Search results for "Larva"
showing 10 items of 632 documents
Morphological abnormalities induced by Fenoxycarb on the ectoparasitic larval stage ofPhanerotoma (Phanerotoma) ocularisKohl (Hym., Braconidae)
1993
The Juvenile Hormone Analog Fenoxycarb at concentrations of 0.001 μg/ml, 0.005 μ/ml, 0.01 μg/ml, 0.05 μg/ml and 0.1 μg/ml had an adverse effect on the ectoparasitic larva of Phanerotoma (Phanerotoma) ocularis when topically applied. The total percentage of abnormalities obtained was higher (63.3 %-93.3 %) if the treatment was applied on the third substage than when it was applied on the fourth substage (53.3 %-76.7%). The activity rate was concentration dependent for both substages. Zusammenfassung Durch Fenoxycarb-Behandlung hervorgerufene Abnormitaten bei Larven des Ektoparasiten Phanerotoma (Phanerotoma) ocularis Kohl (Hym., Braconidae) Topikalbehandlung der Larven von Phanerotoma (Phane…
The stream-dwelling larva of the Ruwenzori River Frog, Amietia ruwenzorica, its buccal cavity and pathology of chytridiomycosis
2012
Tadpoles of Amietia ruwenzorica (Pyxicephalidae, Cacosterninae) were collected in the Ruwenzori Mountains, Uganda(identified by DNA barcoding). The ventrally directed enlarged oral disc with a high number of labial tooth rows (LTRF9(4)/9(1)) and the narrow tail with robust caudal musculature characterise them as stream-dwellers. We name this mor-photype the 'common or standard type of stream-adaptation', because special additional adhesive organs are missing in A.ruwenzorica. The uniserially arranged oral teeth of the spoon-shaped type with 16 to 18 cusps per tooth are known fromother anuran larvae, especially from pyxicephalids. The buccal morphology resembles generalized tadpoles with som…
p class="ZootaxaTitle"First description of immature stages of Gastropini, Gastrops willistoni Cresson (Diptera: Ephydridae) preying on eggs in a foam…
2020
The third instar larva and puparium of Gastrops willistoni Cresson (Diptera: Ephydridae), preying on eggs in a foam nest of Leptodactylus knudseni Heyer (Anura: Leptodactylidae), in a central Amazonian dryland forest (Brazil) are described for the first time. The fusiform larva has a short breathing tube, its anterior spiracles are fan-shaped and posterior spiracles with three spircular openings. Pupa is ovoid with a broad anterior margin and bifurcate posterior tip. The taxonomic relationship of the frog egg predators, Gastrops Williston and Typopsilopa Cresson, are discussed.
Attempts to re-colonise water insects in German brooks
2009
Attempts were made to reintroduce water insects (five stonefly species and one mayfly species) into several third order streams in Rhineland-Palatine and Hessen, Germany. All these streams had been strongly affected by waste water and rubbish and had lost most of their macroinvertebrates. As a consequence of the installation of several purification plants in the past three decades, water quality has improved. Since no stoneflies returned, 700–1300 eggs of three different species (Isoperla goertzi, I. oxylepis, and I. grammatica) were exposed in the Selz brook (1997). In February 1998 a few larvae and in 1999 about 10,000 eggs of Perla marginata were added in the Walluf brook, and in 1998, 5…
Social structure in termite societies
1989
The societies of Isoptera and Hymenoptera differ in two general features. 1. The termite societies are bisexual. From a primitive symmetry between both sexes, many asymmetries appeared during the course of their evolution. These asymmetries are related either to a sexual dimorphism, or a biased sex ratio, or both, and are differently expressed in the separate castes of a given species. 2. The hemimetabolous development allows a termite to take part in the social tasks before the end of its postembryonic development, and even to reproduce at a larval stage (neoteny). Thus Isoptera exhibit a polymorphism of larvae, unlike Hymenoptera where a polymorphism of imagoes is observed. Moreover, an i…
Parasite assemblages in the Western whip snakeHierophis viridiflavus carbonarius(Colubridae) from southern Italy
2012
AbstractParasite assemblages of the Western whip snakeHierophis viridiflavus carbonariuswere investigated from the Calabria region in southern Italy. A total of 14 parasite taxa including 6 nematodes, 3 acanthocephalans, 2 cestodes, 2 digeneans and a single pentastomid was identified. Within the study area,H. v. carbonariusserves as the final host for seven species of helminths, of which only four (Hexametra quadricornis,Kalicephalus viperae,Paracapillaria sonsinoiandRenifer aniarum) can be considered as snake specialists, while one (Oswaldocruzia filiformis) is shared with other reptiles and amphibians, and two (Paradistomum mutabileandRhabdias fuscovenosa) with lizards. A large proportion…
Combined statistical and mechanistic modelling suggests food and temperature effects on survival of early life stages of Northeast Arctic cod (Gadus …
2015
Abstract Understanding the causes of the large interannual fluctuations in the recruitment to many marine fishes is a key challenge in fisheries ecology. We here propose that the combination of mechanistic and statistical modelling of the pelagic early life stages (ELS) prior to recruitment can be a powerful approach for improving our understanding of local-scale and population-scale dynamics. Specifically, this approach allows separating effects of ocean transport and survival, and thereby enhances the knowledge of the processes that regulate recruitment. We analyse data on the pelagic eggs, larvae and post-larvae of Northeast Arctic cod and on copepod nauplii, the main prey of the cod lar…
Unpredictability of fish recruitment: interannual variation in young-of-the-year abundance
2000
In 1989-1998, vendace larvae Coregonus albula were sampled in Finnish lakes following a stratified random sampling design. The abundance of young-of-the-year vendace after the first growing season was estimated using catch-per-unit-effort statistics. The number or total area of nursery places hardly limited the recruitment of vendace in the study lakes. The major proportion of prerecruit mortality of vendace occurred in the larval phase and larval sampling produced significant information on young-of-the-year survival. Although larval abundances and recruitment were clearly associated only in Lake Onkamo, generally high larval abundance was needed to produce high number of recruits.
Larval competition in Drosophila melanogaster: frequency-dependence of viability
1988
The application of the overfeeding technique (interruption of the competition during larval development) to the study of larval competition in two-strain cultures of Drosophila melanogaster demonstrates the following points: (1) viability is a function of competition time; (2) viability becomes more frequency-dependent as competition time increases; (3) the dynamics of the “inner” subpopulation (adults that have passed all their development in a crowded condition) and “outer” subpopulation (adults coming from larvae recovered by interruption of competition) vary with time as regards frequency-dependence; and (4) the wild type strain Oregon is the active agent in competition with the strain …
The culturable bacterial community of frass produced by larvae of Rhynchophorus ferrugineus Olivier (Coleoptera: Curculionidae) in the Canary island …
2012
Aims: Larvae of the red palm weevil (RPW) Rhynchophorus ferrugineus Olivier (Coleoptera: Curculionidae) feed inside palm stem tissues, making galleries and producing a wet fermenting frass. We characterized the culturable bacteria associated with frass produced by tunnelling larvae inside the Canary island date palms and investigated the role of frass and gut bacteria in plant polymers breakdown. Methods and Results: A culture-dependent method was used to isolate bacteria from frass and noninfested palm tissues. Bacterial isolates were grouped into operational taxonomic units based on polymorphisms in the ITS-PCR profiles, and representative isolates were identified by partial sequencing …