(2006, 2007, 2008). It was less important and somewhat less complicated to establish the most suitable time for spraying in the case of the chlorpyrifos + cypermethrin combination in comparison with the pyrethroids applied separately. The effectiveness of the tested insecticides was markedly influenced by the time of spraying. The effects of the pyrethroids applied singly achieved results comparable to those of the chlorpyrifos + cypermethrin combination only at the optimal spraying time. The most suitable time for spraying varied from the point when the first females appeared in yellow water traps in somewhat higher quantities to the time when a substantial proportion of caught females was able to lay eggs.

The effects of two pyrethroid (lambda-cyhalothrin, alpha-cypermethrin) and two neonicotinoid (acetamiprid, thiacloprid) insecticides on B. pisorum L. eggs were compared under field conditions in the Czech Republic in 2005–2007. The main objective of the study was to find out what real effects can be expected from the available insecticides registered in Europe when applied at the time of the first egg occurrence on lower pods. In general, the rates of Bruchus pisorum egg (+ first instar larvae) survival were significantly lower with all the insecticides compared in the study, in each of the three years (2005, 2006, 2007). The tested insecticides showed some ovicidal effects and also some larvicidal effects. The tested pyrethroids (lambda-cyhalothrin, alpha-cypermethrin) showed somewhat higher effectiveness in comparison with the neonicotinoids (acetamiprid, thiacloprid). Alpha-cypermethrin was the most effective in all three years. In 2006 and in 2007 this insecticide significantly reduced the rates of egg survival in comparison with acetamiprid. In contrast, acetamiprid was the least effective insecticide in each of the three years.

Seidenglanz M., Rotrekl J., Smýkalová I., Poslušná J., Kolařík P. (2010): Differences between the effects of insecticidal seed and foliar treatments on pea leaf weevils (Sitona lineatus L.) in the field pea (Pisum sativum L.). Plant Protect. Sci., 46: 19-27.Tested seed treatments (two doses of thiamethoxam, thiamethoxam + fludioxonil + metalaxyl-M; two doses of clothianidin + beta-cyfluthrin) showed high effects on pea leaf weevils (Sitona lineatus L.) which approved relatively long-lasting and sufficient protection of several bottom nodes of stipules simultaneously. The effects of foliar treatments (chlorpyrifos + cypermethrin; acetamiprid, lambda-cyhalothrin) sometimes were evident only on the node which was determined as the youngest node at the time of spraying. The effects of the compared seed and foliar treatments on the reduction of S. lineauts larvae numbers on roots were not proven as positive. It is possible to conclude that the foliar application had no real effect in this sense at all. However, positive significant effects of thiamethoxam and clothianidin + beta-cyfluthrin on root nodulation in general were recorded. Especially higher doses of the seed treatments increased overall nodulation from 43% till 363%.

Seidenglanz M., Poslušná J., Rotrekl J., Kolařík P., Hrudová E., Tóth P., Havel J., Bernardová M.

Seidenglanz M., Huňady I., Poslušná J., Løes A.-K. (2011): Influence of intercropping with spring cereals on the occurrence of pea aphids (Acyrthosiphon pisum Harris, 1776) and their natural enemies in field pea (Pisum sativum L.). Plant Protect. Sci., 47: 25-36.Occurrences of pea aphids and their natural enemies (syrphids, mummies caused by entomopathogenic fungi Beauveria sp. and by the parasitic wasp Aphidius ervi) were compared in monocultures and mixtures of field peas and spring cereals in three seasons (2008)(2009)(2010). At the beginning of colonisation, the occurrence of aphids was not substantially influenced by intercropping with cereals. However, the numbers of pea aphids located on inflorescences started to decline earlier in mixtures compared with monoculture. More syrphids (eggs + larvae) were found in mixtures than in monoculture, and more syrphid eggs were found in young aphid colonies (10 to 20 individuals) in mixtures. Intercropping did not influence the occurrence of fungal mummies (Beauveria sp.), but mixtures tended to have more aphid colonies infested by A. ervi in 2008 and 2009.