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Arthropod-Plant Interactions
https://doi.org/10.1007/s11829-018-9616-y
ORIGINAL PAPER
Impact of insecticides on oilseed rape bud infestation with eggs
and larvae of pollen beetle (Brassicogethes aeneus (Fabricius))
Meike Brandes
1
· Udo Heimbach
1
· Bernd Ulber
2
Received: 28 April 2017 / Accepted: 24 May 2018
© Springer Science+Business Media B.V., part of Springer Nature 2018
Abstract
One of the main insect pests in oilseed rape is the pollen beetle (Brassicogethes aeneus (Fabricius), syn. Meligethes aeneus).
To maximize efficiency of control of this pest, insecticides are required that ideally, not just prevent yield losses by bud
feeding of overwintered pollen beetles, but simultaneously minimize the reproduction of the pest, thereby reducing the size
of the following generation infesting next year’s oilseed rape. The neonicotinoid active substance thiacloprid is known to
reduce bud infestation with eggs and larvae. However, the mechanisms by which this occurs as well as the effects of other
active substances are not known. In this study, the effects of the neonicotinoid insecticide Biscaya (a.i. thiacloprid) and
the pyrethroids Mavrik (tau-fluvalinate) and Karate Zeon (lambda-cyhalothrin) applied at the bud stage of winter oilseed
rape with recommended field rates on infestation of buds with eggs and larvae of pollen beetles were tested in field trials in
Germany in 2013–2015. In additional greenhouse experiments, it was investigated whether effects on bud infestation were
caused by lethal effects on pollen beetle or by insecticidal residues on plants causing sublethal effects. In the field trials,
application of Biscaya and Mavrik significantly reduced the percentage of buds containing eggs and larvae in contrast to
Karate Zeon. In 2014 and 2015, 14 days after application, bud infestation on the main raceme was reduced by 86 and 82%,
respectively, in Biscaya-treated plots and by 51 and 71%, respectively, in Mavrik-treated plots compared to the untreated
plots. In the greenhouse experiments, the lowest percentage of bud infestation with eggs and larvae was recorded on Biscaya-
treated plants whereas on Mavrik-treated plants, there was no significant difference compared with the control. The results
of the field trials show that Biscaya and Mavrik reduced oilseed rape bud infestation with eggs and larvae of pollen beetles
primarily by lethal effects on overwintered pollen beetles or by repellency. However, Biscaya had additional effects on egg
laying, which was supported by the greenhouse experiments.
Keywords Oviposition · Population development · Thiacloprid · Tau-fluvalinate · Lambda-cyhalothrin
Introduction
Brassicogethes aeneus (Fabricius) (Coleoptera: Nitidulidae),
syn. Meligethes aeneus is the most common species of pol-
len beetle in Europe (Nilsson 1988b; Williams 2010) and
the only species of this genus with economic importance
(Thieme et al. 2010). After leaving the hibernation sites in
spring, the beetles immigrate into crops of oilseed rape. Dur-
ing the bud stage, they bite into buds to get access to pol-
len, thereby causing injuries and abortion of buds, resulting
in podless stalks and substantial yield loss (Nilsson 1987).
Following maturation feeding, females start egg-laying into
buds. The timing and extent of oviposition in winter oil-
seed rape depends on temperature (Fritzsche 1957; Fergu-
son et al. 2015), time of ovarial maturity and availability of
medium sized buds (Nilsson 1988c).
For oviposition, females prefer buds of 2–3 mm length
(Fritzsche 1957; Nilsson 1988c; Ekbom and Borg 1996;
Ferguson et al. 2015). This bud size allows the first instar
larvae (L1) to develop for the longest possible period in
a single bud (Nilsson 1994). No eggs were found in buds
Communicated by Heikki Hokkanen.
* Meike Brandes
meike.brandes@julius-kuehn.de
1
Institute for Plant Protection in Field Crops and Grassland,
Federal Research Centre for Cultivated Plants, Julius Kühn-
Institut, Messeweg 11/12, 38104 Braunschweig, Germany
2
Section of Agricultural Entomology, Department
for Crop Sciences, Georg-August-University Göttingen,
Grisebachstraße 6, 37077 Göttingen, Germany
@Phil_Robichaud
@deepthiw
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