Research on the Flight Evolution of Melolontha Melolontha L. (Coleoptera, Scarabaeidae) Species in the Central of Moldavia Conditions, Romania

The cockhafer (Melolontha melolontha L.) is the most widespread and best known bug. It is a polyphagous bug, being harmful both in adulthood and in larva stage. The researches were conducted at Agricultural Research and Development Station (A.R.D.S.) of Secuieni, Neamţ county, Romania, and followed the evolution of adult flight, during 1993 - 2012 with a light trap help. The gatherings and records were made daily from 1 April to 31 October every year, during the observation period. Dividing the observation period into four stages of five years each, it was found that the largest number of specimens, 38059, was collected in the second stage (1998 - 2002), followed by the third stage (2003 - 2007) with 18167 specimens, first stage with 12173 specimens, and the lowest number of 286 specimens was recorded in the fourth stage (2008 - 2012). The adults flight started in all the years in the second or the third decade of April and lasted until the second or the third decade of May, with the exception of 1995 si 2009 when he finished in the first decade of June. The average duration of the flight was 39 days. The maximum flight curve was reached, in all years of observation, in the third decade of April and first decade of May. The maximum intensity of flight curves was recorded every three years, as follows: 1994, 1997, 2000, 2003, 2006, 2009, 2012. This shows that, in Secuieni conditions, the insect has one generation at 3 years. Highest intensity of flights has been in the years 2000, when the top flight was conducted by 38059 specimens, 2003 with 13912 specimens/flight and 1997 with 10221 specimens/flight.