Individual study: Evaluation of herbivore-induced plant volatiles for monitoring green lacewings in Washington apple orchards
Jones V.P., Steffan S.A., Wiman N.G., Horton D.R., Miliczky E., Zhang Q.-H. & Baker C.C. (2011) Evaluation of herbivore-induced plant volatiles for monitoring green lacewings in Washington apple orchards. Biological Control, 56, 98-105
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Use chemicals to attract natural enemies
A randomised, replicated, controlled study in 2008 in four apple Malus domestica orchards in Washington State, USA (Jones et al. 2011) found more green-eyed lacewings Chrysopa oculata (8-145 lacewings/trap) and green lacewings Chrysopa nigricornis (86-446 lacewings) in trees with iridodial-methyl salicylate lures than control trees without lures (0-3 and 0-7 lacewings, respectively). Benzaldehyde attracted higher numbers of the lacewing Chrysopa plorabunda in treated (6-64 lacewings/trap) compared to control trees (0-1 lacewings), but had little effect on green-eyed and green lacewing captures. Across all three species, there were mixed effects of iridodial alone, methyl salicylate alone, cis-3-hexen-1-ol and cis-3 hexenyl acetate. An additional experiment in two orchards found that squalene lures or mixed lures containing this chemical attracted more green lacewings (8-24 lacewings/trap day) than iridodial-methyl salicylate lures (2-4 lacewings). More green lacewings were caught with higher squalene doses. Six chemical lures (in 5-cm diameter plastic tubing) were placed in white plastic delta traps and compared with control traps containing distilled water. Each treatment was replicated four times in each orchard. Delta traps and lures were placed 1.5-3.0 m high in the canopy and lacewing captures were monitored 1-2 times/week.