The glycolytic enzymes activity in the midgut of diabrotica virgifera virgifera (Coleoptera: Chrysomelidae) adult and their seasonal changes

The western corn rootworm, Diabrotica virgifera virgifera LeConte (Coleoptera: Chrysomelidae) is an important pest of maize. The diet of the D. virgifera imago is rich in starch and other polysaccharides present in cereals such as maize. Therefore, knowledge about enzymes involved in digestion of such specific food of this pest seems to be important. The paper shows, for the first time, the activities of main glycolytic enzymes in the midgut of D. virgifera imago: endoglycosidases (a-amylase, cellulase, chitinase, licheninase, laminarinase); exoglycosidases (a- and b-glucosidases, a- and b-galactosidases) and disaccharidases (maltase, isomaltase, sucrase, trehalase, lactase, and cellobiase). Activities of a-amylase, a-glucosidase, and maltase were the highest among assayed endoglycosidases, exoglycosidases, and disaccharidases, respectively. This indicates that in the midgut of D. virgifera imago a-amylase, a-glucosidase and maltase are important enzymes in starch hydrolysis and products of its digestion. These results lead to conclusion that inhibition of most active glycolytic enzymes of D. virgifera imago may be another promising method for chemical control of this pest of maize

Wpływ zapraw nasiennych i insektycydów nalistnych stosowanych w kukurydzy przeciwko Oscinella frit L. na liczebność wciornastków

Background. Thrips constitute a group of common maize pests in Poland. Although in recent years their population and harmfulness in maize fields have increased, they are still not covered by chemical control due to the lack of approved insecticides. Material and methods. A study was carried out in 2010-2012 in southeastern Poland to test the potential indirect effects of non-selective seed dressings and foliar insecticides applied in the spring to control the frit fly (Oscinella frit L.) on the population of thrips without the need for separate treatments. Seed dressings containing imidacloprid (Gaucho 600 FS and Couraze 350 FS) and methiocarb (Mesurol 500 FS), as well as foliar insecticides containing lambda-cyhalothrin (Karate Zeon 050 CS) and a mixture of thiacloprid with deltamethrin (Proteus 110 OD) were used in the experiment. Results. In the study years thrips infested maize plants from mid-May to the first ten days of October. They were most abundant from the end of June to mid-August, with a single population peak between 11 and 20 July. All the tested insecticides used in spring to control O. frit had an indirect insecticidal effect on thrips. The highest effectiveness of seed dressings and foliar insecticides was observed until mid-June, which did not allow for the effective protection of maize plants against feeding thrips. Conclusion. The insecticidal effect of the tested products ended before the most abundant occurrence of thrips, and, therefore, these pests have to be controlled separately with chemical treatments on later dates.Wciornastki należą do grupy powszechnie występujących szkodników kukurydzy w Polsce. Choć w ostatnich latach wzrosła ich liczebność i szkodliwość na polach kukurydzy, to nie są objęte zwalczaniem chemicznym z powodu braku zarejestrowanych insektycydów. W związku z tym w latach 2010-2012 w południowo-wschodniej Polsce wykonano badania, których celem było sprawdzenie, czy nieselektywne zaprawy nasienne i insektycydy nalistne stosowane w okresie wiosennym do zwalczania ploniarki zbożówki (Oscinella frit L.) mogą pośrednio redukować również liczebność wciornastków bez konieczności ich odrębnego zwalczania. W doświadczeniu wykorzystano zaprawy nasienne zawierające imidachlopryd (Gaucho 600 FS oraz Couraze 350 FS) oraz metiokarb (Mesurol 500 FS), a także insektycydy nalistne zawierające lambda-cyhalotrynę (Karate Zeon 050 CS) oraz mieszaninę tiachloprydu i deltametryny (Proteus 110 OD). W latach badań wciornastki zasiedlały kukurydzę od połowy maja do pierwszej dekady października. Okres ich najliczniejszego występowania przypadał od końca czerwca do połowy sierpnia, z jednym szczytem liczebności przypadającym pomiędzy 11 a 20 lipca. Wszystkie badane insektycydy stosowane wiosną przeciwko O. frit wykazały pośrednie oddziaływanie owadobójcze na wciornastki. Najwyższą skuteczność zapraw nasiennych oraz preparatów nalistnych obserwowano do połowy czerwca, co nie pozwalało skutecznie zabezpieczyć roślin kukurydzy przed żerowaniem wciornastków. Owadobójcze oddziaływanie badanych insektycydów zakończyło się przed licznym pojawem wciornastków, stąd też owady te muszą być zwalczane oddzielnie zabiegami chemicznymi wykonywanymi w późniejszym czasie

THE EFFECT OF SELECTED PESTICIDES ON THE GROWTH OF ENTOMOPATHOGENIC FUNGI HIRSUTELLA NODULOSA AND BEAUVERIA BASSIANA

The effect of three pesticides used in corn protection: Targa Super 05 (chizalofop-P-ethyl), Roundup 360SL (glyphosate) and Karate Zeon 050CS (lambda-cyhalothrin), on the growth of entomopathogenic fungi Hirsutella nodulosa Petch and Beauveria bassiana (Bals.) Vuill. was evaluated under laboratory conditions. Fungi isolates were cultured on Sabouraud’s medium with addition of pesticides at three different concentrations. H. nodulosa was more susceptible to pesticides than B. bassiana. The most inhibitory effect on tested entomopathogenic fungi showed chizalofop-P-ethyl herbicide. Lambda-cyhalothrin at the recommended field dose showed minor toxic effect on entomopathogenic fungi, which suggests the possibility of compatible use of this insecticide with biopesticides based on the tested species

Cydalima perspectalis in Poland—8 Years of Invasion against the Background of Three Other Invasive Species

The box tree moth (Cydalima perspectalis) origins from East Asia. In Europe, it was recorded for the first time in 2007, and in Poland in 2012. By the end of 2020, it was found all over Poland. There are no published data on the range of C. perspectalis occurrence in Poland because it is not a quarantine pest in the European Union and is not subject to official monitoring. Data collected in 2018–2020 via a website dedicated to monitoring, for the first time, illustrate the current range and its largest concentrations in southern and central Poland. The monitoring confirmed that the main directions of the invasion are related to the main communication routes of Poland (south-north) and are of a long-distance character. The dispersal pattern corresponds to the model developed for Cameraria ohridella: a stratified dispersal model that considers long-distance road/rail transport. The second important factor contributing to the invasion of C. perspectalis are large human communities enabling rapid local dispersion (a diffusion model). Comparing its invasion with the monitoring data from 2007–2013 of two other invasive pests of Poland: Ostrinia nubilalis and Diabrotica virgifera, shows that a diffusion model best describes the spatial spread of these pests only to uninhabited neighboring areas

<i>Cydalima perspectalis</i> in Poland—8 Years of Invasion against the Background of Three Other Invasive Species

The box tree moth (Cydalima perspectalis) origins from East Asia. In Europe, it was recorded for the first time in 2007, and in Poland in 2012. By the end of 2020, it was found all over Poland. There are no published data on the range of C. perspectalis occurrence in Poland because it is not a quarantine pest in the European Union and is not subject to official monitoring. Data collected in 2018–2020 via a website dedicated to monitoring, for the first time, illustrate the current range and its largest concentrations in southern and central Poland. The monitoring confirmed that the main directions of the invasion are related to the main communication routes of Poland (south-north) and are of a long-distance character. The dispersal pattern corresponds to the model developed for Cameraria ohridella: a stratified dispersal model that considers long-distance road/rail transport. The second important factor contributing to the invasion of C. perspectalis are large human communities enabling rapid local dispersion (a diffusion model). Comparing its invasion with the monitoring data from 2007–2013 of two other invasive pests of Poland: Ostrinia nubilalis and Diabrotica virgifera, shows that a diffusion model best describes the spatial spread of these pests only to uninhabited neighboring areas

The quantitative changes of ground beetles (Col., Carabidae) in BT and conventional maize crop in southern Poland

Abstract: In the southern part of Poland, ground beetle fauna was studied in the first large-scale Bt maize experiment. The aim of this study was to determine the long term impact of the Bt maize cultivar in comparison to conventional plants, on selected non-target arthropods. The DKC 3421 YG cultivar (Bt maize) and the respective isogenic non-Bt varieties (DKC 3420) were cultivated at two locations: (a) Budziszów near Wrocław and in Głuchów near Rzeszów in the south-eastern region of Poland, in the 2008–2010 growing seasons. For comparative analysis, two additional non-Bt cultivars sprayed with a lambda-cyhalotrine insecticide were also included. To monitor population density of surface-active invertebrates of the Carabidae family, eighty pitfall traps were used at each location. The average number of ground beetle populations in the Bt-maize cultivar DKC 3421 YG did not significantly differ from the number of beetles in the conventional ones. Significant differences between the number of beetles occurred on individual dates only. Usually, these differences related to the considerably smaller total number of beetles in the whole replication. Probably, the variation in the number of beetles was caused by climatic factors or the terrain layout, therefore it cannot be related to the cultivar effect. Key words: Bt-maize, conventional plants, ground beetles, quantitative change

Egg Laying and Caterpillar Hatching Dynamics of Ostrinia Nubilalis Hbn. on Maize (Zea Mays L.) in South-Eastern Poland

During the study years, the European corn borer (ECB) (Ostrinia nubilalis Hbn.) females began depositing eggs on maize plants between the last ten days of June and the first ten days of July. A maximum number of eggs on plants was found at the beginning of the second ten days of July and at the beginning of the third ten days of July. The last egg clusters were recorded in August. During the five years of the study period, the female oviposition period lasted from 4.5 to 8 weeks. The shortest oviposition period took place during the warm and dry years, while the longest period was during the rainy and relatively cold years. During the study years, within the entire flight period, O. nubilalis females deposited from 1,564 to 3,393 eggs on 200 observed plants. The average number of eggs per cluster in the study years was from 10.0 to 15.2. The beginning of caterpillar hatching, based on the observation of empty egg clusters, was recorded in the last ten days of June or in the first and second ten days of July. Mass hatching of the caterpillars was observed in the second and third ten days of July, and only in 2004 was it in the first ten days of August. The last empty egg clusters were recorded in the second and in the third ten days of August