This key requires a microscope or a powerful hand-lens. I have included all Cicindela species known from CT excepting the extirpated C. limbalis (which may not have been firmly established in the state and which would key out to C. purpurea but occurs only in soils of high clay content). The key is amended from Hamilton (1925), Knisley (1991), and Beatty & Knisley (1982) and has been tested with larvae of all species included except C. formosa. Each species is coded to indicate its rarity in the state- 1/14 is the most rare (C. limbalis) and 14/14 is the least rare (C. repanda). Don't be intimidated by the terminology--figures are provided for all the important morphological characters, which, once understood, should allow confident identification of any larval Tiger Beetle from Connecticut. If you think you have found a rare species (ranked 1/14-9/14) you should arrange to have the identification verified and the data submitted to the Natural Diversity Database. Collectors of Tiger Beetles in CT should read the section on collecting.

Collecting Larvae: To collect Cicindela larvae one must first find the larval burrow which for most species is indicated by a perfectly round hole ca. 5 mm in diameter with no surrounding debris (the holes of ants and wasps usually have small piles of dirt near the openings). Once a hole is found it is necessary to insert a long, pliable, thin but sturdy object, such as a grass stem, into the hole. Then the burrow can be carefully excavated using the grass stem as a guide to avoid losing the hole in the process. In most cases a larva will be found 6-12" down. The larva should be kept alive in moist soil so that it can be dropped into almost boiling water to fix the tissues (without fixation the specimen will darken and weaken). Then the larva should be stored in 70-90% ethanol in a tightly sealed vial. Be sure to label all specimens carefully. Good Luck!

Key to the 3rd instar larvae of 13 species
of Cicindela known from Connecticut.

by

Derek S. Sikes
Department of Ecology and Evolutionary Biology
University of Connecticut
Storrs, CT 06269

contracted by the Connecticut Department of Environmental Protection, 1998.

1a. Maxillary palps composed of 3 segments (fig. 1). . . . . .2 1b. Maxillary palps composed of 2 segments (presumed extirpated from CT; rarity: 2/14; last seen in CT in 1950; occurs on undisturbed marine beaches; Federally Threatened Species). . . . . .C. dorsalis Say Fig. 1. Head, ventral view: 3 segmented maxillary palps and galea with 3 stout setae

2a. (1a) U-shaped ridge on the posterior portion of the frons (fig. 2) with 2 distinct setae (occasionally these setae are broken off, look for the points of attachment which are visible indications of absent setae. . . . . .3 2b. U-shaped ridge on the posterior portion of the frons with 3 or 4 distinct setae. . . . . .9 Fig. 2. Head, dorsal view: U-shaped ridge on posterior portion of frons

3a.(2a) Inner hooks of the 5th abdominal tergite (fig. 3a- see also fig. 5) with never more than 2 setae on the shoulder (these are apical setae-some species also have a few subapical setae, however, the total of all the setae on the inner hooks is never as great as that of C. marginata) . . . . . .4 3b. Inner hooks of the 5th abdominal tergite with usually more than 8 setae (10-11; fig 3b- see also fig. 5) on the shoulder; rarity: 8/14; marine tidal flats; note: this is the easiest CT species to identify as a larva because no other CT species has this abundance of setae on the inner hooks. . . . . .C. marginata Fab.   Fig. 3a. Inner and median hooks of the 5th abdominal tergite Fig. 3b. Inner hooks of C. marginata

4a. (3a) Pronotum chestnut brown and setae on head and pronotum brown (not white or clear); a common species, often found along sandy forest paths, most shade-tolerant Cicindela species in CT; rarity: 13/14. . . . . .C. sexguttata Fab. 4b. Pronotum not chestnut brown, setae on dorsal aspect of head and pronotum white, other setae brown.. . .5

5a.(4b) Median hooks (fig. 3a) with 3 distinct setae all nearly equal in length. . . . . .6 5b. Median hooks with only 1 or 2 distinct setae (if 3 then one seta is much smaller than the others). . . . . .8

6a.(5a) Ninth abdominal sternite with posterior margin bearing 2 groups of 3 setae each (tip to find this segment: count abdominal segments backwards from the easily found 5th segment which bears the dorsal hooks). . . . . .7 6b. Ninth abdominal sternite (fig. 4) with posterior margin bearing 2 groups of 4 or more setae each; this species, although rare, can be found in both marine (back-beach areas of sparse vegetation and moist, unshifting sand) and inland habitats; rarity: 7/14. . . . . .C. tranquebarica Herbst Fig. 4. Ninth abdominal sternite with posterior margin bearing 2 groups of 4 setae.

7a.(6a) Antenna with basal segment bearing 5 or 6 setae. . . . . .11 7b. Antenna with basal segment bearing 7 to 11 setae. . . . . .12

8a.(5b) Inner hooks with the spine-like apical projection never more than 1/6th the entire length of the hook (fig. 5a); among the 3 most common CT species; larval burrows more shallow than other species, ca. 6" deep or less; rarity:14/14. . . . . .C. repanda Dejean. 8b. Inner hooks with the spine-like apical projection 1/3 or more the entire length of the hook;( fig. 5b) presumed extirpated from CT-last seen in 1973; rarity: 3/14. . . . . .C. purpurea Olivier 5a. 5th tergite of C. repanda 5b. 5th tergite of C. limbalis (identical to that of C. purpurea) 5c. Inner hooks of C. repanda, C. purpurea & C. limbalis. Fig. 5. Inner hooks on the 5th tergite

9a.(2b) Head and pronotum light brown, not metallic; basal segment of the galea with 4 stout setae on the mesal margin (fig. 1-figure shows galea with 3 stout setae); inner hooks bearing 4 setae; larval burrow differs greatly from that of other Cicindela species: main burrow 12-20" deep and vertical but about 2/3" from the top it curves horizontally and opens into a small pit; occurs in large, +undisturbed, dry sand dunes or pits- not on beaches; rarity: 5/14. . . . . .C. formosa Say 9b. Head and pronotum metallic, shining, not brown; basal segment of the galea with 3 stout setae on the mesal margin ; inner hooks bearing 2 OR 4 setae. . . . . .10 Fig. 1. Head, ventral view: 3 segmented maxillary palps and galea with 3 stout setae.

10a.(9b) Inner hooks bearing 2 setae; head and pronotum bright coppery color, smaller (secondary) setae on pronotum numerous & dense; undisturbed marine and river or lake beaches; rarity: 6/14. . . . . .C. hirticollis Say 10b. Inner hooks bearing 4 setae; head and pronotum purplish bronze, few smaller (secondary) setae on pronotum; among the 5 most common CT species-rarity: 11/14; common in large, dry, sand pits. . . . . .C. scutellaris Say

11a.(7a) Abdominal sclerites indistinct; among the 3 most common CT species- adults emerge in late summer, rarity:12/14. . . . . .C. punctulata Olivier 11b. Abdominal sclerites distinct; rarity: 9/14; occurs in open areas of high rock content, such as grantitic outcrops or gravelly sandpits, adults emerge in late summer . . . . .C. rufiventris Dejean

12a.(7b) Pronotal setae sparse, ca. 20 setae total on disc (exclusive of marginal setae); among the 5 most common CT species-rarity 10/14. . . . . .C. duodecimguttata Dejean. 12b. Pronotal setae dense, over 60 setae total on disc (exclusive of marginal setae); Federally Threatened Species; rarity:4/14; Knisley (1991) noted that "C. puritana larvae are rather easily distinguished from C. repanda [the most common sympatric congeneric] and most other species by the large number of pronotal setae. This difference occurs in both second and third instars. The setae of C. puritana are also more slender and thus less distinct than setae of other species. This pronotal setal number character was successfully used in the field by examining hand held larvae with a hand lens (10x). C. puritana is clearly seen to have more than twice as many pronotal setae as C. repanda.." The burrows of C. puritana (ca. 8-12" deep) are also about twice as deep as those of C. repanda.; occupies beaches of large rivers . . . . ..C. puritana G. Horn

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