Journal of Pest Science (2018) 91:575–584
Quantifying the respective and additive eects of nectar plant crop
borders and withholding insecticides on biological control of pests
in subtropical rice
· Xusong Zheng
· Facheng Zhang
· Hongxing Xu
· Yajun Yang
· Guihua Chen
· Zhongxian Lu
Anne C. Johnson
· Geo M. Gurr
Received: 7 June 2017 / Revised: 2 December 2017 / Accepted: 8 December 2017 / Published online: 12 December 2017
© Springer-Verlag GmbH Germany, part of Springer Nature 2017
Conservation biological control avoids the need for mass releases of costly agents and the risks associated with introduc-
ing exotic agents by promoting existing natural enemies. This is done by alleviating insecticide-induced mortality and by
manipulating the habitat to provide resources such as nectar, but there is a dearth of information on the relative and interac-
tive eﬀects of these two approaches. Here we used a large-scale factorial experiment with plots comprised of entire ﬁelds to
test the eﬀects of, and interactions between, withholding insecticides and planting borders of sesame (Sesamum indicum)
on natural enemies and pests over 2 years. We used yellow sticky traps, sweeping netting and sentinel bait plants to monitor
natural enemies and pests in the canopy and basal zones of the rice crop. Numbers of rice planthopper egg parasitoids and
lepidopterous egg parasitoids in the rice canopy, as well as planthopper parasitism rates, were signiﬁcantly greater in plots
that were unsprayed and bordered by sesame, and scarcest in sprayed crops without sesame. Spraying of sesame-bordered
crops gave parasitoid numbers similar to sprayed crops without sesame. Spiders in the canopy were signiﬁcantly reduced in
numbers by spraying, but there was no main eﬀect of sesame borders. This study demonstrates that withholding insecticides
and sowing nectar plant borders each have measurable as well as additive beneﬁts on in-crop densities of ecosystem service
providers responsible for predating and parasitising pests but the identity of the natural enemy determines the impact of
these management practices.
Keywords Conservation biological control · Ecological engineering · Ecosystem services · Habitat manipulation · Rice
planthopper · Functional group
A large-scale factorial experiment in rice over 2 years
examined the eﬀects of withholding insecticides and of
sesame nectar plant borders.
Parasitoid numbers and planthopper parasitism rates were
the greatest in unsprayed and sesame-bordered plots, and
the lowest in sprayed crops without sesame (representing
normal farm management).
Spiders were signiﬁcantly reduced in numbers by spray-
ing, but there was no main eﬀect of sesame borders.
Spraying of sesame-bordered crops gave natural enemy
numbers similar to sprayed crops without sesame.
Communicated by B. Lavandero.
Electronic supplementary material The online version of this
article (https://doi.org/10.1007/s10340-017-0946-9) contains
supplementary material, which is available to authorized users.
* Zhongxian Lu
Key Laboratory of Information Traceability for Agricultural
Products, MOA, Institute of Plant Protection
and Microbiology, Zhejiang Academy of Agricultural
Sciences, No. 198, Shiqiao Rd, Hangzhou 310021, China
Graham Centre, Charles Sturt University, Orange 2800,
Jinhua Plant Protection Station, Jinhua 321017, China