Bats have gotten a bad name around the world as having allegedly started the coronavirus (Covid-19) pandemic (snakes in China may have been responsible) that has turned the world upside down. But Israeli and Danish scientists have found that insect-eating bats could definitely be useful – protecting the multi-billion-dollar cotton industry. 

Insects who prey upon agricultural crops can be devastating, but massive use of pesticides is both expensive and harmful to the environment. Conservation biological control (CBC) is an alternative and sustainable method that seeks to encourage natural enemies such as predators of insect pests in agroecosystems. 

Researchers from Ben-Gurion University of the Negev (BGU) in Beersheba investigated the feeding habits of Kuhl’s pipistrelle – a small bat that roosts and forages in urban and agricultural habitats. They found that the bat preyed upon a number of different insects that threaten crops and livestock. Among them, one of the most destructive pests of cotton crops is the pink bollworm.

Their findings were published yesterday in Molecular Ecology under the title “An appetite for pests: Synanthropic insectivorous bats exploit cotton pest irruptions and consume various deleterious arthropods.” 

“CBC seeks to minimize the deleterious effects of agricultural pests by enhancing the efficiency of natural enemies,” the authors wrote. “Despite the documented potential of insectivorous bats to consume pests, many synanthropic [undomesticated plant or animal species living closely alongside and benefiting from human beings] bat species are still underappreciated as beneficial species.

The lead author is a former master’s-degree student Yuval Cohen, supervised by Prof. Carmi Korine and Dr. Shirli Bar-David of the Mitrani Department of Desert Ecology in the Swiss Institute for Dryland Environmental and Energy Research at BGU’s Jacob Blaustein Institutes for Desert Research, in collaboration with Martin Nielsen and Dr. Kristine Bohmann of the Section for Evolutionary Genomics, Natural History Museum in Copenhagen, Denmark.

The team used DNA traces of prey found in the droppings of bats to identify which insects they ate. They discovered that as the pink bollworm population increased, the bats hunt them more than other insects. This is especially important as pink bollworm is a growing concern to cotton farmers around the world since it is capable of developing resistance to pesticides and genetically modified cotton. 

“Our study highlights the benefits of insect eating bats that are abundant in human habitats, but their contribution to humans was poorly known,” explained Cohen. Korine and Bar-David added: “We recommend that farmers adjust their thinking and consider bats their good friends.”

In addition, Kuhl’s pipistrelle feeds on a range of other potential disease transmitters such as mosquitos or other annoying insects such as midges. The findings indicate that the bats could potentially contribute to suppress additional unwanted insects around humans.

The results offer important evidence of the crucial ecosystem service provided by a common bat species,” said Korine. “We should be aware of the functional importance of common species of bats in urban environments for ecosystem functioning and human society. Particularity now when bats are negatively and often unjustifiably stereotyped due to COVID-19.” 

The study is part of ongoing research on the role of insect-eating bats in pest suppression in other agriculture systems such as corn, vineyards, apples and date plantations carried out by Korine’s group.

The research took place in cotton fields in Emek Hefer, Israel with the assistance of the Israel Seeds Ltd., the Israel Cotton Board Ltd. and regional cotton pest consultants.