Dry weight and fat content of spruce bark beetles (Ips typographus, L., Coleoptera) from different stages of dispersal
Frank Bohlander University of Applied Sciences Erfurt, Germany; Study of  Forestry 
Dry weight and fat content in male and female spruce bark beetles (1) freshly emerged from a lap rearing, caught inside forest with (2) pheromone slot traps, (3) avoiding pheromone traps and caught with accompanying passive flight traps (4) landing on trap trees, and (5) walking on trap trees for an unknown time, were analysed. 
Male and female beetles from (1) the lap rearing had a dry weight of 5,2mg  (+/- 0,23) and 4,8mg +/- 0,24). Males and females from (2) pheromone slot traps 4,5 mg (+/-0,8) and 4,2 (+/-0,8), respectively. In case of (3) passive flight traps, males weight 4,7mg (+/-0,6) and females 4,1mg (+/-0,8). Males landing on trap trees 4,7mg (+/- 0,9) females 4,5mg (+-/0,9) and (5) 4,2mg (+/- 0,8) and 4,6mg (+/-) 0,6), respectively. 
The content of lipids in the bark beetles was measured in acyl ester equivalents (nmol/mg dry weight) The males and females of the five groups (1-5) showed noteworthy differences. (1) 976/886 nmol/mg; (2) 369/365; (3) 624/539; (4) 452/445); (5) 460/361. Moreover, the amount of acyl ester equivalents within the 4 groups from the forest showed high variances. 
Due to the different energetic status beetles could be differentiated. Beetles caught with pheromone traps seemed to be strongly exhausted, whereas beetles caught by passive traps had the highest average reserves. In accordance with other findings Ips typographus seems to be more susceptible to pheromone signals when his energetic reserves decrease.

07 - Dry weight and fat content of spruce bark beetles Ips typographus, L., (Coleoptera) from different stages of dispersal