Crown Rot, Collar Rot, Root Rot, Stem Rot

Phytophthora Spp. including,
P. ramorum, P. cactorum, P. cinnamomi, P. palmivora, P. citricola, P. nicotianae, P. ramora

World wide.

The pathogen survives in soil for several years as spores, especially in poorly drained soils. Too deep planting may contribute to the severity of this disease. Cool, wet weather favors development of the disease in the spring.

Phytophthora is a Soil borne fungal pathogen. Cankers may be seen at or below the soil line and may extend into the root system.  The infection can also invade the trunk or main stem.  Susceptible scions can be infected at the bud union. Infected bark is brown and often slimy when wet. When the bark is pulled away, the cambium and phloem will be an orange, reddish brown color. The cankers caused by the fungus girdle the tree, resulting in poor vegetative growth and chlorotic foliage that may turn purple in the autumn. A severely infected tree may die. Trees may be killed in one growing season or may linger for a number of growing seasons.

This fungus survives cold weather and drought as thick walled resting spores (oospores) in infected tissue or in soil. The resting spores are capable of surviving extended periods of time in soil. The fungus may build up to high levels in the soil in a short period under favorable conditions – i.e. during wet, cool periods. Under moist conditions, they germinate, forming another type of structure called a sporangium. A sporangium is a minute reproductive structure produced by the fungus in response to free water. The sporangia germinate in the presence of free water, releasing numerous one-celled, motile spores called zoospores. Zoospores swim through a thin film of water, contact roots or lower trunks of potential hosts, germinate, and infect. Although host wounds are frequent infection courts (areas where infections are initiated), the fungus can also directly penetrate host tissue. The fungus grows through host vascular tissue eventually girdling the tree. As the host dies, the fungus forms resting spores in the decaying tissue. Research revealed that the fungus is readily transported in irrigation water. Few agricultural soils should be considered free of the fungus once they have been irrigated. Infection is most likely to occur during cooler weather, i.e. early spring and fall. Research has indicated that trees are most susceptible during the bloom period.

Phytophthora palmivora is a ubiquitous pathogen causing many different diseases on a wide range of plants. The pathogen is believed to have originated in Southeast Asia but is now pantropical. It causes significant losses to farmers of tropical fruit and vegetable crops.

P. palmivora infects a thousand or more plant species including ornamental, horticultural and agricultural crops. It is also a common soil inhabitant. Important horticultural hosts include cocoa, canker, papaya (fruit rot), durian (fruit rot) canker, pineapple heart rot, citrus canker, black pepper foot rot and coconut bud rot.

P. palmivora thrives under humid wet conditions, and as a result can cause significant losses in many economically important tropical fruit crops. Symptoms include root rots, collar rots, stem cankers, leaf blights and fruit rot. In the nursery, the pathogen can lead to heavy losses through seedling blight.

Primary inoculum originates from the soil and infected plant material. The pathogen is disseminated through rain splash, insects and human activity intothe canopy of trees, where symptoms appear. Secondary inoculum spreads rapidly through wind and rainsplash, contact and vector activity (Fig e) in humid weather.

AKA…SOD

Phytophthora ramorum is the oomycete plant pathogen known to cause the disease sudden oak death (SOD). The disease kills oak and other species of trees and has had devastating effects on the oak populations in California and Oregon, as well as being present in Europe. Symptoms include bleeding cankers on the tree’s trunk and dieback of the foliage, in many cases eventually leading to the death of the tree.

It also infects a great number of other plant species, significantly woody ornamentals such as Rhododendron, Viburnum, and Pieris, causing foliar symptoms known as ramorum dieback or ramorum blight. Such plants can act as a source of inoculum for new infections, with the pathogen-producing spores that can be transmitted by rainsplash and rainwater.

First reported in 1995, and the origins of the pathogen are still unclear, but most evidence suggests it was repeatedly introduced as an exotic species.[

The disease is known to exist in California’s coastal region between Big Sur, in Monterey County and southern Humboldt County. It is confirmed to exist in all coastal counties in this range, as well as in all immediately inland counties from Santa Clara County north to Lake County. It has not been found east of the California Coast Ranges, however. It was reported in Curry County, Oregon (just north of the California border), in 2001. Sonoma County has been hit hardest, having more than twice the area of new mortality of any other county in California.

In North America
It was first discovered in California in 1995 when large numbers of tanoaks (Lithocarpus densiflorus) died mysteriously, and was described as a new species of Phytophthora in 2000. It has subsequently been found in many other areas, including Britain, Germany, and some other U.S. states, either accidentally introduced in nursery stock, or already present undetected.

In tanoaks, the disease may be recognized by wilting new shoots, older leaves becoming pale green, and after a period of two to three weeks, foliage turning brown while clinging to the branches. Dark brown sap may stain the lower trunk’s bark. Bark may split and exude gum, with visible discoloration. After the tree dies back, suckers try to sprout the next year, but their tips soon bend and die. Ambrosia beetles (Monarthrum scutellare) will most likely infest a dying tree during midsummer, producing piles of fine white dust near tiny holes. Later, bark beetles (Pseudopityophthorus pubipennis) produce fine, red boring dust. Small black domes, the fruiting bodies of the Hypoxylon fungus, may also be present on the bark. Leaf death may occur more than a year after the initial infection and months after the tree has been girdled by beetles.

In coast live oaks and Californian black oaks, the first symptom is a burgundy-red to tar-black thick sap bleeding from the bark surface. These are often referred to as bleeding cankers.

In addition to oaks, many other forest species may be hosts for the disease; in fact, it was observed in the USA that nearly all woody plants in some Californian forests were susceptible to P. ramorum.[4] including rhododendron, madrone (Arbutus menziesii), evergreen huckleberry (Vaccinium ovatum), California bay laurel (Umbellularia californica), buckeye (Aesculus californica), bigleaf maple (Acer macrophyllum), toyon (Heteromeles arbutifolia), manzanita (Arctostaphylos spp.), coast redwood (Sequoia sempervirens), Douglas fir (Pseudotsuga menziesii), coffeeberry (Rhamnus californica), honeysuckle (Lonicera hispidula), and Shreve oak (Quercus parvula). P. ramorum more commonly causes a less severe disease known as ramorum dieback/leaf blight on these hosts. Characteristic symptoms are dark spots on foliage and in some hosts the dieback of the stems and twigs.[5] The disease is capable of killing some hosts, such as rhododendron, but most survive. Disease progression on these species is not well documented. Redwoods exhibit needle discoloration and cankers on small branches, with purple lesions on sprouts that may lead to sprout mortality.

In Europe, Ramorum blight was first observed on rhododendron and viburnum in the early 1990s, where is was initially found mainly on container-grown plants in nurseries. The principal symptoms were leaf and twig blight. 
By 2007, it had spread throughout nurseries and retail centers in 16 European countries, and had been detected in gardens, parks, and woodlands in at least eight countries. It has not caused significant harm to European oak species.

In 2009, the pathogen was found to be infecting and killing large numbers of Japanese larch trees (Larix kaempferi) in the United Kingdom at sites in the English counties of Somerset, Devon, and Cornwall. It was the first time in the world that Phytophthora ramorum had been found infecting this species. Since then, it has also been found extensively in larch plantations in Wales and in southwest Scotland, leading to the deliberate felling of large areas. The UK Forestry Commission noted that eradication of the disease would not be possible, and instead adopted a strategy of containing the disease to reduce its spread. Symptoms of the disease on larch trees include dieback of the tree’s crown and branches, and a distinctive yellowing or ginger colour beneath the bark. In August 2010, disease was found in Japanese larch trees, in Counties Waterford and Tipperary in Ireland.

The closely related Phytophthora kernoviae causes similar symptoms to P. ramorum, but infects the European beech.

Crown Rot, Collar Rot, Root Rot, Stem Rot

Phytophthora Spp. including,
P. ramorum, P. cactorum, P. cinnamomi, P. palmivora, P. citricola, P. nicotianae, P. ramora

World wide.

The pathogen survives in soil for several years as spores, especially in poorly drained soils. Too deep planting may contribute to the severity of this disease. Cool, wet weather favors development of the disease in the spring.

Phytophthora is a Soil borne fungal pathogen. Cankers may be seen at or below the soil line and may extend into the root system.  The infection can also invade the trunk or main stem.  Susceptible scions can be infected at the bud union. Infected bark is brown and often slimy when wet. When the bark is pulled away, the cambium and phloem will be an orange, reddish brown color. The cankers caused by the fungus girdle the tree, resulting in poor vegetative growth and chlorotic foliage that may turn purple in the autumn. A severely infected tree may die. Trees may be killed in one growing season or may linger for a number of growing seasons.

This fungus survives cold weather and drought as thick walled resting spores (oospores) in infected tissue or in soil. The resting spores are capable of surviving extended periods of time in soil. The fungus may build up to high levels in the soil in a short period under favorable conditions – i.e. during wet, cool periods. Under moist conditions, they germinate, forming another type of structure called a sporangium. A sporangium is a minute reproductive structure produced by the fungus in response to free water. The sporangia germinate in the presence of free water, releasing numerous one-celled, motile spores called zoospores. Zoospores swim through a thin film of water, contact roots or lower trunks of potential hosts, germinate, and infect. Although host wounds are frequent infection courts (areas where infections are initiated), the fungus can also directly penetrate host tissue. The fungus grows through host vascular tissue eventually girdling the tree. As the host dies, the fungus forms resting spores in the decaying tissue. Research revealed that the fungus is readily transported in irrigation water. Few agricultural soils should be considered free of the fungus once they have been irrigated. Infection is most likely to occur during cooler weather, i.e. early spring and fall. Research has indicated that trees are most susceptible during the bloom period.

Atropellis apiculata   (fungus)
A. arizonicum, A. pinicola, A. piniphila, A. tingens

Pines tahe are affected include, A. apiculata (Virginia pine), A. arizonicum (ponderosa pine), A. pinicola (Austrian, lodgepole, Scots, sugar, eastern white, and western white pines), A. piniphila  (Bishop, jack, loblolly, lodgepole, ponderosa, shortleaf, Virginia, western white, and whitebark pines), A. tingens  (Austrian, cluster, jack, loblolly,  lodgepole,  pitch, pond,  ponderosa, red, Japanese red, sand, Scots, shortleaf, slash, Table Mountain, Virginia, and eastern white pine).

These diseases are found throughout the continental United States.

Contibuting to the spread are poor sites and overcrowding.

Symptoms vary with species, region, and site. “Flags” of brown needles appear throughout thin crowns. Partially girdled branches appear healthy, but die after complete girdling. Perennial cankers are almost oval, the bark usually remaining on their faces. Surrounding tissue becomes sunken with little shriveling and no separation. “Target” cankers usually result. Beneath the face of the canker is a characteristic blue-black discoloration of the wood and masses of cup-shaped fruiting bodies (apothecia). Young trees are attacked most severely.

Ascospores dispersed by wind during summer and early autumn invade branches and twigs through wounds. A telltale mark of tiny brown spots, each with a drop of resin, is left at each invasion site. Dark brown mycelium permeates the sapwood to cause a blue-black stain. Eventually,  apothecia  develop singly or in groups and release  ascospores within. This process continues annually as the canker expands.

Pine Bark Beetles (conifers)



Ips spp. And Others (beetle)

Their larvae are very small (3/16 in. long when mature) and white, while adults are 1/10-3/8 in. long; red brown to black, shiny with parallel sides; 3-6 spinesat ends of wings.
 Tunnels or gallaries are curved, S-shaped, or inverted-Y, tortuous or straight and parallel.
 Many various pines, Douglas fir, fir, and spruce are their host trees.
Found throughout the United States: Alaska, east, southeast, Canada, British Columbia, Quebec to Nova Scotia.
Poor site, drought, injuries, nutritional deficiencies will attract them to weakened trees.
 Dieback occurs on the upper terminals and laterals branches tunneling under the  bark with egg galleries with 3 or more larval mines issuing from each egg pocket.
The rapidity of development and number of generations varies with different seasons and localities. Usually 1-3 summer generations and 1 overwintering. Overwinter as adults, larvae, or pupae beneath the bark of trees killed the previous season. Attacks may be primary or secondary.

Conifers  (AKA..Pine Bark Beetles)
Ips spp. (beetle)

Their larvae are very small (3/16 in. long when mature) and white, while adults are 1/10-3/8 in. long; red brown to black, shiny with parallel sides; 3-6 spinesat ends of wings.
Tunnels or gallaries are curved, S-shaped, or inverted-Y, tortuous or straight and parallel.

Many various pines, Douglas fir, fir, and spruce are their host trees and found throughout the United States: Alaska, east, southeast, Canada, British Columbia, Quebec to Nova Scotia.

Poor site, drought, injuries, nutritional deficiencies will attract them to weakened trees.

Dieback occurs on the upper terminals and laterals branches tunneling under the bark with egg galleries with 3 or more larval mines issuing from each egg pocket.

The rapidity of development and number of generations varies with different seasons and localities. Usually 1-3 summer generations and 1 overwintering. Overwinter as adults, larvae, or pupae beneath the bark of trees killed the previous season. Attacks may be primary or secondary.

PINE NEEDLE SCALE
The pine needle scale is considered a key pest of pines in landscapes, nurseries, and Christmas tree plantations in Pennsylvania.

HOSTS:
mugo pine, P. mugo; Austrian pine, Pinus nigra; red pine, P. resinosa; Scots pine, P. sylvestris; eastern white pine, P. strobus; Douglas-fir, Pseudotsuga menziensii; most spruces, Picea spp.; and cedars, Cedrus spp.

IDENTIFACATION:
Crimson red eggs are apparent in early spring beneath the female’s white waxy cover. The waxy cover (Image 2) of the female is about 3 mm long, white with a yellow tip at the narrowed front end (Image 3). The waxy cover of the male is white and only 2 mm long. Adult males are small winged insects that resemble tiny parasitic wasps, but they only have one pair of wings with very few veins. The crawler stage of this armored scale insect is reddish.

LIFE CYCLE:
This pest overwinters as females and eggs beneath the waxy cover of the female. As many as 40 eggs may be found under each scale. In mid-to late May these hatch into crawlers which move over the needles for a few days and then settle down to feed. After settling down, they secrete the characteristic waxy covering over their bodies. These scales usually reach maturity by early July. Males emerge, mate with the females, and then die. A second generation of eggs is laid in mid-July; these scales mature in September.

DAMAGE:
This species removes plant fluids from needles with their piercing-sucking mouthparts, causing them to turn yellowish brown. A severe infestation may cause a reduction in plant health, sparse foliage, and death of infested twigs. The foliage of severely infested trees may take on a white-washed appearance.

Fusarium moniliforme var. subglutinans (fungus)

 Pine trees susceptible include Bishop, eastern white, loblolly, longleaf, Monterey, sand, Scots, shortleaf, slash, Table Mountain, and Virginia pines.

Regions affected include, Southeastern United States, California, Texas.

 Factors that contribute are, Physical wounding (including lawn mowers, weed-eaters, and climbing spurs), insects (tip moth, midge, bark beetles, deodar weevil) which may serve as vectors, and other fungus infections (eg. gall rust).

 Symptoms of pine pitch canker include, resin-soaked lesions around wounds, girdling twigs and small branches; developing into perennial cankers on trunks and large branches. Bark remains on canker faces. Diseased bark reddish-brown; underlying sapwood is yellow-brown and impregnated with resin. Resin exudes from lesions and cankers to run down bark or onto foliage below. Shoot dieback, tip wilting, and branch incurving (“shepherd’s crook”) follow.

 Macroconidia produced on small, cushion-like, salmon-colored sporodochia (approximately 1/16 in. wide and 1/32 in. high) on dead shoots and twigs, generally on needle fascicle scars. They are present all year, but most evident in autumn and winter. Conidia are colorless, having from 1 – 4 cells, curved, elongate, and pointed; disseminated by wind, insects, and splashing water throughout the year.

Cunninghamella meinickella (fungus)

Pine trees found to be infected include. Jeffrey, Monterey, and ponderosa pines.

Nutrient abnormalities, crowding, poor sites, basal or root wounding are main contibutating factors.

Found mainly in California.

Symptoms include, needles fade to whitish green, becoming yellow to brown, falling prematurely. Exudation of yellow pitch on roots and root collars. Occurs near old stumps. Infected trees are weak and predisposed to bark beetle infestation.

This fungus is completely soilborne as a common soil saprophyte. Infection generally occurs from germination of small spiny spores which attach to the bark. During spring thaws or rains they germinate and grow into any small wounds, entering and eventually invading the phloem and xylem, blocking the flow of nutrients. The tree responds with a copious flow of pitch at the point of invasion.