Search results for "Larva"
showing 10 items of 632 documents
Risultati della lotta biologica contro ilDacus oleae Gmel. a mezzo dell'Opius concolor Sz. siculus Mon.
1965
The Author reports on the essays of artificial biological control of the olive fly (Dacus oleaeGmel.) made by himself andGenduso with the specific parasiteOpius c. siculusMon. found in Sicily. The Authors followingDelanoue's technic have bred theseOpius in laboratory on larvae ofCeratitis capitataWied; so they were able to release: in 1961 — 1000Opius in a small olive plantation near Palermo; in 1962 — 24000Opius in the island of Pantelleria (Sicily); in 1963 — 40000Opius in the island of Salina (Eolic Islands-Sicily); in 1964 — 180000Opius also in the island of Salina.
Aportaciones al conocimiento de los mosquitos (<i>Diptera, Culicidae</i>) de alta montaña presentes en la Península Ibérica
2009
Several larval samplings of mosquitoes (Diptera, Culicidae) in different mountainous regions of the peninsular Spain were carried out. A total of 2796 specimens belonging to 18 species were collected, nevertheless the 72.5 % of these finds includes only three of them (Cx. hortensis hortensis, Cx. pipiens and Cs. longiareolata). The adaptation capacity to a varied typology of water bodies together with the marked multivoltinism that characterizes their biotic cycles are postulated as two of the principal reasons that explain their abundances. The altitudinal distribution as well as some information about the bioecology of all the species captured are also exposed.
Fluence Rate or Cumulative Dose? Vulnerability of Larval Northern Pike (Esox lucius) to Ultraviolet Radiation
2007
Newly hatched larvae of northern pike were exposed in the laboratory to four fluence rates of ultraviolet radiation (UVR; 290-400 nm) over three different time periods, resulting in total doses ranging from 3.0 +/- 0.2 to 63.0 +/- 4.4 kJ.m(-2). Mortality and behavior of the larvae were followed for 8-12 days, and growth measured at the end of the experiment. Also, the principle of reciprocity-that the UVR-induced mortality depends on the cumulative dose, independent of fluence rate-was tested. Fluence rates higher than 1480 +/- 150 mW.m(-2) caused mortality and growth retardation. The highest fluence rate (3040 +/- 210 mW.m(-2)) caused 100% mortality in 5 days. All fluence rates caused beha…
Quality attracts parasites: host condition‐dependent chemo‐orientation of trematode larvae
2015
Summary Environmental factors impairing physiological condition of organisms are assumed to predispose them to parasite infections. This is because host immune function is typically condition-dependent. However, poor physiological condition has been reported to reduce host susceptibility to parasites in various systems. We examined whether such an effect can be due to altered exposure of hosts to active parasite transmission stages by investigating chemo-orientation of free-swimming cercariae larvae of a parasite Echinoparyphium aconiatum towards its snail host Lymnaea stagnalis. We used both long-term and short-term feeding treatments to manipulate the body condition and physiological trai…
Übertragung von Verhaltensweisen durch Transplantation von Anlagen neuroanatomischer Strukturen bei Amphibienlarven: I. Xenoplastischer Austausch von…
2010
By transplantation of parts of the neural plate (latter medulla oblongata) from Xenopus laevis (Daud.) to Hymenochirus boettgeri (Torn.) larval chimaeras were obtained, which showed donorlike rhythmical movements of the mouth and pharyngeal region, movements which the host species lacks. Nevertheless, some of these tadpoles were still able to catch small prey in a reaction which is typical for the host and lacking in the donor.
Prevalence of Borrelia burgdorferi in Ixodes ricinus ticks collected from moose (Alces alces) and roe deer (Capreolus capreolus) in southern Norway
2010
As part of a larger survey, ears from 18 roe deer (Capreolus capreolus) and 52 moose (Alces alces) shot in the 2 southernmost counties in Norway were collected and examined for Ixodes ricinus ticks. Seventy-two adult ticks, 595 nymphs, and 267 larvae from the roe deer, and 182 adult ticks, 433 nymphs, and 70 larvae from the moose were investigated for infection with Borrelia burgdorferi sensu lato (s.l.). The results showed the presence of B. burgdorferi s.l. DNA in 2.9% of the nymphs collected from roe deer and in 4.4% of the nymphs and 6.0% of the adults collected from moose. The spirochetes were not detected in adult ticks from roe deer, or in larvae feeding on roe deer or moose. In comp…
A New Species of Palarus Latreille from Spain with a Comparative Study on Nesting Behavior and Larvae in the Genus (Hymenoptera: Sphecidae)
1992
Palarus almerienis n. sp. is described from Spain (including imago, larva, and nesting habits). P. confusus Turner, currently considered a subspecies of P. ambustus Klug, is raised to full species status. The most important differences among the three species involve sculpture of the mesopleuron. The geographical distribution of these three taxa is discussed. Females of P. almeriensis excavate unicellular nests and capture not only Hymenoptera (the usual prey of the genus), but also Diptera (Stratiomyiidae). They make temporary closures and store the prey in the gallery before transferring it to the cell, which they dig during provisioning. Several species of Diptera (Miltogramminae) are na…
New data on the early development of Hysterothylacium aduncum (Nematoda, Anisakidae).
1998
This note reports on incidental observations of the early development of the third-stage larvae of Hysterothylacium aduncum from gadid fishes. Gravid H. aduncum females were collected from Pollachius virens, Pollachius pollachius. Gadus morhua, and Molva molva in Norwegian waters. The eggs were incubated at 20 per thousand salinity and 5 C. Spontaneous hatching of third-stage larvae was observed 10-25 days after egg deposition. These larvae were long lived and could infect Acartia tonsa copepods, the infections being maintained for up to 34 days. The morphology of the third-stage larvae in the copepods and some traits of the life cycle were similar to those reported in previous studies. How…
Diel Feeding Features of Juveniles of Two Sparids in the Stagnone di Marsala Coastal Sound (Western Sicily, Italy)
2001
Diet composition, feeding rhythms, gastric evacuation rates, daily rations of Diplodus puntazzo (Gmelin 1789) and Sarpa salpa (Linneo 1758) juveniles were studied in order to investigate their trophic ecology, niche breadth and overlap. These Sparids were collected in the Stagnone di Marsala (Western Sicily), in April 1997, in a 24 hour sampling period. Gastric content of 86 specimens of D. puntazzo (standard length = 31.9 ± 6.6 mm; body wet weight = 1.0 Ī 0.5 g) and of 100 specimens of S. salpa (standard length = 32.3 ± 2.9 mm; body wet weight = 0.6 Ī 0.2 g) were examined. Amphipoda and Tanaidacea were the most frequent prey items in stomach content of D. puntozzo, while Hydrozoa, Bryozoa …
Comparison of sampling methods for semipelagic animals in two deep basins of Lake Saimaa
1996
The efficiency of different methods for sampling semipelagic animals was compared in the deep basins of Lake Paasivesi and Lake Puruvesi of the complex Lake Saimaa, Finland, during 1990–92. Certain semipelagic animals, such as Mysis relicta, amphipods and larvae of Chaoborus flavicans, are important bioindicators of water and benthic quality. However, owing to their high mobility and vertical migrations they are difficult to sample quantitatively with traditional benthic methods.