Search results for "INSECT"
showing 10 items of 2033 documents
Characteristics of the spermathecal contents of old and young honeybee queens.
2009
Sperm are often stored, for a long time after mating, in females of various animal species. In case of the queen honeybee (Apis mellifera), sperm remain fertile for several years in the spermatheca. Little information is available regarding the effect of long-term storage of sperm on its fertility. To evaluate this, enzymes and/or sperm have been analysed from the spermatheca of 75 queens of various ages (0 year Y0, n=14; one year Y1, n=14; two years Y2, n=7; virgin queen VQ, n=40) and semen samples have been taken from 46 drones. The sperm from the spermatheca of older queens move more slowly (F=11.45, P < 0.0001) and show different movement patterns (Chi2=90.0, P < 0.0001) from those of t…
Photoperiodic regulation of cold tolerance and expression levels of regucalcin gene in Drosophila montana
2011
Temperature-induced plasticity of cold tolerance has been reported in many insect species, but cold tolerance can also be affected by changes in day (or night) length. In the present study we elucidate the direct and indirect effects of photoperiod on the cold tolerance of females of two Drosophila montana strains--one which possesses a robust photoperiodic diapause and another which does not. In the diapause-strain the time needed for recovery from chill coma showed a positive correlation with day length, but diapause itself played only a minor role in photoperiodic acclimation. The strain that was not able to enter to diapause as a response to day length also lacked photoperiodic cold acc…
Molecular characterization of a new adult male putative calycin specific to tergal aphrodisiac secretion in the cockroach Leucophaea maderae
2001
0014-5793 (Print) Journal Article Research Support, Non-U.S. Gov't; Lma-p18 is an epicuticular surface protein specific to the tergal gland aphrodisiac secretion of Leucophaea maderae adult males. Native Lma-p18 was purified and the complete cDNA sequence was determined by RT-PCR using primers based on Edman degradation fragments. Northern blot and in situ hybridization analyses showed that Lma-p18 is expressed exclusively in the anterior part of male tergal gland, which is exposed only during sexual behavior. Sequence analysis indicated that Lma-p18 belongs to the calycin superfamily and is very similar to Lma-p22, the first known male-specific tergal protein in L. maderae. Lma-p18 and Lma…
An inhibitory sex pheromone tastes bitter for Drosophila males
2007
1932-6203 (Electronic) Journal Article; Sexual behavior requires animals to distinguish between the sexes and to respond appropriately to each of them. In Drosophila melanogaster, as in many insects, cuticular hydrocarbons are thought to be involved in sex recognition and in mating behavior, but there is no direct neuronal evidence of their pheromonal effect. Using behavioral and electrophysiological measures of responses to natural and synthetic compounds, we show that Z-7-tricosene, a Drosophila male cuticular hydrocarbon, acts as a sex pheromone and inhibits male-male courtship. These data provide the first direct demonstration that an insect cuticular hydrocarbon is detected as a sex ph…
A new species of Charinus Simon, 1892 (Amblypygi, Charinidae) from termite nests in French Guiana
2015
The genus Charinus is represented by 51 species, distributed in all tropical regions. Their small size allows them to use a wide range of micro-habitats, from caves, litter to insect nests. The new species C. sillami sp. nov. was found into termite nests of three different species: Neocapritermes taracua, Spinitermes sp. and Embiratermes neotenicus. Only Paracharon caecus (Paleoamblypygi: Paracharontidae) was previously known to be associated with Isoptera. Eleven species of Charinus were previously known from Northern South America. Charinus sillami sp. nov. is the second species of the genus occurring in French Guiana. An updated key of Northern South-American species is provided.
Mushroom bodies enhance initial motor activity in Drosophila.
2009
The central body (or central complex, CCX) and the mushroom bodies (MBs) are brain structures in most insect phyla that have been shown to influence aspects of locomotion. The CCX regulates motor coordination and enhances activity while MBs have, thus far, been shown to suppress motor activity levels measured over time intervals ranging from hours to weeks. In this report, we investigate MB involvement in motor behavior during the initial stages (15 minutes) of walking in Buridan's paradigm. We measured aspects of walking in flies that had MB lesions induced by mutations in six different genes and by chemical ablation. All tested flies were later examined histologically to assess MB neuroan…
Female-released sex pheromones mediating courtship behavior in Lysiphlebus testaceipes males.
2013
Ethological aspects and chemical communication at close-range between the sexes of Lysiphlebus testaceipes Cresson (Hymenoptera: Braconidae) have been investigated through behavioral bioassays and chemical analysis. The attractiveness toward males of whole-body extracts of females and males in hexane and acetone was evaluated, adopting male fanning behavior as a key behavioral component. Also, the activity of polar and nonpolar fraction of female-body extract in hexane obtained using solid-phase extraction technique was investigated. In order to identify cuticular compounds, male and female whole-body extracts with hexane and acetone were analyzed by gas chromatography-mass spectrometry. Th…
The insectivorous batPipistrellus nathusiiuses a mixed-fuel strategy to power autumn migration
2012
In contrast to birds, bats are possibly limited in their capacity to use body fat as an energy source for long migrations. Here, we studied the fuel choice of migratoryPipistrellus nathusii(approximate weight: 8 g) by analysing the stable carbon isotope ratio (δ13CV-PDB) of breath and potential energy sources. Breathδ13CV-PDBwas intermediate betweenδ13CV-PDBof insect prey and adipocyte triacylglycerols, suggesting a mixed-fuel use ofP. nathusiiduring autumn migration. To clarify the origin of oxidized fatty acids, we performed feeding experiments with captiveP. nathusii. After an insect diet, bat breath was enriched in13C relative to the bulk and fat portion of insects, but not deviating fr…
Antagonistic effects of hypertrehalosemic neuropeptide on the activities of 6-phosphofructo-1-kinase and fructose-1,6-bisphosphatase in cockroach fat…
2001
Hypertrehalosemic neuropeptides from the corpora cardiaca such as the decapeptide Bld HrTH bring about a profound switch in the metabolic activity of cockroach fat body during which production of the blood sugar trehalose is stimulated while the catabolism of carbohydrate (glycolysis) is inhibited. The mechanisms of the metabolic switch are not fully understood. Incubation of isolated fat body from the cockroach Blaptica dubia with 10(-8) M Bld HrTH, for 10-60 min, stimulated glycogen breakdown and increased the content of the substrates of both the glycolytic enzyme 6-phosphofructo-1-kinase (PFK, EC 2.7.1.11) and the gluconeogenic enzyme fructose-1,6-bisphosphatase (FBPase, EC 3.1.3.11) in…
Structure and function of prothoracic glands and oenocytes in embryos and last larval instars of Oncopeltus fasciatus Dallas (Insecta, Heteroptera).
1976
1. Active prothoracic glands and oenocytes of last larval stage are both characteristized by well-developed smooth and rough endoplasmic reticulum (ER). Prothoracic glands also show plasma membrane infoldings, but not oenocytes which contain a large number of pleomorphic vesicles. 2. The fine structure of embryonic oenocytes corresponds after blastokinesis with that of active larval and adult cells. Thus, an activity in the late embryo can be assumed. Embryonic prothoracic glands reveal no signs of activity: smooth and rough ER are absent. The subcellular structure resembles that of organ anlagen, i.e. not yet fully differentiated tissue. Hormone synthesis is not likely. 3. Ecdysone titer w…