Vesper mice

The genus Calomys, commonly known as vesper mice, belongs to the family Cricetidae and the order Rodentia. These small rodents are significant pests in South American agricultural landscapes. Beyond causing direct damage to agricultural yields, they are recognized as vectors for various zoonotic diseases, posing risks not only to plants but also to human health within the farming community.

These pests primarily target cereal crops, including corn and wheat, as well as various legumes. They are highly adaptable to agricultural ecosystems, often exploiting the abundance of food provided by monoculture plantations. Their feeding habits during the critical stages of grain development lead to substantial biomass loss and decreased harvest quality.

The biology of Calomys is defined by high reproductive rates and a short developmental cycle. They are capable of year-round breeding in favorable climates, which allows their populations to spike rapidly. This rapid proliferation makes early detection and continuous monitoring essential for any successful crop protection strategy in infested regions.

Damage assessment reveals that these rodents cause severe harm by consuming seeds, cutting seedlings at the base, and feeding on ripening ears. The infestation not only reduces yield quantity but also contaminates the field environment with urine and feces, which significantly compromises product quality and may lead to market rejection of the harvested grain.

Integrated pest management (IPM) is the most effective approach to control vesper mice populations. Key strategies include:

• Deep tillage to destroy burrow systems and nesting sites.
• Maintaining clean field borders to eliminate alternative food sources.
• Strategic placement of rodenticides in bait stations to avoid environmental contamination.
• Promoting biodiversity by encouraging the presence of natural predators such as hawks and owls.