Using insects and bacteria to dispose of nematode-infected pine timber
Author of the article:CHEN Hao-Nan YAN Zhen-Tian YANG Shi-Zhang LIU Yu-Sheng CHEN Bin
Author's Workplace：Chongqing Key Laboratory of Vector Insects; Institute of Entomology and Molecular Biology, Chongqing Normal University, Chongqing 401331, China; Chongqing Station of Forest Pests Control and Quarantine, Chongqing 400700, China; Institute of Environmental Biology and Insect Resources, College of Plant Protection, Shandong Agriculture University, Taian 271018, China
Key Words：pine wood nematode disease; conversion treatment; Pleurotus pulmonarius; Protaetia (Liocola) brevitarsis (Lewis)
Abstract：
[Objectives] To investigate a new, pollution-free method of
disposing of pine wood infected with nematodes and provide new ideas for the
effective utilization of spent mushroom substrates used in the production of
edible fungi. [Methods] The ability of the fungi Pleurotus
pulmonarius and larvae of the beetle Protaetia (Liocola) brevitarsis (Lewis) to dispose of pine wood infected with nematodes was investigated.
Eight strains of P. pulmonarius (X1, X2, X3, X4, X5, X6, X7, X8) and 1
strain of Pleurotus ostreatus (P) were classified using by antagonistic
tests. Two kinds of culture medium were provided to these strains: 1) 81% saw
dust, 15% bran, 2% lime and 2% gypsum; 2) 66% saw dust, 15% bran, 15%
cottonseed hull, 2% lime, 2% gypsum. The strains of P. pulmonarius were
inoculated into a culture medium made of nematode-infected pine sawdust which was
cultured at 25℃
for 30-40 d after which the hyphal growth rate was calculated. P. (Liocola) brevitarsis larvae were fed broken, spent mushroom substrate under
different environmental conditions and were weighed after 15 d. Larval frass
and surplus spent mushroom substrates were collected, and feed intake, feed
utilization rate, insect body conversion rate and approximate digestibility
calculated. The seed germination index (GI) was used to test the phytotoxicity
of the larval frass and spent mushroom substrate to P. pulmonarius. [Results] The optimum temperature for P. brevitarsis larvae to feed on spent, P. pulmonarius mushroom
substrate was 27 ℃
and the optimum water content was 55%-65%. 3rd instar larva were the most
efficient feeders. Under optimum feeding conditions, 4.62 g of 3rd instar
larvae and 80.22 g of larvae frass could be obtained from 100 g of spent P.
pulmonarius substrate. The GI of spent P. pulmonarius substrates was < 50%, and there was still some phytotoxicity. The GI of
larval frass was > 50% and there was no phytotoxicity. [Conclusion] The
edible fungus P. pulmonarius and larvae of the beetle P. brevitarsis larvae can be used to
decompose nematode-infected pine wood.