Ecologically acceptable usage of derivatives of essential oil of sweet basil, Ocimum basilicum, as antifeedants against larvae of the gypsy moth, Lymantria dispar

Ethanol solutions of five fractions obtained from essential oil of sweet basil Ocimum basilicum L. (Lamiales: Lamiaceae) (F1-F5) were tested for their antifeedant properties against 2nd instar gypsy moth larvae, Lymantria dispar L. (Lepidoptera: Lymantriidae), in laboratory non-choice and feeding-choice experiments. Prior to bioassays, the chemical composition of each fraction was determined by gas chromatography analyses. Significant larval deterrence from feeding was achieved by application of tested solutions to fresh leaves of the host plant. The most effective were F1 (0.5%), F4 (0.05, 0.1, and 0.5%), and F5 (0.1 and 0.5%), which provided an antifeedant index > 80% after five days. A low rate of larval mortality was observed in no-choice bioassay. In situ screening of chlorophyll fluorescence as an indicator of plant stress level (assessed by the induced fluorometry) confirmed that the tested compounds did not cause alternations in the photosynthetic efficiency of treated leaves

CONTRIBUTION TO THE KNOWLEDGE OF THE GROUND BEETLE FAUNA FROM SERBIA (COLEOPTERA: CARABIDAE)

During a two-year period of research on the ground beetle fauna in agroecosystems in northern Serbia 19,003 carabid specimens were collected. A total of 67 species from 29 genera were identified. Harpalus distinguendus (Duftschmid, 1812), Amara aenea (De Geer, 1774), Poecilus cupreus (Linnaeus, 1758), and Amara similata (Goeze, 1777) were the dominant species in the winter oilseed rape and winter wheat. The ground beetle genera richest in species were Harpalus, Amara, Calathus, Poecilus and Brachinus. Seven species were new for the ground beetle fauna of Serbia: Calathus cinctus Motschulsky, 1850, Laemostenus complanatus (Dejean, 1828), Brachinus nigricornis Gebler, 1829, Cychrus attenuatus (Fabricius, 1792), Patrobus septentrionis Dejean, 1828, Anchomenus cyaneus Dejean, 1828 and Pterostichus leonisi Apfelbeck, 1904. Three species were recorded for the first time for Vojvodina Province in Serbia: Harpalus signaticornis (Duftschmid, 1812), Harpalus taciturnus Dejean, 1829 and Patrobus atrorufus (Ström, 1768). Newly recorded species were collected in epigeic pitfall traps. Six of them were found in oilseed rape while one was found in winter wheat

New data on spider fauna from northern Serbia

During two years of research on the epigeic fauna in agroecosystems of northern Serbia, which was conducted as a part of SEE-ERA NET PLUS project no. 51, 5488 spider specimens were collected at three fields with oilseed rape (Brassica napus var. oleifera), turnip rape (Brassica rapa x chinensis) and winter wheat (Triticum aestivum) as subsequent crop at Stari Žednik (Vojvodina). A total of 62 species from 15 families were identified. Pardosa agrestis and Xysticus kochi were the dominant species in the studied fields. Spider families with significant presence were Lycosidae, Linyphiidae, Thomisidae, Gnaphosidae, Theridiidae and Philodromidae. Seven species are new to the spider fauna of Serbia. [Projekat Ministarstva nauke Republike Srbije, br. 173038

Pherocon AM trapping and the “Whole plant count” method — A comparison of two sampling techniques to estimate the WCR adult densities in Central Europe

Pherocon AM (PhAM) trapping and visual counting are two commonly used methods for identifying maize fields in the USA that contain a sufficient number of adult western corn rootworms (WCR), Diabrotica virgifera virgifera LeConte to cause economic root damage by larvae the following year. Therefore, the estimation of adult WCR population plays an important role in management decisions (rotation or treatment). The goals of this study were (1) to compare adult WCR data obtained by PhAM trapping to “whole plant count” data in different maize developmental stages, (2) to determine the period in which the data obtained by both methods show the highest correlation, (3) to determine the regression curve between capture of WCR on PhAM as an independent variable and number of WCR observed by visual plant count, and (4) to determine if the “whole plant count” method can serve as a substitution for PhAM trapping under European conditions. Three samplings were conducted in 2006 in 38 fields in Croatia and one sampling was conducted in 22 fields in Serbia. Sampling in Croatia was conducted when maize plants were in the R 65-69, R 73-77 and R 79-85 developmental stages according to BBCH identification keys of maize. Sampling in Serbia was conducted when maize plants reached R 69-71 developmental stages. Three to six PhAM traps were placed in each 0.5 to 4 ha maize field seven days prior to sampling. Visual counts were conducted on the same day as trap inspections. Adult WCR densities in the PhAM traps were correlated to adult densities on whole plants. Statistical analyses comparing the results of PhAM trapping with the visual “whole plant count” method showed that there is a significant medium to strong correlation between them. Correlation coefficients varied depending on the data used in the analysis. When sampling was conducted in the first half of August (maize developmental stages R 69-77), the correlation coefficients were the highest (r(R 6971) = 0.8677 and r(R 73-77) = 0.706). Coefficients of determination were the highest as well [r2(R 69-71) = 0.753; r2(R 73-77) = 0.4984]. Therefore, the most appropriate period for sampling is during the first half of August. At that time, the majority of the maize plants were between the R 69 and R 77 developmental stages. According to the results, 0.5–1 visually determined adult/plant corresponds to 40 adults/trap/week. This shows that both methods are equally useful for estimating the population densities of WCR in the Central European region