Bats: the new allies against tomato pests

Bats could become unexpected allies for farmers battling crop pests, according to a new trial underway in the tomato fields of Extremadura.

The project is taking place on farms that supply Nestlé’s factory in Miajadas (Cáceres). Working alongside researchers from the Museu de Ciències Naturals de Granollers and the BETA Technological Centre at the University of Vic, teams have installed 30 nesting boxes next to fields to attract local bats into the agricultural landscape.

Early signs of occupancy are promising. More than 170 bats are already using the boxes, with breeding colonies detected in four of them. The initiative aims to build stable bat populations in farming areas where natural roosting sites are scarce.

However, the research goes beyond simply providing shelter. To discover exactly what the bats are eating, scientists have collected 600 samples of guano (bat droppings) for DNA analysis. The findings will reveal which insects the bats are consuming and determine their effectiveness as natural predators of common tomato pests.

The next phase of the trial will introduce smart technology to track the colonies. Researchers plan to install a new model of 'smart' nesting box capable of remotely and autonomously monitoring bat activity on a daily basis, allowing scientists to cross-reference colony growth with insect levels in the crops.

The trial forms part of a wider regenerative agriculture programme across the farms supplying the Miajadas plant. Other measures include planting cover crops between tomato harvests, increasing organic matter to cut back on synthetic fertilisers and leaving uncultivated zones as refuges for beneficial wildlife.

The DNA results will ultimately establish whether encouraging native bat populations can serve as a viable method of biological pest control for tomato growers.