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The side effects of methoxyfenozide, indoxacarb, pyridaben, acetamiprid, azadirachtin A, spinosad, and propargite on Aphidius colemani, Aphidoletes aphidimyza, and Neoseiulus cucumeris were tested under laboratory conditions. Methoxyfenozide had low toxic effect on all three species, causing mortality after 24 h in 4.4, 11.4, and 29.3% of N. cucumeris, A. colemani, and A. aphidimyza, respectively. Similarly, indoxacarb caused mortality after 24 h in 11.9, 20.0, and 24.9% of A. aphidimyza, N. cucumeris, and A. colemani, respectively. In general, N. cucumeris exhibited the lowest sensitivity to all the insecticides. In contrast, A. colemani was highly sensitive to most of the tested insecticides. Methoxyfenozide was shown to significantly reduce fecundity of A. aphidimyza. In contrast, there was no effect of pure azadirachtin A on A. colemani fecundity. Results showed that both methoxyfenozide and indoxacarb would be suitable for use in the integrated pest management (IPM) because of their low toxic effect against all of the tested model species of natural enemies.

Psota V., Ouředníčková J., Falta V., 2010. Control of Hoplocampa testudinea using the extract from Quassia amara in organic apple growing. Hort. Sci. (Prague), 37: 139-144.In 2008 and 2009 the effects of quassin and neoquassin (oxygenated triterpenes) on apple sawfly (Hoplocampa testudinea Klug, 1814) were studied. In the Czech Republic, monitoring was carried out in small-plot trials and in one laboratory experiment. The extract containing quassin and neoquassin was made by boiling wood chips of a tropical shrub Quassia amara L. (Sapindales: Simaroubaceae). The experimental dosages were 3, 4.5, 6, and 9.25 kg of wood chips/ha. Spray treatment with the quassia extract was carried out just before most larvae hatched out. It was statistically proven that the extract from the wood of Q. amara reduced the apple sawfly infestation of fruitlets. Extract in the dosage corresponding to 3-4.5 kg of quassia wood chips for 1/ha appeared as optimal. The efficacy of these dosages was approximately 40-50%, and the efficacy above 80% was record.

Rodent bark gnawing is common during winter in times of low or unavailable food supply. During the growing season, it is a rare phenomenon, but can occur due to low food supply and/or poor food quality resulting from climatic influence. We evaluated this unusual damage of apple tree (Malus domestica) orchards by rodents in two localities in the Czech Republic. In 2019, 24% of trees in the orchard in Brno were gnawed by the common vole (Microtus arvalis) population. Damage in the Holovousy orchard by water vole (Arvicola amphibius) was inspected in 2020 and showed that 15% of trees were damaged with massive root gnawing. These findings were compared with gnawing in forest beech plantations in 2019, with up to 13% of trees damaged. Three rodent species (Microtus agrestis, M. arvalis and Clethrionomys glareolus) participated in the damage. Detailed description of the various vole species’ damage in vegetation period, which somehow differs from winter time damage, may help in the future in early recognition and early application of plant protection in times when this phenomenon may reappear.

BACKGROUND We investigated several aspects that could affect the role of the European earwig (Forficula auricularia) as a generalist predator in orchards: (i) seasonal activity in apple orchards, (ii) effectiveness of two cardboard trap types (roll vs tape) to enhance earwig densities, (iii) the effect of pesticides (chlorpyrifos‐methyl, spinosad, indoxacarb, spirotetramat, pirimicarb, sulphur, fluopyram tebuconazole) on earwig survival and behaviour, and (iv) the perception of European fruit growers of the earwigs’ role as a predator or pest. RESULTS The highest activity of earwigs in apple trees was observed in summer. Roll traps were a more effective capture method than tape traps. The roll traps also significantly increased earwig abundances in trees. Only the earwigs exposed to the insecticides indoxacarb, spinosad and chlorpyrifos‐methyl had significantly higher mortality and more erratic behaviour than earwigs from the control treatment. Earwigs from orchards with long‐term (>10 years) application of chlorpyrifos‐methyl had significantly lower mortality when exposed to this insecticide than earwigs from nonsprayed orchards. The fruit growers perceived earwigs as natural enemies of aphids and psyllids but also as pests. However, they regarded the damage caused by earwigs as economically unimportant without the necessity for management against them. CONCLUSION Fruit growers can increase earwig densities by installing rolled cardboard bands around trees. The highest seasonal activity of European earwigs coincides with applications of insecticides in orchards. This could disturb the earwigs' potential to suppress pest populations because several insecticides widely used in orchards have lethal and sublethal effects on earwigs even though they seem to develop some degree of pesticide resistance over time. © 2020 Society of Chemical Industry