Search results for " Larva"
showing 10 items of 77 documents
Effetti collaterali di una miscela a base di azadiractina ed oli minerale paraffinico sui parassitoidi di Phyllocnistis citrella Stainton (Lep.: Grac…
2000
Investigations on Tuta absoluta (Lepidoptera: Gelechiidae): larval infestation on the tomato cultivated in open field and evaluation of five essentia…
2019
Abstract The tomato miner Tuta absoluta Meyrick (Lepidoptera: Gelechiidae) is a Neotropical species, which cause serious damages to tomato in spread areas. It appeared in 2008 in Italy, where it seriously threatened tomato production both in greenhouse and open field cultivations. In this work a study on infestation by this leafminer on leaves was conducted in an organic cultivation of tomato (Lycopersicon esculentum Mill.) "Pizzutello" variety in Sicily (Italy), and the insecticidal activity of 5 essential oils (EOs) on T. absoluta was evaluated in laboratory. EOs of basil, cypress, laurel, peppermint and Spanish oregano were used against 3rd- and 4th-instar larvae to assess contact effect…
Different key roles of mesoscale oceanographic structures and ocean bathymetry in shaping larval fish distribution pattern: A case study in Sicilian …
2016
Fish larvae data collected in year 2009 were used to examine the effects of particular environmental conditions on the structure of larvalassemblages in two oligotrophic Mediterranean areas (the Southern Tyrrhenian Sea and the Strait of Sicily). For this purpose, relationships with environmental variables (temperature, salinity and fluorescence), zooplankton biomass, water circulation and bathymetry are discussed. Hydrodynamic conditions resulted very differently between two study areas. The Southern Tyrrhenian Sea was characterized by moderate shallow circulation compared to the Strait of Sicily. In this framework, distribution pattern of larval density in the Tyrrhenian Sea was mainly dri…
Digestive Enzymes in Larvae and Juveniles of Farmed Sharpsnout Seabream (Diplodus puntazzo) (Cetti, 1777)
2011
The ontogenetic development and pattern of main digestive enzyme activities (proteases, carbohydrases and lipases) were investigated in farmed sharpsnout seabream Diplodus puntazzo larvae and juveniles, during the passage from the larval stage to adult (from 21 to 277 days after hatching - DAH). Larvae showed exponential growth, thus confirming that Rotifers and Artemia nauplii are suitable preys for early feeding of D. puntazzo larvae. Pepsin activity was low in the larvae, but it increased afterwards in relation with stomach development. In juveniles, levels of specific activity of trypsin, chymotrypsin and elastase were lower compared to that recorded in larvae. A decrease in the activit…
Environmental Conditions along Tuna Larval Dispersion: Insights on the Spawning Habitat and Impact on Their Development Stages
2022
Estimated larval backward trajectories of three Tuna species, namely, Atlantic Bluefin Tuna (Thunnus thynnus, Linnaeus, 1758), Bullet Tuna (Auxis Rochei, Risso, 1801) and Albacore Tuna (Thunnus alalunga, Bonnaterre, 1788) in the central Mediterranean Sea, were used to characterize their spawning habitats, and to assess the impact of changes due to the major environmental parameters (i.e., sea surface temperature and chlorophyll-a concentration) on larval development during their advection by surface currents. We assumed that the environmental variability experienced by larvae along their paths may have influenced their development, also affecting their survival. Our results showed that the …
The hydrophilie of the larval test of Ascidiae: functional role played by test cells
2012
Ascidian swimming larvae are entirely surrounded by a hyaline extracellular coat, called as tunic or test, on which numerous test cells adhere. The functional role played by test cells in larvae of various ascidian species consists in depositing submicroscopic structures known as ornaments and/or substances of proteoglycan nature in the larval test surface. The deposition of ornaments would render the larval test hydrophilic and thus allow the larvae to swim being immersed in sea water. Ultrastructural investigations reported in literature on larvae of Cionidae and Ascididae families have not evidenced the presence of ornaments in the swimming larval test. For these Ascididae families it ha…
Chemosensory Receptors in the Larval Maxilla of Papilio hospiton
2022
Among the butterflies of the genus Papilio (Lepidoptera: Papilionidae), Papilio hospiton (Géné) has a geographical distribution limited to the Mediterranean islands of Sardinia (Italy) and Corsica (France). This is mainly due to the host range that includes only a few plant species of Apiaceae and Rutaceae growing on these islands. In a previous electrophysiological investigation conducted on the maxillary gustatory system of larvae of P. hospiton and its closely phylogenetically related species Papilio machaon, a significantly higher spike activity was shown for the gustatory neurons of lateral and medial styloconic sensilla in P. hospiton when bitter compounds were tested. This effect was…
Early stages of test formation in larva of Ascidia malaca (Tunicata, Ascidiacea): ultrastructural and cytochemical investigations.
2003
Abstract The swimming larvae of ascidians are entirely covered by a hyalin coat called tunic, or test. This covering consists of two cuticular layers, C 1 and C 2 , which surround an inner compartment composed of an amorphous hyalin matrix with numerous fibrils dispersed inside. Data from the literature agree on the key role played by the cells of the larval ectodermic layer in the synthesis and secretion of larval test components. In the present article are reported ultrastructural and cytochemical investigations made during test formation in the swimming larva of Ascidia malaca . Besides confirming the role played by ectodermic cells during the early stages of test formation, the investig…
Identificación y caracterización de proteínas de Strongyloides stercoralis de utilidad para el diagnóstico y control de la enfermedad mediante técnic…
2016
El nematodo Strongyloides stercoralis es el principal causante de la estrongiloidiasis humana. Debido a la capacidad del parásito de perpetuar un ciclo autoinfectivo la infección puede prolongarse durante años en el hospedador, dando lugar a una enfermedad crónica en personas inmunocompetentes, mientras que en condiciones de inmunosupresión puede desembocar en cuadros clínicos graves con elevadas tasas de mortalidad. La región de La Safor valenciana ha sido considerada foco endémico de este parásito desde hace más de un siglo, habiéndose diagnosticado cientos de casos desde entonces, suponiendo un problema sanitario en la región. La presente Tesis contribuye a la mejora en el conocimiento p…