A map was made of the distribution of macroalgae groupings in shallow waters of Admiralty Bay. The map was plotted on the basis of analysis of color reversal air photograph taken from a helicopter. A significant agreement of the results of the pictures analysis with the field studies was found. Also a number of areas not covered by field studies was determined as the ones of probable occurrence of macroalgae. A detailed map of distribution of four distinguished forms of macroalgae groupings was plotted for a small area in the region of Shag Point. Each of these forms is characterised by different association of algal species.
The trials conducted with selected chemical and biological insecticides in 1998-2000 showed the highest effectiveness of Karate Zeon 100 CS (lambda-cyhalotrine) in European corn borer (ECB) larvae control in sweet corn. The efficacy of biological insecticides containing Bacillus thuringiensis ssp. kurstaki: Biobit 3.2 WP and Lepinox WDG was very variable between the years. Reasons for insufficient efficacy of these products are discussed. The most appropriate time for the application of a chemical insecticide against ECB larvae are plant developmental stages since the beginning of pollen shedding to full blooming (63–67 BBCH scale). The efficacy of treatment was the highest at that time.
Observations on the development of the horse chestnut leafminer on red horse chestnut (Aesculus x carnea H.) were carried out in Wrocław, Lower Silesia, Poland, in 2001–2003. Three generations of the pest were recorded to lay eggs on the red horse chestnut leaves. Although females of each generation deposited eggs abundantly, the hatching larvae died after a short period of feeding in the plant’s leaves and the species did not complete its development on this tree. Mostly L1 and L2 larvae were found inside the leaf mines. The observed leaf damage was, therefore, negligible.