The Curculionidae are a family of weevils, commonly called snout beetles or true weevils. They are one of the largest animal families with 6,800 genera and 83,000 species described worldwide. They are the sister group to the family Brentidae.
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 in which they cultivate 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 attack 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.
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.
Xyleborini are a tribe of ambrosia beetles, highly specialized weevils of the subfamily Scolytinae. Much of the ambrosia beetle fauna in Eurasia and the Americas consists of Xyleborini species. Some Xyleborini are notorious invasive species.
Xyleborus glabratus, the redbay ambrosia beetle, is a type of ambrosia beetle invasive in the United States. It has been documented as the primary vector of Raffaelea lauricola, the fungus that causes laurel wilt, a disease that can kill several North American tree species in the family Lauraceae, including redbay, sassafras, and avocado.
Euwallacea fornicatus is a species complex consisting of multiple cryptic species of ambrosia beetles, known as an invasive species in California, Israel and South Africa. The species has also been unintentionally introduced into exotic greenhouses in several European countries. As the rest of the ambrosia beetles, E. fornicatus larvae and adults feed on a symbiotic fungus carried in a specific structure called mycangium. In E. fornicatus, the mycangium is located in the mandible. The combination of massive numbers of beetles with the symbiotic fungus kills trees, even though the fungus alone is a weak pathogen.
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.
Xylosandrus crassiusculus, known generally as the Asian ambrosia beetle or granulate ambrosia beetle, is a species of tropical bark beetle in the family Curculionidae. It is native to Asia and has spread to Africa, Europe, Australasia and the Americas. The adult beetle is reddish-brown and some 2 to 3 mm long.
Xylosandrus germanus, known generally as the alnus ambrosia beetle or black stem borer, is a species of ambrosia beetle in the family Curculionidae. 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.
Cnestus is a genus of ambrosia beetles.
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.
Euwallacea interjectus, is a species of weevil native to Asia but introduced to Westerns parts of the world.
Euwallacea piceus, is a species of weevil native to Oriental Asia but introduced to African and other Westerns Pacific parts of the world. It is a serious pest in tropical and subtropical parts of the Americas.
Xyleborinus andrewesi, is a species of weevil widely distributed throughout the Old World tropics and introduced to many New World countries.
Debus emarginatus, is a species of weevil widely distributed throughout the Old World tropics.
Xylosandrus discolor, is a species of weevil found in Australia, Micronesia, Myanmar, China, India, Sri Lanka, Indonesia, Malaysia, Taiwan and Thailand.
Xylosandrus morigerus, is a species of weevil widespread throughout Afrotropical, Australian, Neotropical, Oceania and Oriental regions. It is also introduced to Palearctic regional countries.
Cnestus gravidus is a species of weevil found in Bangladesh, Sri Lanka, India, Myanmar, Laos, Thailand, Vietnam and China.
Euwallacea perbrevis, commonly known as tea shot-hole borer, is a species of weevil native to South and South-East Asia through to Australia, but introduced to Western countries.
Ambrosiella roeperi is the fungal symbiont of the granulate ambrosia beetle, Xylosandrus crassiusculus, facilitating this insect’s capacity to accumulate on and damage a diverse array of woody plants from around the world. It is one of several important nutritional partners derived from order Microascales that sustain and are transported by xylomycetophagous scolytine beetles.
