Eurygaster integriceps
Encyclopedia
Eurygaster integriceps is a species of shield bug
in the family Pentatomidae
, commonly known as the sunn pest or corn bug. It is native to much of northern Africa, the Balkans and western and central Asia. It is a major pest of cereal
crops especially wheat
, barley
and oat
s.
varies but it is usually light brown. The body is a broad oval about 12 millimetre (0.47244094488189 in) long. The scutellum is wide and chitin
ous and covers the wings and the whole abdomen
. The insect lives for about a month during which time the females lay twenty eight to forty two eggs
. These are laid in batches each having two neat rows of seven eggs, on the underside of leaves and on the stems of the host plant, or sometimes on weeds. The eggs take six to twenty eight days to hatch and the nymph
s moult five times while they feed on the leaves, stems and ears
of cereal crops for the next twenty to forty five days. They grow fastest at an air temperature of 20–24 °C (68–75.2 F). The second and third instar
s have a pale abdomen and dark head and thorax. The fourth instar has the rudiments of fore wings and the fifth instar, the rudiments of hind wings as well.
, Greece
, Bulgaria
and Romania
. In Asia it occurs in Turkey
, Syria
, Lebanon
, Iran
, Iraq
, Afghanistan
and Pakistan
and the republics of Kazakhstan
, Kyrgyzstan
, Tajikistan
, Turkmenistan
and Uzbekistan
. In Russia
it has spread into the central and Volga Basin regions, the Northern Caucasus, the Chelyabinsk
region and Bashkortostan
.
on winter crops, the early sowing of spring crops, the selection of varieties resistant to the pest and varieties that ripen early and can be harvested early, autumn ploughing in of crop residues and the spraying of crops with pesticide
s, which should only be done when pest populations rise to economically damaging levels.
Research is being undertaken at the Natural Resources Institute at the University of Greenwich
. This project aims to assess the economic thresholds for pest populations, the possible role of egg parasitoids and the possible use of pathogenic fungi to control the pests. Also being investigated is the role of semiochemicals
in enabling individual bugs to locate potential mates and suitable host plants, and whether such chemicals could be used as a possible means of control. There is also an initiative to identify resistant strains of cultivated and wild cereals with the objective of developing the germplasm
.
A study published in 2008 identified several entomopathogenic nematodes that showed promise as biocontrol agents.
Pentatomidae
Pentatomidae, Greek pente meaning five and tomos meaning section, is a family of insects belonging to order hemiptera that includes some of the stink bugs and shield bugs. Their antennae are 5-segmented, which gives the family its scientific name. Their bodies are usually shield-shaped...
in the family Pentatomidae
Pentatomidae
Pentatomidae, Greek pente meaning five and tomos meaning section, is a family of insects belonging to order hemiptera that includes some of the stink bugs and shield bugs. Their antennae are 5-segmented, which gives the family its scientific name. Their bodies are usually shield-shaped...
, commonly known as the sunn pest or corn bug. It is native to much of northern Africa, the Balkans and western and central Asia. It is a major pest of cereal
Cereal
Cereals are grasses cultivated for the edible components of their grain , composed of the endosperm, germ, and bran...
crops especially wheat
Wheat
Wheat is a cereal grain, originally from the Levant region of the Near East, but now cultivated worldwide. In 2007 world production of wheat was 607 million tons, making it the third most-produced cereal after maize and rice...
, barley
Barley
Barley is a major cereal grain, a member of the grass family. It serves as a major animal fodder, as a base malt for beer and certain distilled beverages, and as a component of various health foods...
and oat
Oat
The common oat is a species of cereal grain grown for its seed, which is known by the same name . While oats are suitable for human consumption as oatmeal and rolled oats, one of the most common uses is as livestock feed...
s.
Morphology and biology
The colour of the sunn pestSunn pest
A sunn pest is an insect belonging to a group representing several genera of the 'shield bug' and 'stink bug' Families, with the species Eurygaster integriceps being the most economically important...
varies but it is usually light brown. The body is a broad oval about 12 millimetre (0.47244094488189 in) long. The scutellum is wide and chitin
Chitin
Chitin n is a long-chain polymer of a N-acetylglucosamine, a derivative of glucose, and is found in many places throughout the natural world...
ous and covers the wings and the whole abdomen
Abdomen
In vertebrates such as mammals the abdomen constitutes the part of the body between the thorax and pelvis. The region enclosed by the abdomen is termed the abdominal cavity...
. The insect lives for about a month during which time the females lay twenty eight to forty two eggs
Egg (biology)
An egg is an organic vessel in which an embryo first begins to develop. In most birds, reptiles, insects, molluscs, fish, and monotremes, an egg is the zygote, resulting from fertilization of the ovum, which is expelled from the body and permitted to develop outside the body until the developing...
. These are laid in batches each having two neat rows of seven eggs, on the underside of leaves and on the stems of the host plant, or sometimes on weeds. The eggs take six to twenty eight days to hatch and the nymph
Nymph (biology)
In biology, a nymph is the immature form of some invertebrates, particularly insects, which undergoes gradual metamorphosis before reaching its adult stage. Unlike a typical larva, a nymph's overall form already resembles that of the adult. In addition, while a nymph moults it never enters a...
s moult five times while they feed on the leaves, stems and ears
Ear (botany)
An ear is the grain-bearing tip part of the stem of a cereal plant, such as wheat or maize. It can also refer to "a prominent lobe in some leaves".The ear is a spike, consisting of a central stem on which grows tightly packed rows of flowers...
of cereal crops for the next twenty to forty five days. They grow fastest at an air temperature of 20–24 °C (68–75.2 F). The second and third instar
Instar
An instar is a developmental stage of arthropods, such as insects, between each molt , until sexual maturity is reached. Arthropods must shed the exoskeleton in order to grow or assume a new form. Differences between instars can often be seen in altered body proportions, colors, patterns, or...
s have a pale abdomen and dark head and thorax. The fourth instar has the rudiments of fore wings and the fifth instar, the rudiments of hind wings as well.
Distribution
The sunn pest is found in Northern Africa, AlbaniaAlbania
Albania , officially known as the Republic of Albania , is a country in Southeastern Europe, in the Balkans region. It is bordered by Montenegro to the northwest, Kosovo to the northeast, the Republic of Macedonia to the east and Greece to the south and southeast. It has a coast on the Adriatic Sea...
, Greece
Greece
Greece , officially the Hellenic Republic , and historically Hellas or the Republic of Greece in English, is a country in southeastern Europe....
, Bulgaria
Bulgaria
Bulgaria , officially the Republic of Bulgaria , is a parliamentary democracy within a unitary constitutional republic in Southeast Europe. The country borders Romania to the north, Serbia and Macedonia to the west, Greece and Turkey to the south, as well as the Black Sea to the east...
and Romania
Romania
Romania is a country located at the crossroads of Central and Southeastern Europe, on the Lower Danube, within and outside the Carpathian arch, bordering on the Black Sea...
. In Asia it occurs in Turkey
Turkey
Turkey , known officially as the Republic of Turkey , is a Eurasian country located in Western Asia and in East Thrace in Southeastern Europe...
, Syria
Syria
Syria , officially the Syrian Arab Republic , is a country in Western Asia, bordering Lebanon and the Mediterranean Sea to the West, Turkey to the north, Iraq to the east, Jordan to the south, and Israel to the southwest....
, Lebanon
Lebanon
Lebanon , officially the Republic of LebanonRepublic of Lebanon is the most common term used by Lebanese government agencies. The term Lebanese Republic, a literal translation of the official Arabic and French names that is not used in today's world. Arabic is the most common language spoken among...
, Iran
Iran
Iran , officially the Islamic Republic of Iran , is a country in Southern and Western Asia. The name "Iran" has been in use natively since the Sassanian era and came into use internationally in 1935, before which the country was known to the Western world as Persia...
, Iraq
Iraq
Iraq ; officially the Republic of Iraq is a country in Western Asia spanning most of the northwestern end of the Zagros mountain range, the eastern part of the Syrian Desert and the northern part of the Arabian Desert....
, Afghanistan
Afghanistan
Afghanistan , officially the Islamic Republic of Afghanistan, is a landlocked country located in the centre of Asia, forming South Asia, Central Asia and the Middle East. With a population of about 29 million, it has an area of , making it the 42nd most populous and 41st largest nation in the world...
and Pakistan
Pakistan
Pakistan , officially the Islamic Republic of Pakistan is a sovereign state in South Asia. It has a coastline along the Arabian Sea and the Gulf of Oman in the south and is bordered by Afghanistan and Iran in the west, India in the east and China in the far northeast. In the north, Tajikistan...
and the republics of Kazakhstan
Kazakhstan
Kazakhstan , officially the Republic of Kazakhstan, is a transcontinental country in Central Asia and Eastern Europe. Ranked as the ninth largest country in the world, it is also the world's largest landlocked country; its territory of is greater than Western Europe...
, Kyrgyzstan
Kyrgyzstan
Kyrgyzstan , officially the Kyrgyz Republic is one of the world's six independent Turkic states . Located in Central Asia, landlocked and mountainous, Kyrgyzstan is bordered by Kazakhstan to the north, Uzbekistan to the west, Tajikistan to the southwest and China to the east...
, Tajikistan
Tajikistan
Tajikistan , officially the Republic of Tajikistan , is a mountainous landlocked country in Central Asia. Afghanistan borders it to the south, Uzbekistan to the west, Kyrgyzstan to the north, and China to the east....
, Turkmenistan
Turkmenistan
Turkmenistan , formerly also known as Turkmenia is one of the Turkic states in Central Asia. Until 1991, it was a constituent republic of the Soviet Union, the Turkmen Soviet Socialist Republic . Turkmenistan is one of the six independent Turkic states...
and Uzbekistan
Uzbekistan
Uzbekistan , officially the Republic of Uzbekistan is a doubly landlocked country in Central Asia and one of the six independent Turkic states. It shares borders with Kazakhstan to the west and to the north, Kyrgyzstan and Tajikistan to the east, and Afghanistan and Turkmenistan to the south....
. In Russia
Russia
Russia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects...
it has spread into the central and Volga Basin regions, the Northern Caucasus, the Chelyabinsk
Chelyabinsk
Chelyabinsk is a city and the administrative center of Chelyabinsk Oblast, Russia, located in the northwestern side of the oblast, south of Yekaterinburg, just to the east of the Ural Mountains, on the Miass River. Population: -History:...
region and Bashkortostan
Bashkortostan
The Republic of Bashkortostan , also known as Bashkiria is a federal subject of Russia . It is located between the Volga River and the Ural Mountains. Its capital is the city of Ufa...
.
Ecology
The adults mostly overwinter in leaf litter in woods but some find refuge among rough vegetation. When the temperature reaches about 13 °C (55.4 °F) they seek out cereal crops, start to feed on the stems, leaves and developing seed heads, mate and lay their eggs. There is only one generation each year so adults and nymphs can be found feeding together on the ripening grain. If the insects are not fully developed when the crop is harvested, some nymphs and young adults feed and mature on fallen grain and other crop residues before flying off to their winter quarters. In Syria, they spend about nine months in hibernation.Economic significance
Over fifteen million hectares in the affected areas of west and central Asia suffer from infestations with this pest. The number of pests varies enormously from year to year and a significant attack may occur about once in every seven years, potentially causing yield losses worth tens of millions of dollars. The loss in yield of grain has been estimated at 50–90% in wheat and 20–30% in barley. While feeding, the sunn bugs inject proteolytic and amlolytic enzymes into the wheat causing breakdown of the gluten which reduces the quality of the flour resulting in the production of inferior dough. Traditional control methods include the early application of fertilizerFertilizer
Fertilizer is any organic or inorganic material of natural or synthetic origin that is added to a soil to supply one or more plant nutrients essential to the growth of plants. A recent assessment found that about 40 to 60% of crop yields are attributable to commercial fertilizer use...
on winter crops, the early sowing of spring crops, the selection of varieties resistant to the pest and varieties that ripen early and can be harvested early, autumn ploughing in of crop residues and the spraying of crops with pesticide
Pesticide
Pesticides are substances or mixture of substances intended for preventing, destroying, repelling or mitigating any pest.A pesticide may be a chemical unicycle, biological agent , antimicrobial, disinfectant or device used against any pest...
s, which should only be done when pest populations rise to economically damaging levels.
Integrated pest management
Researchers at the Entomology Research Laboratory at the University of Vermont and agricultural researchers working throughout the infested region have been co-operating since 1997 to produce an integrated management plan for the sunn pest. Various on-going research projects are taking place. Additionally, an international forum, SunnPestNet, has been set up to improve communication between researchers and agriculturalists from all over the world.Research is being undertaken at the Natural Resources Institute at the University of Greenwich
University of Greenwich
The University of Greenwich is a British university located in the London Borough of Greenwich, London, England. The main campus is located on the grounds of the Old Royal Naval College, a central location within the Maritime Greenwich UNESCO World Heritage Site.-History:The history of the...
. This project aims to assess the economic thresholds for pest populations, the possible role of egg parasitoids and the possible use of pathogenic fungi to control the pests. Also being investigated is the role of semiochemicals
Semiochemical
A semiochemical is a generic term used for a chemical substance or mixture that carries a message. These chemicals acts as messengers within or between species...
in enabling individual bugs to locate potential mates and suitable host plants, and whether such chemicals could be used as a possible means of control. There is also an initiative to identify resistant strains of cultivated and wild cereals with the objective of developing the germplasm
Germplasm
A germplasm is a collection of genetic resources for an organism. For plants, the germplasm may be stored as a seed collection or, for trees, in a nursery.-See also:*Germ plasm, the germ cell determining zone...
.
A study published in 2008 identified several entomopathogenic nematodes that showed promise as biocontrol agents.