| Platypus apicalis | |
|---|---|
 | |
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Arthropoda |
| Class: | Insecta |
| Order: | Coleoptera |
| Family: | Curculionidae |
| Genus: | Platypus |
| Species: | P. apicalis |
| Binomial name | |
| Platypus apicalis | |
Platypus apicalis, known by its common name the New Zealand pinhole boring beetle, is a wood-boring beetle endemic to New Zealand and found throughout the North and South Island in a range of environments.
The colour of Platypus apicalis is mainly dark-brown, with yellow basal joint of antennae, metathorax and femora. The body is cylindrical in cross section and greatly elongated from front to rear. It is less than 2 mmm wide and about 5.8 mm long. [1] [2] The mandibles of adults are oriented downward. The terminal segment of the antennae is dorso-ventrally flattened and larger than the other antennal segments. [2] The mesothoracic wings are modified into a hardened wing case. [3] A narrow longitudinal groove is present on the middle of the pronotum. The elytra bear parallel longitudinal grooves, are mainly smooth but pubescent at their rear end and sides, and are sloping downward at their posterior end. [1] [2]
Platypus apicalis exhibits sexual dimorphism. The elytrae of males bear tooth like projections at their posterior end. The body of females is more pubescent than this of males, lack elytral teeth, and have a more rounded shape. [4] Adult males release a strong and distinguishable odor to attract a female upon digging a breeding gallery. Females have not been found to release this scent. [4]
Eggs are round, less than 1 mm in diameter, and have a creamy appearance. [2] Young larvae are flat and have fleshy projections on sides. In contrast, fully grown larvae are white, cylindrical and legless with yellow coloured heads. At this stage the mandibles begin to orient downward and ridges start to appear on the top of the prothorax. [4]
Platypus apicalis only occurs in New Zealand. More specifically, it occurs on the West coast of the South Island and the centre of the North Island in natural beech wood forests and in certain exotic plantations, such as these of eucalyptus. [5] [6]
The habitat preference of this species is predominantly dead beech wood forest, including Red Beech, Silver Beech and Black beech. [6] Platypus apicalis appear in dead tissues surrounding trees and larvae. Few fungi are related to pinhole borer closely, they benefit beetles in different ways. Ambrosia fungi provide food that they depend on. Pathogenic fungi which can infect or even kill live tree is carried by insects. [7] The beetle has no preference for hard or soft wood as it resides inside the Beech trees and some Eucalyptus species. Platypus resides in the dead wood of the tree but when numbers grow due to sufficient breeding material, healthy trees are threatened by their invasion. [5] They are considered pests at times to native forests but only when they threaten healthy trees. [6] Their main pest area is the forestry plantations where they colonise and render some high-quality timber useless due to imperfections and colour change in the timber. [6] Their nests are more likely to kill the part of living tree. The beetles occur commonly along the North Island, South Island and Chatham Island, however, has not spotted in some eastern forests such as Balmoral and Eyrewell State forests, Canterbury [8]
Platypus apicalis can be a pest in high-quality timber plantations. [6] It vectors fungi that develop into the wood, altering its color. In addition, their tunnels, which go deep into the wood, create imperfections in the finished timber, which also weakens it. [6]
The life cycle begins with a male adult boring a tunnel into a host tree and releasing fungal spores along the way. Fungal species, particularly ambrosia fungi, serve as the primary food for the beetle, which gives the name of the nickname to the beetle, "Ambrosia Beetles". [9] [10] This tunneling process usually occurs within the early summer months of November and December. [2] Once the tunnel is several centimetres long, the insect will release an odour that acts as an attractant to female insects. If enough male beetles do this at once, it leads to so called "mass attacks" on trees where swarms of beetles attack a single host specimen. [9] However, not like the other bark beetles that they rely on the inner tunnel, adults and larvae both will soon acquire the primary food. During the feeding stage, yeasts are likewise transmitted by bark beetles, but their precise role has not been discovered yet. [11] Copulation occurs at the tunnel entrance and afterward the female goes into the tunnel and begins the process of making a nest. The male continues to enlarge the tunnel and remove excess frass (excreta). [9] The tunnel is initially radial but eventually has a sharp right angle and moves towards the heartwood of a tree. [2] Meanwhile the female lays the first batch of egg containing four to seven eggs. Following this, another branch of the tunnel is then started by the male and eventually a second egg batch is laid. The pair will feed the larvae until they reach maturity using specialized structures called mycangia, which is located on the head of the adult. At this point 8–10 months have passed since copulation. [2]
While the exact time of larval hatching is not yet certain, it is known that there is a period of two years from the time the nest is laid to the time that fully grown beetles emerge from hosts. During this time the larvae go through several stages. Initially the larva simply extend the tunnels of the parents. [2] These extensions differ from the parents in that the tunnels are concave rather than flat. During this time, the larvae grow bigger in size and begin to take on some adult features. [2] After a period of several months, the larva excavate pupal chambers within the tree. [2] The larvae then enter the chambers and become pupas, intermediate insect form. [2] Finally, when two years have passed since the egg laying, adult beetles emerge from the chambers and exit the tree. This occurs during the summer months of January to March. The average number of beetles per tree is 115. [2] The adult beetles then go out into the forest and look for a new host tree. The lifecycle is then repeated. The average lifespan of an adult pinhole beetle is estimated to be 3–4 years. [12]
Platypus apicalis is classified as an ambrosia wood-boring beetle. [9] Beetles in the category survive by boring tunnels into the xylem (water transport tissue) and phloem (food transport tissue) of a host tree species. [10] Ambrosia beetles have a symbiotic relationship with a category of fungus known as Ambrosia. Fungal spores are contained within the gut of Ambrosia beetles and as beetles bore into a tree, they release the spores. The fungus is then cultivated within the tree and used by the beetles as a food sources. [10] The xylem and phloem tissue of the tree is merely a medium for the fungus, it is not a source of food for the beetle. [2] Platypus aplicalis do not feed on the wood they bore, instead they eat the yeast that accumulates on the bored tunnels. This yeast provides a steady diet for both adults and larvae (. [2]
Along with the Ambrosia fungi, pathogenic fungi is associated with the fully grown beetles. This fungi has been known to infect and kill the host tree when it is attacked by the adult beetles. [12] Populations of the insect are currently controlled by agricultural cultural practices; there are no effective predators of the insect; there is a species of parasitic nematode known to situate with the insect, but its effectiveness in population control is unknown. [12] Scientists have tested strains of B. bassiana, B. brongniartii and Metarhizium anisopliae which are found in southern beech forests or in places where no Platypus are found. [5] They were tested on both the adult and larvae stages of the insect, a total of 10 isolates where tested and scientists found that all killed the adult stage of the insect. [5] This provides a natural and common control method that could be used in the future to help control the population of the Platypus apicali. [5]
New Zealand Platypus species Platypus apicalis, Platypus caviceps and Platypus gracilis have an imperative impact in transmitting airborne and water-borne spore to contaminate the injuries, as there would be no effect from atmosphere on organisms developing in many parts of the nation. Spores can be either liberated from mycelium creating on the surface of corrupted trees or other wood surfaces or by wind-borne frass sullied with spores and mycelial parts from frightening little creature tunneling in polluted tissue. There is in like manner the affirmation of underground spread, probably through either root joins root contact or underground vectors. displayed that C. australis was not subject to P. subgranosus for transmission or for entry to the trees, despite the way that P. subgranosus are of critical in ailment spread through opportunity of polluted frass and the making of wounds in concentrated on trees [13]
Platypus apicalis has both biodiversity and economic impacts. [2] From a biodiversity perspective, the beetles are a threat to beech trees. While some trees have been known to survive, in most cases the combination of the tunnels through the xylem and phloem and the subsequent fungal infection prove lethal. This and the fact that it has no known predators and few parasites makes it a potential threat to beech tree population numbers. [2] There is also the threat of the species escaping New Zealand via exports of lumber. Beech species exist throughout much of the world and it is conceivable that the insect could survive quite well elsewhere. [2] From an economic standpoint, the tree reduces the amount of native timber available. [2] Even if a tree is not killed outright, the invasion often causes defects such as concealed rot pockets and irregular wood cores. [2] Damaged trees are also easy targets for other species of fungi. This not only affects logging companies, but also associated industries.
The New Zealand Pinhole Borer beetle is technically a wood-boring beetle, but its pheromones more closely resemble bark beetles because it retains an aggression pheromone, allowing Platypus apicalis to cause large-scale mortality to their hosts. [14] This chemical is produced in their hind gut. [2]
Ambrosia beetles are beetles of the weevil subfamilies Scolytinae and Platypodinae, which live in nutritional symbiosis with ambrosia fungi. The beetles excavate tunnels in dead or stressed trees into which they introduce fungal gardens, their sole source of nutrition. After landing on a suitable tree, an ambrosia beetle excavates a tunnel in which it releases its fungal symbiont. The fungus penetrates the plant's xylem tissue, extracts nutrients from it, and concentrates the nutrients on and near the surface of the beetle gallery. Ambrosia fungi are typically poor wood degraders, and instead utilize less demanding nutrients. Symbiotic fungi produce and detoxify ethanol, which is an attractant for ambrosia beetles and likely prevents growth of antagonistic pathogens and selects for other beneficial symbionts. The majority of ambrosia beetles colonize xylem of recently dead trees, but some colonize stressed trees that are still alive, and a few species attack healthy trees. Species differ in their preference for different parts of trees, different stages of deterioration, and in the shape of their tunnels ("galleries"). However, the majority of ambrosia beetles are not specialized to any taxonomic group of hosts, unlike most phytophagous organisms including the closely related bark beetles. One species of ambrosia beetle, Austroplatypus incompertus exhibits eusociality, one of the few organisms outside of Hymenoptera and Isoptera to do so.
A bark beetle is the common name for the subfamily of beetles Scolytinae. Previously, this was considered a distinct family (Scolytidae), but is now understood to be a specialized clade of the "true weevil" family (Curculionidae). Although the term "bark beetle" refers to the fact that many species feed in the inner bark (phloem) layer of trees, the subfamily also has many species with other lifestyles, including some that bore into wood, feed in fruit and seeds, or tunnel into herbaceous plants. Well-known species are members of the type genus Scolytus, namely the European elm bark beetle S. multistriatus and the large elm bark beetle S. scolytus, which like the American elm bark beetle Hylurgopinus rufipes, transmit Dutch elm disease fungi (Ophiostoma). The mountain pine beetle Dendroctonus ponderosae, southern pine beetle Dendroctonus frontalis, and their near relatives are major pests of conifer forests in North America. A similarly aggressive species in Europe is the spruce ips Ips typographus. A tiny bark beetle, the coffee berry borer, Hypothenemus hampei is a major pest on coffee plantations around the world.
Frass refers loosely to the more or less solid excreta of insects, and to certain other related matter.
The term woodboring beetle encompasses many species and families of beetles whose larval or adult forms eat and destroy wood. In the woodworking industry, larval stages of some are sometimes referred to as woodworms. The three most species-rich families of woodboring beetles are longhorn beetles, bark beetles and weevils, and metallic flat-headed borers. Woodboring is thought to be the ancestral ecology of beetles, and bores made by beetles in fossil wood extend back to the earliest fossil record of beetles in the Early Permian (Asselian), around 295-300 million years ago.
The term mycangium is used in biology for special structures on the body of an animal that are adapted for the transport of symbiotic fungi. This is seen in many xylophagous insects, which apparently derive much of their nutrition from the digestion of various fungi that are growing amidst the wood fibers. In some cases, as in ambrosia beetles, the fungi are the sole food, and the excavations in the wood are simply to make a suitable microenvironment for the fungus to grow. In other cases, wood tissue is the main food, and fungi weaken the defense response from the host plant.
Dioryctria sylvestrella, the new pine knot-horn or maritime pine borer, is a moth of the family Pyralidae. It is found in Europe, parts of Asia and North Africa. The adult is a small mottled brown and white insect with a wingspan of 28 to 35 mm. The moth flies in a single generation from June to October and is a pest of maritime pine and several other species of pine, on which the caterpillars feed.
Platypodinae is a weevil subfamily in the family Curculionidae. They are important early decomposers of dead woody plant material in wet tropics; all but two species are ambrosia beetles that cultivate fungi in tunnels excavated in dead wood as the sole food for their larvae. They are sometimes known as pinhole borers.
The European spruce bark beetle, is a species of beetle in the weevil subfamily Scolytinae, the bark beetles, and is found from Europe to Asia Minor and some parts of Africa.
The foamy bark canker is a disease affecting oak trees in California caused by the fungus Geosmithia sp. #41 and spread by the Western oak bark beetle. This disease is only seen through the symbiosis of the bark beetles and the fungal pathogen. The bark beetles target oak trees and bore holes through the peridermal tissues, making tunnels within the phloem. The fungal spores are brought into these tunnels by the beetles and begin to colonize the damaged cells inside the tunnels. Symptoms of the developing fungus include wet discoloration seeping from the beetle entry holes as the fungus begins to consume phloem and likely other tissues. If bark is removed, necrosis of the phloem can be observed surrounding the entry hole(s). As the disease progresses, a reddish sap and foamy liquid oozes from entry holes, thus giving the disease the name foamy bark canker. Eventually, after the disease has progressed, the tree dies. This disease is important because of its detrimental effects on oak trees and its ability to spread to several new Californian counties in just a couple of years.
Xylosandrus compactus is a species of ambrosia beetle. Common names for this beetle include black twig borer, black coffee borer, black coffee twig borer and tea stem borer. The adult beetle is dark brown or black and inconspicuous; it bores into a twig of a host plant and lays its eggs, and the larvae create further tunnels through the plant tissues. These beetles are agricultural pests that damage the shoots of such crops as coffee, tea, cocoa and avocado.
Platypus cylindrus, commonly known as the oak pinhole borer, is a species of ambrosia beetle in the weevil family Scolytinae. The adults and larvae burrow under the bark of mature oak trees. It is native to Europe.
Xyloterinus is a genus of typical bark beetles in the family Curculionidae. This is a monotypic genus and the one described species is Xyloterinus politus. It is native to North America where it infests both hardwood and softwood trees, as well as stacks of logs.
Xylosandrus germanus, known generally as the alnus ambrosia beetle or black stem borer, is a species of ambrosia beetle in the family Curculionidae. X. germanus poses challenges in woody ornamental species and orchard crops such as apples and pecan. Furthermore, X. germanus is recognized or suspected to act as a vector for plant pathogens to varying extents, potentially leading to the decline of trees. The black stem borer is native to eastern Asia, but is an invasive species in Europe and North America. This species carries and feeds on associated ambrosia fungus, Ambrosiella grosmanniae.
Xyleborinus saxesenii, commonly known as the fruit-tree pinhole borer, is a species of ambrosia beetle in the family Curculionidae. It is native to the Palaearctic region but has been introduced in many locations, including North America. X. saxesenii typically live in freshly dead wood, but it has also been reported to attack live trees. Such attacks on live trees may lead to economic damage.
Platypus quercivorus, the oak ambrosia beetle, is a species of weevil and pest of broad-leaved trees. This species is most commonly known for vectoring the fungus responsible for excessive oak dieback in Japan since the 1980s. It is found in Japan, India, Indonesia, New Guinea, and Taiwan.
Oemona hirta, the lemon tree borer, also known as the whistling beetle or the singing beetle, is a longhorn beetle endemic to New Zealand. Its larvae are generalist feeders, boring into the wood of a wide variety of trees, native and introduced. When citrus orchards were first established in New Zealand, this beetle started inflicting serious damage, and so gained the name "lemon tree borer". Four species within the genus Oemona have been identified, suggesting that more species could be found. When disturbed by predators or humans, the adult beetle stridulates creating a "rasp" or "squeak" sound by rubbing its thorax and head together against an area of thin ridges. Māori would eat a liquid called "pia manuka", which was produced by manuka trees when its wood was damaged by the larvae. When Captain Cook first arrived in NZ, his naturalists, Banks and Solander, collected a lemon tree borer in their first collection between 1769 and 1771. This oldest collected specimen can be found in the British Museum. A few years after the first collection, the species would be first described by the Danish naturalist Fabricius in 1775.
Euplatypus parallelus, previously known as Platypus parallelus, is a species of ambrosia beetle in the weevil family Curculionidae. The adults and larvae form galleries in various species of tree and logs. It is native to Central and South America but has spread globally, is present in Africa and is well established in tropical Asia.
Arrenodes is a genus of primitive weevils belonging to the family Brentidae, containing a single described species, Arrenodes minutus, commonly known as the oak timberworm. These beetles are pests of hardwoods in North America. Adult oak timberworms are shiny, elongate, and range 7 to 25 mm in length. They are reddish-brown to brownish-black in coloration, with yellow spots on their elytra. Adults display strong sexual dimorphism; females have long, slender, straight mouthparts, while males possess flattened, broadened mouthparts with large mandibles. Males are known to be aggressive and use these large mandibles for combat. These mandibles are also used in courtship. Larvae are elongate, cylindrical, white, and curved. They have three pairs of jointed legs on the thorax and one pair of prolegs near the end of the abdomen.
Xyleborus dispar is a species of bark beetle commonly called the Pear blight beetle, or the European shothole borer. It is an invasive species in North America, and can be a pest in orchards and forests throughout its range.
Xyleborus perforans, commonly known as island pinhole borer, is a species of weevil native in the Oriental region through to Australia but shows a cosmopolitan distribution due to introduction to many parts of the world.