At WeedOut we use Arbor Systems' Wedgle Direct-Inject Tree Treatment System. The Wedgle was highlighted in the Integrated Pest Management of Midwest Landscapes manual as the only injection application method using a liquid injection that did not require a drilled hole. Tree trunk injections to deliver nutrients and insecticides are beneficial, but can seriously injure a tree if they are given improperly, according to"Modern Arboriculture" reference text. Arborists and consumers should avoid using a trunk injection method that involves drilling holes in the tree as part of the application process.
Dutch Elm Disease
Dutch elm disease (DED) is a fungal disease of elm trees which is spread by the elm bark beetle. Although believed to be originally native to Asia, the disease has been accidentally introduced into America and Europe, where it has devastated native populations of elms which had not had the opportunity to evolve resistance to the disease. The name Dutch elm disease refers to its identification in the Netherlands in 1921; the disease is not specific to the Dutch Elm hybrid.
Oak Wilt Oak wilt is a fungal disease that can quickly kill an oak tree. It is caused by the fungus Ceratocystis fagacearum. Symptoms vary by tree species but generally consist of leaf discoloration, wilt, defoliation, and death. The fungus is spread from diseased to healthy trees by insect vectors or via connections between tree roots. Management of the disease consists mainly of preventing infection by avoiding tree wounds, removing diseased trees and digging trenches that disrupt root connections. Chemical treatments are available and are mostly preventative as well. Oak wilt is an important disease of oak for timber production and of oak trees in urban areas.
Pine Wilt Pine wilt is caused by the North American native pinewood nematode (Bursaphelenchus xylophilus).
 Where it is indigenous it is not major pathogen of native pine species, but in North America it causes wilt in a few non-native North American pine species. In has been introduced into Japan and China, where it has become a troubling disease of Japanese red pines (Pinus densiflora) and black pines (Pinus thunbergii). Over 46 million cubic meters of trees have been lost alone in Japan over a 50 year period. It is spread among conifers by pine sawyer beetles (Monochamus spp). The nematodes can reproduce quickly in the sapwood under favorable conditions within susceptible pine species, causing wilting and death, sometimes in only a few weeks. North America lumber products are under export restrictions because of the nematode. In the Midwest United States it has killed many Scots pines (Pinus sylvestris), and this attractive tree is no longer recommended for landscaping uses there Sphaeropsis blight
Sphaeropsis blight is a disease that affects pines worldwide. This disease was previously known as Diplodia tip blight. Sphaeropsis blight is considered to be a "disfiguring disease" that attacks pine trees that are growing under stressful conditions. Sphaeropsis blight does not typically kill the tree, but will significantly disfigure the tree if not properly cared for or controlled. Most commonly, Sphaeropsis blight attacks Austrian (Pinus nigra), Scotch (P. sylvestris), and red (P. resinosa) pine trees. This disease is a problem in the United States, nationwide, from coast to coast, and can be found worldwide.
Emerald Ash Borer
The emerald ash borer (Agrilus planipennis or Agrilus marcopoli and EAB) is a green beetle native to Asia. In North America the borer is an invasive species, highly destructive to ash trees in its introduced range. The potential damage of this insect rivals that of Chestnut blight and Dutch Elm Disease. Since its accidental introduction into the United States and Canada in the 1990s, and its subsequent detection in 2002, it has spread to 14 states and adjacent parts of Canada. It has killed at least 50 - 100 million ash trees so far and threatens to kill most of the 7.5 billion ash trees throughout North America. The insect threatens the entire North American Fraxinus genus, unlike past invasive tree pests, which have only threatened a single species within a genus. The green ash and the black ash trees are preferred. White ash is also killed rapidly, but usually only after green and black ash trees are eliminated. Blue ash displays some resistance to the emerald ash borer by forming callous tissue around EAB galleries; however, they are usually killed eventually as well.
Webworms Fall webworm, Hyphantria cunea, is a moth in the family Arctiidae known principally for its larval stage, which creates the characteristic webbed nests on the tree limbs of a wide variety of hardwoods in the late summer and fall. It is mainly an aesthetic pest and is not believed to harm otherwise healthy trees. It is well-known to commercial tree services and arboriculturists.
Bagworms The Evergreen Bagworm (Thyridopteryx ephemeraeformis), commonly known as bagworm, eastern bagworm, common bagworm, common basket worm, or North American bagworm, is a moth that spins its cocoon in its larval life, decorating it with bits of plant material from the trees on which it feeds. The evergreen bagworm's case grows to a length of over 6 cm, tapered and open on both ends. Newborn larva are blackish and turn brown to tan as they grow, mottled with black. The heads and thorax develop a yellow tint as they grow to a full length of 24 to 32 mm. Adult males resemble bees, having a 25 mm wingspan with transparent wings (Greek thuris window + pterux wing) and black furry bodies. Adult females are maggot-like with yellowish-white soft bodies 19 to 23 mm long and small tufts of hair near the end of the abdomen. The cream colored eggs are 0.75 mm in diameter. The evergreen bagworm thrives in the eastern United States as far west as Nebraska, north into New England and bordering the Gulf of Mexico south throughout Texas. Large populations in forested areas are rare. With scarce predators in urban areas, evergreen bagworms often thrive in urban habitats. When disturbed, the larva will retract its head into its case and hold the front opening closed. Mature larva may remain in the host tree or drag its case nearby before attaching itself for the pupa stage. Arborvitae and red cedar are the favored host trees of the evergreen bagworm, but cypress, juniper, pine, spruce, apple, birch, black locust, elm, maple, poplar, oak, sycamore, willow, and over 100 other species are also attacked. Leaves and buds are both fair game for food. Bagworms are commonly parasitized by ichneumonid wasps, notably Itoplectis conquisitor. Predators include vespid wasps and hornets. Woodpeckers and sapsuckers can feed on the larva from their cases. Eggs hatch from early April to early June (earlier in the south) and larvae emerge from the carcass of their mother in her case. Newborn larva emerge from the bottom of the hanging case and drop down on a strand of silk. The wind often blows the larva to nearby plants where it begins its new case from silk and fecal material before beginning to add leaves and twigs from its host. When mature in mid-August, the larva wraps silk around a branch, hangs from it, and pupates head down. The silk is so strong that it can strangle and kill the branch it hangs from over the course of several years as the branch grows. Adult males transform into moths in four weeks to seek out females for mating. The female never leaves the cocoon, requiring that the male mate with her through the open end at the back of the case. She has no eyes, legs, wings, antennae, and can't eat, but she emits a strong pheromone to attract a mate. After her death with hundreds to several thousand eggs still inside, her offspring hatch and pass through her body, pupal shell and case over several months emerging to start their own cases. Later, her pupal case can be found, full of the yellow remains of eggshells. The bagworm has a voracious appetite and is considered a serious pest. Host trees develop damaged foliage that will kill the tree if left unchecked. If caught early enough in an infestation, the cases from the previous year can be picked off by hand before the end of May. They are easiest to detect in the fall after their cases have turned brown, especially on evergreen trees. Various bacterial sprays such as Bt/Spinosad
and stomach insecticides such as carbaryl (Sevin) are used to control infestations.