Cicindela tranquebarica viridissima
Fall, 1910
Greenest Tiger Beetle
Cicindela tranquebarica viridissima is a highly localized of the widespread Oblique-lined , distinguished by its exceptionally bright metallic green coloration. Formerly ranging along much of the Santa Ana River from Orange County to Mentone and possibly the San Jacinto River, it now survives only in two small : along the Santa Ana River adjacent to Riverside, and near Bautista Creek in Hemet, California. exhibit a distinctive with fall , winter dormancy underground, and spring re-emergence for .
Pronunciation
How to pronounce Cicindela tranquebarica viridissima: //ˌsɪsɪnˈdɛlə ˌtræŋkwəˈbærɪkə vɪˌrɪdɪˈsɪmə//
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Identification
Distinguished from other C. tranquebarica by its exceptionally bright, almost luminous green coloration—other subspecies range through , reddish, , or nearly black. The combination of bright green color with the specific riverside in the Riverside/Hemet area of California separates it from C. denverensis (Green Claybank ) and other green tiger beetles in the region. The reduced whitish elytral markings help separate it from more heavily patterned subspecies.
Appearance
display brilliant metallic green and , representing the brightest green coloration among all of C. tranquebarica. The body is with large, prominent . Whitish markings on the elytra are present but reduced compared to some other subspecies. Legs are long and slender, adapted for rapid running. are large and sickle-shaped. The overall size is moderate for the , with adults slightly more robust than related such as C. repanda or C. limbalis.
Habitat
Restricted to sandy or sandy-clay soils along river corridors, specifically the Santa Ana River and Bautista Creek. consists of open, sparsely vegetated ground near watercourses with suitable substrate for burrowing. The requires areas with enough bare ground for hunting and larval burrow construction, but with access to soil for winter dormancy.
Distribution
to southern California. Currently known from only two localities: the Santa Ana River adjacent to Riverside, and near Bautista Creek in Hemet. Formerly more widespread along the Santa Ana River system from Orange County upstream to Mentone, and possibly along the San Jacinto River.
Seasonality
emerge in September and October, actively hunt during warm fall days, then burrow underground for winter dormancy. The same individuals re-emerge in March, April, and May for mating and . Activity is strictly and temperature-dependent.
Diet
are active of small and other . are , seizing passing from their burrow entrances with large, sickle-like .
Life Cycle
with . are laid in spring by overwintered . develop through three in vertical burrows in the soil, with the third instar representing the longest developmental stage. occurs in the burrow, with adults emerging in fall. Adults overwinter underground and do not reproduce until the following spring, creating a 'spring-fall' adult activity pattern with summer spent as larvae and .
Behavior
are fast-moving, that run swiftly and engage in short, low when pursuing or escaping disturbance. They are active and alert on warm days. When threatened, they may short distances and alight facing the threat to reduce their profile, or seek shelter by burrowing into soil. At night and during cold or inclement weather, adults burrow into the soil for shelter. Males court females using -specific mandibular and pronotal notch interactions.
Ecological Role
in its restricted riparian . and control of small . As a habitat with extremely limited range, serves as an for intact riverine sand habitats in southern California.
Human Relevance
Subject of concern due to extreme range restriction and loss from urban development along southern California river systems. The ' decline illustrates the impacts of riparian habitat degradation in urbanizing regions. No known economic importance or direct human interactions.
Similar Taxa
- Cicindela tranquebarica kirbyiAnother of C. tranquebarica, but occurs in the Great Plains and Rocky Mountain regions rather than California; has broader maculations and is less brilliantly green.
- Cicindela tranquebarica (nominate subspecies)Eastern with more extensive elytral markings and typically less vivid green coloration; distribution.
- Cicindela denverensisGreen Claybank shares metallic green coloration but occurs in different (clay banks, often at higher elevations) and has different geographic range (Rocky Mountain region).
More Details
Conservation Status
This has experienced severe range contraction due to urban development along the Santa Ana River corridor. Formerly continuous has been fragmented and destroyed, leaving only two isolated .
Larval Burrow Characteristics
Based on observations of related , likely construct burrows 5-6mm in diameter with the classic form: nearly circular with slight D-shaped flattening on one side and smoothly beveled edges. Burrows are slightly larger than those of smaller .