Forest Insects Essay, Research Paper

Forest Insect

BALSAM WOOLLY ADELGID ( Adelges Piceae )

Today & # 8217 ; s woods are under a uninterrupted compound of physical emphasiss. In North America illustrations of this are apparent in all parts, whether it be the subjugation of Great Lakes woodland & # 8217 ; s to acid precipitation, the entry of 100s of 1000s of forested estates out west to fire of the ruinous degree, or one-year itinerant moth defoliation of full mountain sides in north cardinal Pennsylvania. These dangers are out at that place and they are merely a smattering of the prospective damaging agents that exist in forested countries.

The focal point of this term paper will be on the nature and features of an insect that inhabits a cone-bearing species of North America. Adelges piceae, normally known as the balsam woolly adelgid/aphid, exists by agencies of a parasitic relationship with specific trees native to the United States and Canada. The insect is a detrimental factor that must be dealt with before it claims victims our cone-bearing woods and ecosystems can & # 8217 ; t live without.

Adelgis piceae was by chance introduced to North America from Europe and has become an of import plague of true firs ( Abies sp. ) . The scope of the adelgid includes all of the Maritime Provinces, New England, down through the Appalachians, and is found throughout the Pacific Northwest. Currently it devastates bases of subalpine fir ( Abies lasiocarpa ) and severely affects growing of Ag fir ( Abies amabilis ) in many countries. This insect is now an urban plague of cosmetic firs and a major Christmas-tree plantation job, particularly with Fraser fir ( Abies fraseri ) turning in the Appalachians ( Edmonds, 2000 ) . Presumably it is capable of distributing over much of the scope of its host. Although, the aphid by and large does non survive temperatures below -34 grades C, but may prevail at lower temperatures on the lower parts of tree boles protected by snow ( Harris, 1978 ) .

A summarized life history of Adelgis piceae would read as follows. The immature adelgid ( nymph ) over-winters on the bark of trees. Depending on climatic conditions, the nymph will come out of hibernation in late April to early May. By July the nymph reaches maturity and begins puting eggs. Females, there are no males, may put over 200 eggs throughout a six hebdomad period ( Harris, 78 ) . The adelgid that hatches is called a sycophant and represents the merely nomadic phase of the insect & # 8217 ; s life. The dark purple to black nymph is really little and is blown about the air current as it moves about on the tree. This is how the insect spreads to other trees.

While in the sycophant phase, the nymph hunts for a desirable location to settle down and provender. When a favourable location is found, the adelgid attaches itself to the tree by infixing its long mouthparts into the life bark. Once it is attached and begins feeding, it becomes sedentary and starts releasing the white waxen stuff that covers it & # 8217 ; s organic structure.

In late September and early October the 2nd coevals matures and begins puting eggs. It is the nymphs that hatch from these eggs that attach themselves to the bark and hibernate during the winter, puting the following seasons eggs the undermentioned July. Two coevalss are common in most countries, but every bit many as four coevalss may o

ccur in lowland vales ( Holtrop, 95 ) .

The aphid sucks the sap from the populating bark of the tree. As it feeds, it injects spit, which causes increased tissue growing of the tree. This tissue growing consequences in differing harm depending on the location of the hurt. Infestations of the tree most frequently occur in the undermentioned locations: under lichens or in clefts on the bark of chief roots or big subdivisions, along branch nodes of roots in the Crown of the tree, and around new growing buds of branchlets ( Holtrop, 95 ) .

Heavy infestations on the bole and chief subdivisions are milky, looking as a mass of bantam cotton balls or spots of wool. The adelgid hurt on the bole obstructs the flow of H2O and foods between the roots and Crown of the tree. It is noted by Mr. Harris that swelling may besides happen, but this normally goes unnoticed because the tree dies within two to three old ages.

Damage to the buds and Crown is more obvious. Enlarged and contorted roots and branchlets stand out from the healthy 1s as leaf dies out. Buds are killed or growing is inhibited by the adelgids, and as old acerate leafs are shed they are non replaced by new growing. Holtrop notes that as a consequence the tree becomes progressively thin, and that this type of harm may prevail for many old ages before the tree dies.

Direct control of the Adelgis piceae in forest bases is impractical by methods known at nowadays. High value trees in Parkss and baby’s rooms can be treated successfully with insect powders if all above-ground parts of trees can be exhaustively drenched. This International Relations and Security Network & # 8217 ; T to state that there is no hope for septic forest bases. Losingss in forest bases can be minimized by intensive film editing of trees of the genus Abies before serious tree mortality occurs and before deceasing trees become unsuitable for salvage.

Of premier concern is the bar of spread to uninfested countries. Strict ordinance of tree motion will assist to curtail infestation spread. It should besides be noted that several species of imported predaceous insects have non been successful in cut downing the job ( Harris, 78 ) .

In decision, I would wish to explicate what foremost turned me on to the idea of researching this insect. This past summer I took a hebdomad & # 8217 ; s holiday to The Great Smoky Mountains National Park in Tennessee and North Carolina. I was stunned by the copiousness of wildlife and flora nowadays throughout the park and was amazed at how healthy and vigorous each species appeared to be. Then we hiked to the highest point in the Smokies, Clingman & # 8217 ; s Dome.

It was apparent instantly that something was impacting the trees environing the 6,700 pess tall work of nature. Upon farther probe, I was informed that it was the fir trees, Frasier fir to be specific, that lined the versants with their decaying remains. My initial reaction was to cuss a common marauder of our cone-bearing species present at higher lifts, acerb rain. To my surprise though, I subsequently read that it wasn & # 8217 ; t the acerb precipitation claiming the lives of the brilliant firs, it was the balsam woolly adelgid. An insect less than 2mm long was responsible for the death of 100s of old-growth Frasier firs. At that minute I felt the thirst for cognition and I have now quenched that thirst through the authorship of this paper.