The hawthorn shield bug (''Acanthosoma haemorrhoidale'') is a common

Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a Continent#Subcontinents, subcontinent of Eurasia ...

shield bug The Pentatomoidea are a superfamily of insects in the Heteroptera suborder of the Hemiptera order. As Hemiptera, they share a common arrangement of sucking mouthparts. The roughly 7000 species under Pentatomoidea are divided into 21 families (1 ...

. Its chief food is haws, the fruit of the hawthorn tree, but adults can overwinter on a diet of leaves, and individuals can be found on many potential food plants, including

pedunculate oak ''Quercus robur'', commonly known as common oak, pedunculate oak, European oak or English oak, is a species of flowering plant in the beech and oak family, Fagaceae. It is a large tree, native to most of Europe west of the Caucasus. It is widel ...

sessile oak ''Quercus petraea'', commonly known as the sessile oak, Cornish oak, Irish Oak or durmast oak, is a species of oak tree native to most of Europe and into Anatolia and Iran. The sessile oak is the national tree of Ireland, and an unofficial embl ...

and

whitebeam The whitebeams are members of the family Rosaceae, comprising subgenus ''Aria'' (or, according to some authorities, its own genus) of genus ''Sorbus'', and hybrids involving species of this subgenus and members of subgenera ''Sorbus'', ''Torminar ...

. They may grow up to long, and are

camouflage Camouflage is the use of any combination of materials, coloration, or illumination for concealment, either by making animals or objects hard to see, or by disguising them as something else. Examples include the leopard's spotted coat, the ...

d in shades of green and brown. Like many so-called "stink bugs", they may release unpleasant odours when disturbed.

Biology

The dark green scutellum band is

trapezoid A quadrilateral with at least one pair of parallel sides is called a trapezoid () in American and Canadian English. In British and other forms of English, it is called a trapezium (). A trapezoid is necessarily a Convex polygon, convex quadri ...

al in shape, and extends from the dorsal pronotum to the forewing hemelytral membrane which accounts for the final third of the main body length. The front wings lie flat when the insect is not flying, with the sclerotized pronotum and corium regions coloured dark red. The

compound eyes A compound eye is a visual organ found in arthropods such as insects and crustaceans. It may consist of thousands of ommatidia, which are tiny independent photoreception units that consist of a cornea, lens, and photoreceptor cells which distin ...

are also red. There is a speckled pigmentation extending from the upper dorsal

thorax The thorax or chest is a part of the anatomy of humans, mammals, and other tetrapod animals located between the neck and the abdomen. In insects, crustaceans, and the extinct trilobites, the thorax is one of the three main divisions of the cre ...

to the

abdominal The abdomen (colloquially called the belly, tummy, midriff, tucky or stomach) is the part of the body between the thorax (chest) and pelvis, in humans and in other vertebrates. The abdomen is the front part of the abdominal segment of the torso. ...

region. The tarsi are 2-segmented and antennae 5-segmented. As a

heteroptera The Heteroptera are a group of about 40,000 species of insects in the order Hemiptera. They are sometimes called "true bugs", though that name more commonly refers to the Hemiptera as a whole. "Typical bugs" might be used as a more unequivocal al ...

herbivore A herbivore is an animal anatomically and physiologically adapted to eating plant material, for example foliage or marine algae, for the main component of its diet. As a result of their plant diet, herbivorous animals typically have mouthpart ...

of mainly green leafed trees and red berries, the species feeds by injecting

saliva Saliva (commonly referred to as spit) is an extracellular fluid produced and secreted by salivary glands in the mouth. In humans, saliva is around 99% water, plus electrolytes, mucus, white blood cells, epithelial cells (from which DNA can be ...

enzymes from the posterior section of the rostrum into plant tissue, partially digesting it, then sucks up the resulting liquid through the anterior section of the

rostrum Rostrum may refer to: * Any kind of a platform for a speaker: **dais **pulpit * Rostrum (anatomy), a beak, or anatomical structure resembling a beak, as in the mouthparts of many sucking insects * Rostrum (ship), a form of bow on naval ships * Ros ...

. The rostrum is a modified proboscis formed by the interlocking of

mandibular In anatomy, the mandible, lower jaw or jawbone is the largest, strongest and lowest bone in the human facial skeleton. It forms the lower jaw and holds the lower teeth in place. The mandible sits beneath the maxilla. It is the only movable bone ...

and maxillary stylet into a double-tubed elongation covered by the labium. The structure is needle shaped and penetrates beyond the

cuticle A cuticle (), or cuticula, is any of a variety of tough but flexible, non-mineral outer coverings of an organism, or parts of an organism, that provide protection. Various types of "cuticle" are non- homologous, differing in their origin, structu ...

and

epidermis The epidermis is the outermost of the three layers that comprise the skin, the inner layers being the dermis and hypodermis. The epidermis layer provides a barrier to infection from environmental pathogens and regulates the amount of water rele ...

layer to access the vascular tissue of the

mesophyll A leaf ( : leaves) is any of the principal appendages of a vascular plant stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, ste ...

layer of the leaf. The rostrum pricks into berries to access fruit sugars. As a stress response, ''A. haemorrhoidale'' can produce an orange secretion from gland openings in the thorax.

Distribution and behaviour

The hawthorn shield bug is found across Europe, from

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 ...

Russia Russia (, , ), or the Russian Federation, is a List of transcontinental countries, transcontinental country spanning Eastern Europe and North Asia, Northern Asia. It is the List of countries and dependencies by area, largest country in the ...

, and is common in the southern part of

Great Britain Great Britain is an island in the North Atlantic Ocean off the northwest coast of continental Europe. With an area of , it is the largest of the British Isles, the largest European island and the ninth-largest island in the world. It is ...

. Its distribution appears to be spreading north, being reported as far north as

Manchester Manchester () is a city in Greater Manchester, England. It had a population of 552,000 in 2021. It is bordered by the Cheshire Plain to the south, the Pennines to the north and east, and the neighbouring city of Salford to the west. The t ...

only in 1892, but having now extended its range to

Northern England Northern England, also known as the North of England, the North Country, or simply the North, is the northern area of England. It broadly corresponds to the former borders of Angle Northumbria, the Anglo-Scandinavian Kingdom of Jorvik, and the ...

and even the

Scottish Highlands The Highlands ( sco, the Hielands; gd, a’ Ghàidhealtachd , 'the place of the Gaels') is a historical region of Scotland. Culturally, the Highlands and the Lowlands diverged from the Late Middle Ages into the modern period, when Lowland Sco ...

. In Britain and North Western Europe the species is generally active between the months of April and October, although specimens can reappear from

hibernation Hibernation is a state of minimal activity and metabolic depression undergone by some animal species. Hibernation is a seasonal heterothermy characterized by low body-temperature, slow breathing and heart-rate, and low metabolic rate. It most ...

during periods of unseasonable warm weather in the winter. The hawthorn shield bug is a distinctive species, but could be confused with the birch shield bug, ''

Elasmostethus interstinctus The birch shieldbug (''Elasmostethus interstinctus'') is species of shield bug in the Acanthosomatidae family. Shield bugs are often called "stink bugs" because they excrete a foul smelling liquid that is used to deter predators. Distribution Th ...

''.

References

External links

* {{Taxonbar, from=Q1077448 Acanthosomatidae Hemiptera of Europe Bugs described in 1758 Taxa named by Carl Linnaeus

Biology

Distribution and behaviour

See also

References

External links