Rhizophagus grandis | |
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Rhizophagus grandis head | |
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Species: | R. grandis |
Binomial name | |
Rhizophagus grandis Gyllenhal, 1827 | |
Rhizophagus grandis is a species of predatory beetle in the family Monotomidae. [1] R. grandis is a specialist predator on the larvae of the great spruce bark beetle (Dendroctonus micans), a pest of spruce trees (Picea), and is found in Eurasian forests where its prey is found.
R. grandis spends its whole life in association with its prey, living underneath the bark of spruce trees. It is specifically attracted by volatile chemicals, monoterpenes, present in the frass produced by the bark beetle larvae as they tunnel under the bark of their host tree. [2]
During the twentieth century, D. micans has been steadily increasing its range, and R. grandis has tended to follow. The effects of the predator were apparent when both spread into Germany around the beginning of the century, and after D. micans had invaded Georgia in the 1950s, the first programme for its biological control involving R. grandis was established there in 1963. Since then, rearing of the predatory beetle has been undertaken in Georgia, using cut logs infested with D. micans. When the pest species spread into Turkey, further biocontrol programmes were implemented in that country. [3]
It has been found that R. grandis is also attracted to the frass produced by the black turpentine beetle ( Dendroctonus terebrans ) and the southern pine beetle (Dendroctonus frontalis), closely related bark boring beetles found in the United States. The larvae of D. frontalis are not gregarious, but those of D. terebrans are, and biological control of the latter pest by R. grandis may be possible. An attempt to do this was made when small numbers of the predator were imported from Belgium and released in Louisiana in 1988. [4]
Biological control or biocontrol is a method of controlling pests, whether pest animals such as insects and mites, weeds, or pathogens affecting animals or plants by using other organisms. It relies on predation, parasitism, herbivory, or other natural mechanisms, but typically also involves an active human management role. It can be an important component of integrated pest management (IPM) programs.
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.
Adelges tsugae, the hemlock woolly adelgid or HWA, is an insect of the order Hemiptera native to East Asia. It feeds by sucking sap from hemlock and spruce trees. In its native range, HWA is not a serious pest because populations are managed by natural predators and parasitoids and by host resistance. In eastern North America it is a destructive pest that threatens the eastern hemlock and the Carolina hemlock. HWA is also found in western North America, where it has likely been present for thousands of years. In western North America, it primarily attacks western hemlock Tsuga heterophylla and has only caused minor damage due to natural predators and host resistance. Accidentally introduced to North America from Japan, HWA was first found in the eastern United States near Richmond, Virginia, in 1951. The pest is now found from northern Georgia to coastal Maine and southwestern Nova Scotia as well as areas of western Michigan near the eastern Lake Michigan shoreline. As of 2015, 90% of the geographic range of eastern hemlock in North America has been affected by HWA.
Verbenone is a natural organic compound classified as a terpene that is found naturally in a variety of plants. The chemical has a pleasant characteristic odor. Besides being a natural constituent of plants, it and its analogs are insect pheromones. In particular, verbenone when formulated in a long-lasting matrix has an important role in the control of bark beetles such as the mountain pine beetle and the Southern pine bark beetle.
The ant beetle, also known as the European red-bellied clerid, is a medium size insect, rather soft-bodied, with strong mandibles that can tear between the hard sclerotized integument of bark beetles. Larvae and adults are common predators of bark beetles in Europe.
Cleridae are a family of beetles of the superfamily Cleroidea. They are commonly known as checkered beetles. The family Cleridae has a worldwide distribution, and a variety of habitats and feeding preferences.
Dendroctonus is a genus of bark beetles. It includes several species notorious for destroying trees in the forests of North America. The genus has a symbiotic relationship with many different yeasts, particularly those in the genera Candida and Pichia that aid in digestion and pheromone production.
Xanthocryptus novozealandicus, the lemon tree borer parasite, is a wasp in the family Ichneumonidae. It is a native insect of New Zealand. It is also found in Australia and New Guinea. Females hunt for larvae of wood-boring beetles around March, including the lemon tree borer, a native cerambycid that tunnels into citrus trees, grapes and many native species. When a suitable host is found, the female pushes her ovipositor through the wood and injects her eggs into the grub. This has the incidental benefit of helping to control some pests. X. novozealandicus prefers to prey on second year lemon tree borer larvae. This specific parasite prefers to prey on larger second year larvae due to its larger size.
Dendroctonus rufipennis, the spruce beetle, is a species of bark beetle native to British Columbia, Newfoundland and Labrador, Nova Scotia, Ontario, Quebec, Northern Manitoba, the Yukon, Alaska, Colorado, Wyoming, Montana, and Maine. They are known to destroy forests of spruce trees including Engelmann, White, Sitka, and Colorado blue spruce. Adults average 4 to 7 mm in length.
Lebia grandis is a ground beetle in the family Carabidae found in North America. It is a specialist predator on the eggs and larvae of Colorado potato beetles, and its larvae are obligate parasitoids of Colorado potato beetle pupae.
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.
Ips is a genus of beetles in the family Curculionidae, the true weevils. They are bark beetles, members of the subfamily Scolytinae. Species are distributed throughout the Northern Hemisphere. Some are known as introduced species in Australia and Africa. Many species are pests of forest trees, especially pines and spruces. They are known commonly as engraver beetles, ips engraver beetles, and pine engravers.
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.
Dendroctonus valens, also known as the red turpentine beetle, is a species of bark beetle characterized by a dark-reddish brown hue. It is native to forests across North and Central America. In its adult form, these beetles range from six to ten millimeters in length. A notable characteristic about them is their use of acoustic signals and chemical cues when engaging in what is a very complex mating process.
Dendroctonus micans, the great spruce bark beetle, is a species of bark beetle native to the coniferous forests of Europe and Asia. The beetles burrow into the bark of spruce trees and lay eggs which develop into larvae that feed on the woody layers under the bark.
Dendroctonus terebrans, the black turpentine beetle, is a species of bark beetle native to the eastern United States. Its larvae tunnel under the bark of pine trees, weakening and sometimes killing the trees.
Dendroctonus adjunctus, the roundheaded pine beetle, is a species of bark beetle in the family Curculionidae found in North America. A parasite, the roundheaded pine beetle feeds on and eventually kills pine trees of several species in Guatemala, Mexico, and the Southern United States.
Rhynocoris marginatus is a species of assassin bug in the family Reduviidae. It is a predator of other insects and is found in Asia. Crops in India on which it has been found feeding on pests include sugarcane, pigeon pea, cardamom, cotton, tea, and peanuts. The insects are potentially useful in biological control because they are more resistant to pesticides than are the pests on which they feed.
Arrenodes minutus, commonly known as the oak timberworm, is a species of primitive weevil in the family Brentidae. 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 3 pairs of jointed legs on the thorax and 1 pair of prolegs near the end of the abdomen.