Search results for "Insect Science"
showing 10 items of 1011 documents
Ovicidal Activity of Maternally Applied Ecdysteroids in the Large Milkweed Bug (Heteroptera: Lygaeidae)
1982
Exogenous ecdysteroids (ecdysone, 20-hydroxyecdysone and makisterone A) administered to reproducing females of Oncopelus fasciatus (Dallas) reduced egg hatch drastically. The ovicidal activity apparently stemmed from ecdysteroids—unchanged hormone or metabolites—transferred from mother into oocyte. Different stages of embryogenesis were affected. Makisterone A, the predominant ecdysteroid in normal embryos, is by far the most effective ecdysteroid.
Intrarectal immunization with rotavirus 2/6 virus-like particles induces an antirotavirus immune response localized in the intestinal mucosa and prot…
2006
ABSTRACTRotavirus (RV) is the main etiological agent of severe gastroenteritis in infants, and vaccination seems the most effective way to control the disease. Recombinant rotavirus-like particles composed of the viral protein 6 (VP6) and VP2 (2/6-VLPs) have been reported to induce protective immunity in mice when administered by the intranasal (i.n.) route. In this study, we show that administration of 2/6-VLPs by the intrarectal (i.r.) route together with either cholera toxin (CT) or a CpG-containing oligodeoxynucleotide as the adjuvant protects adult mice against RV infection. Moreover, when CT is used, RV shedding in animals immunized by the i.r. route is even reduced in comparison with…
Redescription of Chiropturopoda nidiphila Wiśniewski & Hirschmann (Acari: Uropodina) from a woodpecker’s tree holes, including all development stages…
2021
All development stages of Chiropturopoda nidiphila Wiśniewski & Hirschmann, 1983 are described, which has previously been known only from the deutonymph stage. The species is closely associated with tree holes excavated by woodpeckers. Chiropturopoda nidiphila was redescribed and the genus diagnosis was completed. The description of the species morphology is based largely on scanning (SEM) electronograms. Diagnoses differentiating all of the known species of the genus Chiropturopoda are provided, including their developmental stages.
Chemical Ecology of Floral Resources in Conservation Biological Control.
2023
Conservation biological control aims to enhance populations of natural enemies of insect pests in crop habitats, typically by intentional provision of flowering plants as food resources. Ideally, these flowering plants should be inherently attractive to natural enemies to ensure that they are frequently visited. We review the chemical ecology of floral resources in a conservation biological control context, with a focus on insect parasitoids. We highlight the role of floral volatiles as semiochemicals that attract parasitoids to the food resources. The discovery that nectar-inhabiting microbes can be hidden players in mediating parasitoid responses to flowering plants has highlighted the co…
Macroscytus raunoi, a new burrower bug species from Papua New Guinea (Hemiptera: Heteroptera: Cydnidae: Cydninae)
2016
Abstract Macroscytus raunoi, a new species of the genus Macroscytus Fieber, 1860, is described from the Morobe Province on the northern coast of Papua New Guinea. The new species is similar in its morphological characters to Australian M. arnhemicus J. A. Lis, 1999. Differences in morphology and male genitalia which enable separation of both species are provided.
Role of volatile and contact pheromones in the mating behaviour of Bagrada hilaris (Heteroptera: Pentatomidae)
2008
Volatiles and contact pheromones involved in the mating behaviour of the Painted bug, Bagrada hilaris Burmeister (Het- eroptera: Pentatomidae), were investigated in behavioural and chemical experiments. Vertical open Y-shaped olfactometer bioassays showed that odour from males attract females but not males, while that from females did not attract either gender. Adult females were also attracted by hexane extracts of volatile compounds collected from males. In open arena bioassays, males displayed the characteristic steps of courtship behaviour in the presence of virgin females. Such courtship behaviour was displayed in the presence of females killed by freezing, but not in the presence of f…
Identification, characterization and analysis of expression of genes encoding arylalkylamine N-acetyltransferases in the pea aphidAcyrthosiphon pisum
2013
Most organisms exhibit some kind of rhythmicity in their behaviour and/or physiology as an adaptation to the cyclical movements of the Earth. In addition to circadian rhythms, many organisms have an annual rhythmicity in certain activities, such as reproduction, migration or induction of diapause. Current knowledge of the molecular basis controlling seasonal rhythmicity, especially in insects, is scarce. One element that seems to play an essential role in the maintenance of both circadian and seasonal rhythms in vertebrates is the hormone melatonin. In vertebrates, the limiting enzyme in its synthesis is the arylalkylamine N-acetyltransferase (AANAT). Melatonin is also present in insects bu…
Photoperiodic effects on diapause-associated gene expression trajectories in EuropeanLeptinotarsa decemlineatapopulations
2014
Behavioural and physiological changes during diapause, an important strategy of insects for surviving harsh seasonal conditions, have been intensively studied. The genetic and molecular mechanisms underpinning diapause development are less well known. We took a candidate gene approach to study prediapause gene expression patterns in the Colorado potato beetle (Leptinotarsa decemlineata), an invasive insect that has rapidly spread northwards to high seasonality environments. Newly eclosed beetles originating from southern (Italy) and northern (Russia) Europe were reared under short- [12 h light (L):12 h dark (D)] and long-day (18L:6D) photoperiods for 10 days. This time period includes the s…
Photoperiodic regulation of life-history traits before and after eclosion: egg-to-adult development time, juvenile body weight and reproductive diapa…
2012
Photoperiod is the main environmental cue used by northern insects to predict the forthcoming seasonal changes and to adjust their life-history traits to fit these changes. We studied the effects of photoperiod on egg-to-adult development time, juvenile body mass and female reproductive diapause in two northern Drosophila montana populations with different patterns of voltinism. The most interesting findings were consistent between the populations: (1) when maintained before eclosion in short day conditions, representing early autumn, the flies developed faster and were lighter than when maintained in long day conditions, representing early summer, (2) photoperiodic time measurement is appa…
Northern Drosophila montana flies show variation both within and between cline populations in the critical day length evoking reproductive diapause
2013
Reproductive diapause, and its correct timing, plays an important role in the life cycle of many insect species living in a seasonally varying environment at high latitudes. In the present paper we have documented variation in the critical day length (CDL) for adult reproductive diapause and the steepness of photoperiodic response curves (PPRCs) in seven clinal populations of Drosophila montana in Finland between the latitudes 61 and 67°N, paying special attention to variation in these traits within and between cline populations. The isofemale lines representing these populations showed a sharp transition from 0% to 100% in females' diapause incidence in the shortening day lengths, indicate…