Tiger Beetle Nocturnal Perching

Ellipsoptera hamata lacerata | "Road to Nowhere" Dixie Co., Florida

During last week’s 48-hour blitz through Florida, I spent one evening blacklighting at the famed “Road to Nowhere” tiger beetle hot spot and encountered this male individual of Ellipsoptera hamata lacerata¹ clinging to the grass near my light.  A quick search of the surrounding area revealed a number of similarly perched individuals, including a mating pair and all representing the same species.

¹ Males (identified by the brushy pads under the foretarsi) of this species are distinguished from the closely related E. marginata, which co-occurs with E. hamata lacerata along the Gulf coast of Florida, by the lack of a distinct tooth on the underside of the right mandible.

Like many species in this and related tiger beetle genera, E. hamata is diurnal but also highly attracted to lights at night. This is thought to be related to nocturnal dispersion behaviors (Pearson and Vogler 2001) intended to avoid higher daytime predation risks. Nocturnal perching on foliage is also common among diurnally-active species in riparian habitats and seems also to be an adaptation for reducing predation. Pearson and Anderson (1985) noted that perched beetles removed from the grass and placed on the ground were often quickly preyed upon by larger nocturnally-active tiger beetles. At “Road to Nowhere” this might include the slightly larger Habroscelimorpha severa which occurred in enormous numbers alongside this species on the mud flats, or the much larger Tetracha virginica which occurred in fair numbers on the adjacent road.

REFERENCES:

Pearson, D. L. and J. J. Anderson.  1985. Perching heights and nocturnal communal roosts of some tiger beetles (Coleoptera: Cicindelidae) in southeastern Peru.  Biotropica 17(2):126–129.

Pearson, D. L. and A. P. Vogler. 2001. Tiger Beetles: The Evolution, Ecology, and Diversity of the Cicindelids.  Cornell University Press, Ithaca, N.Y., xiii + 333 pp.

Copyright © Ted C. MacRae 2011

19 thoughts on “Tiger Beetle Nocturnal Perching

  1. What a superb photo! Is that beetle actually resting its chin* on the top of the stalk? I’m going to have to go out with the spotlight to see what I can find before the nights warm up again and everything gets hyperactive.

    *Once upon a time, I would’ve been able to name all the parts of an insect head. Not any longer!

    • Yes, the mandibles are resting on the top of the grass stem. Others that I saw had their jaws clamped around the grass stem in the same way the bees and wasps do when roosting.

      The warmer the night, the more you’re likely to see!

    • Many tiger beetles – primarily those that live in sandy habitats – do hunker down in burrows, while those that frequent clay soils I’ve seen secreted behind cracks and crevices in the soil. This is the first time I’ve seen nocturnal roosting behavior as described in the literature. However, photos of such behavior always show the beetles just sitting on leaves – I’ve never seen or heard reports about them clamping the stems with their jaws like I observed that night.

    • I suspect it is more likely with species that live in habitats where the soil is too wet to either burrow into or find cracks and crevices in which to hide.

      Any idea how many UK tiger species there are?

  2. I spend a lot of time hiking around the deserts of Nevada looking at the amazing desert creatures. I never thought to put up lights at night and see what they attract. Great idea, I will let you know what I find.

    Also great post on the tiger beetle, amazing looking beetle, the dung beetle must be envious.

  3. This is a VERY cool shot; I’ve never seen anything quite like it before…I never would have thought to look on the tips of grass blades for tigers!!!

    • Thanks Geek. I’ve learned over the years that it pays to examine the shrubbery and ground all around the blacklight, as many things are attracted to the vicinity without actually coming to the sheet.

  4. Pingback: Return to Nowhere « Beetles In The Bush

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