Monday, February 2, 2009


LADY BIRD

Ladybirds ( Commonwealth English), also known as ladybugs ( North American English) or lady beetles (most scientists prefer this name), are a family (Coccinellidae – "little sphere") of beetles. The name is thought to allude to the Blessed Virgin Mary in the Catholic faith. Ladybirds are found worldwide, with over 4,500 species described, more than 450 native to North America alone. Ladybirds are small insects, ranging from 1 mm to 10 mm (0.04 to 0.4 inches), and are usually yellow, orange, or red with small black spots on their carapace, with black legs, head and feelers. As the family name suggests, they are usually quite round in shape. Because they are useful, colourful, and harmless to humans, ladybirds are typically considered cute even by people who hate most insects. Some people consider them to be a sign of good luck.



Biology
Ladybirds are brightly coloured to ward away potential predators. This defence works because most predators associate bright colours (especially orange and black or yellow and black) with poison and other unpleasant properties. This phenomenon is called aposematism. In fact, most ladybirds are indeed toxic to smaller predators, such as lizards and small birds; however, a human would have to eat several hundred ladybirds before feeling any effects. Adult ladybirds are able to reflex-bleed from their leg joints, releasing their oily yellow toxin with a strong repellent smell. This becomes quite obvious when one handles a ladybird roughly.

The ladybird beetle copulates for up to nine hours at a time, and males may have three 90-minute orgasms in one session. Ladybirds lay eggs which hatch into a larval state. The larvae then go into a pupal stage before becoming an adult ladybird.

Ladybirds lay extra infertile eggs with the fertile eggs. These appear to provide a backup food source for the larvae when they hatch. The ratio of infertile to fertile eggs increases as with scarcity of food at the time of egg laying. (Perry & Roitberg, 2005)


Commercial usage
Ladybirds are beneficial to organic gardeners because most species are insectivores, consuming aphids, fruit flies, thrips, and other tiny plant-sucking insects that damage crops. In fact, their name is derived from "Beetle of Our Lady", recognising their role in saving crops from destruction. Today, they are commercially available from a variety of suppliers.

In agriculture, ladybirds, like other beetles, can find protection in beetle banks.


Culture
Ladybirds are and have for very many years been favourite insects of children. The insects had many regional names (now mostly disused) such as the lady-cow, May-bug, golden-knop, golden-bugs ( Suffolk); and variations on Bishop-Barnaby (Barney, Burney) Barnabee, Burnabee, and the Bishop-that-burneth.

The ladybird is immortalised in the children's nursery rhyme extant:

Ladybird, ladybird, fly away home

Your house is on fire and your children are gone

All except one, and that's Little Anne

For she has crept under the warming pan.
and ancient (recounted in an 1851 publication):

Dowdy-cow, dowdy-cow, ride away heame,
Thy house is burnt, and thy bairns are tean,
And if thou means to save thy bairns
Take thy wings and flee away!
The name which the insect bears in the various languages of Europe is clearly mythic. In this, as in other cases, the Virgin Mary has supplanted Freya, the fertility goddess of Norse mythology; so that Freyjuhaena and Frouehenge have been changed into Marienvoglein, which corresponds with Our Lady's Bird. There can, therefore, be little doubt that the esteem with which the lady-bird, or Our Lady's cow, is still regarded and is a relic of ancient beliefs. In parts of Northern Europe, tradition says you get a wish granted if a ladybird lands on you. In Italy, it is said by some that if a Ladybird flies into your bedroom, it is considered good luck. In central Europe, a ladybird crawling across a girl's hand is thought to mean she'll get married within the year. In Russia a ladybird is called Божья-Коровка (God's cow) and a popular children's rhyme exists with a call to fly to the sky and bring back bread.

The ladybird is the symbol of the Dutch Foundation Against Senseless Violence, as you can see in the logo here. Other companies using ladybirds as their corporate logo include: Ladybird Books (owned by Pearson PLC and the Ladybird range of children's clothing sold by Woolworth's in the UK.


Notable species
Note that not all individuals show the number of spots suggested by their names:


Asian lady beetle, Harmonia axyridisSeven-spotted lady beetle, Coccinella septempunctata
Two-spotted lady beetle, Adalia bipunctata
Convergent lady beetle, Hippodamia convergens
Thirteen-spotted lady beetle, Hippodamia tredecimpunctata
Spotted lady beetle, Coleomegilla maculata
Twice-stabbed lady beetle, Chilocurus stigma
Mexican bean beetle, Epilachna varivestis Mulsant
Asian lady beetle, Harmonia axyridis
Mealybug Ladybird, Cryptolaemus montrouzieri
For a complete list of genera, see list of Coccinellidae genera.