Wasps are common insects, often observed during warmer months. Their behaviors and dietary habits frequently spark curiosity, particularly regarding whether they eat their own kind. Understanding their diet involves looking beyond casual observations to grasp the nutritional needs that drive their foraging activities.
Are Wasps Cannibalistic?
Wasps generally do not actively hunt and consume other living wasps as a regular part of their diet. Cannibalism is uncommon among most wasp species. However, it can occur under specific, rare circumstances. For instance, European hornets and certain yellow jacket species may exhibit cannibalistic tendencies when food sources become severely limited, turning to their own kind as a last resort for protein. This allows stronger individuals within a colony to sustain themselves during extreme hunger.
Brood cannibalism, where a queen consumes her own offspring, is another exceptional case. This can happen under significant stress, such as severe food scarcity, to manage resources or maintain her survival. Research on certain solitary wasp larvae, like Isodontia harmandi, reveals that sibling cannibalism can routinely occur within communal brood cells when prey provided by the mother is insufficient. Larger larvae might consume smaller or newly hatched siblings for their own development. Wasps may also scavenge on nestmates that have already died, which is scavenging rather than active predation.
What Wasps Really Eat
The diet of wasps changes significantly with their life stage. Adult wasps primarily consume sugary substances to fuel energy-intensive activities like flying and foraging. Their preferred sources include nectar from flowers, fruit juices, tree sap, and honeydew secreted by aphids. This explains why they are often seen around ripe fruit or sweet human foods, especially in late summer when natural sugar sources are less abundant.
Developing wasp larvae require a protein-rich diet for growth. Worker wasps actively hunt various insects and arthropods, such as caterpillars, flies, spiders, and meat scraps. They chew these up and feed them to the larvae in the nest, providing essential protein. Larvae, in turn, secrete a sugary liquid that adult wasps consume. This exchange ensures larvae receive protein and adults gain carbohydrates.
Why Wasp Interactions Can Seem Like Cannibalism
Certain wasp behaviors can be misinterpreted as cannibalism due to aggression or scavenging. Wasps are highly territorial, especially when defending their nests. They may engage in aggressive disputes with other wasps, particularly from rival colonies, which can involve physical altercations. If a wasp from one colony approaches another’s nest, it might be aggressively chased, attacked, or even killed by the defending wasps.
Wasps also frequently fight over food resources. When multiple wasps are attracted to a concentrated food source, such as fallen fruit or human food, competition can arise. These interactions, involving pushing, biting, or chasing, can appear violent, leading observers to believe wasps are attacking each other for consumption. However, they are typically competing for access to the food item itself. Wasps are opportunistic scavengers and will consume carrion, including dead insects. If a dead wasp is found, others might scavenge its remains, which is a common behavior among many insect species and distinct from active predation.