Sirex juvencus
Encyclopedia
Sirex juvencus is a wasp
that can be found in Europe
, Siberia
, Sakhalin Island, Japan
, the Philippines
, Algeria
, New Zealand
, and several other countries. Its common name is steely-blue wood wasp because of its colour.
are red and brown or red and black. They exhibit sexual dimorphism
, which means that the male and female are morphologically different. The female body has a metallic bluish black colour with yellowish reddish legs and the last part of the abdomen is triangular shaped and wide at the base. The ovipositor
, which deposits the eggs, is as long as the abdomen or a little longer. The eggs are white and elongated and the larva
e are cylindrical, white, and can measure up to 40 mm (1.6 in). The male body has a metallic black body with the first two sets of legs being reddish and the back legs being black. The abdomen is black with bluish-black dots on some parts of the abdomen and brownish dots on other parts.
e in the summer. Once they are adults, they chew through the surface and leave a hole that is 4 millimetre in diameter. Most of the time, this species only has one generation every 2 years.
Wasp
The term wasp is typically defined as any insect of the order Hymenoptera and suborder Apocrita that is neither a bee nor an ant. Almost every pest insect species has at least one wasp species that preys upon it or parasitizes it, making wasps critically important in natural control of their...
that can be found in Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
, Siberia
Siberia
Siberia is an extensive region constituting almost all of Northern Asia. Comprising the central and eastern portion of the Russian Federation, it was part of the Soviet Union from its beginning, as its predecessor states, the Tsardom of Russia and the Russian Empire, conquered it during the 16th...
, Sakhalin Island, Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
, the Philippines
Philippines
The Philippines , officially known as the Republic of the Philippines , is a country in Southeast Asia in the western Pacific Ocean. To its north across the Luzon Strait lies Taiwan. West across the South China Sea sits Vietnam...
, Algeria
Algeria
Algeria , officially the People's Democratic Republic of Algeria , also formally referred to as the Democratic and Popular Republic of Algeria, is a country in the Maghreb region of Northwest Africa with Algiers as its capital.In terms of land area, it is the largest country in Africa and the Arab...
, New Zealand
New Zealand
New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...
, and several other countries. Its common name is steely-blue wood wasp because of its colour.
Description
Male adults are about 8–28 mm (0.31496062992126–1.1 ) long, and female adults are about 15–32 mm (0.590551181102362–1.3 )long. The antennaeAntenna (biology)
Antennae in biology have historically been paired appendages used for sensing in arthropods. More recently, the term has also been applied to cilium structures present in most cell types of eukaryotes....
are red and brown or red and black. They exhibit sexual dimorphism
Sexual dimorphism
Sexual dimorphism is a phenotypic difference between males and females of the same species. Examples of such differences include differences in morphology, ornamentation, and behavior.-Examples:-Ornamentation / coloration:...
, which means that the male and female are morphologically different. The female body has a metallic bluish black colour with yellowish reddish legs and the last part of the abdomen is triangular shaped and wide at the base. The ovipositor
Ovipositor
The ovipositor is an organ used by some animals for oviposition, i.e., the laying of eggs. It consists of a maximum of three pairs of appendages formed to transmit the egg, to prepare a place for it, and to place it properly...
, which deposits the eggs, is as long as the abdomen or a little longer. The eggs are white and elongated and the larva
Larva
A larva 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 are cylindrical, white, and can measure up to 40 mm (1.6 in). The male body has a metallic black body with the first two sets of legs being reddish and the back legs being black. The abdomen is black with bluish-black dots on some parts of the abdomen and brownish dots on other parts.
Reproduction
Adults fly from July to August to mate and once they have mated, the female will drill several holes in wood and drop 1 to 5 eggs into that hole. The female can lay up to 100 eggs. Once the larvae hatch, they feed off of the wood, but in the middle of summer they dig deeper into the wood until they are 15–17 mm (0.590551181102362–0.669291338582677 ) into it. The larvae stay there all winter and in April, they feed off of sap from the tree. The larvae then make tunnels horizontally that are covered with shredded wood. Before they turn into a pupa, they would have made tunnels 80 millimetre long where they will stay for the winter. They would finally turn into pupaPupa
A pupa is the life stage of some insects undergoing transformation. The pupal stage is found only in holometabolous insects, those that undergo a complete metamorphosis, going through four life stages; embryo, larva, pupa and imago...
e in the summer. Once they are adults, they chew through the surface and leave a hole that is 4 millimetre in diameter. Most of the time, this species only has one generation every 2 years.