Dragonflies require water to survive because their life cycle is fundamentally linked to aquatic habitats. These ancient insects, belonging to the order Odonata, spend different phases of their lives in water and air. Although the winged adult is a highly mobile aerial predator, the species’ continuation depends entirely upon a freshwater environment for biological transformation and emergence.
The Essential Aquatic Life Stage
The majority of a dragonfly’s existence is spent underwater in its larval stage, known as the nymph. This aquatic phase can last from a few months up to five years, making water the primary habitat. During this period, the nymph is a voracious predator, feeding on aquatic creatures ranging from mosquito larvae to small fish.
The nymph’s physiology is adapted for a submerged life. Respiration occurs through specialized gills located inside the insect’s rectum. Water is pumped in and out of the abdomen, facilitating oxygen exchange. This method of breathing also provides rapid locomotion; forcefully expelling water from the rectum allows the nymph to achieve bursts of jet propulsion to escape or pursue prey. The quality and permanence of the water body are paramount, as factors like oxygen levels and freedom from toxic substances impact the nymph’s ability to develop and undergo metamorphosis.
Water’s Role in Adult Dragonfly Reproduction
Upon emerging as a winged adult, the dragonfly remains tied to its aquatic birthplace for reproduction. Males of many species establish and defend territories surrounding suitable bodies of water, which are the only locations females visit for mating. The mating process often occurs near or directly over the water, positioning the female to deposit her eggs immediately after fertilization.
The method of oviposition, or egg-laying, varies but always requires water or water-adjacent substrates. Some species, such as hawkers, are “endophytic.” The female uses a specialized ovipositor to insert her eggs within the tissues of aquatic plants, rotting wood, or mud near the water surface. Other dragonflies, including skimmers, are “exophytic” and lack a cutting ovipositor. These females fly low over the water, repeatedly tapping the tip of their abdomen on the surface to sprinkle their eggs directly into the water.
Adult Hydration Needs
While the adult dragonfly spends its days as a mobile aerial hunter, it still needs hydration. Maintaining proper fluid balance is necessary for metabolic efficiency, especially during flight in warm environments. The primary source of moisture for the adult is the diet of soft-bodied insect prey consumed mid-flight.
Moisture absorbed from prey is usually sufficient for daily survival. However, during hot days or intense activity, dragonflies perform a behavior known as skimming. This involves briefly dipping their mouths into the water surface while flying to replenish lost fluids. This dipping also serves a secondary function for some species, providing thermal regulation.