Researches on feeding behavior and the amount of damage on potato plant by leptinotarsa decemlineata (SAY) (Coleoptera: Chrysomelidae)

The study aimed to find out the feeding behavior, correlation among number of individuals and the amount of damage by Leptinotarsa decemlineata (Say) (Coleoptera: Chrysomelidae). Experiments conducted in a controlled climate room conditions at temperature 25±1ºC, relative humidity 55 ± 5% and photoperiod 16:8 h, using L. decemlineata individuals. Experiments on the feeding behavior of L. decemlineata were carried out with all individual larvae periods and female individuals during the preoviosition period, female individuals during the oviposition period and young male individuals seperately and individually on the potato plant. In terms of results, within the period of observation of 1 hour, the total feeding period completed by the fourth-stage larvae with the longest average of 3.284,00±1,03 seconds. The female individuals in the oviposition period were individuals who completed this period in the shortest time with an average of 786,00±1,12 seconds. The duration of a feeding period was the longest for an average of 716,06±85,93 seconds in the individuals of the second-stage larvae. This period lasted at least 257,52±24,24 seconds on the average in the first-stage larvae. When the feeding number was taken into consideration, this number was found mostly in the first larval period with an average of 5,00±0,07. The minimum number of feeding was recorded in female individuals in the oviposition period with an average of 1,70±0,10. In the studies of amount of damage, the areas where L. decemlineata individuals consumed at different biological periods for 4 hours on the leaves of the potato plant were calculated. According to the results obtained from these studies, with the area consumed 328,39±41,21 mm2, the fourth-stage larvae took the first place. The individuals in this biological period followed the female individuals during the preoviosition period with 317,54±36,40 mm2, female individuals during the oviposition period with 281,75±16,51 mm2, young male individuals with 280,41±26,01 mm2 and the third-stage larvae with 119,02±20,26 mm2. After the second-stage larvae, which consumed 20,94±2,99 mm2, the individuals in the first-stage consuming 7,47±0,79 mm2 area consumed the least amount of area. Also, a correlation was found between number of individuals and the amount of damage caused by them.