Long-term dynamics density of populations of interspecific cereal aphids (homoptera, aphididae) throughout the growing season of winter wheat under steppes Ukraine

Abstract

The peculiarities of composition and nutritive cereal aphids plants are divided into two groups of biological, migratory and non migratory. In place of food can be divided cereal aphids, which are harmful to the aerial organs of grasses and roots. The most harmful and widespread cereal aphids that feed on the above ground organs of wheat. In non migratory cereal aphids usually overwinter eggs on the leaves of winter crops, perennial and wild grass. In the southern regions of possible wintering adults. Spring revived the larvae developing in wingless females founding. Last parthenogenetic multiply and produce several generations. There winged females founding fly to other plants, including grasses in spring, where they continue to multiply. The number of generations of aphids and fertility depend largely on the weather. After harvesting the spring crop insects feed on the windfall, wild grasses and then migrate to the shoots of winter. In spring, with the onset of cold weather, there are female-polonosky that reviving larvae that turn into winged males and wingless females. After mating, females lay overwintering eggs.

With no harmful migratory species most common cereal aphids - Schizaphis (Toxoptera) graminum Rond., United Cereal aphids - Sitobion (Macrosiphum) avenae F., barley (Russian wheat) aphids - Diuraphisnoxia (Mordvilko) (Brachycolusnoxius Mordv.) Aphids and corn - Rhopalosiphummaidis Fitch. Migrating aphids living on grasses in the summer and autumn migrate its primary host plant, usually tree or shrub. They are insects overwinter in the egg stage. Spring revived the larvae from the eggs that give rise to numerous colonies on the leaves. The deterioration of the living conditions of aphids on trees leads to lifestyle changes. GH Shaposhnikov attributes this deterioration with increasing plant tissues in the synthesis of organic compounds that cause a depletion of tissue leaves non-protein nitrogen content in plants decreasing water concentration of juice increased and its osmotic pressure. There winged females migrate to the founder of cereals, where cereal aphids reproduce parthenogenetic during the summer. In autumn there are winged individuals who are moving into primary forage plants. The emergence and subsequent remihrantov bisexual generation mostly stimulated by short photoperiod combined with decreasing temperature. Since migratory species the most important are the usual cereal Schizaphis (Toxoptera) graminum Rond., And bird cherry -zlakova Rhopalosiphumpadi L. and Rosa Cereal - Metopolophium dirhodum Walk. Aphids.

Harmful cereal aphids is also reflected in the decrease of sowing qualities of seeds, germination and vigor. Of great importance in this case is that eating cereal aphids promotes harmful contamination of seeds microflora. And other consumer reduced grain quality. Thus, great food cereal aphids in winter wheat leads to poor quality of flour. At the same time, some researchers did not note the similarity reduce cereal aphids damaged seeds. Great cereals and cereal aphids rose, feeding on leaves, "intercept" assimilates transported to the ear.

Objective: To study the characteristics of seasonal fluctuations in long-term dynamics of interspecific state density populations of cereal aphids (Nomoptera, Aphididae) during the growing season of winter wheat under steppes of Ukraine.

Methods: Experimental studies conducted over the years 2014-2016. In terms of stationary experiments agricultural companies Syngenta AG with. Little Robin Belotserkovsky district, Kyiv region Lybed sort of winter wheat.

In spring and summer route obstezhennyahobliky state population density of cereal aphids was carried out by systematic review of research on the plant site every 7 days at 10 locations evenly under the scheme of the letter Z selected 10 plant samples are equivalent to one stem, repetition 4 - fold.

In the autumn growing season of winter wheat account population density of states of cereal aphids carry out entomological net cutting method with variable bags series performed with 50 strokes with the following terms of 100 strokes entomological nets.

During the winter wheat growing season in spring and summer during the years 2014-2016. The total density of states of interspecific populations of cereal aphids ranged from 1-17 copies. / Stem ear.

In the autumn growing season of winter wheat during the 2014-2016 biennium. Total density of states of interspecific populations of cereal aphids ranged from 5-50 copies. / 100 strokes entomological nets.

The results of long-term observations of the dynamics of the density of harmful insect herbivores cereal aphids in winter wheat crops. Determined that the highest density of pests in crops of winter wheat in 2016 was in the range of 6.0 to 17.0 copies per 1 plant in the spring and summer growing season crops, and in autumn the highest density was in 2016 at around 10, 0 - 50.0 copies per 100 strokes nets.

Based on our own research suggested making timely monitoring of harmful insect herbivores cereal aphids to install and needs EPSH chemical crop protection from herbivores winter wheat. Proposals to make timely route inspection records pest density in two winter wheat growing season: spring, summer and autumn.

Keywords: interspecific populations, long-term dynamics, koktsinelidy, spring, summer, autumn, growing season, winter wheat