where did the hemlock wooly adelgid come from
Japan
title: Hemlock woolly adelgid text: 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 of 2015, 90% of the geographic range of eastern hemlock in North America has been affected by HWA. An adult individual body length is typically 0.8 mm, and is oval in shape. The tiny brown-colored insect has title: Hemlock woolly adelgid text: "Laricobius osakensis" from Japan, a relative of "L. nigrinus". They have shown promise in field trials. The environmentally safest chemical control methods for treating individual trees are nontoxic insecticidal soap and horticultural oil. These are sprayed on the foliage and smother the insects as they dry. Most trees need to be treated on a yearly basis. Toxic systemic insecticides may be applied to the foliage and bark of a tree and can persist in killing the adelgid for up to four years after application. Caution must be used, and restraint exercised around bodies of water. Soil drenches/soil injections/bark sprays are title: Hemlock woolly adelgid text: four thread-like stylets that are bundled together and function as a mouthpart. Three times the length of its body, the stylet bundle pierces the host plant's parenchymatic ray tissue to derive nutrition from stored reserves. It may also inject a toxin while feeding. The resulting desiccation causes the tree to lose needles and not produce new growth. Hemlocks stricken by HWA frequently become grayish-green rather than a healthy dark green. In the northern portion of the hemlock's range, death typically occurs 4 to 10 years after infestation. Trees that survive the direct effects of the infection are usually weakened and title: Hemlock woolly adelgid text: used in larger trees that cannot be completely sprayed with insecticidal soaps or foliage insecticides. Tree roots absorb and transport the product into the foliage and kill hemlock woolly adelgid. Soil drenches must be applied when soil moisture is adequate for the tree roots to absorb the product. These products should not be used in close proximity to bodies of water. Trunk injections are used for large trees that are near water or where soils are too rocky for soil injections or drenches. The chemical is injected directly into the tree and transported to the twigs and needles where the title: Hemlock woolly adelgid text: may die from secondary causes. The presence of HWA can be identified by its egg sacs, which resemble small tufts of cotton clinging to the underside of hemlock branches. In North America, the hemlock woolly adelgid asexually reproduces and can have two generations per year. Both generations are parthenogenetic and exclusively female. In its native Asian habitat, a third winged generation called sexupera occurs, although this generation's sexual reproduction requires a species of spruce not found in the Eastern United States, and therefore dies, areas of West Virginia as of 2017 are heavily infested with this form. Between 100 and