Crop Pests and Diseases are now Detected by Dogs

By Katrina Hall

The global climate is changing and food demands are increasing. As a result, the threat of crop pests and diseases could mean widespread hunger, especially for at-risk populations. The nature of many agricultural pests and pathogens compound this problem. They are hard to detect, widespread, and highly specified.

Containing these diseases can only happen once they’ve become detectable. Consequently, this often means that large amounts of crops have been damaged past the point of recovery and containment. One disease alone can cause financial losses in the hundreds of millions. A single outbreak of Karnal bunt fungus in north Texas caused a $250 million loss in revenue in 2001.

More Food, More Pests?

The world’s food supply faces increased biological threats due to climate change, increased travel between countries, and increases in large-scale food production. The need for food increases each year as well, with a predicted nine billion people in need by 2050.  Mass agriculture of staple crops, such as wheat, rice, palm, cassava, and various fruit and vegetables, face dangers unique to each crop:

• Cassava Mosaic Virus: This virus produces ‘s’ shaped stalks, stunted plant growth, and low yields.

• Coconut Rhinoceros beetle: The ‘Coconut’ Red Rhinoceros Beetle (X. glabratus) spreads fungus called Raffaelea Lauricola that kills redbay and avocado trees, effectively starving their pollinators.

• Wheat Rust: This fungus is caused by Puccinia triticina (Brown Leaf Rust), and it reduces wheat kernel yield and size. It is a prolific spreader that is present in major wheat-growing sites worldwide.

• Citrus Greening: This virus is rampant in the southeastern U.S. as well as citrus and other orchards worldwide. As of 2019, the disease has reduced Florida citrus production by 75%.

Additionally, the loss of staple foods to crop pests and diseases can contribute to livestock malnutrition. Roughly 36% of the world’s crops are grown for feeding livestock. In some developing countries, these animals are essential to meeting a minimum caloric intake. Thus, famine in developing countries can commonly be exacerbated by a secondary loss in crop-dependent food supplies, such as cattle or goats.

However, a potential solution to the malnutrition of both humans and livestock lies in an unforeseen place.

Teaching Old Dogs New Tricks

A dog’s sense of smell is consistently strong, with some odors detectable in parts per trillion. The scent abilities of our four-legged canine friends have an ancient history of benefits. This includes successful applications in hunting, national security, border patrol, medicine and agriculture. This skill also makes them well suited for training in detecting crop pests and diseases.

Dogs have a particular knack for new scents, described as a form of neophilia. “This technology is thousands of years old – the dog’s nose; we’ve just trained dogs to hunt new prey: the bacteria that causes a very damaging crop disease,” says U.S. Department of Agriculture researcher Timothy Gottwald.