''Berberomeloe majalis'', the red-striped oil beetle, is an insect in the genus '' Berberomeloe'', in the family of

Blister Beetle Blister beetles are beetles of the family Meloidae, so called for their defensive secretion of a blistering agent, cantharidin. About 7,500 species are known worldwide. Many are conspicuous and some are aposematically colored, announcing their ...

s. It is native to the western

Mediterranean Basin In biogeography, the Mediterranean Basin (; also known as the Mediterranean Region or sometimes Mediterranea) is the region of lands around the Mediterranean Sea that have mostly a Mediterranean climate, with mild to cool, rainy winters and w ...

Description

It has a typical length around 5 cm (2 in.). Its large size and the bright red bands around its body make it unmistakable; its coloration is

aposematic Aposematism is the advertising by an animal to potential predators that it is not worth attacking or eating. This unprofitability may consist of any defences which make the prey difficult to kill and eat, such as toxicity, venom, foul taste or ...

, reflecting its ability, in common with other oil or blister beetles in the family

Meloidae Blister beetles are beetles of the family Meloidae, so called for their defensive secretion of a blistering agent, cantharidin. About 7,500 species are known worldwide. Many are conspicuous and some are aposematically colored, announcing their ...

, to squirt a caustic liquid if attacked. In Spain however this beetle varies extensively in color. Populations of entirely black specimens without any red markings are found scattered over much of the distribution range of ''B. majalis''. These populations are often found close to populations consisting of red-striped specimens, but both morphs seem to be spatially segregated and no mixed series have been found in the field. Entirely black and red-striped specimens of ''Berberomeloes majalis'' are equally poisonous.

Distribution and habitat

The red-striped oil beetle is found in dry places in

Portugal Portugal, officially the Portuguese Republic ( pt, República Portuguesa, links=yes ), is a country whose mainland is located on the Iberian Peninsula of Southwestern Europe, and whose territory also includes the Atlantic archipelagos of ...

and the Mediterranean regions of

Spain , image_flag = Bandera de España.svg , image_coat = Escudo de España (mazonado).svg , national_motto = ''Plus ultra'' (Latin)(English: "Further Beyond") , national_anthem = (English: "Royal March") , i ...

and North Africa, from

Morocco Morocco (),, ) officially the Kingdom of Morocco, is the westernmost country in the Maghreb region of North Africa. It overlooks the Mediterranean Sea to the north and the Atlantic Ocean to the west, and has land borders with Algeria to ...

Tunisia ) , image_map = Tunisia location (orthographic projection).svg , map_caption = Location of Tunisia in northern Africa , image_map2 = , capital = Tunis , largest_city = capital , ...

. They live in sunny, dry places, either in open grassland in woodland with light tree cover. They can be found from sea level to altitudes as high as 3000 m in the

Sierra Nevada The Sierra Nevada () is a mountain range in the Western United States, between the Central Valley of California and the Great Basin. The vast majority of the range lies in the state of California, although the Carson Range spur lies primarily ...

Ecology

The

imago In biology, the imago (Latin for "image") is the last stage an insect attains during its metamorphosis, its process of growth and development; it is also called the imaginal stage, the stage in which the insect attains maturity. It follows the f ...

lives on

pollen Pollen is a powdery substance produced by seed plants. It consists of pollen grains (highly reduced microgametophytes), which produce male gametes (sperm cells). Pollen grains have a hard coat made of sporopollenin that protects the gametophyt ...

. The larvae are exclusively

parasitic Parasitism is a close relationship between species, where one organism, the parasite, lives on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The entomologist E. O. Wilson has c ...

, mainly living in the nests of solitary wild bees. The female lays between 2000 and 10000 eggs, but most of these fail to reach maturity either for lack of food or through predation. In contrast with the adult, the larvae are only about 3mm long, and their development proceeds through

hypermetamorphosis Hypermetamorphosis, or heteromorphosis,P.J. Gullan & P.S. Cranston. 2010. The Insects: An Outline of Entomology, 4th Edition. Wiley-Blackwell. is a term used in entomology that refers to a class of variants of holometabolism, that is to say, com ...

. The various larval stages are therefore of different forms. Unlike the larvae of beetles of the genus ''

Meloe The blister beetle genus ''Meloe'' is a large, widespread group commonly referred to as oil beetles. They are known as "oil beetles" because they release oily droplets of hemolymph from their joints when disturbed; this contains cantharidin, a ...

'', the first stage larva does not cling on to a potential host, but has to actively seek a host out. Once the larva has consumed the egg and stored

nectar Nectar is a sugar-rich liquid produced by plants in glands called nectaries or nectarines, either within the flowers with which it attracts pollinating animals, or by extrafloral nectaries, which provide a nutrient source to animal mutualists ...

and pollen from a bee's nest, they leave it. They then moult again, and emerge with their back legs formed. From this stage they pupate, and emerge from the

chrysalis A pupa ( la, pupa, "doll"; plural: ''pupae'') is the life stage of some insects undergoing transformation between immature and mature stages. Insects that go through a pupal stage are holometabolous: they go through four distinct stages in their ...

as adults. If a larva accidentally selects a

honey bee A honey bee (also spelled honeybee) is a eusocial flying insect within the genus ''Apis'' of the bee clade, all native to Afro-Eurasia. After bees spread naturally throughout Africa and Eurasia, humans became responsible for the current co ...

as host, it dies in the hive.

References

External links

Meloidae Beetles described in 1758 Taxa named by Carl Linnaeus {{Meloidae-stub