Search results for "Entomology"

Festschrift zum 60. Geburtstage von Professor Dr. Embrik Strand [Festschrift zum sechzigsten Geburtstage von Professor Dr. Embrik Strand], Vol.2

1936

Jubilāram veltīti ārvalstu zoologu un paleontologu raksti vācu, franču, angļu, itāliešu u.c. valodās.

IPM-recommended insecticides harm beneficial insects through contaminated honeydew

2020

The use of some systemic insecticides has been banned in Europe because they are toxic to beneficial insects when these feed on nectar. A recent study shows that systemic insecticides can also kill beneficial insects when they feed on honeydew. Honeydew is the sugar-rich excretion of hemipterans and is the most abundant carbohydrate source for beneficial insects such as pollinators and biological control agents in agroecosystems. Here, we investigated whether the toxicity of contaminated honeydew depends on i) the hemipteran species that excretes the honeydew; ii) the active ingredient, and iii) the beneficial insect that feeds on it. HPLC-MS/MS analyses demonstrated that the systemic insec…

Biological protection against grape berry moths. A review

2018

International audience; Grape is a major crop, covering 7.5 M ha worldwide, that is currently being confronted with three main challenges: intensive pesticide use that must be reduced, invasion by new pests/diseases, and climate change. The biological control of pests and vectors would help address these challenges. Here, we review the scientific literature on the biological control of grape moths by macroorganisms (excluding nematodes). Two components, biological control with an active human role, mainly using biocontrol agents through inundation or inoculation, and conservation biological control, are considered. The major points are the following. (1) Tortricid grape moths seriously dama…

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.

"Zooloģija un dzīvnieku ekoloģija" : Latvijas universitātes 79. zinātniskās konference, Bioloģijas sekcija : Referātu tēžu krājums

2021

A model species for agricultural pest genomics: the genome of the Colorado potato beetle, Leptinotarsa decemlineata (Coleoptera: Chrysomelidae)

2018

AbstractThe Colorado potato beetle is one of the most challenging agricultural pests to manage. It has shown a spectacular ability to adapt to a variety of solanaceaeous plants and variable climates during its global invasion, and, notably, to rapidly evolve insecticide resistance. To examine evidence of rapid evolutionary change, and to understand the genetic basis of herbivory and insecticide resistance, we tested for structural and functional genomic changes relative to other arthropod species using genome sequencing, transcriptomics, and community annotation. Two factors that might facilitate rapid evolutionary change include transposable elements, which comprise at least 17% of the gen…

Diapause affects cuticular hydrocarbon composition and mating behavior of both sexes inDrosophila montana

2018

Environmental cues, mainly photoperiod and temperature, are known to control female adult reproductive diapause in several insect species. Diapause enhances female survival during adverse conditions and postpones progeny production to the favorable season. Male diapause (a reversible inability to inseminate receptive females) has been studied much less than female diapause. However, if the males maximized their chances to fertilize females while minimizing their energy expenditure, they would be expected to be in diapause at the same time as females. We investigated Drosophila montana male mating behavior under short‐day conditions that induce diapause in females and found the males to be r…

Pre-imaginal exposure to Oberon® disrupts fatty acid composition, cuticular hydrocarbon profile and sexual behavior in Drosophila melanogaster adults

2021

International audience; Oberon® is a commercial formulation of spiromesifen, a pesticide inhibitor of lipid biosynthesis via acetyl CoA carboxylase, widely used in agricultural crop protection. However, its mode of action requires further analysis. We currently examined the effect of this product on Drosophila melanogaster as a non-target and model organism. Different concentrations of spiromesifen were administered by ingestion (and contact) during pre-imaginal development, and we evaluated its delayed action on adults. Our results suggest that spiromesifen induced insecticidal activity on D. melanogaster. Moreover, spiromesifen treatment significantly increased the duration of larval and …

Large variation in mitochondrial DNA of sexual and parthenogenetic Dahlica triquetrella (Lepidoptera: Psychidae) shows multiple origins of parthenoge…

2013

Background Obligate parthenogenesis is relatively rare in animals. Still, in some groups it is quite common and has evolved and persisted multiple times. These groups may provide important clues to help solve the ‘paradox of sex’. Several species in the Psychidae (Lepidoptera) have obligate parthenogenesis. Dahlica triquetrella is one of those species where multiple transitions to parthenogenesis are postulated based on intensive cytological and behavioural studies. This has led to the hypothesis that multiple transitions from sexuals to diploid parthenogens occurred during and after the last glacial period, followed by transitions from parthenogenetic diploids to parthenogenetic tetraploid…

Sex-pairing pheromones and reproductive isolation in three sympatric Cornitermes species (Isoptera, Termitidae, Syntermitinae)

2011

International audience; The species-specificity of pairing has been studied in three sympatric Neotropical termites: Cornitermes bequaerti, Cornitermes cumulans and Cornitermes silvestrii (Termitidae, Syntermitinae). Bioassays showed that sex attraction was highly species-specific between C. bequaerti and C cumulans but not between C. cumulans and C. silvestrii. The sex-pairing pheromone of the three species is secreted by the tergal glands of female alates. It consists of a common compound (3Z,6Z,8E)-dodeca-3,6,8-trien-1-ol. In C. bequaerti, this polyunsaturated alcohol is the only compound of the sex-pairing pheromone, whereas it is associated with the oxygenated sesquiterpene (E)-nerolid…