Week 4 - Day 19 - Timber Pests

ESSENTIAL READING BEFORE COMMENCEMENT OF COURSE:

Urban Pest Management in Australia: 2004 Edition, UNSW Press, Sydney

by J Gerozisis and P Hadlington - Chapter 19 - Pages 221 to 240;Chapter 20 - Pages 241 to 249;Chapter 21 - Pages 249 to 255 .

Chapter 19 – Termites - classification - behaviour and castes - colonies - ground mound - arboreal mound or tree nest - pole nest - subterranean nest - tree wood - biology - castes - the queen - macropterous queen - supplementary queens or neotenics - the king - workers - soldiers - reproductives - nymphs - caste determination - colonising flight - food - moisture and temperature - common termite species - family mastotermitidae - giant termite - family kalotermitidae - west indian dry-wood termite - ring ant termite - family termopsidae - dampwood termite - family rhinotermitidae - heterotermes ferox - schedorhinotermes spp. - family termitidae - microcerotermes turneri - compass termite - nasutitermes spp. - control of termites

Chapter 20 – Fungal Decay - the fungi - the life cycle of fungal decay - the decay fungi - brown rot fungi - white rot fungi - soft rot fungi - frequency of rot types in service - requirements of decay fungi - the role of water in fungal decay of wood - sources of water - ground water - detection of decay in subfloor timbers - some specific fungi - mould fungi - sapstain fungi - the  dry rot fungus - clarification of frequently used terms - rising damp - prevention of decay - durability of timbers - detection of the cause of dampness and decay - subfloor ventilation - rising damp - subfloor drainage - further issues relating to subfloor ventilation - the use of preservatives and preservatised timbers - equipment to assist during inspections

Chapter 21 – Miscellaneous Timber Pests & Effects - pests of decaying and decayed wood - dampwood borer - syndesus cornutus - pentarthrum australe - decay moths - carpenter ants - casual timber pests - sawflies - hide beetles - solitary beetles - defibration of timber - marine pests - common pest species - crustaceans - molluscs - prevention and control - use of resistant timber - use of metal sheathing - use of plastic coating - use of chemically treated timber - use of paints - use of floating collar - changing environment

Pest Species

Trees are subject to damage by means other than insect attack.  These means may take the form of ringbarking, by cutting with mower blades, building up of ground level at base of tree, fire, too severe lopping of branches, bad drainage, concreting or in some form altering the natural habitat of the tree. Insect pests which cause damage and sometimes the destruction of a tree can be grouped under the following headings:

• Leaf eating insects.
•  Sap sucking insects.
• Bark and wood damaging insects.
  

  Leaf Eating Insects
  Some of the main leaf-eating insects are:
  Gregarious Sawflies            (e.g.  Perga affinis affinis - steel-blue sawfly, P. dorsalis - steel-blue sawfly).
  The larvae of these insects form the repulsive looking clusters commonly seen during the day, congregated around a stem and, if brushed against regurgitate Eucalyptus oils which have been stored in a fore gut diverticulum.  They attack trees belonging to the genera Eucalyptus and Angophora.
  The female lays her eggs in the leaves of the host tree.  When the larvae hatch they feed upon the leaves of the tree during the night and remain ' in clusters during the day.  When fully fed they can attain the length of 50-75 mm. After approximately 3-4 months feeding they pupate in earthen cocoons in the ground.  On emerging, the adult wasp is a brightly coloured, active, day flying creature.  Under optimum conditions, one generation occurs per year.
  Attack is usually noticed in spring or early summer.  There are other sawflies which attack ironbark, Callistemon (bottle brush), tea-tree and Cypress pine.
  Leaf Blister Sawfly
  (Phylacteophaga spp)
  This pest attacks many eucalypt species and brush box.  The female wasp lays her eggs in the leaf.  The larvae on hatching feed between the leaf surfaces giving the impression of blistering.  The larvae feed for a period of up to 30 days and reach a size of 10-15 mm before pupating in the blistered leaf.  The pupae remain in the resting stage for 14 days before emerging as adult wasps 15-20 mm long.  There may be three to six generations per year.  Large trees are usually not severely affected.
  Cup Moths
  (Doratifera spp)
  These attack eucalypts, brush box and angophoras (native apples).  The name is derived from the cup-like pupal case from which the adult moth emerges. Eggs are laid on the leaves and for protection are covered by a furry substance.  The larvae are spiny caterpillars, which feed on the leaves for 2-3 months.  If handled or brushed against these spines cause a painful rash. The pupal stage of 2-10 months is spent in a cup-like pupal case on the stems of trees. There are usually two generations per year and attack is most prolific from spring to mid­summer.
  Christmas Beetles
  (Anoplognathus spp)

  The adult beetle is a bright metallic colour and seen in great numbers around lights at Christmas time.  As adults they feed on the leaves of various eucalypts. Eggs are laid in the soil and on hatching the larvae remain in the soil feeding on the roots of trees, plants, etc. for 6-9 months. Once fully-grown they pupate still in the soil for 1-3

  months from which they emerge as adult beetles. There is only one generation per year.
  (Paropsis spp & Chrysophtharta spp)

  Both the larval and adult stages feed on the leaves of eucalypts. The adult lays her eggs in batches on a leaf or in a rosette pattern around the stems.  On hatching the larvae feed on the leaves for 2-4 months until fully grown.  The pupal stage takes 1-12 months and is spent in the soil. There is usually only one generation per year.
  Case Moths
  (Hyalarcta huebneri & Hyalarcta nigrescens)
  Depending upon the species, these pests will attack eucalypts, brush box or Pinus species.  The adult moth lays her eggs on leaves or the bark. The larvae feed on leaves for three to six months, living in their case, which is often covered in twigs.  Once fully fed they pupate in their case for 2-10 months. There is normally only one generation per year. H. huebneri can be a serious defoliator of pines.
  Gumleaf Skeletonizer Moth
  (Uraba lugens)
  Eggs are laid by the female moth in masses on the surface of leaves of eucalypts or brush box. The larvae commence by eating the leaves leaving only a skeleton but when infestations are severe the entire leaf is eaten.  Length of time spent in the larval stage is usually 2-3 months. The pupal stage is spent in cocoons on the bark of the tree or under loose bark and occupies from 2-9 months.
  The hairs from the larvae can cause serious irritation if handled. In the larval stage they appear to have two or three heads, one upon the other, due to their habit of stacking empty head capsules onto the head of the larva. There are usually one to two generations per year.
  White Cedar Moths
  (Leptocneria reducta)Eggs are laid in clusters on leaves and stems of the white cedar, Melia azedarach. The larvae are greedy feeders and quickly defoliate trees, usually in autumn, leaving , bare tree to seek others on which to feed.  Two to three months is usually the time spent in the larval stage.  They are covered with irritating hairs and may reach 45 mm in length. The pupal stage of three to nine months is spent under bark or debris in the vicinity of trees. Due to their processional habit in seeking other trees, the larvae often become a problem on walls, ceilings, etc. of homes in their line of procession. There can be one or two generations per year.
  White Stemmed Gum Moth
  (Chelepteryx collest)
  These insects attack scribbly gum and brush box.  Eggs are laid on stems or in the pupal cocoon. The larvae are large hairy grubs up to 125 mm in length.  They feed on the leaves during the night and hide during the day.  The hairs on their body can cause irritating rashes when touched. The pupal stage is spent in a cocoon, which is attached to branches of the tree. There is only one generation per year.  They seldom cause serious damage. There are other leaf-eating insects but these are usually of lesser importance than those described.

  SAP SUCKING INSECTS

  Aphids
  (Various species eg.  Cinara juniperi - juniper aphid)

  Damage by aphids is usually associated with pine trees especially ornamental cypress pines.  The nymphs and adults pierce and suck the sap from the trees, causing extensive damage and often the death of the tree. Eggs are laid under the bark of the tree yet, in other instances, the young may be born alive. Aphids hide during the day on the tree but come out at night to feed.  Their habit of secreting

  honeydew will attract ants and will also cause the formation of black sooty mould. There can be one or two generations per year.
  Mealy Bugs
  (Various species eg.  Nipaecoccus aurilanatus Norfolk Island pine or golden mealy bug)
  These yellow banded insects are common pests of the Norfolk Island pine.  They are roundish in shape and 3-4 mm long. Eggs are laid on the foliage or branches of the tree.  The young and the adults feed upon the tree causing extensive damage.  Quite often they are controlled by the white larvae of a ladybird beetle. There is only one generation per year.
  Psyllids
  (Various species eg- Mycopsylia fici - Moreton Bay fig psyllid)
  Eggs are laid on the foliage and on hatching the young feed on the leaves giving them the appearance of being burned.  Premature leaf fall may occur.  Feeding is carried out between the surfaces of the leaf both by the young and adults. Eggs hatch in up to 30 days and the young mature in 2-3 months. There can be several generations per year.
  Leaf Hoppers
  These are insects belonging to the superfamily Cicadelloidea of the order Hemiptera.  These pests attack eucalypts and acacias.  Eggs are laid on leaves or stems and the young, on hatching, in company with the adults, feed on sap from the leaves and stems.
  The size varies from 3-7 mm and there are many differently coloured species. Ants will also attend these insects leading to the presence of a black sooty mould.  Large numbers of leafhoppers can debilitate a tree and cause malformation of the small branches. There can be a couple of generations per year.
  SThese insects all belong to the order Hemiptera.  White wax and pink wax scale are pests of a wide variety of trees.  Gum tree scale (Eriococcus coriaceus) attacks some eucalypts, particularly scribbly gum.  The female is pink and 2-3 mm in length whereas the male is white and 10-15 mm in length.  The male is usually found above the female on the stem. Ants will often attend an infestation of scale insects seeking the sugary exudation secreted by the scale insects.  Black sooty mould usually accompanies the infestation.  Attack also produces debilitation and malformation of the leaves.
  Gall Forming Insects
  There are hundreds of species of insects, which produce swollen areas in small stems and leaves known as "galls".  These insects include some species of flies, wasps, psyllids and coccids (scale insects).  Galls have a characteristic shape which is constant for the particular species causing the infestation.  Identification of the insects responsible for the formation of galls is a very difficult task. Gall formation arises through the female insect laying its eggs in the leaves or stems.  The young insects feed on the leaves and stems causing distortions and abnormalities of the leaves and stems.  There are usually one or two generations per year.
  Thrips
  These are insects belonging to the order Thysanoptera.  They will attack a wide variety of fruits, vegetables, shrubs and trees including liquid amber, oaks, elms and maples.  The insects themselves are small (2-4mm), with fringed with fine hair. Summer time may produce veritable "plagues" of these insects with large numbers of them being trapped on washing hung out to dry.
  Bark & Wood Damaging Insects
  See Timber Borers

Useful website links:
http://www.ipminstitute.org/school_biblio_buildings.htm#Wood