Why kill melaleuca tree

Today, Florida spends large amounts of money and resources each year to protect and preserve our wild wetland habitat. One of our most prominent plant invaders, however, was originally introduced to Florida in a deliberate attempt to destroy swamp habitat. The Melaleuca Tree is a member of the myrtle family, Latin name Myrtacea. There are about species in the Melaleuca genus, found mostly in Australia but also extending into Malaysia and some of the Solomon Islands.

The species that concerns us is Melaleuca quinquenervia. In its native Australia, it is known as the paperbark, the tea tree, or the punk tree. In appearance, it is a smallish tree, about feet high, with lance-shaped evergreen leaves, bottle-brush clusters of flowers, and its most prominent feature—a light-colored bark that peels extensively from the trunk, making it look something like an American birch tree. The leaves contain camphor and smell like medicine when crushed.

The oil from a closely related tree, M. In its native Australia, the Melaleuca grows along waterways and marshes. It produces an immense quantity of fruits and seeds, which make it a valuable food source for birds and fruit-eating bats. It is often intentionally planted as a nectar source for beehives, and is also widely used as an ornamental tree or windbreak. Because Melaleuca uses large quantities of water, it is not commonly found in the large dry Outback areas.

In some parts of Australia the tree is being threatened by loss of its habitat through development, and conservation measures are being taken to protect it.

One idea was to plant lots of Melaleuca trees, which would then take up large amounts of water through their roots and respire it away through their leaves, helping to dry up the swamps. By the Australian trees were a common sight in South Florida. Since they grew so rapidly, they were also planted in parks and backyards as ornamentals, along canals and ponds as support props for banks, and some were commercially grown for their wood. It turned out to be a disaster.

With no natural checks on their growth, the trees exploded, quickly invading nearly the whole of south Florida. Larvae are most damaging, feeding on one side of a leaf through to the cuticle on the opposite side, which produces a window-like feeding scar Fig.

This damage may persist for months, ultimately resulting in leaf drop Fig. Adult feeding on young and mature leaves is characterized by holes Fig. Oviposition occurs mainly during daylight hours from September to March in Florida Center et al. Eggs are laid singly, or in small clusters, on the surface of young leaves, usually near their apex, or on stems of young shoots. A hardened black-to-tan coating of frass and glandular materials covers individual eggs.

In Florida, larvae are absent or uncommon from April to August unless damage-induced regrowth is present Center et al. Pupation occurs in the soil, usually beneath the host plant. Egg-to-adult development requires about 50 days. Females survive up to 10 months and can produce more than 1, eggs. Adults can be collected year round.

The Melaleuca psyllid, B. Melaleucae , severely damages M. Nymphs are parasitized by Psyllaephagus sp. Hymenoptera: Encyrtidae and preyed on by coccinellids Coleoptera and lygaeids Hemiptera in Australia. This psyllid was collected in northern and southeastern Queensland and northern New South Wales during field surveys in Australia.

Collection records also exist for Western Australia and the Northern Territory. Psyllids, both adults and nymphs, reportedly feed on phloem sap through the stomata Clark, ; Woodburn and Lewis, ; however, nymphs cause the most damage by inducing defoliation and sooty mold growth on excreted honeydew. Populations of B. Melaleucae grow rapidly, causing moderate leaf curling, discoloration, defoliation, and plant mortality.

Adults of B. Melaleucae mate throughout the day and the male grasps the female with large abdominal claspers parameres before mating. Females oviposit on leaves or stems of host plants and lay an average of 78 eggs. Each egg is attached to the leaf by a pedicel that is inserted into the plant tissue to absorb water White, Most eggs hatch within 18 days.

Nymphs of B. Melaleucae congregate on leaves and secrete white, flocculent threads, which can completely cover the nymphs. These secretions facilitate easy detection at field sites. Like all psyllids, B.

Melaleucae has five instars Hodkinson, and development from egg to adult takes 28 to 40 days. Purcell et al. The defoliating melaleuca sawfly, L. Records also indicate its presence in New Guinea Smith, Larvae are voracious leaf feeders and dense populations cause complete defoliation. Defoliation stresses trees and reduces flowering during subsequent years Burrows and Balciunas, Adults do not feed on the plant tissue.

They are frequently observed swarming around the bases of trees. Larvae burrow into the papery bark of M. It therefore should be an excellent agent for use in wetter areas, where other agents are less effective. Females are parthenogenic, producing all males when unmated, while mated females produce both males and females. Burrows and Balciunas provide a detailed description of the life history of L.

The life cycle from egg to adult takes approximately 12 weeks. Females insert eggs into the tissue along the edges of leaves using their saw-like ovipositors. The subsequent egg batches form a line along the leaf margin, and harden and turn brown with age. Females oviposit up to eggs in their lifetime, which are heavily parasitized in Australia. The neonate larvae feed gregariously, forming a feeding front across the leaf; later instars become solitary feeders.

Three unidentified fly species Diptera: Tachinidae and one wasp species Hymenoptera: Ichneumonidae parasitize larvae. The final instar, or prepupa, does not feed and burrows into the bark of the trunk and lower branches to excavate a chamber in which it enters the pupal stage. In Australia, L. Larval outbreaks also occasionally occur during cooler months.

The toxic peptides lophyrotomin and pergidin, which have been reported in three other sawflies from around the world Oelrichs et al. Consumption of large quantities of larvae of a related sawfly from Eucalyptus sp. Therefore, the decision to release L. Preliminary data indicate that the nematode initiates gall production Giblin-Davis et al. Fergusonina sp. Galls on M. They have the potential to impede branch and foliage growth, and retard flower formation resulting in reduced seed set.

These galls also may act as nutrient sinks, reducing plant vigor Goolsby et al. However, the gall production is seasonal, with highest densities occurring during periods of maximum leaf bud production, usually during winter and spring Goolsby et al. The flies are heavily parasitized by several species of parasitic Hymenoptera in Australia.

Grossenbacher and Duggar first described B. Taxonomy, biology, and ecology of this fungus are discussed in Punithalingam and Holliday , Morgan-Jones and White , and Rayachhetry et al. The mode of entry into stem tissues is assumed to be through wounds, frost-induced cracks, sun-scorched bark, lenticels, or branch stubs. Stems of healthy plants callus rapidly, and the fungus may remain latent under the callus tissues, causing perennial cankers when trees are stressed.

Infected plants may die back, show vascular wilt, or crown thinning. Affected vascular tissues usually appear brown to black in color Rayachhetry et al.

Puccinia psidii , commonly known as guava rust, has been reported on 11 genera and 13 species in the family Myrtaceae in Central America, Caribbean Islands, and South America Laundon and Waterston, ; Marlatt and Kimbrough, In , P. Figueiredo et al. Alston, and reported three spore stages uredospore, teliospore, and basidiospore in its life cycle.

Only uredinial pustules have been observed on M. No alternate host has been discovered and it is assumed to be autoecious Figueiredo et al. Guava rust attacks both foliage and succulent stems of vigorously growing M. Rust disease on M. Severe infections cause foliage distortion, defoliation, localized swellings on twigs, and tip diebacks Rayachhetry et al. Oxyops vitiosa is now established at many locations in south Florida where larvae or adults were released; however, rate of spread is limited Center et al.

Slowly expanding O. Habitats with short hydroperiods, dry winter conditions, and abundant young foliage favor growth and development of O.

Oxyops vitiosa populations did not establish in permanently aquatic sites because of the soil requirement for pupation Center et al.

Dispersal occurs more rapidly at sites where the trees are scattered savannah-like in open areas. Other factors such as geographical location, hydroperiod, wind direction, life stage released, or date of release do not affect the rate of overall dispersal Pratt, unpub.

Also, adults seem to move from unsuitable trees tall, dense stands with a paucity of young foliage onto trees that provide acceptable foliage smaller, bushier, open-grown trees with an abundance of young foliage Center et al. Oxyops vitiosa adults feed on both old and new foliage as well as on emerging vegetative and reproductive buds Fig. Early instars feed only on young succulent foliage, while late instars are less discriminating Fig. Adults feed on both young and mature leaves Figs.

Severe adult or larval feeding results in tip dieback and defoliation Fig. Repeated damage of growing tips removes apical dominance and induces lateral growth from axillary buds. Subsequent new growth acts as a nutrient sink and sustains continual adult and larval weevil populations. Foliar damage, and the subsequent diversion of photosynthetic resources to the development of new foliage, appears to limit reproductive performance of M.

In preliminary studies, flowering of severely damaged M. As a result, existing populations decline as their regenerative capabilities become reduced. The diverse community of insects that damage M. Similarly, the viability 9. The reduction in seed production, and thus the invasibility of M. While removal of existing stands may be best accomplished by other means herbicides and mechanical removal , a reduction in canopy seed production through biological control should enhance the efficacy of the overall management program Laroche, The diversity and abundance of native plant species in areas invaded by M.

Long-term monitoring programs have been initiated by establishing permanent plots in M. Currently, the M. Additional quarantine space is needed to improve and accelerate host testing of additional agents. Construction of a new facility designed for this purpose began at Fort Lauderdale during December The primary focus of the Fort Lauderdale Invasive Plant Research Laboratory has been the release of new agents as they become available, and the evaluation of those agents that establish.

To combat the M. Because M. In addition to O. Melaleucae which have already been released, other insects are either waiting for field-release permission or undergoing evaluation in Australia or in U. Therefore, evaluation of the performance of released agents in the field and their relationship with predators and pathogens in Florida should continue with special emphasis on 1 measuring changes in the reproductive potential of existing trees and monitoring for signs of population decline and habitat recovery; 2 assessing the impact of predators, parasitoids, and pathogens on the released biological control agent populations; 3 monitoring other plant species to validate host specificity research and determine whether non-target effects occur; and 4 developing and integrating selected fungal agents into the suite of herbivorous biological control agents.

Alfieri, S. Langdon, J. Kimbrough, N. El-Gholl, and C. Diseases and Disorders of Plants in Florida. Bulletin Allen, Jr. R Sinclair, and J. Evapotranspiration of vegetation of Florida: perpetuated misconceptions versus mechanistic processes.

Alexander, T. Hofstetter, and F. Comparison of transpiration of cajeput Melaleuca quinquenervia and sawgrass Cladium jamaicense. Florida Scientist 40 Suppl. Austin, D. Exotic plants and their effects in southeastern Florida. Environmental Conservation. Balciunas, J. Burrows, and M. Insects to control Melaleuca I: status of research in Australia.

Aquatics 16 4 : Field and laboratory host ranges of the Australian weevil, Oxyops vitiosa Coleoptera: Curculionidae , a potential biological control agent for the paperbark tree, Melaleuca quinquenervia. Biological Control 4: Aquatics 17 2 : Barlow, B.

Contribution to a revision of Melaleuca Myrtaceae : Brunonia 9: Patterns of differentiation in tropical species of Melaleuca L. Proceedings of the Ecological Society of Australia Blake, B. A revision of Melaleuca leucadendron and its allies Myrtaceae. Contributions from the Queensland Herbarium , No. Bodle, M. Ferriter, and D. The biology, distribution, and ecological consequences of Melaleuca quinquenervia in the Everglades, pp.

In Davis, S. Ogden eds. Everglades: The Ecosystem and Its Restoration. Boland, D. Brooker, G. Chippendale, N. Hall, B. Hyland, R. Johnston, D. Kleinig, and J. Forest Trees of Australia. Nelson Wadsworth, Publ. Buckingham, G. Quarantine host range studies with Lophyrotoma zonalis , an Australian sawfly of interest for biological control of melaleuca, Melaleuca quinquenervia , in Florida, U.

Biocontrol Burrows, D. Biology, distribution and host-range of the sawfly, Lophyrotoma zonalis Hym, Pergidae , a potential biological control agent for the paperbark tree, Melaleuca quinquenervia. Entomophaga Host-range and distribution of Eucerocoris suspectus Hemiptera: Miridae , a potential biological control agent for the paperbark tree Melaleuca quinquenervia Myrtaceae. Environmental Entomology Center, T. Van, M. Rayachhetry, G. Dray, S. Wineriter, M. Purcell, and P. Field colonization of the Melaleuca snout beetle Oxyops vitiosa in south Florida.

Biological Control Clark, L. The general biology of Cardiaspina albitextura Psyllidae and its abundance in relation to weather and parasitism. Australian Journal of Zoology Source s : Ken Langeland kal ifas.

View Photo. Control measures for the troublesome tree will be demonstrated for residents and other land managers at eight South Florida sites in Broward, Collier, Hendry, Lee and Palm Beach counties. Langeland, a specialist on aquatic and invasive plants, said the tree invades moist, open habitats, forming dense, often impenetrable stands of trees. Native wildlife is threatened because the tree crowds out beneficial native plants.

By the early s, only 50 years after it was introduced, melaleuca had spread over hundreds of thousands of acres. In , it was found in Everglades National Park, and by it covered , acres in South Florida.