J Pest Sci (2018) 91:515–522
Seed treatment of maize with Bacillus pumilus strain INR‑7
aﬀects host location and feeding by Western corn rootworm,
Diabrotica virgifera virgifera
Joseph O. Disi
· Joseph W. Kloepper
· Henry Y. Fadamiro
Received: 26 February 2017 / Revised: 11 October 2017 / Accepted: 16 October 2017 / Published online: 26 October 2017
© Springer-Verlag GmbH Germany 2017
Diabrotica virgifera virgifera, an important pest of
maize, uses host metabolites as cues for host location
and as phagostimulants. However, little is known about
how beneﬁcial rhizobacteria mediate host selection by D.
We tested if treatment of maize seeds with Bacillus pumi‑
lus strain INR-7 mediates host selection and feeding of
D. v. virgifera larvae.
Diabrotica virgifera virgifera larvae showed less attrac-
tion to INR-7-treated (24%) than untreated plants (76%).
Furthermore, weight of larvae-fed INR-7-treated plants
was signiﬁcantly reduced.
Bacillus pumilus shows promise for integration into cur-
rent D. v. virgifera management strategies.
The structural and spatial diﬀerences in terrestrial plants
ensure that plants function eﬀectively in their environment.
Plant roots interact with soil and rhizosphere microorgan-
isms, including plant growth-promoting rhizobacteria
(PGPR). PGPR elicit plant growth, and some also suppress
soil pathogens (Kloepper and Schroth 1981; Bhattacharyya
and Jha 2012). Some PGPR strains also induce host plant
resistance against foliar plant diseases and herbivorous
insects (Zehnder et al. 1997; Jetiyanon and Kloepper 2002;
Kloepper et al. 2004a; Ryu et al. 2007; Van der Ent et al.
2009; Noumavo et al. 2013; Pineda et al. 2012; Liu et al.
Studies have shown that the eﬃcacy of rhizobacteria
as biological control agents against foliar pathogens is
Abstract Western corn rootworm (WCR), Diabrotica vir‑
gifera virgifera is an important pest of maize and the costs
of control and yield loss are estimated at $1 billion per year
in the USA. As a specialist herbivore, WCR has evolved
to use host odors and secondary plant metabolites as cues
for host location and phagostimulants. This study reports
that rhizobacteria applied as seed treatments to maize aﬀect
host-seeking behavior of WCR larvae. The results of a dual-
choice test showed that a signiﬁcantly higher percentage
(76%) of WCR larvae chose untreated control plants than
plants treated with the single Bacillus pumilus strain INR-7
(24%). In no-choice feeding tests, WCR larvae-fed INR-
7-treated plants weighed signiﬁcantly less than larvae-fed
untreated plants or plants treated with bacilli blends. Overall,
the results demonstrate that B. pumilus INR-7 can enhance
resistance of maize against damage by WCR larvae. The
implication of these ﬁndings is discussed in the context of
using beneﬁcial rhizobacteria in integrated pest management
of corn rootworm.
Keywords Bacillus species · Bacilli mixtures ·
Coleoptera · Chrysomelidae · Induced systemic resistance ·
Communicated by I. Hiltpold.
Electronic supplementary material The online version of this
article (doi:10.1007/s10340-017-0927-z) contains supplementary
material, which is available to authorized users.
* Henry Y. Fadamiro
Department of Entomology and Plant Pathology, Auburn
University, Auburn, AL 36849, USA