Insects and Diseases Envirothon Training Glenn “Dode” Gladders

Symptoms vs. Signs Symptoms  Changes in the plant’s appearance that indicate something is happening. Ex: crown dieback, wilting, cankers. Signs  Indications of the insect or disease itself. Ex: frass, pitch tubes, fungal fruiting bodies.

The Envirothon Five Know these 5: 1.Emerald Ash Borer 2.Asian Longhorned Beetle 3.Southern Pine Beetle 4.Gypsy Moth 5.Sudden Oak Death For each, know: 1.Native/non-native 2.Present in Delaware? 3.Host species 4.Symptoms & Signs 5.Type of damage 6.Control measures

Emerald Ash Borer This non-native beetle has not been found in Delaware. It is a major pest in the northern Midwest. It creates galleries in the cambial layer of infested ash trees, girdling the tree. Adults are bright green and easy to identify.

Emerald Ash Borer galleries D-shaped exit hole Crown dieback

Asian Longhorned Beetle This beetle was imported from China in wooden pallets. It has been found in New York, New Jersey, and Chicago. ALB represents a major threat to numerous types of trees, particularly the maples.

Asian Longhorned Beetle The beetle develops within the xylem (wood) and then bores its way out. Eventually the many exit holes will destroy the phloem and kill the tree.

Asian Longhorned Beetle Large exit holes are conspicuous signs of ALB infestation.

Asian Longhorned Beetle Infested trees must be removed, and chipped to destroy all beetles.

Asian Longhorned Beetle Infestations are dealt with very seriously. All host trees in the “core” zone are chipped and replaced with non-host species. A quarantine is placed on the movement of plant materials from the infestation zone.

Asian Longhorned Beetle Packing materials are inspected at ports of entry.

Southern Pine Beetle Like EAB, this beetle carves galleries which girdle and kill trees. Unlike EAB, it is native. Delaware is at the northern end of its distribution. It can be a problem in our State but is a much more serious pest in the South.

Southern Pine Beetle Infested stands can be detected with aerial surveys. Infested pines display brown foliage.

Southern Pine Beetle Small round exit holes S-shaped galleries Pitch tube

Southern Pine Beetle Infested trees can be cut and burned, chipped, or sprayed.

Southern Pine Beetle Adults can be lured into traps using pheromones and turpentine. This can be helpful for detection as well as control.

Gypsy Moth This non-native insect was introduced into Massachusetts in Since then it has spread throughout the northeast, including Delaware.

Gypsy Moth Host trees are damaged through defoliation. Larvae feed on the leaves of many broadleaved species, particularly the oaks.

Gypsy Moth The damage is done by the larvae.

Gypsy Moth Pure oak stands can be completely defoliated.

Gypsy Moth When severe defoliation occurs several years in a row, widespread mortality can result.

Gypsy Moth Egg masses are easily seen in the fall. Adults can also be trapped using pheromone lures. These methods can assess the population and determine the need for a control program the following spring. Control is mainly through the use of a bacterial spray called Bt.

Sudden Oak Death (SOD) This non-native fungal disease has not been found in Delaware but has been introduced into several eastern States from California. It could affect many species in Delaware, including the red oaks, which are valuable for timber and wildlife. We are currently surveying for this disease.

Sudden Oak Death (SOD) Symptoms of the disease in oak trees include bleeding, oozing cankers. Later, leaves suddenly turn brown. Eventually, cankers girdle the tree.

Sudden Oak Death (SOD) Symptoms on many landscaping plants include brown leaf spots and twig dieback.

Sudden Oak Death (SOD) Quarantines are in place to prevent the transport of infected plant materials from California to other States. We began surveying for SOD this year and will intensify the survey grid in The introduction of SOD would have serious implications for Delaware’s forests as well as urban landscaping.

Sudden Oak Death (SOD) There is no “control” available in areas that are generally infested (parts of California). In other areas, the focus is on prevention and quick response after detection. Cut, pile, and burn is an accepted prescription in new detection areas.