Laricobius nigrinus | |
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Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Arthropoda |
Class: | Insecta |
Order: | Coleoptera |
Suborder: | Polyphaga |
Family: | Derodontidae |
Genus: | Laricobius |
Species: | L. nigrinus |
Binomial name | |
Laricobius nigrinus Fender, 1945 | |
Laricobius nigrinus is a species of tooth-necked fungus beetle in the family Derodontidae. [1] [2] It is native to western North America, and it is being studied as a biological control agent for the hemlock woolly adelgid. [3] It was first released in 2003 and continues to be reared and released across the Northeast to control infestations. [4]
Laricobius nigrinus was first described by Kenneth Fender in 1945 from specimens collected in Oregon. [5] Laricobius is one of four genera in Derodontidae. [6] The genus has a Holarctic distribution, with most species native to Asia. [6]
Adult beetles have a black body, clubbed antennae with eleven segments, and two ocelli. Their palps, antennae, and tarsi are dark brown to red. The head is partially visible from above. [7] They are usually 2.3-2.9 mm long, with no significant sex differences in size. [7] The species can be distinguished from other black Laricobius by its toothed pronotal margin. [6] Its eggs are yellow and oblong, usually laid in the ovisacs of A. tsugae. [7] The larvae have three segmented antennae, a well-developed head with twelve stemmata and hairy abdominal segments. [7] They are "oligopod type" larvae, with three pairs of thoracic legs, and no prolegs. The larvae start as yellow before darkening to yellow green/yellow brown with maturity. Pupae resemble the adult form, and individuals can be sexed in pupal form. [7]
All members of Laricobius feed on members of Adelgidae, and Laricobius nigrinus is specialized on the hemlock woolly adelgid. [7] The predatory life history of Laricobius is unique among the family as most derodontids are fungal feeders. [6] L. nigrinus is native to hemlock forests in the Pacific Northwest. It can be found throughout the western U.S. and Canada, and specimens in the U.S. Museum of Natural History have been collected as far north as the southeastern Yukon. [8] It has a univoltine life cycle, completing one generation per year. Eggs are laid in early spring, and its development is synchronized with the winter/spring generation of A. tsugae. [8] Females lay an average of 100 eggs during their lifetimes. [9] L. nigrinus goes through four larval instars, and the larvae use secretions to glue debris and adelgid wool to themselves as camouflage. [7] Fourth instar larvae drop to the ground as prepupae and complete their development in the soil before emerging as adults in the fall. Similar to its prey, L. nigrinus is dormant during the summer months, aestivating as a pupa. The adult beetles feed on adult adelgids, while the larvae feed on the eggs of the spring progrediens generation. [8] They have a temperature dependent development, and cannot complete development above 21 °C. [10] They are significantly more active during the day than at night. Their flight behavior is responsive to prey densities, and they will only fly when their food source is scarce. [11] They use scent to home in on adelgids at close range, and respond to the odors of the adelgid's native host tree, western hemlock as well as the odors of western white pine and white spruce. [12]
Due to its narrow prey specificity and geographic range, L. nigrinus was approved by USDA-APHIS for release as a biological control agent in 2000. [8] Field releases began in 2003, and populations have expanded to cover a wide range of A. tsugae infestation. [8] As of 2021 it has been released in 18 states, and has established in Pennsylvania, Maryland, New York, New Jersey, Virginia, Georgia, West Virginia, North Carolina, Tennessee, Connecticut, Massachusetts, Maine, and New Hampshire. Releases are continuing throughout the infestation range. [13] [4] It has been shown to strongly impact A. tsugae densities in experiments conducted in their native range, [14] and a recent study found that L. nigrinus has a significant impact on the mortality of A. tsugae eggs at caged release sites. [15] Studies are ongoing to determine the rate of hybridization between L. nigrinus and its native congener, Laricobius rubidus which feeds on pine bark adelgid. [16]
The Japanese beetle is a species of scarab beetle. Due to the presence of natural predators, the Japanese beetle is not considered a pest in its native Japan, but in North America and some regions of Europe, it is a noted pest to roughly 300 species of plants. Some of these plants include rose bushes, grapes, hops, canna, crape myrtles, birch trees, linden trees, and others.
Tsuga canadensis, also known as eastern hemlock, eastern hemlock-spruce, or Canadian hemlock, and in the French-speaking regions of Canada as pruche du Canada, is a coniferous tree native to eastern North America. It is the state tree of Pennsylvania. Eastern hemlocks are widespread throughout much of the Great Lakes region, the Appalachian Mountains, the Northeastern United States, and Maritime Canada. They have been introduced in the United Kingdom and mainland Europe, where they are used as ornamental trees.
Derodontidae is a family of beetles, in its own superfamily, Derodontoidea, sometimes known as the tooth-necked fungus beetles. Beetles of this family are small, between 2 and 6 mm in length, typically with spiny margins on their pronotum that give them their name, though the genus Laricobius lacks these spines. Unusual among beetles, they have two ocelli on the top of their heads.
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, HWA has affected 90% of the geographic range of eastern hemlock in North America.
The European corn borer, also known as the European corn worm or European high-flyer, is a moth of the family Crambidae. It is a pest of grain, particularly maize. The insect is native to Europe, originally infesting varieties of millet, including broom corn. The European corn borer was first reported in North America in 1917 in Massachusetts, but was probably introduced from Europe several years earlier. Since its initial discovery in the Americas, the insect has spread into Canada and westwards across the United States to the Rocky Mountains.
The Adelgidae are a small family of the Hemiptera closely related to the aphids, and often included in the Aphidoidea with the Phylloxeridae or placed within the superfamily Phylloxeroidea as a sister of the Aphidoidea within the infraorder Aphidomorpha. The family is composed of species associated with pine, spruce, or other conifers, known respectively as "pine aphids" or "spruce aphids". This family includes the former family Chermesidae, or "Chermidae", the name of which was declared invalid by the ICZN in 1955. There is still considerable debate as to the number of genera within the family, and the classification is still unstable and inconsistent among competing authors.
Cyphocleonus achates is a species of true weevil known as the knapweed root weevil. It is native to southern Europe and the Mediterranean and is used as an agent of biological pest control against noxious knapweeds, especially spotted knapweed. It has recently been spotted in India.
The hemlock moth, also known as the defoliating hemlock moth or poison hemlock moth, is a nocturnal moth species of the family Depressariidae. Of Palaearctic origin, it was first found in North America in 1973 when it was accidentally introduced. The moth is now widespread throughout the northern half of the United States, southern Canada, northern Europe, and, more recently, New Zealand and Australia. The larval form grows to around 10 mm, while the adults wingspan is between 17 mm and 19 mm.
The thistle tortoise beetle is a species of beetle in the subfamily Cassidinae and the genus Cassida. The thistle tortoise beetle can be recognized by its green, rounded back and it can be found on thistle plants in many regions of North America and Europe. The thistle tortioise beetle was first discovered in 1902 in Lévis, Quebec. In 1931, Nellie F. Paterson was the first to document the mature larva. Later, the instar larva of this species was first recorded in 2004 by Jolanta Świętojańska. The thistle tortoise beetle exhibits multiple defense behaviors, such as a flexible shield, providing a barrier against the mandibles of predators, and an excretion that protects the eggs as well.
Laricobius is a genus of beetles in the family Derodontidae, the tooth-necked fungus beetles.
Coleomegilla maculata, commonly known as the spotted lady beetle, pink spotted lady beetle or twelve-spotted lady beetle, is a large coccinellid beetle native to North America. The adults and larvae feed primarily on aphids and the species has been used as a biological control agent. Based on name connotation and to avoid confusion with other species also called "spotted ladybeetle", spotted pink ladybeetle is probably the most appropriate common name for this species.
Cycloneda sanguinea, also known as the spotless lady beetle, is a widespread species of ladybird beetle in the Americas.
Hylobius transversovittatus is a species of weevil in the family Curculionidae. It is native to the Old World where both adults and larvae feed on purple loosestrife. This plant is regarded as an invasive species in North America and the weevil has been introduced into both the United States and Canada in an effort to control the plant.
Laricobius osakensis is a species of Derodontid beetle native to Japan. Described in 2011, it feeds exclusively on hemlock woolly adelgid, an invasive insect species that is destroying huge numbers of hemlock trees in eastern North America. It has shown promise as a biological control agent in field trials.
Clitostethus is a genus of dusky lady beetles in the family Coccinellidae, including over 40 species, many of which were formerly placed under the genus name Nephaspis.
Scymnus coniferarum, the conifer lady beetle, is a species of dusky lady beetle in the family Coccinellidae. It is found in western North America.
Laricobius rubidus is a species of tooth-necked fungus beetle in the family Derodontidae. It is found in North America. Studies are ongoing to determine the rate of hybridization between L. rubidus, which feeds on pine bark adelgid, and its native congener, Laricobius nigrinus, which is being studied as a biological control agent for the hemlock woolly adelgid.
Eucryptorrhynchus brandti, the snout weevil, is an insect in the weevil family. In its native range in China, it causes significant damage to its single host, Ailanthus altissima, tree of heaven. Thus the weevil is under study as a biological control of tree of heaven in regions where the tree is non-native. In particular, the insect acts as a vector for Verticillium nonalfalfae, a soilborne fungus that causes verticillium wilt.
Sasajiscymnus tsugae, formerly Pseudoscymnus tsugae, is a species of insect in the family Coccinellidae. It feeds on the hemlock woolly adelgid.
Nathan Peterson Havill is an American entomologist and evolutionary biologist. Havill is a Research Entomologist with the United States Forest Service in Hamden, Connecticut and is internationally recognized on the phylogeny of Adelgidae.