Entomological Review (2022) 102, 286-302

V.G. Kaplin and P. Yu. Lysikov (2022)
Distribution of the European wheat stem sawfly Cephus pygmaeus (L.) (Hymenoptera, Cephidae) in the Russian Federation and the dynamics of its density and harmfulness in the forest-steppe of the Middle Volga Region
Entomological Review 102 (2), 286-302
Abstract: The most favorable conditions for the European wheat stem sawfly Cephus pygmaeus occur in wheat crops in the steppes and forest-steppes in the south of European Russia and West Siberia. The density and harmfulness of the pest decrease toward the mountainous areas, to the north and northeast, and with transition from steppes and forest-steppes to broad-leaved, small-leaved, and especially mixed forests. The current climate warming is accompanied by increasing density and harmfulness of C. pygmaeus in the regions of widespread wheat cultivation adjacent to the West Siberian pest focus within Altai Territory. In the forest-steppe of the Middle Volga region, the pest density has steadily declined in the last 40 years due to the spread of no-till techniques in wheat cultivation. The main factor of wheat resistance to C. pygmaeus in the forest-steppe of the Middle Volga region seems to be the small outer culm diameter (less than 2.6 mm). The spread of no-till farming combined with cultivation of high-yielding sawfly-resistant wheat varieties with partially filled culms approved for use in the Russian Federation has led to the pest density decreasing below its economic threshold level and, correspondingly, less extensive use of insecticides and an increase in the density and effectiveness of entomophages. Damage to productive stems of soft winter wheat by sawfly larvae was insignificant, only 0.5–1.1%. The thousand kernel weight in the wheat ears from the damaged culms decreased by 5–15%, and the total kernel mass in such ears, by 6.5% as compared with intact stems. A decrease in winter wheat yield was 0.6–1.2%. The loss of spring wheat crop due to the sawfly was on average one-tenth that of winter wheat crop. The use of insecticides against the European wheat stem sawfly is not recommended due to their low efficiency, while agrotechnical and biological techniques are preferable. Among entomophages, Collyria coxator (family Ichneumonidae) is the most effective against sawfly larvae.
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Link to article at publishers website

Research topic(s) for pests/diseases/weeds:
surveys/sampling/distribution
population dynamics/ epidemiology
Research topic(s) for beneficials or antagonists:
surveys/distribution/isolation

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Cephus pygmeus	Wheat (Triticum)	Russia (Eur.)
Collyria coxator (parasitoid)	Cephus pygmeus	Wheat (Triticum)	Russia (Eur.)