Acknowledgements
		I would like to express my sincere gratitude to my friends Zdravko Kolev (Helsinki) and Dr Stoyan Beshkov (Sofia) for their permanent support and many interesting discussions on entomological topics, also for providing invaluable literature.   My special thanks to Dr Stoyan Beshkov for providing many high quality photographs for this website.   I would like to thank Prof Dr Horst Aspöck (Vienna) for his support and many discussions on entomological topics.   I thank Dr Alexi Popov (Sofia) and Dr Milen Marinov (Sofia) for the valuable scientific information and literature.