Ladybugs (family Coccinellidae) are recognizable, brightly colored beetles often associated with gardens and agriculture. Gardeners value them as allies due to their beneficial habits. Cultivators often wonder if these insects pose a threat to plants, specifically cannabis. Ladybugs primarily hunt and feed on other insects, not plant material.
The Ladybug Diet: What They Prefer to Eat
Ladybugs are classified as beneficial predatory insects, meaning their diet is primarily composed of other small arthropods. The adult beetles and their larvae are both voracious eaters, actively hunting for soft-bodied pests, eggs, and larvae found on plants. This makes them highly valued in both conventional and organic growing operations.
The preferred food source for many common ladybug species is the aphid, a sap-sucking insect that can quickly devastate cannabis and other crops. Ladybugs also consume other common cannabis pests, including spider mites, scale insects, whiteflies, and mealybugs. A single adult ladybug can consume up to 75 aphids per day, while the larvae can consume even more before reaching maturity. When their primary prey is scarce, adult ladybugs may supplement their diet with pollen, nectar, or honeydew, but they remain predominantly carnivorous.
Ladybugs and Cannabis Plants: Are They a Threat?
Ladybugs do not pose a threat to cannabis leaves, stems, or flowers because they are not phytophagous. The vast majority of ladybug species are strictly predators, making them harmless to the structure of the cannabis plant itself. If a ladybug is observed resting on a leaf or bud, it is almost certainly searching for prey, seeking a drink of water, or simply moving through the canopy.
There are a few species in the Coccinellidae family, such as the Mexican bean beetle, that are herbivores and can cause damage to certain crops. However, these are exceptions and not the beneficial species commonly introduced into gardens. The beneficial ladybugs are solely focused on consuming the pests that harm the plant. Any minor concerns, such as the occasional sighting of a ladybug’s waste product on a leaf, are negligible when weighed against the significant benefit of natural pest eradication.
Using Ladybugs for Natural Pest Control
Cultivators intentionally introduce ladybugs to their crops as a form of biological pest control, an effective alternative to chemical pesticides. For successful introduction, releasing the beetles at dusk is recommended. The cooler temperatures and lower light levels reduce the likelihood that the ladybugs will immediately fly away from the garden.
Before releasing them, lightly misting the plants with water can encourage the ladybugs to stay, as they are drawn to moisture. Ensure that no chemical pesticides have been used on the plants recently, as residues can harm or kill the beneficial insects. Ladybugs will remain in the garden as long as a sufficient food source, like an aphid or mite infestation, is present. Once the pest population has been successfully eliminated, the ladybugs will typically migrate elsewhere in search of new prey.