Prince Baskettail
Epitheca princeps
Distribution 5
Epitheca princeps, also known as prince baskettails, are found in more than 27 states in the United States, spanning mostly the Midwest 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 (Introduced , Native )
Associations 6
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.
Epitheca princeps larvae can have a parasitic relationship with zebra mussels. Zebra mussels colonize and attach to dragonfly larvae, which reduces larval fitness. This parasitism can hinder the emergence of the larvae, as they may not be able to leave the water and find a safe, sturdy substrate for emergence.
Commensal/Parasitic Species:
- Zebra mussels (Dreissena polymorpha)
Behaviour 7
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 their environment by using 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
Other Communication Modes: vibrations
Perception Channels: visual ; ultraviolet; polarized light ; vibrations
Habitat 8
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 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.
Range depth: 0 to 1 m.
Habitat Regions: temperate ; terrestrial ; freshwater
Terrestrial Biomes: forest
Aquatic Biomes: lakes and ponds; rivers and streams
Wetlands: marsh ; swamp
Other Habitat Features: riparian
Life cycle 9
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 nutritious yolk from the egg in its midgut. 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 to emerge. 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 anterior end of the body emerge next. Then the adult rests for 10 to 20 minutes, which allows its exposed regions 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 the most risky, as the adult is exposed and weak during the resting periods. Most larvae fall to predation at this stage. Only about 1% of E. princeps larvae reach sexual maturity.
Adults undergo 2 phases: 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 ; diapause
Morphology 10
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 have small antennae. The wings of prince baskettails have brown spots on the apical, nodal, and basal portions of all four wings. 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.
Range length: 5.6 to 8.1 cm.
Sexual Dimorphism: female larger; sexes colored or patterned differently
Other Physical Features: ectothermic ; bilateral symmetry
Reproduction 11
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)
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 will fly next to and around her. Then he will return to his oviposition site, waiting for the female to follow him. If a female follows the male, the male will hover 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 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 an orange-colored mass of eggs that resembles a basket, which 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.
Breeding interval: Yearly
Breeding season: May to early July
Range eggs per season: 800 to 2600.
Range gestation period: 2 to 3 weeks.
Key Reproductive Features: seasonal breeding ; sexual ; fertilization (Internal ); oviparous ; sperm-storing ; 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: no parental involvement; pre-fertilization (Protecting: Male, Female); pre-hatching/birth (Provisioning: Female, Protecting: Male, Female)
Sources and Credits
- (c) Dan Irizarry, some rights reserved (CC BY-NC-SA), http://www.flickr.com/photos/8739828@N04/5582213964
- (c) Phil Myers, Museum of Zoology, University of Michigan-Ann Arbor, some rights reserved (CC BY-NC-SA), https://animaldiversity.org/collections/contributors/phil_myers/odonata/Corduliidae/Epicordulia0009/medium.jpg
- (c) Phil Myers, Museum of Zoology, University of Michigan-Ann Arbor, some rights reserved (CC BY-NC-SA), https://animaldiversity.org/collections/contributors/phil_myers/odonata/Corduliidae/Epicordulia0015/medium.jpg
- (c) Phil Myers, Museum of Zoology, University of Michigan-Ann Arbor, some rights reserved (CC BY-NC-SA), https://animaldiversity.org/collections/contributors/phil_myers/odonata/Corduliidae/epicordulia_princeps0005/medium.jpg
- (c) The Regents of the University of Michigan and its licensors, some rights reserved (CC BY-NC-SA), http://eol.org/data_objects/31393013
- (c) The Regents of the University of Michigan and its licensors, some rights reserved (CC BY-NC-SA), http://eol.org/data_objects/31393022
- (c) The Regents of the University of Michigan and its licensors, some rights reserved (CC BY-NC-SA), http://eol.org/data_objects/31393019
- (c) The Regents of the University of Michigan and its licensors, some rights reserved (CC BY-NC-SA), http://eol.org/data_objects/31393014
- (c) The Regents of the University of Michigan and its licensors, some rights reserved (CC BY-NC-SA), http://eol.org/data_objects/31393016
- (c) The Regents of the University of Michigan and its licensors, some rights reserved (CC BY-NC-SA), http://eol.org/data_objects/31393015
- (c) The Regents of the University of Michigan and its licensors, some rights reserved (CC BY-NC-SA), http://eol.org/data_objects/31393017
