Over 350,000 species
described to date (12,500 in Europe, 4100 in UK, 415 of which are aquatic at all or some stage in their lives), and the back rooms of museums
are full of more new species. So if you want to be remembered fund taxonomy and have a beetle named after you! 3485 new species were described in 2011. There are more beetle species than all the vascular plants, and six
times the number of vertebrates. For what this implies to the religious amongst us see the quote from J. B. S. Haldane below.
25% of all described animals and plants are beetles.
They are found in every habitat except salt water and polar ice caps.
Around 2450 species so far have are parasitoids.
The order Coleoptera is divided
into around 170 different families.
They are holometabolous, i.e.
they undergo complete metamorphosis with a distinct larval, pupal and adult
stage. With the principal feeding as a larva, and the sexually mature stage as
an adult. So every adult beetle you see was once an egg, a larva, a pupa, and finally the adult beetle.
Beetle larva come in a variety of shapes. The head is followed by a body of 12 segments. The first three segments have legs in some species, and are legless in others. The antennae are usually short. Larval life is devoted to feeding.
Adults range in length from 0.4 - 200.0 mm, and up to 75.00 mm in width.
Most have two pairs of wings,
with the front pair (elytra) forming a hard, protective covering over the rear
membranous flight wings.
They have biting mouthparts.
Glowworms are not worms, but
beetles belonging to the family Lampyridae.
When attacked or handled roughly beetles can reflex bleed a brown fluid which tastes bad, and sometimes smells bad, causing some predators to drop them.
The word Coleoptera was first used by Aristotle; coleo = shield + ptera = wing in Greek.
The first true beetles date from the Triassic around 230 million years ago. During the Jurassic the beetles diversified greatly.
The first beetle-like insects date from 270 million years ago and were found in what is Eastern Europe today.
Beetles and God
"If one could conclude as to the nature of the Creator from a study of creation, it would appear that God has an inordinate fondness for stars and beetles." —J.B.S. Haldane, 1951.
Tree fogging experiments in a Panama rainforest found the the number of beetle species in 1 hectare exceeded 41,000 (Terry Erwin, 1982, and Coleopterist's Bulletin). Now this study was performed one time, and counted only those beetles that were caught falling into umbrella-like traps under the trees that were fogged with insecticide. It did not count those that landed on the ground, got caught in branches or leaves, etc. Nor did it count ground, underground or boring beetles. Nor did it count beetle larvae. So, all this proves is that there is a vast number of beetle species.
1. antenna The antennae of different families vary greatly in shape and size, and are usually used in identification. A drawing showing just a few of the many different insect antennae shapes. The antennae are concerned with taste and smell.
3. labial palp
5. compound eye
9. elytron (plural elytra)
16 - 21 abdominal sternites,
21 aka anal sternite