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The total amount of the identified phenolics was similar in leaves of both cultivars noninfested by the insects. However, higher content of ferulic acid and o-coumaric acid was found in the less acceptable triticale (Lamberto cv.) than in more acceptable Marko cv. After infestation an increase in content of the most phenolics was observed. The cereal leaf beetle brought the highest changes in the gallic, chlorogenic, salicylic, syringic and ferulic acid. The grain aphid feeding resulted in the increase of gallic, chlorogenic, vanilic, caffeic, syringic and salicylic acids. Moreover, much higher induction of phenolic biosynthesis occurred within seedlings of Lambero cv. than in Marko one. The differences in phenolic acids level within triticale tissues induced by the chewing and sucking-piercing insects are discussed.
This study on blooming biology, nectar secretion, pollen production and insect visitation of Aquilegia vulgaris L. was carried out in 2009 and 2011 in Lublin. The peak of flower opening during the day was between 5.00 and 7.00 (GMT +2). The flowers are protandrous with the female phase beginning approx. on the 3rd day of anthesis. The dynamics of nectar secretion and pollen shed from anthers (progressing from the central part of the androecium outwards) support the reproductive system. The amount of nectar accumulated in the spurs increased from the bud stage and was the highest in the phase with approx. ¾ of dehisced anthers, usually on the 3rd day of flower life. Then, towards the end of anthesis, the amount of secreted and accumulated nectar decreased. The number of anthers developed per flower varied from 41 to 61 (mean = 49.1). The mass of pollen per 100 anthers averaged 6.7 mg. Pollen production per flower (mean = 3.28 mg) slightly varied between years and was mainly correlated with the number of developed anthers. Estimated pollen yield was 1.69 g per m2 and sugar yield 1.22 g per m2. Species from the genus Bombus were the main flower visitors, with B. terrestris being the most frequent forager.
This study investigated the floral biology and pollen quantity and quality of Campanula bononiensis L. (Campanulaceae), a protected species in Poland. Observations and measurements were made during the years 2007–2009 in natural phytocoenoses from the Festuco-Brometea class situated within the Lublin area, SE Poland. A considerable decrease (approx. 87%) in population density was observed. Significant variations both in the amount of pollen (18.5%–34.8 % of pollen in the total anther dry weight, i.e. 0.5–1.5 mg per 10 anthers) and in pollen viability (38.8–97.0%) were noted. Both a low amount of pollen and low pollen viability may reduce the reproductive success of individuals. The most frequent visiting insects were bees (Apoidea), including solitary bees 45.7%, honeybees 20.4%, and bumblebees 11.4%. Dipterans, coleopterans (weevils), lepidopterans and ants were also recorded, implying a strong impact of C. bononiensis on insect biodiversity within grasslands.
Badania polowe i laboratoryjne prowadzono w celu oszacowania możliwości wykorzystania piętnówki zmiennej (Mamestra dissimilis Knoch., Lepidoptera: Noctuidae) do regulacji zachwaszczenia spowodowanego przez Rumex confertus (Willd.). W naturalnym siedlisku szczawiu badano dynamikę jego wzrostu oraz liczbę gąsienic piętnówki zmiennej zasiedlających roślinę w okresie 50 dni. Największą liczbę gąsienic odłowiono pod koniec pierwszej dekady czerwca, w czasie gdy roślina żywicielska miała już w pełni wykształconą rozetę. W warunkach laboratoryjnych badano wzrost masy ciała gąsienic oraz ich żerowanie w temperaturze 20°C. Zależności pomiędzy masą zjedzonych liści szczawiu omszonego a przyrostami masy larw L4 i L5 były statystycznie istotne (r = 0,97 i r = 0,88). Stwierdzono bardzo progresywny charakter żerowania larw L4, opisany równaniem 1. stopnia (r = 0,98). Wyliczono, że każdego dnia w ciągu 20 dni żerowania larwy zjadły o 5,9 mg więcej liści. Natomiast dla gąsienic L5 związek ten miał charakter funkcji 2. stopnia (r = 0,96). Oszacowana masa liści szczawiu omszonego, która uległa skonsumowaniu przez larwy piętnówki zmiennej w warunkach naturalnych, wyniosła 159,3 g, co stanowiło około 11% utraty biomasy żywiciela.
Maize (Zea mays L.) hybrid with the Bt transgene from the bacterium Bacillus thuringensis (Bt) (DKC 3421 YG) and its non-Bt near-isoline (DKC 3420) as well as Polish cultivar Bosman (HR Smolice) were subjected to drought stress and/or the two-spotted spider mite (Tetranychus urticae, Acarina: Tetranychidae) feeding to assess changes in the relative water content (RWC) and dry weight (DW) in leaves of different age (leaf: 7th, 8th, 9th, 10th). All plants were at the vegetative stage and grew under greenhouse conditions. The effect of both abiotic and biotic stress was analysed 4 and 6 days after treatment. The experiments conducted in two series showed that among examined maize cultivars, T. urticae feeding decreased RWC in Bosman cv. leaves only, while drought altered leaf RWC of plants in a similar manner – the older the leaf, the greater reduction of RWC. Drought alone and drought accompanied by T. urticae feeding significantly decreased RWC of maize leaves in all cultivars (DKC 3421 YG, DKC 3420, Bosman). Concluding, drought had a greater impact on leaf RWC of young maize plants than mite feeding.
The pea aphid (Acyrthosiphon pisum) presents a considerable threat to bean family plants. In order to determine its feeding preferences, the following plants were tested: field pea (Pisum sativum), common bean (Phaseolus vulgaris), soya bean (Glycine max), lentils (Lens culinaris), narrow-leaf lupine (Lupinus angustifolius), white lupine (Lupinus albus), yellow lupine (Lupinus luteus) and broad bean (Vicia faba). Selected biometric parameters were used to evaluate feeding acceptance. The results of performer experiment showed that pea and broad bean are more often infested and colonized by the pea aphid than soya bean, lentils or yellow lupine. Narrow-leaf lupine, white lupine and common bean are not exposed to pea aphid feeding and they are not make a suitable habitat for the development of this insect.
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