Soil tillage and crop rotation differently affect biodiversity and species assemblage of ground beetles inhabiting winter wheat fields

J. Gailis*, I. Turka and M. Ausmane

Latvia University of Agriculture, Faculty of Agriculture, Institute of Soil and Plant Sciences, Liela street 2, LV-3001 Jelgava, Latvia
*Correspondence: janis.gailis@llu.lv

Abstract:

This paper continues studies on ground beetles (Carabidae) in differently managed winter wheat (Triticum aestivum) fields in Latvia. The main task of those studies was to assess how different soil tillage regimes (ploughing and non-inverse tillage) and different pre-crops (winter wheat and spring rapeseed (Brassica napus) affect assemblage and biodiversity of ground beetles in winter wheat fields. The research was carried out in the Latvia University of Agriculture Research and Study Farm ‘Pēterlauki’ (56°30’39.38’’N; 23°41’30.15’’E) during vegetation season of 2013. The results were compared with the results of similar research carried out at the same place during 2012. Totally 57 ground beetle species were observed in studied fields in 2013. Total species assemblage varied between both consecutive vegetation seasons of the research, however these were minor differences not connected with studied agro-ecological factors. Dominance structure of ground beetle species was significantly different between both vegetation seasons – species which were dominant and subdominant in 2012 became subdominant and dominant one year later, accordingly. Annual effects of soil tillage regime and pre-crop on ground beetle dominance structure also were observed, however some differences were recognized between both vegetation seasons. In case, if weed control was successful, higher ground beetle biodiversity might be observed in ploughed fields pre-cropped with spring rapeseed. Otherwise, significantly higher ground beetle biodiversity may be observed in harrowed soil independently from the pre-crop.

Key words:

Carabidae, Latvia, non-inverse tillage, ploughing, pre-crop, Triticum aestivum

Antennal sensilla in ground beetles (Coleoptera, Carabidae)

A. Ploomi¹, E. Merivee¹, M. Rahi², J. Bresciani³, H. P. Ravn⁴, A. Luik¹ and V. Sammelselg⁵

¹Institute of Plant Protection, Estonian Agricultural University, Kreutzwaldi 64, 51014, Tartu, Estonia; e-mail: angela@eau.ee
²Institute of Zoology and Botany, Estonian Agricultural University, Riia 181, 51014 Tartu, Estonia
³Veterinary and Agricultural University, Bülowsvej 13, DK 1870, Frederiksberg C, Denmark
⁴Danish Forest and Landscape Research Institute, Hoersholm Kongevej 11, DK 2970, Hoersholm, Denmark
⁵Institute of Physics, University of Tartu, Riia 142, 51014 Tartu, Estonia

Abstract:

The antennal sensilla of male and female ground beetle species Bembidion lampros Hbst., Bembidion properans Steph. and Platynus dorsalis Pont. (Coleoptera, Carabidae) were investigated by using a scanning electron microscope. The filiform antennae of ground beetles consist of the scape, pedicel and 9 flagellomeres. Thirteen different sensillar types were distiguished. These were: four types of sensilla chaetica, two types of sensilla trichodea, six types of sensilla basiconica, pit-organs sensilla coeloconica, and small domes sensilla campaniformia. Sensilla chaetica 4 occur only on the antennae of P. dorsalis, and sensilla trichodea 1 only on the antennae ofBembidion species. No sexual differences in the types of sensilla were found on the antennae of these three species. The possible functions are discussed and three types of sensilla were considered as olfactory, sensilla trichodea 2 and sensilla basiconica 1 and 2. Olfactory sensilla trichodea 2 and sensilla basiconia 1 form clear dorsal and ventral sensillar fields on the flagellomeres, which seems to be common in ground beetles.

Key words: