Search results for "Larva"

Effects of the insect growth regulator cyromazine on the fecundity, fertility and offspring development of Mediterranean fruit fly,Ceratitis capitata…

1995

Addition of cyromazine to adult diet affected negatively the development of Ceratitis capitata Wied. (Dipt., Tephritidae) offspring. Five concentrations of cyromazine (0.00001 mg/ml, 0.01 mg/ml, 0.1 mg/ml, 1 mg/ml and 10 mg/ml) have been tested. A reduction of Mediterranean fruit fly populations has been found mainly due to the effects of fertility and larval development. At these concentrations, cyromazine does not affect Ceratitis capitata fecundity.

Larval distributions of the ectoparasitoid waspEurytoma robustarelative to the host tephritid gall flyUrophora cardui

2003

Parasitism may explain the patchy distributions of host populations. The present paper is a study of larval distributions of the parasitoid Eurytoma robusta in galls of the tephritid gall fly Urophora cardui . It focuses on E. robusta ’s choice of U. cardui gall and whether this changes relative to the rate of parasitism. Oviposition patterns were inferred by direct counts of larvae in galls and genetically, for both species, using indirect relatedness estimates between gall-members. Furthermore, rates of parasitism in four populations were monitored for 4 years. The modal distribution of E. robusta larvae per gall was one and independent of the level of parasitism. The mean number of E. ro…

Biomphalaria Snails and Larval Trematodes

2011

Biomphalaria snails and larval trematodes , Biomphalaria snails and larval trematodes , کتابخانه مرکزی دانشگاه علوم پزشکی تهران

Effect of the juvenile hormone analogue fenoxycarb applied via the host on the parasitoid Phanerotoma (Phanerortoma) ocularis Kohl (Hym. Braconidae)

1993

Abstract Concentrations of 0.001, 0.005, 0.01, 0.05 and 0.1 μg/ml of fenoxycarb (Ro 13-5223) were applied topically to larvae of Ephestia kuehniella Zeller parasitized by Phanerotoma (Phanerotoma) ocularis Kohl. The effect of the treatment and concentration on parasitism rates, preimaginal mortality and emergence rates of the parasitoid were studied comparatively for each larval instar of the host considered. The preimaginal mortality was high when the fenoxycarb was applied on the first larval instar of the host (23–46%) and more higher when applied to the sixth larval instar of the host (40–86%). Consequently, fenoxycarb treatment of the last larval instar of the host produced a reduction…

The filter apparatus of Rana temporaria and Bufo bufo larvae (Amphibia, Anura)

1985

In larvae of Rana temporaria and Bufo bufo the location of filter apparatus within the larval organization, the arrangement of the morphological parts as branchial food trap, ventral velum, and filter rows, as well as their surface anatomy, are similar to that of other species of Orton's larval type IV. The means by which mucous with its entrapped food particles is transported from the filter rows to the esophagus is finally resolved. The dorsally positioned ciliary cushion extends far ventrally between the filter plates. From their contact with the filter rows, the cilia transport the mucous to Kratochwill's caudally positioned “Flimmerrinne” and from there to the esophagus. The original c…

Hymenopteran specificity of Bacillus thuringiensis strain PS86Q3

2008

Abstract The biological activity of Bacillus thuringiensis (Bt) strain PS86Q3 against five Hymenopteran species was determined by means of bioassays adapted to each species. Four species of sawfly that are important pests of conifers (Diprion pini, Gilpinia hercyniae and Pristiphora abietina) or ornamental plants (Arge rosae), as well as the non-target honeybee, Apis mellifera, were studied. Two out of the four sawfly species tested were found to be sensitive to PS86Q3 crystals or spore/crystal suspensions. A sporulated culture of this strain was moderately active on D. pini, and a complete bioassay with solubilized crystals was performed to estimate the LC50 of 4.9 mg/ml. Pristiphora abiet…

Effects of Nonschistosome Larval Trematodes on Biomphalaria Snails

2010

This chapter examines the most salient literature on the development of nonschistosome larval digeneans in Biomphalaria spp. (members of the ­superfamilies Clinostomoidea, Diplostomoidea, Echinostomatoidea, Paramphistomoidea, and Pronocephaloidea). For this purpose, the general biology of the nonschistosome trematode species that use Biomphalaria spp. as ­intermediate hosts are ­analyzed. Thereafter, the main features of these parasitic infections are studied with ­particular emphasis on topics such as the effect of the infections on the snail, the antagonism and/or competition between different digenean species in the snail, the ­immunology of the infection, and the genomic and proteomic a…

Suspension feeding of anuran larvae at low concentrations of Chlorella algae (Amphibia, Anura).

1990

Ingestion and filtering rates in larval Xenopus laevis, Bufo calamita, Rana temporia and Bufo bufo fed suspensions of Chlorella fusca were investigated. Concentrations were measured with a Coulter Counter. (1) For all species, filtration occurred at concentrations far below those reported by other authors for Rana sylvatica feeding on Chlorella pyrenoidosa. For Bufo bufo, only larvae near metamorphosis showed ingestion at low particle concentrations. Since buccopharyngeal ventilation continues even in the absence of food particles, this threshold feeding behaviour in the younger larvae must be due to different mechanisms to those found in Daphnia and Calanus studied by other authors: probab…

Intra- and intergenotypic larval competition in Drosophila melanogaster : effect of larval density and biotic residues

1987

Cytotoxic Activity of Tunicate Hemocytes

1996

Tunicates (protochordates) are filter-feeding marine invertebrates with a worldwide distribution. In their larval form, they exhibit many of the features characteristic of the vertebrates. The larva, with a tail, notochord, and dorsal neural tube, upon settlement undergoes a remarkable metamorphosis in which it loses most of its chordate characteristics and becomes a sessile invertebrate adult. Thus, due to these characteristics, tunicates are considered to be the most primitive members of the phylum Chordata. Owing to their position in the phylogenetic line leading to the vertebrates, they have attained importance as experimental organisms and have been examined by researchers from a varie…