Search results for "Larva"
showing 10 items of 632 documents
Appearance before performance? Nutritional constraints on life-history traits, but not warning signal expression in aposematic moths.
2019
Abstract Trade‐offs have been shown to play an important role in the divergence of mating strategies and sexual ornamentation, but their importance in explaining warning signal diversity has received less attention. In aposematic organisms, allocation costs of producing the conspicuous warning signal pigmentation under nutritional stress could potentially trade‐off with life‐history traits and maintain variation in warning coloration.We studied this with an aposematic herbivore Arctia plantaginis (Arctiidae), whose larvae and adults show extensive variation in aposematic coloration. In larvae, less melanic coloration (i.e. larger orange patterns) produces a more efficient warning signal aga…
Acanthocephalan size and sex affect the modification of intermediate host colouration
2009
Parasitology, 136 (8)
Sexual differences in larval life history traits of acanthocephalan cystacanths
2006
Sexual differences in life history traits, such as size dimorphism, presumably arise via sexual selection and are most readily observed in adults. For complex life-cycle parasites, however, sexual selection may also have consequences for larval traits, e.g., growth in intermediate hosts. Two acanthocephalan species (Acanthocephalus lucii and Echinorhynchus borealis) were studied to determine, whether larval life histories differ between males and females. The size of female A. lucii cystacanths had a much stronger relationship with intermediate host size than males, suggesting females invest more in growth and are consequently more limited by resources. No relationship between host size and…
No evidence of androgenic hormone from the testes of the glowworm, Lampyris noctiluca.
2005
The widely accepted concept, stating that insects have no true sex hormones, and that primary as well as secondary sex characteristics are controlled by the genetic inventory of each single cell, is challenged by the report of Naisse, J. [1966a. Controle endocrinien de la differenciation sexuelle chez l'Insecte Lampyris noctiluca (Coleoptere Malacoderme Lampyride). I. Role androgene des testicules, Arch. Biol. Liege, 77, 139-201] on the discovery of an androgenic hormone in the glowworm, Lampyris noctiluca. This case is of special interest, since it may point to an ancestral mode of sex differentiation in arthropods, considering that androgenic hormones have been discovered and characterize…
Myiasis with Dermatobia hominis in a Sicilian traveller returning from Peru
2007
Summary We report a case of a bot fly infestation of the scalp. A 45-year-old man after returning to Sicily noted a small white “worm” erupting from the upper lesion. Physical examination revealed a superficial furuncular lesion with central pores with sero-sanguineous discharge. The foreign body identified was diagnosed as the larva of the human bot fly, Dermatobia hominis.
Maggot therapy following orbital exenteration
2007
Orbital exenteration is a radical surgery reserved for the treatment of locally invasive or potentially life-threatening orbital tumours.1 Complications occur after 20–25% of exenterations and include tissue necrosis (6%) and infection (3–4%).2–4 In the present report, we describe the management of a post-exenteration orbital infection by the use of maggots. An 82-year-old multimorbid man presented with a fist-sized painless tumour of the left orbit (fig 1A). Computed tomography demonstrated an orbital mass clearly demarcated from the surrounding tissue (fig 1B). After biopsy, the neoplasm was classified as a borderline-malignant extrapleural solitary fibrous tumour. Therefore, a total orbi…
UNC-52/perlecan affects gonadal leader cell migrations in C. elegans hermaphrodites through alterations in growth factor signaling.
2003
0012-1606 doi: DOI: 10.1016/S0012-1606(03)00014-9; The unc-52 gene of Claenorhabditis elegans encodes a homologue of the basement membrane heparan sulfate proteoglycan perlecan. Viable alleles reduce the abundance of UNC-52 in late larval stages and increase the frequency of distal tip cell (DTC) migration defects caused by mutations disrupting the UNC-6/netrin guidance system. These unc-52 alleles do not cause circumferential DTC migration defects in an otherwise wild-type genetic background. The effects of unc-52 mutations on DTC migrations are distinct from effects on myofilament organization and can be partially suppressed by mutations in several genes encoding growth factor-like molecu…
Transient and Permanent Experience with Fatty Acids Changes Drosophila melanogaster Preference and Fitness
2013
Food and host-preference relies on genetic adaptation and sensory experience. In vertebrates, experience with food-related cues during early development can change adult preference. This is also true in holometabolous insects, which undergo a drastic nervous system remodelling during their complete metamorphosis, but remains uncertain in Drosophila melanogaster. We have conditioned D. melanogaster with oleic (C18:1) and stearic (C18:0) acids, two common dietary fatty acids, respectively preferred by larvae and adult. Wild-type individuals exposed either during a transient period of development-from embryo to adult-or more permanently-during one to ten generation cycles-were affected by such…
Aposematism facilitates the diversification of parental care strategies in poison frogs
2021
AbstractMany organisms have evolved adaptations to increase the odds of survival of their offspring. Parental care has evolved several times in animals including ectotherms. In amphibians, ~ 10% of species exhibit parental care. Among these, poison frogs (Dendrobatidae) are well-known for their extensive care, which includes egg guarding, larval transport, and specialized tadpole provisioning with trophic eggs. At least one third of dendrobatids displaying aposematism by exhibiting warning coloration that informs potential predators about the presence of defensive skin toxins. Aposematism has a central role in poison frog diversification, including diet specialization, and visual and acoust…
Fast whole-brain imaging of seizures in zebrafish larvae by two-photon light-sheet microscopy
2022
Light-sheet fluorescence microscopy (LSFM) enables real-time whole-brain functional imaging in zebrafish larvae. Conventional one photon LSFM can however induce undesirable visual stimulation due to the use of visible excitation light. The use of two-photon (2P) excitation, employing near-infrared invisible light, provides unbiased investigation of neuronal circuit dynamics. However, due to the low efficiency of the 2P absorption process, the imaging speed of this technique is typically limited by the signal-to-noise-ratio. Here, we describe a 2P LSFM setup designed for non-invasive imaging that enables quintuplicating state-of-the-art volumetric acquisition rate of the larval zebrafish bra…