Cicindela scutellaris

Geographic Range

Festive tiger beetles are found throughout the eastern United States, from eastern Montana, Wyoming, Colorado, and New Mexico east to the Atlantic Coast as far south as the mid-Florida peninsula and southern Maine. They are found throughout eastern Texas and into southernmost Canada, from Alberta to Quebec. They are not found in the Appalachian Mountains.

• Biogeographic Regions
• nearctic nearctic
  • native native

Habitat

Festive tiger beetles are found in sandy habitats, including dunes, exposed sandy areas in grasslands, road cuts, and the sandy floors of pine and oak-pine forests.

• Habitat Regions
• temperate temperate
• terrestrial terrestrial

• Terrestrial Biomes
• desert or dune desert or dune
• savanna or grassland savanna or grassland
• forest forest

Physical Description

Festive tiger beetles are 11 to 14 mm long and brightly colored. They are the most variable species of tiger beetle in the United States, with 7 or 8 subspecies. Color ranges from deep red to orange, blue, green, and black in various populations. In all populations, however, males have a white labrum and hairy front and females have a dark, even black, labrum (covering of the upper mandible, which forms the roof of the mouth) with hairs near the inner edge of their eyes. The labrum has 3 teeth and there are 15 to 20 large bristles on the first antennae segment. The elytra are rounded on their posterior edge and often have light colored spots on their lateral edges which sometimes fuse to form a light band. In some subspecies the marginal spots form a distinct triangle that points towards the dorsal midline. Some subspecies lack spots on the elytra. The elytra are sometimes marked with a few, scattered indentations. Their legs are relatively short and the body is robust. Male and female tiger beetles are distinguished by the presence of brush-like tarsal pads on the male's forelegs, used to hang on to the female during mating. Females have a shallow groove on their prothorax that helps males to hang on during mating.

The subspecies of festive tiger beetles have been considered incipient species by some researchers, representing differentiation in isolation. However, the striking polymorphism in coloration among subspecies could be adaptations to the particular camouflage and predator avoidance pressures of different regions. Laboratory research on rearing tiger beetles in different conditions shows that color and spotting patterns can be influenced by temperature and moisture. Recognized subspecies include: C. s. scutellaris , with dark green or blue head and thorax and bright orange elytra in the western portion of the range, C. s. flavoviridis , found in central Texas and distinguished by a yellow-green metallic color and 2 to 6 white spots on the elytra, C. s. lecontei , which occurs throughout the northeast and Midwestern states and are either maroon or green on the head, thorax, and elytra and with a light colored border on the elytra, C. s. rugata , found from eastern Texas to western Arkansas and are uniformly blue with no light markings on the elytra, C. s. rugifrons , this subspecies is highly variable, from green to black, and is found along the Atlantic seaboard from Massachusets to the Carolinas, C. s. unicolor , found from Georgia to the Gulf coast and into Missouri and Tennessee, is blue to light green with no white markings, and C. s. yampae , with green head and thorax and purple-red elytra with a wide, white posterior margin and found only in northwestern Colorado.

Like all tiger beetle larvae , ghost tiger beetle larvae are grub-like, with an armored head and an enlarged portion of the 5th abdominal segment that bears two pairs of large hooks. They have large mandibles and 6 small eyes on the head. Larvae establish burrows and wait for passing prey near the top of the burrow, they retreat into the deeper parts of the burrow if disturbed. Festive tiger beetles have 3 instar stages. Third instars are 20 to 24 mm long. The head and pronotum are purple-bronze, with a greenish cast. They have white setae on the head and pronotum and dark setae on the rest of the body.

• Other Physical Features
• ectothermic ectothermic
• heterothermic heterothermic
• bilateral symmetry bilateral symmetry
• polymorphic polymorphic

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

Development

Festive tiger beetles spend their first 14 months in different larval instar stages. They then pupate, metamorphosing into adults.

• Development - Life Cycle
• metamorphosis metamorphosis

Reproduction

There are no specific reports of mating in Cicindela scutellaris . As in most tiger beetles , however, males generally run at females during the mating period and jump on to their backs. They use their jaws and forelegs to hold onto the prothorax of the female, which has a groove that makes it easier to hold on. If the male is not dislodged by the female, then he can successfully copulate with her. Males often continue to hang onto the female for several hours after copulation to prevent another male from mating with her.

• Mating System
• monogamous monogamous
• polygynous polygynous

Festive tiger beetles have been observed mating between May 14 and June 4. Females lay about 50 eggs in dry sand or sandy soils. Each egg is deposited into its own hole, about 5 to 10 mm deep. Larvae develop to the 3rd instar stage in their first summer and hibernate over the winter. In the following spring they become active and begin feeding, then pupate in June and July. They emerge as adults in August, often after a soaking rain. Adults overwinter in a burrow and are sexually mature when they emerge the next spring.

• Key Reproductive Features
• semelparous semelparous
• seasonal breeding seasonal breeding
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual sexual
• fertilization fertilization
  • internal internal
• oviparous oviparous

Females select appropriate sites to lay their eggs, one at a time. Larvae build their burrows at that site, so it is important that the site is well chosen. After the eggs are laid there is no further parental investment.

• Parental Investment
• no parental involvement
• pre-fertilization
  • provisioning
  • protecting
    • female
• pre-hatching/birth
  • provisioning
    • female

Lifespan/Longevity

Lifespan is thought to be 2 years in the wild, with most of this spent in the larval stage.

Behavior

Festive tiger beetles seek shelter from extreme heat by hiding under vegetation or burrowing into holes in the sand, where they also rest for the night. They also thermoregulate behaviorally in other ways, such as basking to warm or holding their bodies above the substrate to cool themselves. These tiger beetles are diurnal. They are active during the spring and fall, becoming inactive in the hottest months of summer, June and July, and in the winter, from October to March. They may emerge on warm, winter days in the southern parts of their range. Both adults and larvae seek shelter in burrows to overwinter. The burrows of larvae are generally 15 to 55 cm deep. They are usually found under the shade of vegetation and not in open areas of shifting sand. Larvae pupate in a chamber dug out of the substrate to one side of their burrow.

• Key Behaviors
• terricolous
• flies
• diurnal diurnal
• motile motile
• sedentary sedentary
• hibernation hibernation
• aestivation
• solitary solitary

Home Range

Home range size is not reported in the literature. Larvae are restricted to their burrows, constituting much of the lifespan of these beetles.

Communication and Perception

Tiger beetles have large eyes and acute vision that they use to help find prey and avoid predators. Interestingly, they can move faster than their visual acuity can keep up. When they see prey, they quickly run after it, but then must stop again to find the prey visually. Tiger beetle adults also have ears (tympana) on their abdomen underneath the elytra. They may be used to help detect predators that produce sounds, such as bats, but more research is needed. Larvae use their eyes to detect danger and prey and are capable of focusing well. They also use vibrations to detect passing animals.

• Perception Channels
• visual visual
• tactile tactile
• acoustic acoustic
• vibrations vibrations

Food Habits

Larvae perch at the entrance to their burrows and prey on passing insects that happen to pass by. When waiting for prey, their heads block the burrow entrance and are usually colored to match the surrounding substrate. Their 5th abdominal segment has an expanded portion with hooks in it to help them hold their position in the burrow. It also makes it difficult to pull larvae out of their burrows. When prey is detected, they pop out of the burrow and grab the prey with their large, curving jaws. They take the prey to the bottom of the burrow to eat them.

Adults use vision to detect and chase after insect prey. They grab them with their large jaws and chew them in the mouth. They use a strong digestive enzyme in the mouth and then swallow the resultant nutrient solution, spitting out the indigestible parts of their prey. The digestive enzyme is so strong that it can eat holes in the bug nets used to capture these beetles. Adults seem to prefer ant prey but will take any small arthropod.

• Primary Diet
• carnivore carnivore
  • insectivore insectivore

• Animal Foods
• insects
• terrestrial non-insect arthropods

Predation

Tiger beetles in general are thought to use their coloration to help camouflage them from predators in their preferred habitats. If detected, they are capable of brief, short flights and can run rapidly. Larvae drop to the bottom of their burrows when disturbed, where they may be difficult to reach. They can also hold onto the walls of their burrow with their enlarged 5th segment, making it difficult to extract them. They may be preyed on by any number of insectivorous animals, including spiders, robber flies ( Asilidae ), lizards, toads, birds, such as flycatchers ( Muscicapidae ) and shrikes ( Laniidae ), raccoons, and skunks. Larvae may be preyed on by ants, hister beetles ( Histeridae ), and soldier beetles ( Cantharidae ). Larvae fall prey to ground-foraging woodpeckers, ants, and wasps.

• Anti-predator Adaptations
• cryptic cryptic

Ecosystem Roles

Festive tiger beetles co-occur throughout much of their range with big sand tiger beetles ( Cicindela formosa ).

Larvae are especially vulnerable to parasitoid wasps, especially the tiphiid wasp genera Methoca and Pterombrus . Parasitoid wasps paralyze a larva with a sting and then lay their eggs on the larva and closes the entrance to the burrow. The parasitoid larvae then consume the tiger beetle larva as they develop and emerge from the burrow as adults. Parasitoid bee-flies ( Anthrax ) lay eggs on the substrate near a tiger beetle larval burrow and roll them into the burrow, where they develop at the bottom and then crawl onto the tiger-beetle larva. When the tiger beetle larva begins to pupate, the bee-fly larvae consume it. Approximately 7% of festive tiger beetle larvae are attacked by parasitoid bee-flies. Mites also parasitize tiger beetles.

Economic Importance for Humans: Positive

Festive tiger beetles are interesting and attractive members of sandy habitat faunas throughout much of eastern North America.

Economic Importance for Humans: Negative

There are no adverse effects of festive tiger beetles on humans.

Conservation Status

Festive tiger beetles are not listed as threatened or endangered currently. Populations are threatened by habitat modifications that destroy or disturb sandy habitats, but their habitat requirements are less stringent than some other species of tiger beetle which are reliant on undisturbed habitats.

Other Comments

Cicindela scutellaris and Cicindela nigrior (autumn tiger beetles) were once thought to make up a distinct subgenus Pachydela , however, molecular analysis suggests that both species are in the temperate tiger beetle group ( Cicindela ). Cicindela nigrior was also previously considered a subspecies of C. scutellaris and they are remarkably similar in many morphological and ecological features. However, Cicindela nigrior males have a black labrum with two white spots and their seasonal activity patterns differ. Cicindela scutellaris is active in spring and fall, whereas Cicindela nigrior is active only in the fall. It has been suggested that these two species are in the process of species divergence in sympatry.

Additional Links

Encyclopedia of Life

Contributors

Tanya Dewey (author), Animal Diversity Web.

References

Choate, Jr., P. 2003. A field guide and identification manual for Florida and Eastern U.S. tiger beetles . Gainesville, FL: University Press of Florida.

Dillon, E., L. Dillon. 1961. A manual of common beetles of eastern North America . Evanston, IL: Row, Peterson, and Company.

Leonard, J., R. Bell. 1999. Northeastern tiger beetles: a field guide to tiger beetles of New England and eastern Canada . New York: CRC Press.

Pearson, D., C. Knisley, C. Kazilek. 2006. A field guide to the tiger beetles of the United States and Canada: Identification, Natural History, and Distribution of the Cicindelidae . New York: Oxford University Press.

Pearson, D., A. Vogler. 2001. Tiger beetles: the evolution, ecology, and diversity of the cicindelids . Ithaca: Cornell University Press.

Wallis, J. 1961. The Cicindelidae of Canada . Winnipeg: University of Toronto Press.