taxonomic and educational products for farmers puts taxonomic research into practice.