''Musgraveia sulciventris'' is a large stink bug found in Australia, 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 rue family, Rutaceae. Plants in the genus produce citrus fruits, including important crops such as oranges, lemons, grapefruits, pomelos, and limes. The genus ''Citrus'' is native to ...

group. Bronze orange bugs suck the

sap Sap is a fluid transported in 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 separ ...

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 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 of architect, ...

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 ) , nickname = Sunshine State , image_map = Queensland in Australia.svg , map_caption = Location of Queensland in Australia , subdivision_type = Country , subdivision_name = Australia , established_title = Before federation , establishe ...

. In 1957, English entomologists Dennis Leston 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 of true bugs. It contains about 240 species of large bugs divided into 3 subfamilies and 56 genera. Tessaratomids resemble large stink bugs (family Pentatomidae) and are sometimes quite colorful. Most tessaratomids ar ...

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 engages and disengages power transmission, especially from a drive shaft to a driven shaft. In the simplest application, clutches connect and disconnect two rotating shafts (drive shafts or line shafts) ...

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 ( grc, νύμφη, nýmphē, el, script=Latn, nímfi, label= Modern Greek; , ) in ancient Greek folklore is a minor female nature deity. Different from Greek goddesses, nymphs are generally regarded as personifications of nature, are ...

, 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, between each moult (''ecdysis''), until sexual maturity is reached. Arthropods must shed the exoskeleton in order to grow or ...

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 Wollongong. Its range of location has spread significantly since European colonization.

Ecology

Its native host plants include the desert lime ('' Citrus glauca''), the Australian finger lime (''

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

''), 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 alkanes, cimicine and

aldehyde In organic chemistry, an aldehyde () is an organic compound containing a functional group with the structure . The functional group itself (without the "R" side chain) can be referred to as an aldehyde but can also be classified as a formyl grou ...

s from glands in the

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 ...

. These compounds primarily serve as protection against fellow

arthropod Arthropods (, (gen. ποδός)) are invertebrate animals with an exoskeleton, a segmented body, and paired jointed appendages. Arthropods form the phylum Arthropoda. They are distinguished by their jointed limbs and cuticle made of chiti ...

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

vertebrate Vertebrates () comprise all animal taxa within the subphylum Vertebrata () (chordates with backbones), including all mammals, birds, reptiles, amphibians, and fish. Vertebrates represent the overwhelming majority of the phylum Chordata, with c ...

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 are a large cosmopolitan family 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 are aquatic. The main example ...

('' Pristhesancus plagipennis''), the predatory

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

bug species '' Amyotea hamatus'', and the

parasitoid wasp Parasitoid wasps are a large group of hymenopteran 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, sooner or later causin ...

s '' Eupelmus poggioni'' and '' Telenomus'' spp.

References

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