Dynamic of Brassicogethes aeneus (F.) (Coleoptera, Nitidulidae) populations in Serbia’s downriver Danube section and their susceptibility to insecticides

Tatjana Popović,Marijana Pražić-Golić,Predrag Milovanović,Petar Kljajić,Goran Andrić

doi:10.5424/sjar/2019172-14219

Abstract

This paper presents data on the dynamic of B. aeneus populations in winter oilseed rape in the downriver section of the Danube in Serbia, which were acquired by yellow water traps and a beating method. Their susceptibility to several insecticides of different classes (organophosphates, pyrethroids and neonicotinoids) (adult vial test and dipping test) was tested over two seasons (2009 and 2010). B. aeneus populations developing under the agroecological conditions that exist in Serbia were monitored to detect the moment of OSR infestation during its sensitive growth stages. Adults were counted, and the data revealed that they infest winter OSR crops during the stem elongation growth stage (BBCH 30-31), reaching a population peak at the green-yellow bud stage (BBCH 57-59), and exceeding the economic threshold, while the populations decreased substantially during the subsequent stage (BBCH 61-69). Laboratory test results did not confirm any changes in B. aeneus susceptibility/resistance to pyrethroid, organophosphate and neonicotinoid insecticides. Migration of B. aeneus populations was monitored as a way of developing predictive models for estimation of infestation severity and the timing of pest outbreaks under agroecological conditions existing in Serbia. As resistance to pyrethroids has been confirmed in B. aeneus populations in many European countries, their susceptibility will be further monitored.

Highlights

The pollen beetle, Brassicogethes aeneus (F.), syn.Meligethes aeneus (F.) (Coleoptera: Nitidulidae), is a major pest in oilseed rape (Brassica napus L.) (OSR)fields in most European countries (Alford et al, 2003), including Serbia (Sekulić & Kereši, 2007; Milovanović et al, 2013)
― Counts of B. aeneus caught by beating method (BM): The first overwintered adults in winter OSR crops were observed when OSR was at the BBCH 30-31 growth stage: on March 15, 2009 on the locations Kovin and Smederevo, and on March 22 in Požarevac; on Locality × method
B. aeneus emerged in winter OSR crops in the downriver stretch of the Danube in Serbia during

Summary

Introduction

The pollen beetle, Brassicogethes aeneus (F.), syn.Meligethes aeneus (F.) (Coleoptera: Nitidulidae), is a major pest in oilseed rape (Brassica napus L.) (OSR)fields in most European countries (Alford et al, 2003), including Serbia (Sekulić & Kereši, 2007; Milovanović et al, 2013). The pollen beetle, Brassicogethes aeneus (F.), syn. Meligethes aeneus (F.) (Coleoptera: Nitidulidae), is a major pest in oilseed rape (Brassica napus L.) (OSR). In Serbia, SE of Europe, only winter. Winter OSR crops have been continually grown in the observed region over many years, and control measures (including biocontrol) have often included insecticides with different modes of action (organophosphates, pyrethroids and neonicotinoids) to control B. aeneus. Yield loss assessments in Europe have been reported to reach 50-60% (Nilsson, 1987), or 80% in spring OSR in Denmark (Hansen, 2003, 2004), while official data for Serbia and its region are missing. Damage is greater in seasons with cold spring because such weather slows down and extends plant development during sensitive growth stages. Harmfulness of B. aeneus depends on their numbers on OSR inflorescences, the timing of their appearance with regard to bud development, the period of time elapsing from the moment of B. aeneus settling to OSR flowering, the variety-depending

Methods

Results

Conclusion