Abstract:

Y-tube olfactometer and EthoVision3.1 behavior instrument were adopted to study the learning ability of Scleroderma sichuanensis at the age of 0-5 day after being stimulated by the smell of a mixture of Batocera horsfieldi excrement and sawdust. S. sichuanensis was released in the lab and field to compare its parasitism with or without learning experience on B. horsfieldi larva at the age of 2-3 day. This experiment was aimed at exploring means for enhancing control effect of S. sichuanensis on B. horsfieldi. The result showed that S. sichuanensis without learning significantly eluded the mixture of B. horsfieldi excrement and sawdust (P<0.05), while S. sichuanensis with learning remarkably increased its taxis to the mixture (P>0.05). EthoVision3.1 behavior instrument analysis indicated that at the smell source area, the density of behavior traces of S. sichuanensis with learning was much higher than that of S. sichuanensis without learning. S. sichuanensis with learning obviously had longer resident time, moving distance and moving time at the smell source area than that of S. sichuanensis without learning (P<0.05). At the gathering area, S. sichuanensis with learning obviously had longer silent time (P<0.05), but had shorter resident time, moving distance and reaction time (P<0.05) than that of S. sichuanensis without learning. The average time it took for S. sichuanensis with learning to find the host was 39.99 s, and the amount of the found hosts in 60 s was 23.33, which were significantly different from that done by S. sichuanensis without learning. In release experiment conducted in the lab the number of S. sichuanensis with learning and B. horsfieldi larva at the age of 2-3 day was at ratios of 1 ∶1, 2 ∶1, 4 ∶1, respectively. It was found out that at the ratio 4 ∶1 S. sichuanensis with learning had the best control effect (P<0.01) with a parasitic rate of 86.67%. Releasing S. sichuanensis in the field also had a good control effect on B. horsfieldi larva at the age of 2-3 day. S. sichuanensis with learning had the best control effect on B. horsfieldi with a parasitic rate of 58.44% when the ratio of S. sichuanensis and B. horsfieldi larva was 4 ∶1.

Key words: Batocera horsfieldi, Scleroderma sichuanensis, learning experience, Populus spp., control effect