''Musgraveia sulciventris'' is a Tessaratomid bug found in

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

, sometimes known as the bronze orange bug. It is considered a pest, particularly to plants in the

citrus ''Citrus'' is a genus of flowering trees and shrubs in the family Rutaceae. Plants in the genus produce citrus fruits, including important crops such as oranges, mandarins, lemons, grapefruits, pomelos, and limes. ''Citrus'' is nativ ...

group. Bronze orange bugs suck the

sap Sap is a fluid transported in the xylem cells (vessel elements or tracheids) or phloem sieve tube elements of a plant. These cells transport water and nutrients throughout the plant. Sap is distinct from latex, resin, or cell sap; it is a s ...

from trees, which causes the flowers and fruit to fall.

Taxonomy

In 1863, Swedish entomologist

Carl Stål Carl Stål (21 March 1833 – 13 June 1878) was a Swedish people, Swedish entomologist specialising in Hemiptera. He was born at Karlberg Castle, Stockholm on 21 March 1833 and died at Frösundavik near Stockholm on 13 June 1878. He was the son ...

described the species as ''Oncoscelis sulciventris'' from a collection near

Moreton Bay Moreton Bay is a bay located on the eastern coast of Australia from central Brisbane, Queensland. It is one of Queensland's most important coastal resources. The waters of Moreton Bay are a popular destination for recreational anglers and are ...

Queensland Queensland ( , commonly abbreviated as Qld) is a States and territories of Australia, state in northeastern Australia, and is the second-largest and third-most populous state in Australia. It is bordered by the Northern Territory, South Austr ...

. In 1957, English entomologists

Dennis Leston Dennis Leston, born Dennis Fingleston (2 February 1917 – 7 October 1981) was an English entomologist best known for his contributions to the study of Heteroptera. Following a start in life as a student of medicine Leston served ...

and G.G.E. Scudder reclassified the bronze orange bug as ''Musgraveia sulciventris,'' due to reorganization of ''Oncoscelis'' and related genera. It is the type species of the genus ''Musgraveia'' and in the

Tessaratomidae Tessaratomidae is a Family (biology), family of Hemiptera, true bugs. It contains about 240 species of large bugs divided into 3 subfamily, subfamilies and 56 genus, genera. Tessaratomids resemble large stink bugs (family Pentatomidae) and are s ...

family.

Description and life cycle

Bronze orange bugs are first found on trees in late winter. Mating takes place between late November through early March. Each mating pair takes 3 to 5 days to produce 10 to 14 eggs. The female lays up to four

clutches A clutch is a mechanical device that allows an output shaft to be disconnected from a rotating input shaft. The clutch's input shaft is typically attached to a motor, while the clutch's output shaft is connected to the mechanism that does the ...

of eggs and deposits them on the undersurface of a leaf. The bright green spherical eggs are around in diameter. The incubation period varies based on current weather conditions. Hatching averages around 7.4 days at 25 °C and 6 percent humidity. As a light green

nymph A nymph (; ; sometimes spelled nymphe) is a minor female nature deity in ancient Greek folklore. Distinct from other Greek goddesses, nymphs are generally regarded as personifications of nature; they are typically tied to a specific place, land ...

, they are difficult to spot and often mistaken for different species. The bronze orange bug has five stages of development known as

instar An instar (, from the Latin '' īnstar'' 'form, likeness') is a developmental stage of arthropods, such as insects, which occurs between each moult (''ecdysis'') until sexual maturity is reached. Arthropods must shed the exoskeleton in order to ...

s. The first instars remain huddled near the eggs. They are transparent pale green with orange eyes. The second instars are more buff or pale yellow. Adults grow to be approximately 25 mm (nearly 1 in) long, and go from orange to their more familiar bronze color as they develop.

Distribution and habitat

''Musgraveia sulciventris'' is found in Queensland and New South Wales in Eastern Australia, as far south as Canberra. Its range of location has spread significantly since European colonization.

Ecology

Its native host plants include the desert lime (''

Citrus glauca ''Citrus glauca'', commonly known as the desert lime, is a thorny shrub or small tree native to Queensland, New South Wales, and South Australia.Burkill, Isaac Henry. 1932. Gardens' Bulletin, Straits Settlements 5 (Index): 3. ''Citrus glauca''.

''), the Australian finger lime (''

Citrus australasica ''Citrus australasica'', the finger lime or caviar lime, is a thorny understorey shrub or small tree of lowland subtropical rainforest in the coastal border region of Queensland and New South Wales, Australia. It has edible fruits which are gr ...

''), and Correas. It has become a major pest of cultivated citrus crops, where it sucks the fluid from new growth and young fruit, causing them to turn yellow and drop off. Whole crops can be devastated. The common name of ''stinkbug'' refers to a malodorous liquid that the insect sprays when threatened. It is composed of

alkane In organic chemistry, an alkane, or paraffin (a historical trivial name that also has other meanings), is an acyclic saturated hydrocarbon. In other words, an alkane consists of hydrogen and carbon atoms arranged in a tree structure in whi ...

s, cimicine and

aldehyde In organic chemistry, an aldehyde () (lat. ''al''cohol ''dehyd''rogenatum, dehydrogenated alcohol) is an organic compound containing a functional group with the structure . The functional group itself (without the "R" side chain) can be referred ...

s from

gland A gland is a Cell (biology), cell or an Organ (biology), organ in an animal's body that produces and secretes different substances that the organism needs, either into the bloodstream or into a body cavity or outer surface. A gland may also funct ...

s in the

thorax The thorax (: thoraces or thoraxes) or chest is a part of the anatomy of 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 di ...

. These compounds primarily serve as protection against fellow

arthropod Arthropods ( ) are invertebrates in the phylum Arthropoda. They possess an arthropod exoskeleton, exoskeleton with a cuticle made of chitin, often Mineralization (biology), mineralised with calcium carbonate, a body with differentiated (Metam ...

s, to which they are lethal. However, the defensive chemicals of ''M. sulciventris'' are known for being among the most debilitating to

vertebrate Vertebrates () are animals with a vertebral column (backbone or spine), and a cranium, or skull. The vertebral column surrounds and protects the spinal cord, while the cranium protects the brain. The vertebrates make up the subphylum Vertebra ...

s, which is likely a defense specifically aimed against birds. They can cause damage to human skin and even cause temporary blindness if sprayed into the eyes. The bronze orange bug can spray the liquid at a target up to 0.6 m (2 ft) away. Insects that prey on the bronze orange bug include the common

assassin bug The Reduviidae is a large cosmopolitan family of the suborder Heteroptera of the order Hemiptera (true bugs). Among the Hemiptera and together with the Nabidae almost all species are terrestrial ambush predators; most other predatory Hemiptera ...

(''

Pristhesancus plagipennis ''Pristhesancus plagipennis'' is an Australian insect in the Reduviidae, assassin bug genus ''Pristhesancus''. Amongst its prey is the bronze orange bug (''Musgraveia sulciventris''), a common garden pest. It is sometimes called the bee-killer as ...

''), the predatory

Asopinae Asopinae are a subfamily of Pentatomidae, stink bugs (family (biology), family Pentatomidae). They are predatory stink bugs that are useful as biological control agents against pests, even against other Pentatomid species, which are all herbivo ...

bug species '' Amyotea hamatus'', and the

parasitoid wasp Parasitoid wasps are a large group of hymenopteran Superfamily (zoology), superfamilies, with all but the wood wasps (Orussoidea) being in the wasp-waisted Apocrita. As parasitoids, they lay their eggs on or in the bodies of other arthropods, ...

s ''

Eupelmus poggioni ''Eupelmus'' is a genus of insects belonging to the family Eupelmidae. The genus has more than 300 species and a cosmopolitan distribution. Species include: * ''Eupelmus achreiodes'' Perkins, 1910 * ''Eupelmus acinellus'' Askew, 2009 * ''Eupel ...

'' and ''

Telenomus ''Telenomus'' is a genus of parasitoid wasps from the subfamily Telenominae. The genus was first described by Alexander Henry Haliday in 1833. Species in this genus parasitise the eggs or immature stages of other insects. Known hosts include: ...

'' spp.

References

{{Taxonbar, from=Q26716020 Tessaratomidae Insects of Australia Insects described in 1863