Why Do Wasps Drink Water?

Several insect species visit puddles, ponds, bird baths and decorative koi ponds, to drink water. However, if there is no water available for them, they will die.

Parasitic wasps need water to help their eggs mature. They can also use water to regulate the humidity in their nest. In addition, they can eat dead animals to add extra nutrition to their larvae. They also take water from water sources with their pincer claws.

However, most parasitic wasps do not use free water. In fact, they rely almost entirely on prey or hosts for food.

A study in Pteromalidae (Hymenoptera) found that females of P. vindemmiae (Hymenoptera: Pteromalidae) benefited from host-feeding. In this study, females were isolated in flat tubes with a water source. They were then filmed for 30 minutes.

The study showed that host-feeding increased the sex ratio and flight capacity of the females. In addition, it boosted their total host-killing capacity in water-deprived environments.

The researchers noted that the amount of time spent feeding on a host was greater in water-deprived wasps than in the control group. They also found that host-feeding increased the longevity of the females by 1.3 days. Moreover, the females benefited from the increased host-feeding rates even when honey was provided.

These results suggest that wasps have evolved a hydration strategy that is unique among other insect species. Parasitic wasps use hemolymph as a water source to compensate for their limited access to free water.