Insect-eating bats as pest suppressors in agriculture systems of Hanadiv Valley

Carmi Korine

Vineyards around the world are important foraging sites for insectivorous bats (insect-eating bats), for whom moths, which are vineyard pests, are an important dietary component. Most species of bats in Israel are insectivorous, feeding on an enormous quantity of insects at night. Insectivorous bats forage in natural areas; some species also forage in farmland. Recent studies emphasise the importance of bats as providers of an important “ecosystem service” for humans: control of pests in agricultural systems. In other words, insectivorous bats have great potential as biological control agents of the community of insects that are agricultural pests. The current study examined the potential of insectivorous bats as biological control agents in the wine-producing areas of Hanadiv Valley.

The main aims of the study are to quantify the potential contribution of insectivorous bats as pest control agents in the vineyard and find methods and management actions that farmers can use to expand bat activity and increase their effectiveness as biological control agents in vineyards.

To study the potent of bats as biological control agents in this branch of agriculture, a study headed by Prof. Carmi Korine was initiated within the framework of the Partnership for Regional Sustainability. This study examines the importance of vineyards in Hanadiv Valley as foraging areas for insectivorous bats.

In the first stage we studied the spatial distribution of insectivorous bats in vineyards with different types of pest control to evaluate their activity and food composition in the farmlands of Hanadiv Valley. The hypothesis is that bat activity in farmlands is related to the type of pest control implemented in them and to the surrounding landscape elements, such as open water sources.

The experiment to increase bat activity in vineyards found that pheromone addition has a positive effect on both species richness and bat activity in the vineyards

The researchers hypothesised that the activity and species richness of these bats will be higher in vineyards managed using integrated pest management, which promotes environmentally friendly pest control and therefore minimises the use of traditional chemical pesticides.

Within the framework of the study the vineyards were sampled using a bat detector that records the bats’ ultrasonic sounds. They use these sounds for different reasons, such as orientation, trapping insects, and interspecific communication. Since most insectivorous bat species have a unique sound, the recording can be analysed using a sound programme to identify the bat species sampled in the vineyards. In addition to monitoring bat sounds, we sampled the community of insect pests in this region.

The study began in spring 2017 and continued through the summer and autumn. To date, the recorded sounds have enabled identification of about six different species of insectivorous bat, of which all are protect species and most are classified as being endangered.

Summary of preliminary results:

Ten species of insectivorous bat, comprising about 52% of all bat species in northern Israel, were documented in the vineyards in Hanadiv Valley. Of these ten documented species, eight are endangered species; this emphasises the importance of vineyards as foraging sites for insectivorous bats.

Bat activity and species richness vary during the year; in summer, as in other parts of Israel, activity is at its peak. The experiment to increase bat activity in vineyards found that pheromone addition has a positive effect on both species richness and bat activity in the vineyards. This management action alone has a positive effect on bat activity; it is also simple and easy to implement and can be a means of increasing bat activity in different agricultural crops.

Other methods for increasing the activity of insectivorous bats are the use a sound generator and construction and installation of small water bodies. The use of ‘bat houses’ has low feasibility; however, they can be used for educating about integrated pest management.

Pipistrellus kuhlii (Kuhl’s pipistrelle)

The highest activity throughout the year in the Hanadiv Valley region was of Pipistrellus kuhlii (Kuhl’s pipistrelle), the most abundant species in Israel, which forages in a range of different farmlands.

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