Cicindela dorsalis
northeastern beach tiger beetle

The white beach tiger beetle (Cicindela dorsalis) can be found in the eastern and southern coastal regions of the United States, stretching from Massachusetts to Florida, and along the Gulf of Mexico from Florida to Texas. It is common to find them in light, sandy areas such as dry riverbeds. (Arnett, Jr. Ph.D., 1985; Grzimek, 1972)

As the common name implies, the white beach tiger beetle can be found in coastal areas with white sandy beaches. Cicindela dorsalis prefers a moderate climate with average temperatures above 15 degrees Celsius. These beetles also prefer a habitat with moderate to arid rainfall totals. (Dunn, 1998a; Dunn, 1998b; O' Toole, 1986)

Adult Cicindela dorsalis can reach 13-15 millimeters in length and can be identified by their long legs, large prominent compound eyes, and eleven-segmented, filiform antennae. Adults also possess bright orange-red hues on the anterior side of their bodies, metallic green legs, and predominantly white wings. Larvae are S-shaped, and have hooks along their abdomen to help keep them in place within their vertical burrow. (Arnett, Jr. Ph.D., 1985; Dunn, 1998a; Dunn, 1998b; Grzimek, 1972)

Female tiger beetles lay eggs individually into small depressions that are later enlarged into burrows by the larvae as they mature, passing through three larval stages, or instars. The pupal stage occurs following the third instar. The larvae are responsible for digging a pupal chamber adjacent to the burrow. The larva will lie on its back and gradually lose mobility in its appendages; eventually its exoskeleton will become a translucent and creamy-white pupa. The pupal stage usually lasts 18-24 days, during which time the pupa becomes darker. The adult Cicindela dorsalis emerges through a slight hole in the dorsal portion of the pupal case, a process which requires two hours to complete. (Drees Ph.D. and Jackman Ph.D., 1998; Dunn, 1998a; Dunn, 1998b)

Mating occurs on warm, humid days. Female tiger beetles lay eggs individually into small depressions that will later be enlarged into burrows by the larvae as it matures. Tiger beetles are only known to produce one generation per year. (Drees Ph.D. and Jackman Ph.D., 1998; Dunn, 1998a; Dunn, 1998b)

Female tiger beetles have sensitive hairs on their abdomens that detect moisture content in the soil. Appropriate soil conditions are essential to larval survival and development, so these hairs play a major role in the females selection of where to oviposit her eggs. (Drees Ph.D. and Jackman Ph.D., 1998; Dunn, 1998a; Dunn, 1998b; Grzimek, 1972)

After oviposition, there is no further known parental investment.

Cicindela dorsalis are "heliophilic", meaning they are inactive on cloudy and cool days. They regulate their activity based upon sunlight intensity, wind, humidity, and air temperature. Most species of tiger beetles become fully active at above 15 degrees Celsius. Both partially developed larvae and adults spend their nights and winters burrowed in the soil. Adult white beach tiger beetles prefer to avoid confrontations with other species. A common tactic is for them to zigzag in short bursts and then fly a short distance, 5 to 20 feet, away from danger. The form and color of the threat is not important, just its size and motion determines the flight response. (Drees Ph.D. and Jackman Ph.D., 1998; Dunn, 1998a; Dunn, 1998b)

This species detects is surroundings visually, and through ground vibrations.

Larvae wait in their burrows to ambush passing prey; their wide head helping to disguise the opening of their burrow. They will usually eat their prey at the bottom of the burrow unless it is too large to fit down the hole. A first instar larva needs at least one meal in order to molt into its second instar. Because instars two and three of require several meals during their development, serious competition for food develops between individuals whose burrows are close to one another. The larvae have adapted to this by having a long developmental period and an ability to feed over a twenty-four hour time period. (Dunn, 1998a; Dunn, 1998b)

Cicindela dorsalis larvae are commonly parasitized by members of Bombyliidae, and Tiphiidae. Adults are preyed upon by amphibians, reptiles, various insectivorous mammals, and many types of birds. (Dunn, 1998a; Dunn, 1998b)

Cicindela dorsalis is considered a beneficial insect, in both larval and adult stages, because they prey on other insects, such as many species of leaf beetles that destroy crop plants. (Drees Ph.D. and Jackman Ph.D., 1998)

Cicindela dorsalis have no negative affect on humans unless they are mishandled, in which case they tend to bite.

Populations of C. dorsalis are in no danger and have no special status.