Six-spotted Green Tiger Beetle – Cicindela sexguttata

 Six-spotted Green Tiger Beetle – Cicindela sexguttata
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Family Carabidae (ground beetles) / Subfamily: Cicindelinae (tiger beetles)
Live adult tiger beetles photographed at Winfield, Illinois, and Florida, USA.
The tiger beetle is an active predator and can frequently be found hunting along footpaths and walkways through deciduous or mixed woodlands. Since the adults overwinter in their original pupal burrows, they are some of the earliest "big" flying insects out and about come springtime. I love the metallic color, and have followed these guys around quite a bit lately (2nd week April) – you can sneak up on them if you move slowly and approach from a low angle – they'll fly off if you blot out large areas of sky – and when it's hot, they can be most uncooperative! These pictures were taken from about 4 inches away.

 The tiger beetles are members of the suborder Adephaga within the Order Coleoptera. Adult tiger beetles are characterized by large, prominent compound eyes and eleven-segmented, filiform antennae. The antennae are inserted on the frons above the clypeus and below the eyes. The head, at the eyes, is wider than the pronotum (as in most common genera of cicindelids).

Adult beetles of the families Cicindelidae and Carabidae (ground beetles) are quite similar morphologically, and some entomologists place the tiger beetles in the subfamily Cicindelinae within the family Carabidae. The ground beetles differ in the following ways: antennae inserted above the mandibles to the side of the clypeus, and below the eyes. Most ground beetles have a head, at the eye, which is narrower than the pronotum.


Male = 12mm

Beetle Mandibles
Baltic amber with beetle inclusion
The genus Magnolia contains about 200 species of flowering trees and shrubs, with innumerable cultivars and varieties being developed all the time. Magnolia is an ancient plant lineage, first appearing in the fossil record about 20 million years ago, while evidence of plants in the family goes back to 90 mya [2]. Plants in Family Magnoliaceae are trees or shrubs, deciduous or evergreen, usually with perfect flowers [3].

Having evolved before pollinators in Hymenoptera (bees, wasps & ants) appeared, the progenitors of our modern ornamental magnolias relied on beetles for their sexual gratification. Their large, showy flowers are a direct result of the plant's strengthening its delicate flower parts against the beetle's comparitively "rough handling" while feeding on pollen.

Left: Primitive beetle ancestor inside 50 million year old Baltic amber [4].

References

  1. Boyd, H.P. 1982. Checklist of Cicindelidae: The tiger beetles. Plexus Publishing, Inc. New Jersey. 31 pp.
  2. Knisley, C.B. and T.D. Schultz. Tiger beetles and a guide to the species of the South Atlantic states.
  3. www.efloas.org, Flora of China, "Magnoliaceae"
  4. Anders L. Damgaard, File:Baltic amber Coleoptera Scraptiidae.JPG under Creative Commons
Order Coleoptera: Beetles are the dominant form of life on earth: one of every five living species is a beetle. Coleoptera is the largest order in the animal kingdom, containing a third of all insect species. There are about 400,000 known species worldwide, ~30,000 of which live in North America.  Beetles live in nearly every habitat, and for every kind of food, there's probably a beetle species that eats it.
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