The Russian wheat aphid (Diuraphis noxia) is an aphid that can cause significant losses in cereal crops. The species was introduced to the United States in 1986 and is considered an invasive species there. This aphid is pale green and up to 2 mm long. Cornicles are very short, rounded, and appear to be lacking. There is an appendage above the cauda giving the aphid the appearance of having two tails. The saliva of this aphid is toxic to the plant and causes whitish striping on cereal leaves. Feeding by this aphid will also cause the flag leaf to turn white and curl around the head causing incomplete head emergence. Its host plants are cereal grain crops including wheat and barley and to a lesser extent, wild grasses such as wheatgrasses, brome-grasses, ryegrasses and anything in the grass family.
The Russian wheat aphid is native to southwestern parts of Asia. It was introduced to many countries in Europe and Africa. It was first found in the U.S. in 1986 in Texas. The species was probably transmitted through wheat imports.[1]
Russian wheat aphids are one of the most significant pests on wheat in the world. It was first identified as a pest in Crimea in 1901. And the origin of D. noxia can be traced back to Eurasia when it was a pest on cereals. Aside from direct damages to crops, they are also vectors for barley yellow dwarf, barley mosaic and sugarcane mosaic viruses.[2]
After its detection in the US in 1986, the Russian wheat aphid quickly became a major pest of wheat and barley. The researches that found D. noxia resistant strains of wheat were in 1996 but genotypes of aphids that were able to overcome these resistance strains began to appear in 2003.[3]
D. noxia feeds on the host plant through the phloem. The result of being a host of an aphid are damages through nutrient drainage which develops into symptoms such as chlorosis, necrosis, wilting, stunting and other growth impairment. The aphid further increases the nutritional drainage of the host plant through eliciting an increase in essential amino acid in the phloem sap by triggering a breakdown of proteins in the host plant.[4]
D. noxia has a variety of effects on the host plant and the subsequent product for which the plant is used. The host plants response to an aphid infestation is a loss of turgor and reduced growth due to water imbalances as the aphid feed on phloem. The aphid also causes reduction in biomass of the whole plant. However, once the aphid is removed the plant quickly recovers absolute growth rate and has increased relative growth. As a result of previous infestation, the recovering plants are more efficient in carbon assimilation that results in increased relative growth rates and compensates for the leaf damages during aphid infestation.[5]
Aphid infestation on wheat also affects the flour that is made from infested wheat plants. Aphid feeding in wheat results in qualitative and quantitative losses in flour yield. Flour derived from aphid infested wheat has a significant negative effect on the gliadin/glutenin ratio which reduces the bread making quality of aphid infested wheat plant flour.[6] However, although it does reduce the quality of flour for bread-making, it is still within acceptable ranges to be usable.[7]
As D. noxia became an invasive species in North America, it is notable that they possess enough endurance to cold temperatures to survive through winter. Aphid populations can overwinter through temperatures between 0 and 5 degrees Celsius. However, temperatures below 10 degrees Celsius will lead to catastrophic decrease in population.[8] In addition to survivability in sub zero temperatures, the aphids are also capable of rapid cold hardiness (RCH) which allows an insect to develop protection against sudden sub freezing temperatures. Moreover, aphids are capable of RCH without any cost to their reproductive capability.[9]
A method to control D. noxia infestation of wheat and barley is through host control. Host control consists of raising crops that possess genes that may contribute to aphid resistance. Research has been conducted to identify the specific genes that can be attributed to aphid resistance and the information marked to assist in breeding aphid resistant strain of wheat or barley. The genes that have been identified so far have been Dn1-Dn9 and Dnx.[10][11] As these genes are marked for selective breeding, it may serve to manage the population of aphids.[10]
Hopper et al.'s research into biological control is based on the non-pest status of D. noxia in Eurasia, its area of origin. It is possible that natural enemies in that area limit the abundance of the aphids, therefore preventing them from becoming pests. Based on the selection of natural enemies of D. noxia in Eurasia, the paper performed a survey of host specificity of different species of parasite from the genus Aphelinus. Although host specificity and range differs from species to species, Aphelinus hordei has a much narrower range that includes D. noxia. The behavior of females of A. hordei oviposition orients the species specificity towards D. noxia. Female A. hordei rarely approaches aphids that are not of the D. noxia variety. Due to this host specificity, the paper suggests that biological control of D. noxia may be viable through A. hordei introduction into the west.[3]
Potassium phosphate was studied as a resistance inducer on wheat plants against D. noxia. It may serve as a method to deal with the population of aphids that have overcome wheat's genetic resistance. The study indicated that potassium phosphate treated plants either a resistant strain or a non-resistant strain both show a decrease in aphid numbers that were feeding. Thus the data suggests treating wheat with potassium phosphate to induce tolerance against D. noxia.[4]
The Russian wheat aphid (Diuraphis noxia) is an aphid that can cause significant losses in cereal crops. The species was introduced to the United States in 1986 and is considered an invasive species there. This aphid is pale green and up to 2 mm long. Cornicles are very short, rounded, and appear to be lacking. There is an appendage above the cauda giving the aphid the appearance of having two tails. The saliva of this aphid is toxic to the plant and causes whitish striping on cereal leaves. Feeding by this aphid will also cause the flag leaf to turn white and curl around the head causing incomplete head emergence. Its host plants are cereal grain crops including wheat and barley and to a lesser extent, wild grasses such as wheatgrasses, brome-grasses, ryegrasses and anything in the grass family.
The Russian wheat aphid is native to southwestern parts of Asia. It was introduced to many countries in Europe and Africa. It was first found in the U.S. in 1986 in Texas. The species was probably transmitted through wheat imports.
Diuraphis noxia es un áfido que puede producir importantes pérdidas en los cultivos de cereales. Este áfido es de color verde pálido y de unos dos milímetros de longitud. La saliva de este pulgón es tóxica para las plantas y causa cambios en la coloración de las hojas de los cereales. Las picaduras de alimentación también causan deformaciones en las hojas. Las plantas huéspedes pueden ser: cereales cultivados incluyendo el trigo y la avena y en menor medida hierbas silvestres como Bromus o Lolium.
Diuraphis noxia (le puceron russe du blé) est une espèce d'insectes hémiptères de la famille des Aphididae, originaire d'Eurasie.
C'est un puceron qui peut causer des pertes significatives dans les cultures de céréales.
Ce puceron est vert clair et peut atteindre 2 mm de long. Les cornicules sont très courtes, arrondies, et semblent faire défaut. Un appendice situé au-dessus de la queue donne l'impression que le puceron possède deux queues.
La salive de ce puceron est toxique pour les plantes et provoque l'apparition de striures blanchâtres sur les feuilles de céréales. Les piqures de ce puceron sur les feuilles supérieures les font blanchir et s'enrouler autour de l'épi, empêchant celui-ci d'émerger.
Les plantes hôtes sont les céréales à paille, notamment le blé et l'orge, mais également le seigle et l'avoine, et dans une moindre mesure les graminées sauvages. On a constaté que ce puceron se nourrissait sur au moins 47 espèces sauvages, telles que Dactylis glomerata, Bromus mollis, Bromus inermis, Bromus rubens, Elymus repens, Elymus angustus, Festuca rubra, Festuca pratensis[1].
L'aire de répartition de Diuraphis noxia est quasi cosmopolite. Elle couvre en effet la totalité de l'Europe, le Proche-Orient, l'Asie centrale et la Sibérie occidentale, l'Amérique du Nord et l'Amérique du Sud, l'Afrique du Nord et l'Afrique australe[1]. Le puceron russe du blé est également présent en Chine occidentale (Xinjiang)[2].
L'espèce a été détectée pour la première fois en Amérique du Nord en 1980 à Mexico. Elle a été introduite accidentellement en mars 1986 près de Lubbock (Texas), d'où elle s'est répandue dans le territoire des États-Unis. Elle est considérée dans ce pays comme une espèce envahissante[3],[4].
Diuraphis noxia (le puceron russe du blé) est une espèce d'insectes hémiptères de la famille des Aphididae, originaire d'Eurasie.
C'est un puceron qui peut causer des pertes significatives dans les cultures de céréales.
Ruska pšenična uš (znanstveno ime Diuraphis noxia) je vrsta pravih listnih uši, ki je velik škodljivec na žitu.
Gre za bledo zeleno žuželko, ki v dolžino doseže do 2 mm. Za rastline je strupena njena slina, ki povzroči odmiranje listov. Na listih se sprva pojavijo svetle proge, kasneje pa listi povsem pobledijo in se zvijejo. Gostiteljske rastline so žita, pri čemer se najraje zadržuje na pšenici in ječmenu, redkeje pa jo lahko najdemo tudi na divjih travah.
Vrsta je domorodna na jugozahodu Azije, od koder se je kasneje razširila po Evropi in Afriki. V ZDA so jo prvič našli v Teksasu, leta 1986. V državo je verjetno prišla s pošiljko pšenice.[1] Danes ima v ZDA status invazivne vrste
Ruska pšenična uš (znanstveno ime Diuraphis noxia) je vrsta pravih listnih uši, ki je velik škodljivec na žitu.
Gre za bledo zeleno žuželko, ki v dolžino doseže do 2 mm. Za rastline je strupena njena slina, ki povzroči odmiranje listov. Na listih se sprva pojavijo svetle proge, kasneje pa listi povsem pobledijo in se zvijejo. Gostiteljske rastline so žita, pri čemer se najraje zadržuje na pšenici in ječmenu, redkeje pa jo lahko najdemo tudi na divjih travah.
Vrsta je domorodna na jugozahodu Azije, od koder se je kasneje razširila po Evropi in Afriki. V ZDA so jo prvič našli v Teksasu, leta 1986. V državo je verjetno prišla s pošiljko pšenice. Danes ima v ZDA status invazivne vrste
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Ячменная тля[1] (лат. Brachycolus noxia) — многоядный вид тли из семейства Настоящие тли (Aphididae). Хотя тля называется ячменной, наибольший ущерб наносится пшенице. Повреждается также рожь, овес.
Ячменная тля (лат. Brachycolus noxia) — многоядный вид тли из семейства Настоящие тли (Aphididae). Хотя тля называется ячменной, наибольший ущерб наносится пшенице. Повреждается также рожь, овес.
