Energy substances played an important role in adversity resistance of insects. In order to clarify the difference of energy substances utilization rates in the larvae of Stegobium paniceum and Lasioderma serricorneunder CO

2

exposure

the contents of polysaccharide

soluble protein and lipid in larvae of these two species were determined after their exposure to CO

2

for 2

4

6

8 h under different CO

2

concentrations (10%、30%、50%、70% and 90%). In addition

the utilization rates of the energy substances in insects were also determined after they were exposed to the different CO

2

concentrations until dead. The results showed that the content of energy substances decreased with increasing CO

2

concentration under the same exposure time or extension of exposure time under the same CO

2

concentration. The content of energy substances were the lowest in both of the two species after these insects were exposed to 90% CO

2

for 8 h

and the content of polysaccharide

soluble protein and lipid in S. paniceum were 13.75

165.42 and 37.25 μg/insect

respectively

which were 14.87

176.14 and 38.49 μg/insect in L. serricorne. Both of the two species performed a similar utilization to the three kinds of energy substances after each CO

2

exposure until dead

with the order of polysaccharide

>

lipid

>

soluble protein

and the utilization rates decreased significantly with the CO

2

concentration increase. Furthermore

there was no significant difference in the soluble protein utilization between the two species

but the utilization rates of polysaccharide and lipidin S. paniceum was significantly higher than that of L. serricorne. The results showed that the CO

2

concentration had significant influences on the energy substances of polysaccharide

soluble protein and lipid in Stegobium paniceum and Lasioderma serricorne larvae

thus we could use CO

2

treatments to affect the physiological index of insects for pest control in the Chinese medicinal materials protection.