Measure date versus economic efficiency of the beet aphid control on sugar beets

Наблюдения и опыты по развитию, вредности и уничтожению бересклетово-свекловичной тли ( Aphis tabac Scop.) на сахарной свекле прoводились в период 1978-1981 и 1983-1984 гг. вблизи г. Вроцлава как центральной площади земледелия в Нижней Силезии, а также в окрестнoстях г. Клодзко, как площади представительной для земледельческих условий Судет. Полученные результаты показали, что оптимальным сроком борьбы с бересклетово-свекловичной тлей как непосредствен вредителем в Нижней Силезии оказалось время после перелета тли с зимних растений-хозяев, т.е. в конце первой или во второй декаде июня. Одно химическое мероприятие проведенное в указанный срок предотвращало удовлетворительно потери урожая. На протяжении 6-летних исследований проводимых в двух разнящихся по отношению к климату районах только в 1978 и 1984 гг. в Прушовицах и в 1981 г. в Клодзко было установлено снижение урожаев на плантациях, на которых мероприятие не проводилось. В указанные периоды тля перелетела рано и в крупных количествах с зимных растений-хозяев на сахарную свеклу вызывая сильное ограничение роста растeний. Экономическая эффективность расходов на уничтожающие тлю опрыски проведенные в годах массового и раннего терлета тли с бересклета (Прушовице 1978, 1984, Клодзко 1981), выраженная показателем покрытия расходов была высокой, колеблясь в пределах 8,3-32,6. Показатель покрития расходов снижался в вариантах опыта с повышенным числом сероприятий.Observations and experiments on the development, harmfulness and control of beet aphid (Aphis fabae Scop.) on sugar beets were carried out in the period 1978-1981 and 1983-1984 on the area situated near Wrocław as an agricultural centre of Lower Silesia and near Kłodzko representative for agricultural conditions of the Sudety mountain region. The obtained investigation results have proved that an optimum date of the beet aphid control as a direct peat in Lower Silesia appeared to be the time after flight of migrants from winter host plants, i.e. at the end of the first ten days or in the second ten days of June. A single chemical measure carried out at that time protected satisfactirily the crops against yield losses. In the period of the 6-year investigations carried out in two country regions differ ng with climatic conditions only in 1978 and 1984 at Pruszowice and in 1981 in Kłodzko the loss of sugar beet yields on plantations without the above measure was found. In the above periods beet aphid settled in great numbers and early sugar beet plants after their migration from winter host plants, causing a strong inhibition of the growth of sugar beet plants. The economic efficiency of aphid-killing sprayings carried out in the years of massy and early flight of aphids from evonymus (Pruszowice 1978, 1984. Kłodzko 1981) expressed by the cost covering index was high ranging within 8.3-32.6. This index decreased in the experimental treatments, in which increased the number of measures

Thrips (Thysanoptera) occuring in spring triticale intercropped with yellow lupine

Doświadczenie przeprowadzono w latach 2001-2003 w Rolniczej Stacji Doświadczalnej Akademii Rolniczej we Wrocławiu. Badano wpływ współrzędnej uprawy pszenżyta jarego z łubinem żółtym na skład gatunkowy i liczebność przylżeńców żerujących na pszenżycie. Podczas trzech lat badań w kłosach pszenżyta zebranych w fazie dojrzałości mlecznej ziarna najwięcej przylżeńców występowało na roślinach rosnących w kombinacji z najmniejszym udziałem pszenżyta, a największym łubinu. W materiale zebranym z kłosów oznaczono łącznie 11 gatunków Thysanoptera. Wyraźnymi dominantami we wszystkich kombinacjach doświadczenia były: Haplothrips aculeatus i Limothrips cerealium. W dynamice populacji omawianych owadów można było wyróżnić jeden (2002) lub dwa (2001, 2003) okresy ich liczniejszego występowania: pierwszy – w fazie kłoszenia się pszenżyta (mniej liczny), drugi (liczniejszy) – w fazie dojrzewania. Wyniki badań nie wykazują jednoznacznego wpływu uprawy współrzędnej pszenżyta jarego z łubinem żółtym na liczebność Thysanoptera żerujących na pszenżycie. Daje się jednak zauważyć tendencja wzrostu liczebności przylżeńców na pszenżycie w uprawie współrzędnej w porównaniu z siewem czystym tej rośliny.The research carried out at the Agricultural Experimental Station of the Agricultural University in Wrocław in 2001-2003 investigated the effect of intercropping spring triticale with yellow lupine on the species composition and abundance of thrips feeding on triticale. During three years of study the greatest number of thrips in cereal ears collected at milk stage was found in the plants grown with the lowest share of triticale and the highest – of lupin. Eleven species of Thysanoptera were identified. The most numerous were Haplothrips aculeatus and Limothrips cerealium. In the seasonal population dynamics one (2002) or two (2001, 2003) periods of a higher occurrence of thrips were recorded; the first one over the ear formation of triticale (lower) and the second one – over plant ripening (higher). There was no clear effect of spring triticale intercropped with yellow lupine on the abundance of thrips feeding on triticale, however there is a tendency of a growing abundance of thrips in triticale intercropped, as compared with its pure stand

Przylżeńce (Thysanoptera) zasiedlajace kłosy ozimej pszenicy twardej (Triticum durum Desf.) w zależności od intensywności ochrony

The objective of this study was to determine the abundance and species composition of thrips collected from ears of Triticum durum Desf. in relation to plant protection intensity. The experiment was set up at the Experimental Research Station of Wrocław University of Environmental and Life Sciences, at Pawłowice (51o09’ N; 17o06’ E), Poland, in 2006-2008. It was conducted on durum wheat plants at three different levels of plant protection intensity and on common winter wheat plants. The samples of thrips were collected from the ears of the plants at the milk maturity stage of the grain. During three years of the research, eight species of thrips were identified from Triticum durum. Most often the eudominants were Haplothrips aculeatus, Limothrips cerealium and L. denticornis. We have demonstrated that there was no statistically significant effect of the plant protection intensity on the thrips abundance. The host species, on the other hand, did not affect the species composition of the studied insects.Celem badań było poznanie liczebności i składu gatunkowego przylżeńców (Thysanoptera) występujących w kłosach pszenicy twardej (Triticum durum Desf.) w zależności od intensywności ochrony tej rośliny. Doświadczenie prowadzono w latach 2006-2008, w Rolniczym Zakładzie Doświadczalnym w Pawłowicach (51o09’ N; 17o06’ E), należącym do Uniwersytetu Przyrodniczego we Wrocławiu. Badaniami objęto pszenicę twardą bez ochrony chemicznej, chronioną środkami chemicznymi oraz porównawczo pszenicę zwyczajną. W celu określenia składu gatunkowego przylżeńców pobierano kłosy, których ziarniaki były w fazie dojrzałości mlecznej. W ciągu trzech lat badań w kłosach pszenicy twardej oznaczono 8 gatunków przylżeńców. Do eudominantów najczęściej należały Haplothrips aculeatus, Limothrips cerealium i L. denticornis. Nie stwierdzono wyraźnego wpływu zastosowanej ochrony roślin na liczebność badanej grupy owadów na pszenicy twardej. W kłosach pszenicy twardej występowały te same gatunki przylżeńców jak w kłosach pszenicy zwyczajnej

Effect of intercropping narrow-leafed lupin with spring triticale on the abundance and diversity of rove beetles

Description of the subject. Intercropping is a kind of polyculture, growing two or more crops together. This practice should improve pest management mainly by increasing predator diversity. It was hypothesized that the intercropping of narrow-leafed lupin with spring triticale would increase the number and diversity of rove beetles compared to monocultures of the aforementioned crops. Objectives. The aim of the research was to determine the effect of intercropping of narrow-leafed lupin with spring triticale on rove beetle abundance and diversity. Method. Over a three-year period, rove beetles were trapped with the use of pitfall traps, and adults were identified to species. The experiment was carried out on a narrow-leafed lupin and spring triticale crop sown as monocultures, and on two mixtures with different proportions of lupin seeds. Results. In total, in all treatments 100 rove beetle species were found, classified into three trophic groups. The most numerous forms were predatory zoophages, which were followed by parasites and saprophages. Staphylinidae abundance and ecological significance decreased with increasing degree of habitat diversity in comparison to crops grown in the pure stand. The same response to intercropping was observed in the case of zoophages. Conclusions. Contrary to what was hypothesized, the abundance and diversity of rove beetle decreased when narrow-leafed lupin and spring triticale were grown together compared to their monoculture. Presumably, the higher abundance of rove beetle in lupin and spring triticale grown in the pure stand is mostly the result of better food supply in monocultures during the whole season

The effect of different seeding densities of linseed (Linum usitatissimum L.) on flax flea beetles (Coleoptera: Chrysomelidae)

Linseed, one of the oldest cultivated crops, is again gaining in importance, mainly due to its nutritional benefi ts and biomedical applications. Th erefore, it is expected that herbivores will also exist in greater abundance. Among them the fl ea beetle, Aphthona euphorbiae Schrank and Longitarsus parvulus Paykull are considered to be serious pests of fl ax grown for fi bre and seeds in Europe. Th e aim of this study was to determine fl ax fl ea beetles’ abundance, species richness and seasonal dynamics on linseed grown at diff erent densities. It was expected that linseed seeding density can signifi cantly aff ect fl ea beetle populations. Th e experiment was carried out in Lower Silesia, Poland, from 2011 to 2013. A genetically modifi ed type of linseed overproducing fl avonoids was used. Flea beetles and the damages they caused were determined on plants and also a sweep net was used for the collection of adult beetles. During the three years of the study 15 species of fl ea beetles were identifi ed from oil fl ax plants, with A. euphorbiae and L. parvulus being dominant. In terms of the total catch, the tendency was for beetle numbers to decrease with increasing plant density. Flax fl ea beetles feeding on linseed plants, irrespective of plant density, had two peaks of abundance. Th e fi rst peak was lower and occurred in June, when plants were at the blooming stage. Th is peak was caused by overwintering adults who colonized crops in spring. Th e second, higher peak of abundance was recorded in the second half of July, when plants were at the ripening stage. Th is peak was formed by adults of the new generation. Each year, at the higher population peak of abundance, the fl ea beetles were most numerous on plants grown at the lowest density. Th ere was one period, lasting either from mid-May to the fi rst few days of June, or from the beginning of June to mid-June, during which the number of holes and damage on plants of each treatment were highest. During the three years of the study there were several cases of signifi cantly higher numbers of fl ea beetle feeding symptoms on plants grown at the lowest density as compared to the medium and highest densities