Tree pest of Gum trees

How healthy are your trees is your trees showing signs of stress are they been attached by a pest/insect. Some tree Pest such as below can damaged and kill your trees if not treated. Thaumastocoris peregrinus, Winter Bronzing Bug is a pest of narrow leafed Eucalytpus trees. It is a cytosol feeder of tree leaves, which means it feeds on the inside material of the tree’s leaves. The symptoms of insect attack are that the tree leaves turn a bronze colour. This tree insect pest can be part of the cause of decline in the tree health of Eucalytpus scoparia a tree in the Sydney basin. Hymenoptera Perga dorsalis, Sawfly larvae If you're out in the bush or a local park during winter, you're likely to happen across a group of 'spitfires' clinging to the branch of a gum tree in the cold. These insects are technically called sawflies, a group of insects closely related to wasps. There are more than 200 species of sawfly in Australia, but the local species is the Steel Blue Sawfly (Perga dorsalis). The name 'sawfly' derives from a 'sawbench' under the abdomen of the female with which she lays eggs. Female wasps, in contrast, use a pointed ovipositor to lay eggs and in some species this doubles as a sting – adult sawflies do not sting and both adults and larvae are completely harmless. Female sawflies use the sawbench to cut the upper surface of a tree leaf and deposit 60-70 eggs into the leaf tissue. The larvae hatch and feed on gum leaves, grouping together for protection in a rosette pattern, similar to the head-outwards stance adopted by Bison when under attack. This is known as a 'ring defence', or cycloalexy. As the larvae grow, they collect in larger groups around branches during the day and spread out to feed at night. Like their cousins, the ants, bees and wasps, sawflies show some social behaviour but only in a primitive way. When feeding at night, larvae tap the branch to keep in constant communication with each other. If an individual becomes lost, it will tap more rapidly until it receives an answer from the rest of the group – if an individual becomes completely separated it will not survive long on its own. The activities of a group of sawfly larvae are governed by a few select individuals that become in effect the leaders of the group. They lead the rest out to feed at night and, if they run out of food, lead the group across the ground to other trees. When large numbers of sawfly larvae are present they are able to defoliate small gum trees, but in general are not a major pest. When ready to pupate, the larvae leave the host tree and burrow down to make mass cocoons in the soil. Here they sit through spring and summer to emerge in early autumn. Adults have no mouthparts and do not feed, living only for a week or so. Not all emerge, however, as many succumb to parasitic flies. These flies, about the size of a blowfly, will lay eggs in the sawfly larvae and the fly maggot literally eats its host from the inside out, eventually emerging from the sawfly's cocoon. . Sawfly larvae have an unusual defensive mechanism that has given them the name 'spitfires'. They store eucalyptus oil in a small sac in their gut, and regurgitate this oil when under threat. Despite their nickname, they are unable to actually spit this fluid and the oil itself is harmless unless eaten (like all eucalyptus oil). In fact it has a very pleasant eucalytpusy smell. Australia is one of the main strongholds of Symphyta, the suborder of insects to which sawflies belong. The Steel Blue Sawfly is one of the few insect species active in Victoria abd NSW during winter, so next time you're in the bush take the time to stop and smell the sawflies. References: Museum Victoria 2012 https://museumvictoria.com.au/about/mv-blog/.../bug-of-the-month-steel-blue-sawfly/ If you are concerned about your trees’ health please contact an Arborist such as Fred Janes at Angophora Consulting Arborist. A level 5 arborist (AQF level 5), qualified in the latest techniques using the International Arborist Associations’ Tree risk Assessments Qualifications (TRAQ). Fred and his team can provide professional advice on how to mitigate the risk and allay any fears that you may have.

Trees and developments

DA Development Applications and Trees: when many people are submitting a Development Application (DA) most consider building plans, site survey and maybe a Landscape plan. Many builders, architect owners forget about their trees and trees in neighbouring properties. If you’re new construction is going to impact on any trees roots root zone either on your property a Neighbouring property including council nature strip you will be required to submit an Arboricutural report/Tree Impact statement prepared by a AQF level 5 Arborist. The development as proposed appears to impact on the root zone of a large canopy tree. Where trees are located within 5 metres of the proposed works, a report from a qualified AQF5 arborist is required which assesses all trees and determines their health, condition and Safe Useful Life Expectancy and specifies tree protection measures where applicable. Reference should be made to retention and management of vegetation provisions in Clause 53 of LEP 2005.” (BMCC) The Arborist/Tree report for Development Application, DA will need to look at the tree Species its health and structural condition, its age, its dimensions the trees Safe Useful Life Expectancy (S.U.L.E) and the Tree Protection Zones (TPZ). The TPZ should be based on the Australian Standard Protection of Trees on Development sites AS 4970-2009. This standard describes the best practice for the planning and protection of trees on development sites. This is based on plant/tree biology and current best practices. Fred Janes AQF level 5 at angophora Consulting Arborist has assisted many Architect builders and home owners in developing a Tree Management Plan for their construction sites. For any or more information please contact me by phone 0418 966 488, e-mail info@angophoraarborist.com.au or leave or leave a message on face book or web page and I will contact you (If you do contact by Facebook or webpage please leave a Phone number and best time to call).