Search results for "aphid"
showing 10 items of 128 documents
Indagini sulle infestazioni di Aphis gossypii Glover su melone invernale (Cucumis melo Var. Helios) in aziende a conduzione biologica della Sicilia o…
2011
Investigations on the aphid infestation occurring on winter melon crops (Cucumis melo var. Helios) in organic farms of western Sicily The winter melon (Cucumis melo L.) is an important crop in Sicily. Previous studies carried out in western Sicily have shown that the aphid species Aphis gossipii is the key pest of winter melon crops.A. gossypii is a cosmopolitan species with very polyphagous habits; this phytophagous insect is capable of serious economic damage due to direct feeding of the sap plant and due to the honeydew secretion and the consequent presence of sooty mold and due to the possible transmission of viruses. The aim of this work was to investigate the levels of aphid infestati…
Clock genes and photoperiodism in the aphid Acyrthosiphon pisum
2017
Aphids have a strong seasonal response, namely the development of a sexual morphs triggered by the shortening of photoperiod in autumn that produce an overwintering egg in which an embryonic diapause takes place. From this egg, an asexual parthenogenetic female emerges giving way to the asexual phase of the aphid life cycle in which several asexual generations occur. Based on the response to short photoperiods, two strains of aphids can be found: the holocyclic develop the seasonal response under short photoperiods, while the anholocyclic do not. The sequencing of the genome of the pea aphid Acyrthosiphon pisum places this species as an excellent model to investigate the the involvement of …
The influence of carrot seed oil and its main component carotol on development and behaviour of Aphis fabae aphids
2005
The behaviour of some aphid species is influenced by different plant odours, especially by plant essential oils, which are the mixtures of terpenes. In our study, carrot seed oil and its main sesquiterpenic component - carotol - were examined as factors influencing the behaviour and development of Aphis fabae Scop. The results of the olfaction experiments showed, that especially carrot seed oil exhibited various activities in the dose-dependent manner. When tested in the amount which did not exceed 0.01 mL of 1% v/v of suspension in water, this substance exhibited strong attractancy toward adult females of Aphis fabae. In contrast, if similar tests were carried out using > 0.1 mL of suspens…
The Phylogenetic Analysis of Variable-Length Sequence Data: Elongation Factor–1α Introns in European Populations of the Parasitoid Wasp Genus Pauesia…
2001
Elongation factor-1alpha (EF-1alpha) is a highly conserved nuclear coding gene that can be used to investigate recent divergences due to the presence of rapidly evolving introns. However, a universal feature of intron sequences is that even closely related species exhibit insertion and deletion events, which cause variation in the lengths of the sequences. Indels are frequently rich in evolutionary information, but most investigators ignore sites that fall within these variable regions, largely because the analytical tools and theory are not well developed. We examined this problem in the taxonomically problematic parasitoid wasp genus Pauesia (Hymenoptera: Braconidae: Aphidiinae) using con…
Molecular phylogeny of Iberian Fordini (Aphididae: Eriosomatinae): implications for the taxonomy of generaFordaandParacletus
2009
Mediterranean representatives of the galling aphid tribe Fordini (Hemiptera: Aphididae: Eriosomatinae) are usually grouped under the subtribe term Fordina. Aphids within Fordina display two-year life cycles, alternating between Pistacia shrubs, where they induce conspicuous galls, and roots of Poaceae species. The high number of morphs present in a given species, the lack of knowledge of the complete cycle in some species, and the similarity between homologous morphs observed in different species pose many taxonomic problems in this group. We present results of a survey to elucidate the phylogenetic relationships among Fordini species present in the Iberian Peninsula and the Canary Islands.…
The compound internal pyrenoid in cultured cells of the green algaMonoraphidium griffithii (Berkel.) Komar.-Legner.
1979
The chloroplast ultrastructure ofMonoraphidium griffithii (Berkel.) Komar.-Legner. has been studied in axenic cultures of various ages. The algae have grown in a complete nutrient solution (illumination about 3,000 lx) and on its agar medium (illumination about 600 lx). The large parietal cup-shaped chloroplast of the cells includes a multiformed compound internal pyrenoid that is situated, especially in older cells, in the central part of the chloroplast opposite to the dictyosome and the nucleus. The chloroplast thylakoids either reach the edge of the pyrenoid or penetrate its matrix and run there parallel in more or less long bits. Starch grains were not found to form any sheath around t…
Las hormigas (Hymenoptera, Formicidae) asociadas a pulgones (Hemiptera, Aphididae) en la provincia de Valencia
2002
Twenty-six species of ants associated with aphids, belonging to twelve genera, are collected. Three subfamilies are identified, being the Formicinae the more represented about number of samples, genera and species. On the other hand, <i>Lasius niger</i> has been the species that is found with a more number of aphids (fifty eight species), and it seems to be the ant with a more capacity to establish associations with the different species of aphids. 224 different associations between the ants and the aphids are established and 164 of them are not recorded in the bibliography consulted for Spain.<br><br>Se han recogido veintiséis especies de hormigas asociadas a pulgon…
Mapping and quantification of cryptochrome expression in the brain of the pea aphid Acyrthosiphon pisum.
2021
Aphids are paradigmatic photoperiodic animals often used to study the role of the circadian clock in the seasonal response. Previously, we described some elements of the circadian clock core (genes period and timeless) and output (melatonin, AANATs and PTTH) that could have a role in the regulation of the aphid seasonal response. More recently we identified two opsins (C-ops and SWO4) as candidate input photoperiodic receptors. In the present report, we focus on the study of cryptochromes (cry) as photoreceptors of the circadian clock and discuss their involvement in the seasonal response. We analyze the expression of cry1 and cry2 genes in a circadian and seasonal context, and map their ex…
Data from: The importance of phytoplankton biomolecule availability for secondary production
2018
The growth and reproduction of animals is affected by their access to resources. In aquatic ecosystems, the availability of essential biomolecules for filter-feeding zooplankton depends greatly on phytoplankton. Here, we analyzed the biochemical composition, i.e., the fatty acid, sterol and amino acid profiles and concentrations as well as protein, carbon, nitrogen, and phosphorus content of 17 phytoplankton monocultures representing the seven most abundant phytoplankton classes in boreal and sub-arctic lakes. To examine how the differences in the biochemical composition between phytoplankton classes affect their nutritional quality for consumers, we assessed the performance of Daphnia, on …
El género <i>Lysaphidus</i> (Hymenoptera: Braconidae) en la Península Ibérica
1995
The genus Lysaphidus Smith, 1944 (Hymenoptera, Braconidae, Aphidiinae) is recorded for the first time from the Iberian Peninsula represented by two species: L. arvensis Stary, 1960, first record for the Iberian Peninsula, and L. santolinae n. sp., both of them parasitoids of Coloradoa Wilson,1910 genus (Homoptera, Aphididae). The mummies were collected on Santolina chamaecyparissus L. and Santolina rosmarinifolia L. (Asteraceae).