The sirex woodwasp (''Sirex noctilio'') is a species of
horntail, native to
Europe
Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a Continent#Subcontinents, subcontinent of Eurasia ...
,
Asia
Asia (, ) is one of the world's most notable geographical regions, which is either considered a continent in its own right or a subcontinent of Eurasia, which shares the continental landmass of Afro-Eurasia with Africa. Asia covers an are ...
, and
northern Africa
North Africa, or Northern Africa is a region encompassing the northern portion of the African continent. There is no singularly accepted scope for the region, and it is sometimes defined as stretching from the Atlantic shores of Mauritania in t ...
.
[New York State Department of Environmental Conservation, Copyright © 2011. Sirex Woodwasp – ''Sirex noctilio''. http://www.dec.ny.gov/animals/7248.html] Adults vary in length from .
This woodwasp is an
invasive species
An invasive species otherwise known as an alien is an introduced organism that becomes overpopulated and harms its new environment. Although most introduced species are neutral or beneficial with respect to other species, invasive species adv ...
in many parts of the world, including
Australia
Australia, officially the Commonwealth of Australia, is a sovereign country comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands. With an area of , Australia is the largest country by ...
,
New Zealand
New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island coun ...
,
North America
North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and th ...
,
South America
South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the sou ...
, and
South Africa
South Africa, officially the Republic of South Africa (RSA), is the southernmost country in Africa. It is bounded to the south by of coastline that stretch along the South Atlantic and Indian Oceans; to the north by the neighbouring coun ...
, where it has become a significant economic pest of pine trees.
The wasp can attack a wide variety of pine species, although some species seem to be more susceptible than others, and stressed trees often are attacked.
During
oviposition
The ovipositor is a tube-like organ used by some animals, especially insects, for the laying of eggs. In insects, an ovipositor consists of a maximum of three pairs of appendages. The details and morphology of the ovipositor vary, but typical ...
, the female wasp lays two eggs with or without a
mucoid substance and a
symbiotic
Symbiosis (from Greek , , "living together", from , , "together", and , bíōsis, "living") is any type of a close and long-term biological interaction between two different biological organisms, be it mutualistic, commensalistic, or para ...
fungus for the
larva
A larva (; plural larvae ) is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle.
...
e to feed on once they hatch.
The mucoid substance is toxic to trees and aids in tree decline. The
arthrospore
An oidium (plural: oidia) is an asexually produced fungal spore that (in contrast to conidia
A conidium ( ; ), sometimes termed an asexual chlamydospore or chlamydoconidium (), is an asexual, non- motile spore of a fungus. The word ''conidium ...
s from the symbiotic fungus, ''
Amylostereum areolatum
''Amylostereum areolatum'' is a species of crust fungus. Originally called ''Thelephora areolata'' in 1828, it was given its current name by French mycologist Jacques Boidin in 1958.
References
External links
*
Russulales
Fungi of Eur ...
'', are also
pathogen
In biology, a pathogen ( el, πάθος, "suffering", "passion" and , "producer of") in the oldest and broadest sense, is any organism or agent that can produce disease. A pathogen may also be referred to as an infectious agent, or simply a g ...
ic.
Characteristics
Adult
The sirex woodwasp has a sturdy, cylindrical body without a waist, but with a pointed
abdomen
The abdomen (colloquially called the belly, tummy, midriff, tucky or stomach) is the part of the body between the thorax (chest) and pelvis, in humans and in other vertebrates. The abdomen is the front part of the abdominal segment of the to ...
. The female body is , and the male is long. Both sexes have long, black, bristle-shaped
antenna
Antenna ( antennas or antennae) may refer to:
Science and engineering
* Antenna (radio), also known as an aerial, a transducer designed to transmit or receive electromagnetic (e.g., TV or radio) waves
* Antennae Galaxies, the name of two collid ...
e, which are rather close together.
''Sirex noctilio'' (Fabricius) – Sirex woodwasp.
' Canadian Food Inspection Agency, www.inspection.gc.ca.[B. Långström et al: ''Non-Coleopteran Insects.'' In: François Lieutier: ''Bark and Wood Boring Insects in Living Trees in Europe: A Synthesis.'' Springer, 2004. , pp. 530–531.]
The body of the male is black, except for the orange middle part of the abdomen. The wings are yellowish-translucent and the antennae are black. The front pair of legs have a yellowish-orange colour, the back pair is heavily thickened and is coloured black on the posterior splint and
tarsus, while the
femur
The femur (; ), or thigh bone, is the proximal bone of the hindlimb in tetrapod vertebrates. The head of the femur articulates with the acetabulum in the pelvic bone forming the hip joint, while the distal part of the femur articulates ...
is orange.
The females are iron blue, and have orange legs and black antennae. This is a notable distinction from ''
S. juvencus'', which has red antennae. The females also have yellowish wings. The
ovipositor
The ovipositor is a tube-like organ used by some animals, especially insects, for the laying of eggs. In insects, an ovipositor consists of a maximum of three pairs of appendages. The details and morphology of the ovipositor vary, but typical ...
is below the tapering tip of the abdomen. The sting is connected with the mycetangia, which are special organs on the abdomen, where the female stores the
oidia
An oidium (plural: oidia) is an asexually produced fungal spore that (in contrast to conidia) is presumed not to constitute the main reproductive preoccupation of the fungus at that time.
The hypha breaks up into component cells/ small pieces and ...
e (asexual fungus spores), from broken segments of
hypha
A hypha (; ) is a long, branching, filamentous structure of a fungus, oomycete, or actinobacterium. In most fungi, hyphae are the main mode of vegetative growth, and are collectively called a mycelium.
Structure
A hypha consists of one or ...
e. These spores are deposited, together with the eggs, in the host tree wood to germinate. Both larvae and adults have strong
mandible
In anatomy, the mandible, lower jaw or jawbone is the largest, strongest and lowest bone in the human facial skeleton. It forms the lower jaw and holds the lower teeth in place. The mandible sits beneath the maxilla. It is the only movable bone ...
s and can drill through lead plates.
Larva
The larvae of the sirex woodwasp are almost colourless and only have three stub-shaped pairs of
sterna. They cut through host wood with their powerful mandibles. They have a pointed, dark tip at their rear end, which presses the drilling dust on the walls of the borehole. They closely resemble other larvae in the genus ''
Sirex''.
[Uwe Sedlag: ''Insekten Mitteleuropas''. dtv, 1986. , pp. 244–245.]
Native and introduced range
![Sirex noctilio distribution](https://upload.wikimedia.org/wikipedia/commons/a/ad/Sirex_noctilio_distribution.PNG)
The native habitat of the sirex woodwasp is the temperate
Palearctic realm
The Palearctic or Palaearctic is the largest of the eight biogeographic realms of the Earth. It stretches across all of Eurasia north of the foothills of the Himalayas, and North Africa.
The realm consists of several bioregions: the Euro-Si ...
, ranging from
Maghreb
The Maghreb (; ar, الْمَغْرِب, al-Maghrib, lit=the west), also known as the Arab Maghreb ( ar, المغرب العربي) and Northwest Africa, is the western part of North Africa and the Arab world. The region includes Algeria, ...
over Europe,
Siberia
Siberia ( ; rus, Сибирь, r=Sibir', p=sʲɪˈbʲirʲ, a=Ru-Сибирь.ogg) is an extensive geographical region, constituting all of North Asia, from the Ural Mountains in the west to the Pacific Ocean in the east. It has been a part ...
, and
Mongolia
Mongolia; Mongolian script: , , ; lit. "Mongol Nation" or "State of Mongolia" () is a landlocked country in East Asia, bordered by Russia to the north and China to the south. It covers an area of , with a population of just 3.3 million ...
, to the
Kamchatka Peninsula
The Kamchatka Peninsula (russian: полуостров Камчатка, Poluostrov Kamchatka, ) is a peninsula in the Russian Far East, with an area of about . The Pacific Ocean and the Sea of Okhotsk make up the peninsula's eastern and w ...
. They live in deep pine-rich forests.
The species has reached other continents, such as Australia, South Africa and North America, through the export of timber and firewood. While invasion was prevented in North America for a long time, the sirex woodwasp established itself in
New Zealand
New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island coun ...
around 1900. There, it contributed to massive pine declines in the first half of the 20th century, spreading to
Tasmania
)
, nickname =
, image_map = Tasmania in Australia.svg
, map_caption = Location of Tasmania in AustraliaCoordinates:
, subdivision_type = Country
, subdi ...
in the 1950s and then to the Australian mainland. Since 1980, it has reached pine plantations in
Uruguay
Uruguay (; ), officially the Oriental Republic of Uruguay ( es, República Oriental del Uruguay), is a country in South America. It shares borders with Argentina to its west and southwest and Brazil to its north and northeast; while bordering ...
, and later also
Argentina
Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the southern half of South America. Argentina covers an area of , making it the List of South American countries by area, second-largest ...
,
Brazil
Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At and with over 217 million people, Brazil is the world's fifth-largest country by area ...
and
Chile
Chile, officially the Republic of Chile, is a country in the western part of South America. It is the southernmost country in the world, and the closest to Antarctica, occupying a long and narrow strip of land between the Andes to the eas ...
; it was found in South Africa in 1994. The population increased in the
Great Lakes
The Great Lakes, also called the Great Lakes of North America, are a series of large interconnected freshwater lakes in the mid-east region of North America that connect to the Atlantic Ocean via the Saint Lawrence River. There are five lakes ...
area from 2004 on; the species had reached
Vermont
Vermont () is a U.S. state, state in the northeast New England region of the United States. Vermont is bordered by the states of Massachusetts to the south, New Hampshire to the east, and New York (state), New York to the west, and the Provin ...
,
New York
New York most commonly refers to:
* New York City, the most populous city in the United States, located in the state of New York
* New York (state), a state in the northeastern United States
New York may also refer to:
Film and television
* '' ...
,
Pennsylvania
Pennsylvania (; ( Pennsylvania Dutch: )), officially the Commonwealth of Pennsylvania, is a state spanning the Mid-Atlantic, Northeastern, Appalachian, and Great Lakes regions of the United States. It borders Delaware to its southeast, ...
,
Ohio
Ohio () is a U.S. state, state in the Midwestern United States, Midwestern region of the United States. Of the List of states and territories of the United States, fifty U.S. states, it is the List of U.S. states and territories by area, 34th-l ...
, and
Michigan
Michigan () is a state in the Great Lakes region of the upper Midwestern United States. With a population of nearly 10.12 million and an area of nearly , Michigan is the 10th-largest state by population, the 11th-largest by area, and t ...
by 2009.
[Jamie Perrie: ''Sirex noctilio Positive Counties per Year''. USDA/APHIS/PPQ, 20 October 2009.] The wasps can swarm between 20 and 50 km (12 and 31 mi), and has been estimated to take until about 2050 to spread to the far southeast of the USA at the current spreading rate.
[Chalkley, D. ]
Diagnostic Fact Sheet for ''Amylostereum areolatum''.
'' Systematic Mycology and Microbiology Laboratory, ARS, USDA. Retrieved on 1 March 2010.[''Economic Analysis of the Potential Impact of ''Sirex noctilio'', with Emphasis on Pines in the Southeastern United States.'' USDA Forest Service, Arlington 2006.]
Subsequently, forestry authorities intensified their pest control methods and additionally started education campaigns, such as warning not to transport firewood over large distances or to store it too long. Through wood export, the wasp could spread to East Asia, West Australia and parts of Africa. Remote locations, such as the
Horn of Africa
The Horn of Africa (HoA), also known as the Somali Peninsula, is a large peninsula and geopolitical region in East Africa.Robert Stock, ''Africa South of the Sahara, Second Edition: A Geographical Interpretation'', (The Guilford Press; 2004 ...
, may be spared from the sirex woodwasp, providing the area is controlled.
The Invasive Species Specialist Group (ISSG) of the
IUCN
The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natu ...
has graded the wasp as heavily
invasive.
[''Sirex noctilio''](_blank)
in th
Global Invasive Species Database
of the IUCN. www.issg.org, 23 November 2009. Retrieved on 22 August 2010.
Ecology
Phenology
The flight time of the adults or
imagines begins in the late summer to early autumn, but the date depends on the region and climate. The males hatch out earlier than females and create swarms which gather around the treetops. The females seek out
leks and couple with the males on the uppermost shoots. Then the females search for suitable host trees, if possible choosing weak and dry wood. They orient on
monoterpene
Monoterpenes are a class of terpenes that consist of two isoprene units and have the molecular formula C10H16. Monoterpenes may be linear (acyclic) or contain rings (monocyclic and bicyclic). Modified terpenes, such as those containing oxygen func ...
hydrocarbon
In organic chemistry, a hydrocarbon is an organic compound consisting entirely of hydrogen and carbon. Hydrocarbons are examples of group 14 hydrides. Hydrocarbons are generally colourless and hydrophobic, and their odors are usually weak or ...
compounds, which weakened trees produce. When a tree is stressed through dryness or exterior injuries, the compounds pervade
osmotic
Osmosis (, ) is the spontaneous net movement or diffusion of solvent molecules through a selectively-permeable membrane from a region of high water potential (region of lower solute concentration) to a region of low water potential (region ...
barriers and escape from the
bark
Bark may refer to:
* Bark (botany), an outer layer of a woody plant such as a tree or stick
* Bark (sound), a vocalization of some animals (which is commonly the dog)
Places
* Bark, Germany
* Bark, Warmian-Masurian Voivodeship, Poland
Arts, e ...
.
The female alights on the bark to drill several holes through the wood to the
xylem
Xylem is one of the two types of transport tissue in vascular plants, the other being phloem. The basic function of xylem is to transport water from roots to stems and leaves, but it also transports nutrients. The word ''xylem'' is derived from ...
, placing one egg in each. At the same time, she inserts spores of ''
Amylostereum areolatum
''Amylostereum areolatum'' is a species of crust fungus. Originally called ''Thelephora areolata'' in 1828, it was given its current name by French mycologist Jacques Boidin in 1958.
References
External links
*
Russulales
Fungi of Eur ...
'' and a
phytotoxic secretion. The holes branch out into several tubes, which lead away radially. The eggs are white, sausage-shaped, and by in size. Small females may lay 20 eggs, while the largest can lay up to 500. Sometimes, eggs are not placed in every tube. In the last tube, the female injects only the secretion and the fungal spores. The females often die after just three or four days, sometimes even during
oviposition
The ovipositor is a tube-like organ used by some animals, especially insects, for the laying of eggs. In insects, an ovipositor consists of a maximum of three pairs of appendages. The details and morphology of the ovipositor vary, but typical ...
(egg-laying), through overexertion.
[''Proposed Program for Management of the Woodwasp ''Sirex noctilio'' Fabricus (Hymenoptera: Siricidae).'' United States Department of Agriculture, 2007.][Eichhorn, O. ''Siricoidea''. In: Wolfgang Schwenke: ''Die Forstschädlinge Europas. Band 4: Hautflügler und Zweiflügler.'' Hamburg 1982. , p. 215.]
Development of larvae
Larvae of sirex woodwasp develop through
arrhenotoky: male larvae develop only from unfertilized eggs, the females only from fertilized ones. Usually, 10 males are produced per female, but the ratio varies between 20:1 and 1:1. The larvae hatch after eight days at the earliest, but in some exterior conditions, they may remain in the egg for several months. At the optimal temperature of around , they hatch out after 10 to 12 days. Although the larvae hatch at two to three days earlier, they are 20% more likely to die. Such extreme temperatures result in slower development, and below , the larvae die. A sufficient interspersion of the wood with the
mycelium
Mycelium (plural mycelia) is a root-like structure of a fungus consisting of a mass of branching, thread-like hyphae. Fungal colonies composed of mycelium are found in and on soil and many other substrates. A typical single spore germinates ...
of the woodwasp is crucial for its hatching, as the fungus prevents the wood from drying out. Without these prerequisites, hatching is not possible. The tree can only ward off the infestation if it floods the boreholes with resin or halts the fungus by producing a wall of
polyphenol
Polyphenols () are a large family of naturally occurring organic compounds characterized by multiples of phenol units. They are abundant in plants and structurally diverse. Polyphenols include flavonoids, tannic acid, and ellagitannin, some ...
s.
![Sirex noctilio hole cropped](https://upload.wikimedia.org/wikipedia/commons/7/70/Sirex_noctilio_hole_cropped.jpg)
Six to twelve larval stages occur. During the first two stages, the larvae live off surrounding fungal tissue, until they reach the inner wood. Up to the fourth stage, they eat through the final summer wood along the
tracheids, and finally towards the heartwood. After the seventh stage, they usually reach their maximum size. While penetrating further, they normally turn either up or down, but they turn back if they meet a foreign borehole, encounter bubbles of resin, or dry out. The larvae only live off the fungal mycelium, which they digest through a secretion. They pupate several centimetres under the bark. Before this, female larvae sequester a secretion containing fungal
oidia
An oidium (plural: oidia) is an asexually produced fungal spore that (in contrast to conidia) is presumed not to constitute the main reproductive preoccupation of the fungus at that time.
The hypha breaks up into component cells/ small pieces and ...
, which adult females incorporate in their mycetangia above their ovipositors. The adults eat through the bark, but, depending on the weather, they remain in the hatch hole for up to three weeks before they leave the wood in warm and sunny weather.
[Morgan 1968, p. 242.]
The period from hatching to pupation lasts 10 days to two years, exceptionally up to six years. Climate is a major factor, because development is slower in colder regions.
Symbiosis
![Pinus palustris Ocala USDAFS](https://upload.wikimedia.org/wikipedia/commons/a/a0/Pinus_palustris_Ocala_USDAFS.jpg)
The sirex woodwasp and ''
Amylostereum areolatum
''Amylostereum areolatum'' is a species of crust fungus. Originally called ''Thelephora areolata'' in 1828, it was given its current name by French mycologist Jacques Boidin in 1958.
References
External links
*
Russulales
Fungi of Eur ...
'' have a
mutualistic symbiotic relationship. The sirex woodwasp is, together with ''
S. juvencus'' and ''
S. nitobei'' from eastern Asia, one of three symbionts of the fungus that in the first instance benefits from its
vector function. Additionally, the wasp creates the optimal conditions for the infestation through the fungus by drilling into the underlying wood layers and weakening the host tree. The fungus has adapted to this process in the course of evolution and only rarely creates fruit bodies.
[Hudson, Harry J.: ''Fungal Biology''. CUP Archive, 1992. , pp. 248–252.]
Conversely, the woodwasp is fully dependent on the symbionts. Decomposition enables the larvae to unlock the wood by producing
white rot. The mycetangia of this and other wasps from the family
Siricidae support a close relationship with
saprobiontic
Saprobionts are organisms that digest their food externally and then absorb the products. This process is called saprotrophic nutrition. Fungi are examples of saprobiontic organisms, which are a type of decomposer.
Saprobiontic organisms feed of ...
fungi. Without the process of decomposition of the host tree and weakening of the infested tree, the development of larvae is arrested. If the tree can recover from the consequences of the wasp secretion, it blocks the boreholes with resin, thus killing the larvae.
Host spectrum
The sirex woodwasp only attacks conifers, especially
pine
A pine is any conifer tree or shrub in the genus ''Pinus'' () of the family (biology), family Pinaceae. ''Pinus'' is the sole genus in the subfamily Pinoideae. The World Flora Online created by the Royal Botanic Gardens, Kew and Missouri Botanic ...
s. In its usual habitat, these are mainly ''
Pinus sylvestris
''Pinus sylvestris'', the Scots pine (UK), Scotch pine (US) or Baltic pine, is a species of tree in the pine family Pinaceae that is native to Eurasia. It can readily be identified by its combination of fairly short, blue-green leaves and or ...
'', ''
P. pinaster'' and ''
P. nigra''. In the Southern Hemisphere and in North America, the wasp attacks exotic and domestic pine species, generally in plantations. Examples include ''
P. radiata'' and ''
P. taeda'' in the United States.
Unlike any other species of Siricidae, the sirex woodwasp can damage relatively healthy trees so heavily, they die back. However, the wasp mainly infests weakened trees; only when the population is high does the insect also attack intact and healthy trees.
Because the wasp larvae and the fungus need living wood, the sirex woodwasp does not infest dry or dead timber. However, wasps may hatch from processed wood which was already infested.
Pines in North America that have been attacked or confirmed as hosts are: Scots (''Pinus sylvestris''), Monterey (''P. radiata''), loblolly (''P. taeda''), slash (''P. elliottii''), shortleaf (''P. echinata''), ponderosa (''P. ponderosa''), lodgepole (''P. contorta''), and jack (''P. banksiana'') (Haugen 1999).
[Haugen, D.A. (1999) ''Sirex noctilio'']
Pest Reports – EXFOR Database
. Retrieved on November 25, 2012 By the spring of 2011, ''S. noctilio'' had been found in Michigan, Pennsylvania, New York, and Vermont.
Symptoms of infestation
![Sirex noctilio tube](https://upload.wikimedia.org/wikipedia/commons/c/cf/Sirex_noctilio_tube.jpg)
Infestation damage can be divided into four categories or phases, depending on whether it is caused by the imago, fungus, larvae or secondary parasites.
The first reaction of the host tree is due to the adult wasp and occurs after 10 to 14 days. A phytotoxic secretion of the wasp impairs metabolism in the shoots and needles, causing loss of water balance. The result is
brown coloration of the needles and leaf drop. As with many other wood pests, fine resin drops in wasp boreholes are found in the central trunk.
[Photograph of an infested tree.](_blank)
Forestry Images. Retrieved on November 24, 2012. Attacked pines tend to develop
flagging. Tip
dieback begins with the needles becoming
chlorotic
In botany, chlorosis is a condition in which leaves produce insufficient chlorophyll. As chlorophyll is responsible for the green color of leaves, chlorotic leaves are pale, yellow, or yellow-white. The affected plant has little or no ability to ...
and changing from green to yellowish-red, finally turning completely brown over a three- to six-month period. The wasp bores -diameter holes in the tree. Unstressed trees may be attacked uniformly along the main stem, while trees with low
osmotic
Osmosis (, ) is the spontaneous net movement or diffusion of solvent molecules through a selectively-permeable membrane from a region of high water potential (region of lower solute concentration) to a region of low water potential (region o ...
phloem
Phloem (, ) is the living biological tissue, tissue in vascular plants that transports the soluble organic compounds made during photosynthesis and known as ''photosynthates'', in particular the sugar sucrose, to the rest of the plant. This tran ...
pressure are preferentially attacked, with denser clusters of boreholes.
During this process, fungal spores germinate in the boreholes, a reaction caused by the dryness of the tree, creating an appropriate environment and an entry for air. The fungus breaks down the
lignin
Lignin is a class of complex organic polymers that form key structural materials in the support tissues of most plants. Lignins are particularly important in the formation of cell walls, especially in wood and bark, because they lend rigidity ...
, causing
white rot. It moves towards the vertically aligned xylem. The vertical profile shows reddish and white streaks which run in the direction of growth.
In the third stage, the larva begins to bore into the wood. By doing this, it eats a path, which at first proceeds towards the trunk centre, before turning and running back to the bark. The paths are not visible in cross-section, because they are heavily blocked with sawdust; they may also be unobserved during wood processing. The lengths of the paths vary, depending on the wood, between in diameter, which depends on the size of the larvae. The exit holes are circular and of very small diameter.
Stressing of the host tree and visible larval boreholes appear in the fourth stage. The infestation is reinforced by further insects or fungi, which in turn may cause more symptoms. Imago, fungus, and larvae together can cause tree death in a period ranging from two weeks to eight months.
[Taylor, K. L. ''The Sirex Woodwasp: Ecology and Control of an Introduced Forest Insect.'' In: Roger Laurence Kitching, R. E. Jones: ''The Ecology of Pests: Some Australian Case Histories.'' CSIRO, 1981. , pp. 231–248][Madden, John L.: Sirex'' in Australasia.'' In: Alan A. Berryman: ''Dynamics of Forest Insect Populations. Patterns, Causes, Implications.'' Washington State University, Pullman 1988. pp. 411–413.]
Natural enemies and parasites
![Rhyssa persuasoria](https://upload.wikimedia.org/wikipedia/commons/1/1c/Rhyssa_persuasoria.jpg)
Birds are the primary natural enemies of the sirex woodwasp. The adults are frequently hunted by
swallow
The swallows, martins, and saw-wings, or Hirundinidae, are a family of passerine songbirds found around the world on all continents, including occasionally in Antarctica. Highly adapted to aerial feeding, they have a distinctive appearance. The ...
s (Hirundidae) and
swift
Swift or SWIFT most commonly refers to:
* SWIFT, an international organization facilitating transactions between banks
** SWIFT code
* Swift (programming language)
* Swift (bird), a family of birds
It may also refer to:
Organizations
* SWIFT, ...
s (Apodidae), both of which prefer males. The
black woodpecker (''Dryocopius martius'') and
great spotted woodpecker (''Dendrocopus major'') consume some larvae, but do not specialize on the sirex woodwasp.
![White-throated Needletail kobble jan05](https://upload.wikimedia.org/wikipedia/commons/e/e1/White-throated_Needletail_kobble_jan05.jpg)
Several parasites have a larger impact on woodwasp populations. These include ''
Ibalia leucospoides
''Ibalia leucospoides'', the knife-shaped ibalia, is a species of ibaliid wasp in the family Ibaliidae.
Subspecies
These two subspecies belong to the species ''Ibalia leucospoides'':
* ''Ibalia leucospoides ensiger'' Norton, 1862
* ''Ibalia leuc ...
'' (
Ibaliidae
The Ibaliidae are a small family of hymenopteran superfamily Cynipoidea. Ibaliidae differ from most of the cynipoids by the larvae being parasitoids on other wasp larvae in the group Siricidae. The Ibaliidae comprise three extant genera of f ...
); ''
Schletterius cinctipes'', ''
Megarhyssa nortoni
''Megarhyssa nortoni'', also known as Norton's giant ichneumonid wasp or the western giant ichneumonid wasp, is a species of large ichneumon wasp.
Subspecies
There are two described subspecies of ''Megarhyssa nortoni'':
*''M. nortoni nortoni'' ( ...
'' (
Ichneumonidae
The Ichneumonidae, also known as the ichneumon wasps, Darwin wasps, or ichneumonids, are a family (biology), family of parasitoid wasps of the insect order Hymenoptera. They are one of the most diverse groups within the Hymenoptera with roughly 2 ...
); and ''
Rhyssa persuasoria''. While ''I. leucospoides'' lay its eggs into the woodwasp's egg and the hatching period is therefore similar to its host's, the ichneumons mentioned lay their eggs on larvae or adult woodwasps; they hatch out later in the springtime. The parasites locate host larvae hidden in the wood using their antennae to detect cues, including the smell of leaking drill dust or fungus mycelium, weak vibrations, or differences in temperature. The majority of these insect
hyperparasite
A hyperparasite, also known as a metaparasite, is a parasite whose host, often an insect, is also a parasite, often specifically a parasitoid. Hyperparasites are found mainly among the wasp-waisted Apocrita within the Hymenoptera, and in two oth ...
s feed on honeydew and
nectar
Nectar is a sugar-rich liquid produced by plants in glands called nectaries or nectarines, either within the flowers with which it attracts pollinating animals, or by extrafloral nectaries, which provide a nutrient source to animal mutualists ...
, both of which affect the woodwasps' sensitivity.
Another parasite is the
nematode
The nematodes ( or grc-gre, Νηματώδη; la, Nematoda) or roundworms constitute the phylum Nematoda (also called Nemathelminthes), with plant-Parasitism, parasitic nematodes also known as eelworms. They are a diverse animal phylum inhab ...
''Beddingia'' (''Deladenus'') ''siricidicola'', which was suggested in the New World in the 1970s as a possible
biological control
Biological control or biocontrol is a method of controlling pests, such as insects, mites, weeds, and plant diseases, using other organisms. It relies on predation, parasitism, herbivory, or other natural mechanisms, but typically also invo ...
. ''B. siricidicola'' causes infertility in female wasps, but does not impair the fertility of males. Inside the host tree, the nematodes primarily feed on fungal mycelium. If they get near the wasp larvae, they infect females, which then couple with males and finally infest the wasp larvae. These eventually exit the tree carrying the nematodes with them. Competition for food between ''B. siricidicola'' and the wasp larvae also occurs, resulting in slower growth and possible starvation of the woodwasp larvae. The population of the Sirex woodwasp is very prone to infestation by ''B. siricidicola''; infestation rates of up to 90% have been recorded. The nematodes are often used to combat the wasps by combining them with the
symbiosis
Symbiosis (from Greek , , "living together", from , , "together", and , bíōsis, "living") is any type of a close and long-term biological interaction between two different biological organisms, be it mutualistic, commensalistic, or parasit ...
partner ''
Amylostereum
''Amylostereum'' is the single genus in the fungal family Amylostereaceae. The genus currently comprises four saprotrophic and parasitic species, which live off living or dead wood. The Amylostereaceae cause white rot in the wood by disintegratin ...
''. The related species ''
B. wilsoni'' has a similar effect, but as it also lives parasitically with the genus ''
Rhyssa'', it is not used for pest control.
Management options
Several biological control agents have been employed to try to limit populations of the sirex woodwasp. ''B. siricidicola'' has been shown to infect up to 70% of the wasps, but delivery and
inoculation
Inoculation is the act of implanting a pathogen or other microorganism. It may refer to methods of artificially inducing immunity against various infectious diseases, or it may be used to describe the spreading of disease, as in "self-inoculati ...
have been a problem when delivering the organism to the tree. The introduction of
hyperparasitic wasps ''
Megarhyssa nortoni nortoni'', ''
Rhyssa persuasoria persuasoria
''Rhyssa'' is a genus of ichneumon wasps belonging to the family Ichneumonidae subfamily Rhyssinae.
Etymology
The Latin name of the genus comes from the Greek and means "wrinkled".
Description
Female of this parasitic species drills deep into ...
'' and ''
Ibalia leucospoides leucospoides'' have been successful but, although a lessening in the numbers of the wasp has been observed, those measures are not stopping its spread, because the predators do not reduce wasp populations below 40% of the local population.
As a consequence of forest damage in Australia and New Zealand, wood imports to those countries have been required to be certified free from living sirex larvae.[Unger, Achim; Schniewind, Arno P. and Unger, Wibke ''Conservation of Wood Artifacts: A Handbook.'' Springer, 2001. , p. 303.]
Treatment has also been attempted with bromomethane
Bromomethane, commonly known as methyl bromide, is an organobromine compound with formula C H3 Br. This colorless, odorless, nonflammable gas is produced both industrially and biologically. It has a tetrahedral shape and it is a recognized ozo ...
(CH3Br), through heat, or by removing the bark.[Gemeine Holzwespe, ''Sirex juvencus'', Riesen Holzwespe, ''Urocerus gigas'', u.a.](_blank)
www.holzfragen.de, 2009. Retrieved on November 25, 2012.
References
External links
Species Profile - Sirex Woodwasp (''Sirex noctilio'')
National Invasive Species Information Center, United States National Agricultural Library
The United States National Agricultural Library (NAL) is one of the world's largest agricultural research libraries, and serves as a national library of the United States and as the library of the United States Department of Agriculture. Located ...
. Lists general information and resources for sirex woodwasp.
Forestry and Agricultural Biotechnology Institute
{{Authority control
Insects described in 1793
Siricidae