Search results for "Nymph"
showing 10 items of 81 documents
Chemistry of pheromonal and defensive secretions in the nymphs and the adults ofDysdercus cingulatus Fabr. (Heteroptera, Pyrrhocoridae)
1991
59 ref.; International audience; The exocrine secretions from the nymphs and the adults of both sexes in D. cingulatus were chemically investigated. Seven compounds were identified in the anterior glands, and eleven in the median dorsoabdominal glands of nymphs and adults of both sexes. Fifty-five compounds were identified in the defensive glands (34 in posterior dorsoabdominal glands ofnymphs and 21 in metathoracic glands of adults), and six in the sternal glandular epithelium of the males. The biological function of the glandular secretions and of their identified compounds were investigated and are discussed.
Do avian predators select for seasonal polyphenism in the European map butterfly Araschnia levana (Lepidoptera: Nymphalidae)?
2012
Seasonal polyphenism in animal colour patterns indicates that temporal variation in selection pressures maintains phenotypic plasticity. Spring generation of the polyphenic European map butterfly Araschnia levana has an orange–black fritillary-like pattern whilst individuals of the summer generation are black with white bands across the wings. What selects for the colour difference is unknown. Because predation is a major selection pressure for insect coloration, we first tested whether map butterfly coloration could have a warning function (i.e. whether the butterflies are unpalatable to birds). In a following field experiment with butterfly dummies we tested whether the spring form is bet…
Cadmium effects on development and reproduction of Oncopeltus fasciatus (Heteroptera: Lygaeidae)
2004
Newly hatched nymphs of the insect Oncopeltus fasciatus were exposed to various concentrations of CdCl2 administered in drinking water until the end of adult life. Significant nymphal mortalities were observed at concentrations above 30 mg Cd/l (corresponding to the LC50). The duration of the nymphal stages increased in proportion to the Cd concentration; at the lowest Cd concentration of 10 mg Cd/l, the median duration was significantly prolonged by one day, while at the highest concentration of 100 mg Cd/l it was increased by 10 days over the control group. The weight of newly emerged adults lineally decreased with Cd concentration, being reduced to half the weight of controls at 100 mg C…
Nymphaeetum candidae Miljan 1933 in Poland
2011
This paper presents the distribution, floristic composition and ecological requirements of the water plant community <em>Nymphaeetum candidae</em> Miljan 1933, belonging to the <em>Potametea</em> class. Until present this community has been reported only from north-eastern Poland. During present studies it was stated also in the south-western part of the country. <em>Nymphaeetum candidae</em> is considered to be a rare and endangered plant community in several countries of Central Europe.
Nymphaeetum albae Vollmar 1947 em. Oberd. in Oberd. et al. 1967, a plant association new to Poland
2011
The paper presents a water plant community new to Poland - <em>Nymphaeetum albae</em> Vollmar 1947 em. Oberd. in Oberd. et al. 1967, belonging to the i class. It was discovered in fishponds in Pokój near Namysłów, Lasowice Małe near Kluczbork and small ponds in Staniszcze Małe near Opole in Silesia (SW Poland). Floristic composition and ecological requirements of this association are presented in the paper. <em>Nymphaeetum albae</em> is considered to be a rare and endangered plant community in Europe.
Preliminary study on the biology, natural enemies and chemical control of the invasive Macrohomotoma gladiata (Kuwayama) on urban Ficus microcarpa L.…
2015
[EN] The phenology and natural enemies of Macrohomotoma gladiata (Kuwayama) (Hemiptera. Homotomidae) on Ficus microcarpa L. in Valencia (Spain) were studied in 2013. During the study, all immature instars of the pest were found on infested shoots indicating overlapping generations. However, two consistent increases in the proportion of the first two nymphal instars were detected in early March and June, possibly suggesting the beginning of spring and summer generations. Eggs of Macrohomotoma gladiata were usually found below the stipules of new healthy shoots, arranged in groups of 15-30 units. First two nymphal instars usually preferred the innermost part of the shoot, whereas the older de…
Significance of butterfly eyespots as an anti-predator device in ground-based and aerial attacks
2003
Many butterfly genera are characterised by the presence of marginal eyespots on their wings. One hypothesis to account for an occurrence of eyespots is that these wing pattern elements are partly the outcome of visual selection by predators. Bicyclus anynana (Satyrinae) has underside spotting on its wings but there is also a seasonal form in which the eyespots are reduced in size or totally absent. This natural variation gives us a useful tool to test the hypothesis that marginal eyespot patterns can decoy the attacking predator by, at least sometimes, diverting attack from vital body parts to the edges of the wings. We used lizards, Anolis carolinensis, and pied flycatchers, Ficedula hypol…
Forests as dispersal barriers for Erebia medusa (Nymphalidae, Lepidoptera)
2000
Summary The nymphalid butterfly Erebia medusa is a typical species of meadows that are poor in nitrogen and fallow land. In forests, it is only found on clearings with meadow-like structures. However, it is missing on wind exposed places, too. 239 imagoes of E. medusa were sampled in the Aggtelek Karst region (north-eastern Hungary) at six different localities at the end of May 1997. The sample sizes varied between 33 and 46. The studied karst area has a typical forest steppe vegetation and is characterised by a mosaic-like distribution of meadows and forests. The sampled butterflies were analysed by allozyme electrophoresis. The level of polymorphism was significantly higher in the samples…
A previously unreported numph cocoon of Alphasida puncticollis on the islet of Lampione (Sicilian Channel) (Coleoptera Tenebrionidae).
2010
In this paper we present an unusual case of cocoons produced by larvae of Tenebrionid Alphasida (Glabrasida) puncticollis (Solier, 1836), which has been observed on the islet of Lampione (Sicilian Channel). Pupal cocoons have never been recorded for species belonging to this genus, and their occurrence results rarely documented within the family Tenebrionidae. Some ecological implications are discussed.
Detection of the Spider Predator, Hololena Nedra By Naïve Juvenile Field Crickets (Gryllus Integer) Using Indirect Cues
2004
Summary In many species, prey detect predators using chemical cues, which may be based on the predator’s previous diet. Furthermore, the predator’s previous hunting strategy and diet may affect the prey’s behavioural strategies to avoid predation. Juvenile Gryllid field crickets face predation by spiders, but the responses of juvenile crickets to spiders are unknown. We studied whether naive juvenile field crickets can detect a predatory spider, Hololena nedra, using chemotactile cues (silk, secretions and excreta). We also studied the effect of the predator’s diet on the juvenile field cricket’s anti-predator behaviour. Cricket nymphs avoided the chemotactile spider cues when the spiders w…