Search results for "larva"

DNA barcoding the phyllosoma of Scyllarides squammosus (H. Milne Edwards, 1837) (Decapoda: Achelata: Scyllaridae)

2016

Scyllarides has the largest number of species with commercial importance within the Scyllaridae family. As for other achelate lobsters, however, little is known of the unique long-lived planktonic phyllosoma stages of any of these tropical and temperate species. Recently, a large and diverse collection of Scyllaridae phyllosoma, compiled from cruises along the Coral Sea and spanning several years, has been analysed. Molecular evidence from DNA-barcoding and phylogenetic analyses is provided here on the identity of S. squammosus phyllosoma larvae, including stages that were previously undescribed or poorly known. As a consequence, the growth and morphological changes that occur during the mi…

DNA-Based Identification of Larvae Offers Insights into the Elusive Lifestyles of Native Olive Seed Wasps in South Africa

2020

Wild and cultivated olives in the Western Cape of South Africa are direct or indirect hosts to a high diversity of Braconidae and Chalcidoidea wasps. Olive-associated Braconidae are known to parasitise the larvae of Bactrocera oleae (Rossi), and probably also Bactrocera biguttula (Bezzi). The lifestyle of olive-associated Chalcidoidea is not fully understood, and may include phytophagous, parasitoid and hyperparasitoid species. Some chalcids could represent olive seed wasps (OSW), a generic term that designates the seed feeders responsible for losses in commercial olive production. In order to obtain direct DNA-based evidence for the lifestyle of four putative OSW – Eupelmus spermophilus Si…

Biology and Behaviour of Cirrospilus diallus and Cirrospilus pictus, Parasitoids of Phyllocnistis citrella

2005

International audience; Studies were carried out on some biological and behavioral aspects of Cirrospilus diallus Walker and Cirrospilus pictus (Nees) (Hymenoptera: Eulophidae) in relation to their host, the citrus leafminer (CLM), Phyllocnistis citrella Stainton (Lepidoptera: Gracillariidae). Adults of both species fed with sugar lived on average 4.45 +/- 0.19 days, whereas adults provided with honey survived on average 40.62 +/- 1.97 days. Rates of host mortality due to parasitoid stings without oviposition were as high as 31.25 and 37.73% for C. pictus and C. diallus, respectively. Both species showed arrhenotokous parthenogenesis. Sex ratios of parasitoids emerging from the 2nd and 3rd …

Differential performance of a specialist and two generalist herbivores and their parasitoids on Plantago lanceolata

2011

The ability to cope with plant defense chemicals differs between specialist and generalist species. In this study, we examined the effects of the concentration of the two main iridoid glycosides (IGs) in Plantago lanceolata, aucubin and catalpol, on the performance of a specialist and two generalist herbivores and their respective endoparasitoids. Development of the specialist herbivore Melitaea cinxia was unaffected by the total leaf IG concentration in its host plant. By contrast, the generalist herbivores Spodoptera exigua and Chrysodeixis chalcites showed delayed larval and pupal development on plant genotypes with high leaf IG concentrations, respectively. This result is in line with t…

Effects of global warming on reproduction and potential dispersal of Mediterranean Cnidarians

2019

Water temperature directly affects life cycles, reproductive periods, and metabolism of organisms living the oceans, especially in the surface zones. Due to the ocean warming, changes in water stratification and primary productivity are affecting trophic chains in sensitive world areas, such as the Mediterranean Sea. Benthic and pelagic cnidarians exhibit complex responses to climatic conditions. For example, the structure and phenology of the Mediterranean hydrozoan community displayed marked changes in species composition, bathymetric distribution, and reproductive timing over the last decades. The regional species pool remained stable in terms of species numbers but not in terms of speci…

2020

Necrobia rufipes (De Geer) (Coleoptera: Cleridae), also known as the red-legged ham beetle, is a newly emerging pest of pet food stores, causing apprehension among producers worldwide. Concerns about this pest are exacerbated by the lack of information about infestation modalities in pet food, while specific monitoring tools are missing. Considering that adequate pet food packaging could limit N. rufipes infestations, information about the penetration modalities in commonly used pet food packaging is needed. Moreover, the development of appropriate monitoring instruments is urgent to detect pest presence early and to reduce chemical treatments for its control. In this paper, the adults’ and…

Interspecific competition/facilitation among insect parasitoids.

2015

Competition for limited resources is a widespread ecological interaction in animals. In the case of insect parasitoids, species can compete for host resources both at the adult stage as well as at the larval stage. Interspecific competition can play a role in sizing and shaping community structures. In addition of being relevant for basic ecological studies, understanding how interspecific competition between parasitoids affects pest suppression is important for biological control. In this opinion paper we review recent advances in the field of interspecific competition among parasitoids in a biological control perspective. We first discuss adult competition, highlighting which factors are …

A multidisciplinary analytical framework to delineate spawning areas and quantify larval dispersal in coastal fish

2019

International audience; Assessing larval dispersal is essential to understand the structure and dynamics of marine populations. However, knowledge about early-life dispersal is sparse, and so is our understanding of the spawning process, perhaps the most obscure component of biphasic life cycles. Indeed, the poorly known species-specific spawning modality and early-life traits, along with the high spatio-temporal variability of the oceanic circulation experienced during larval drift, hamper our ability to properly appraise the realized connectivity of coastal fishes. Here, we propose an analytical framework which combines Lagrangian modeling, network theory, otolith analyses and biogeograph…

Revision of the west african species of scyllarus fabricius, 1775 (Decapoda: Achelata: Scyllaridae), with the description of three phyllosoma stages …

2020

West African species of Scyllarus Fabricius, 1775 (Achelata, Scyllaridae) are poorly known, mostly due to the difficulties of sampling Eastern Atlantic tropical waters. Recent expeditions carried out by the Universidad de Cádiz and the Instituto Español de Oceanografía collected phyllosoma larvae from Cape Verde Islands (CVI) and fresh Scyllarus adults from continental West Africa. Larval stages VII, IX, and X (final stage) of S. caparti Holthuis, 1952 are analyzed using DNA barcoding methods and described for the first time. A comprehensive identification key is provided, summarizing our current knowledge on the phyllosomas of Scyllarus. Together with a revision of museum collections, the …

Constitutive Activation of the Midgut Response to Bacillus thuringiensis in Bt-Resistant Spodoptera exigua

2010

Bacillus thuringiensis is the most effective microbial control agent for controlling numerous species from different insect orders. The main threat for the long term use of B. thuringiensis in pest control is the ability of insects to develop resistance. Thus, the identification of insect genes involved in conferring resistance is of paramount importance. A colony of Spodoptera exigua (Lepidoptera: Noctuidae) was selected for 15 years in the laboratory for resistance to Xentari (TM), a B. thuringiensis-based insecticide, reaching a final resistance level of greater than 1,000-fold. Around 600 midgut ESTs were analyzed by DNA-macroarray in order to find differences in midgut gene expression …