Epitheca princeps

Geographic Range

Epitheca princeps , commonly known as prince baskettails, are found in more than 27 states in the United States, spanning mostly the midwestern and eastern United States. These insects have been reported in Ontario and Quebec, Canada. They are known to range from southern Florida to the southern region of Ontario. They are found in higher densities in Indiana, Illinois, Wisconsin, Michigan, and Florida.

• Biogeographic Regions
• nearctic nearctic
  • introduced introduced
  • native native

Habitat

Prince baskettails, like most Corduliidae , live in and around freshwater swamps and ponds. This species lives in the surrounding vegetation of permanent ponds, lakes or streams, all of which have a slow current. The eggs and larvae live in the water, usually occupying depths of 0.5 m. The water conditions can range from clear to muddy, and a suitable oxygen concentration is necessary for the eggs laid underwater.

• Habitat Regions
• temperate temperate
• terrestrial terrestrial
• freshwater freshwater

• Terrestrial Biomes
• forest forest

• Aquatic Biomes
• lakes and ponds
• rivers and streams

• Wetlands
• marsh marsh
• swamp swamp

• Other Habitat Features
• riparian riparian

Physical Description

Like all dragonflies , prince baskettails have large compound eyes, which basically are numerous smaller eyes fused together. These dragonflies are classified in the family Corduliidae , which includes the "emerald dragonflies", so named because of their emerald-colored eyes. Only prince baskettail males have green eyes; females have bronze or brown eyes, and juveniles have red-brown eyes.

Epitheca princeps has small antennae. All four of its wings have brown spots on the apical, nodal, and basal portions. The wings are brittle and stiff. Females usually are larger and have a more cylindrical and bluntly tipped abdomen, which ends in their ovipositor. Males have a larger segment 9 abdominal region compared to females. Southern prince baskettails are larger than their counterparts in the Midwest, and both regional types have the same markings.

The larvae have dark bodies, which become darker with every molt. Epitheca princeps females produce an orange egg mass. Within the first 24 hours of being fertilized and deposited into the water, the eggs begin to darken to a more brown or gray color.

• Other Physical Features
• ectothermic ectothermic
• bilateral symmetry bilateral symmetry

• Sexual Dimorphism
• female larger
• sexes colored or patterned differently
• sexes shaped differently

Development

Epitheca princeps is hemimetabolous. Like all odonates , it has three life stages--egg, larva, and adult. It exhibits a distinct transition from the larval to the adult stage, during which E. princeps shifts from an aquatic to a terrestrial form.

During the spring and summer, E. princeps females deposit fertilized egg masses in water near the shoreline, at depths of 0.5 m. Fertilized eggs grow and begin to hatch within 2 to 3 weeks. The process of hatching occurs when the embryo uses peristaltic movements to swallow amniotic fluids. The embryo pushes its head into the vitelline membrane until the membrane bursts. The embryo then uses a sclerotized frontal crest (nicknamed the "egg buster") to cut the chorion and free itself from the egg.

Prince baskettails are known for their relatively long larval development, as larvae require 11 months or up to 2 years to develop to their final molt. Larval development is asynchronous, which reduces intraspecific competition among the newly hatched larvae of different broods. Epitheca princeps hatches as a prolarva, which is a brief life stage that does not eat. The prolarva molts into a second form, which is pale and still retains in its midgut nutritious yolk from the egg. As the larva molts, its pigmentation darkens, and it grows in size. Epitheca princeps larvae live underwater, where they are top predators. When hunting underwater, prince baskettails use a prehensile labium to catch their prey. They feed by grasping the prey with their labium and bringing it to their mandibles to engulf and chew the food.

When E. princeps is in its final larval stage, it migrates to greater depths in its underwater habitat. Its defense against the winter cold is to attach to a substrate in the depths and undergo diapause. This strategy is believed to allow the larvae to escape from predators and other potential risks associated with colder temperatures near the shore.

When warmer temperatures return, E. princeps larvae come out of diapause and prepare for metamorphosis. They migrate back toward the shore and remain underwater for about a week. During this time, the wing pads begin to thicken, and the larval exoskeleton completely encases the growing adult. When prince baskettail larvae leave the water, they find and hold a support substrate, which enables successful emergence. Emergence begins when the exoskeleton splits along the middorsal line, and the thorax pushes out. The legs, wings, and the rest of the anterior end of the body emerge next. Then the adult rests for 10 to 20 minutes, which allows the exposed parts of its body to harden. The adult then uses its legs to pull its entire body from the larval exoskeleton.

After emergence, the wings of the adult must expand and harden. The wings become clear and slender as they dry, and the process normally takes about 15 minutes. The transition from aquatic larva to terrestrial adult is risky, as the adult is exposed and weak during the resting periods of emergence. Most larvae fall to predation at this stage. Only about 1% of E. princeps larvae reach sexual maturity.

Adults undergo 2 phases: the prereproductive and reproductive phases. During the prereproductive phase, coloring appears, including the darkening of the basal and nodal spots on the wings. The exoskeleton hardens, and the thoracic muscles develop. During this phase, the gonads develop and mature. Females have a longer prereproductive period than males. Once a prince baskettail matures, it enters the reproductive phase. During the reproductive phase, males search for a mate; males also search for and protect an oviposition site.

• Development - Life Cycle
• metamorphosis metamorphosis
• diapause diapause

Reproduction

Females typically remain separate from males until they are sexually mature. At that point, they return to the water to search for a mate. Epitheca princeps males and females mate with multiple partners. Males dilute or wipe away the sperm of other males when they mate with a female.

• Mating System
• polygynandrous (promiscuous) polygynandrous (promiscuous)

Epitheca princeps mates as early as May. When individuals reach sexual maturity, the males guard an oviposition site near the water source where a female can deposit her eggs. Females typically are solitary, living away from males until they reach sexual maturity.

The primary sense used for finding a mate is vision. Once a male sees a female, he flies next to and around her. Then he returns to his oviposition site, waiting for the female to follow him. If a female follows the male, the male hovers over the female at the oviposition site. While hovering, the male transfers sperm to his penis from a gonopore on his abdomen. This process is called intramale sperm translocation. If the female slows her wing beats per minute while the male hovers over her, the male initiates tandem linkage, wherein he grasps the flying female on her pterothorax to bring her abdomen upward and forward. During copulation, the female swings her abdomen forward toward the male's abdomen, forming a copulation wheel. The male transfers sperm from his penis to the female's sperm storage organ near her ovipositor. He also wipes any other sperm out of her sperm storage organ. This sperm displacement behavior ensures that most of the progeny are fertilized by the female's last mate. Copulation is brief, lasting 3 to 20 seconds.

The female oviposits later in the day, toward dusk. She fertilizes the eggs as they pass the sperm storage organ and exit the ovipositor. A mass of eggs forms under her abdomen. Epitheca princeps females lay this orange-colored mass of eggs, which resembles a basket and has led to the common name of "prince baskettails" for this dragonfly species. The female attaches the egg mass to a substrate in the water, near the shore.

• Key Reproductive Features
• seasonal breeding seasonal breeding
• sexual sexual
• fertilization fertilization
  • internal internal
• oviparous oviparous
• sperm-storing sperm-storing
• delayed fertilization delayed fertilization

Epitheca princeps females hold their eggs in their abdomen until they are ready to fertilize the eggs. The eggs contain yolk to support the embryo. All of the fertilized eggs are encased in a basket-like mass, which the females attach to a substrate underwater. No parental investment occurs after the female deposits the eggs in the water.

• Parental Investment
• pre-fertilization
  • provisioning
  • protecting
    • male
    • female
• pre-hatching/birth
  • provisioning
    • female
  • protecting
    • male
    • female

Lifespan/Longevity

Most of the lifespan of Epitheca princeps is spent in the larval stage. The larval stage can last between 80 days and 2 years, mostly due to the time spent in diapause, avoiding the cold winter temperatures. When the larvae emerge as adults, they can live for up to 2 weeks.

Behavior

Epitheca princeps most often can be observed flying over trees during the day and feeding in swarms during the evening. This species can form swarms of 10 to 30 individuals and may fly with Epitheca cynosura simulans . Epitheca princeps perches to feed on larger food items; it also perches at night. It perches by hanging under twigs, often with its wings elevated. It typically is still perched at dawn, as the sun must heat its muscles before it can begin flying. Species in the genus Epitheca , prince baskettails included, are known for their strong, persistent flights.

Epitheca princeps females are solitary until they reach sexual maturity, generally occupying a range that extends farther from the water source. Males can be territorial; they guard oviposition sites from other male E. princeps and other dragonflies . However, E. princeps often is not the most dominant odonate in the habitat; thus, many Epitheca princeps males cannot patrol close to the shore.

Larvae often enter diapause during the winter. They migrate to deeper waters when temperatures are low, which enables them to avoid predation and the dangers associated with cold temperatures close to the shore.

• Key Behaviors
• flies
• glides
• diurnal diurnal
• crepuscular crepuscular
• motile motile
• sedentary sedentary
• hibernation hibernation
• solitary solitary
• territorial territorial

Home Range

Epitheca princeps stays near a freshwater source and in the surrounding vegetation. The size of the water source tends to be about 1,200 square meters, while the size of the surrounding terrestrial habitat utilized by E. princeps is unknown.

Because E. princeps needs to perch at night, branching trees and vegetation in the home range are essential. Epitheca princeps larvae hatch in freshwater; once they develop as adults, they are fully terrestrial. For adult prince baskettails, the water source is important for oviposition and hydration.

Communication and Perception

The primary sense used by Epitheca princeps is vision, especially in adults hunting prey and seeking mates. Prince baskettails can sense UV and polarized light. Adult antennae are reduced, suggesting that E. princeps does not rely heavily on touch or pheromones to sense its environment. Epitheca princeps larvae perceive the environment through vibrations in the water. By detecting the magnitude of water vibrations, the larvae can sense whether the source of the vibrations is a predator or a prey item.

• Communication Channels
• visual visual

• Perception Channels
• visual visual
• ultraviolet
• polarized light polarized light
• vibrations vibrations

Food Habits

All odonates are predatory. Epitheca princeps adults are classified as insectivorous carnivores, primarily feeding on flies . Epitheca princeps catches prey in its mouth and uses its mandibles to chew before ingesting the prey.

Odonate larvae eat almost anything they can catch, including other odonate larvae, a variety of benthic and planktonic invertebrates, tadpoles, and even small fish. A prince baskettail larva feeds by using its protractile labium to catch prey and transport the food to its mouth.

• Primary Diet
• carnivore carnivore
  • insectivore insectivore

• Animal Foods
• amphibians
• fish
• insects

Predation

Epitheca princeps is most vulnerable to predators as it metamorphoses into an adult, during the transition from an aquatic to a terrestrial habitat.

Larvae are eaten by predators such as adult frogs , fishing spiders , grackles , and red-winged blackbirds . Larger odonate larvae prey on smaller odonate larvae. The dark coloring of larvae camouflages them in their underwater habitat.

• Anti-predator Adaptations
• cryptic cryptic

Ecosystem Roles

Epitheca princeps is one of the top invertebrate predators in the shallow littoral zones of ponds and streams. As a predator, E. princeps helps control the population densities of many pest insect species, such as mosquitoes.

Epitheca princeps serves as prey for organisms such as birds, larger dragonflies , and frogs. Predation among dragonflies is more prevalent during the larval stage relative to predation among adults.

Juvenile Zebra mussels sometimes attach to and colonize dragonfly larvae, including Epitheca princeps . The mass of mussels sometimes reduces movement and righting ability in the dragonflies, and particularly interferes with emergence of the larvae, as colonized larvae may not be able to leave the water and find a safe, sturdy substrate for emergence.

Economic Importance for Humans: Positive

Epitheca princeps , like other dragonflies , is harmless to people. Given its insectivorous habits, E. princeps is helpful to humans when it preys on pest insects. Its presence can be an indicator of freshwater quality.

• Positive Impacts
• controls pest population

Economic Importance for Humans: Negative

There are no known adverse effects of Epitheca princeps on humans.

Conservation Status

Epitheca princeps is not known to have any special conservation needs.

Additional Links

Encyclopedia of Life

Contributors

Nicole Sugai (author), University of Michigan-Ann Arbor, Elizabeth Wason (author, editor), Animal Diversity Web Staff.

References

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Wissinger, S. 1988. Spatial distribution, life history and estimates of survivorship in fourteen-species assemblage of larval dragonflies ( Odonata : Anisoptera ). Freshwater Biology , 20: 329-340.