Search results for "Insect Science"
showing 10 items of 1011 documents
Description of the final instar of Trichomalopsis peregrina (Hymenoptera, Pteromalidae), with data and comments on the preimaginal stages
2007
The preimaginal stages of T. peregrina are described. The egg displays a sculptured chorion, which is found only on those deposited externally. The immature larvae are characterized by their peculiarities in (a) a setose ring on the thoracic and abdominal segments, (b) an anal notch and (c) size and the sensory structures of the head capsule. The final instar is described and illustrated. Morphological structures of diagnostic value are discussed. The most salient character shown by the mature larva of this species lies in the epistoma, which is complete. Resumen. Se describen las fases de huevo y larva de T. peregrina . El huevo, como es característico en los que se depositan externamente,…
Cynipid wasps inducing galls on plants of the genus Picris (Asteraceae) in Europe, with a description of a new species of Phanacis Foerster (Hymenopt…
2008
13 paginas y 8 figuras
Cold tolerance during larval development: effects on the thermal distribution limits of Leptinotarsa decemlineata
2009
Insects' cold tolerance during their development is a surprisingly understudied subject in ecology, despite the fact that subzero temperatures during the growing season are common at high altitudes and latitudes. Subzero temperatures can have detrimental effects on organisms, restricting a species' range. This study addresses the question whether night frosts during the growing season have an instant or delayed negative impact on larval mortality of the Colorado potato beetle, Leptinotarsa decemlineata (Say) (Coleoptera: Chrysomelidae). We also tested whether populations from the centre (Poland) and margins (Russia) of the distribution range of L. decemlineata differ in their responses to s…
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.
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…
Female Oviposition Decisions and Their Impact on Progeny Life-History Traits
2008
An important factor affecting the life-history of an organism is parental investment in reproduction: reproductive decisions are almost invariably costly. Therefore, reproductive decisions should be beneficial in terms of increased offspring number or fitness. For example, egg laying decisions in many insects can influence resource availability of the offspring through changes in the larval density, and resource availability will have effects on many life-history traits. Here we studied whether female reproductive decisions affect offspring fitness in Callosobruchus maculatus seed beetles. Females laid more eggs on black-eye beans than on mung beans. However, when the difference in the surf…
Biological Responses of <I>Rhynchophorus ferrugineus</I> (Coleoptera: Curculionidae) to <I>Steinernema carpocapsae</I> (Nemat…
2013
Rhynchophorus ferrugineus (Olivier 1790) (Coleoptera: Curculionidae) is becoming a serious problem in Mediterranean areas where it is well-adapted, and now is present even in the United States (California). The infestations are primarily in urban areas where chemical control is not advisable and million of Euros are spent to control it. The effects of the entomopathogenic nematode Steinernema carpocapsae (Nematoda: Steinernematidae) on mortality, growth, as well as the immune activity of R. ferrugineus larvae, were investigated. R. ferrugineus mortality exhibited a positive trend with the dosage and duration of exposure to S. carpocapsae. The median lethal dose and median lethal time, impor…
Pathogenicity bioassays of isolates of Beauveria bassiana on Rhynchophorus ferrugineus
2014
BACKGROUND The control of Rhynchophorus ferrugineus (Olivier), the main palm pest in the Mediterranean Basin, is problematic because of its biology and the current restrictions in many European countries on the use of chemical insecticides in urban areas. Entomopathogenic fungi have been studied as potential biological control agents, but information on their natural incidence is limited. Strains of Beauveria bassiana (Balsamo) Vuillemin were isolated from symptomatic insects collected on dead palms, and their pathogenicity against different instars of R. ferrugineus was evaluated in the laboratory. RESULTS The overall percentage of infected insects found in Canary palms was 7%. In laborato…
Effect of conditioned media on three genotypes ofDrosophila melanogaster: Physical, chemical, and biological aspects
1986
The uric acid contents in larvae, pupae, and culture media were studied during larval and pupal development in three genotypes of Drosophila melanogaster reared in both crowded and noncrowded conditions. The uric acid content and the response of genotypes in media supplemented with 10 and 15 mg/ml of uric acid were correlated with the outcome obtained in conditioned media. In addition, the behavior of genotypes in conditioned media is explained in terms of the physicochemical properties of the conditioned media, which include uric acid content, the amount of food ingested, the degree of free water, the physical disturbance within the cultures, and the particular response of each genotype to…