New cell lines from Ephestia kuehniella: characterization and susceptibility to baculoviruses

New cell lines from embryos of Ephestia kuehniella were recently developed. Primary cultures were initiated in September 2002 from 2 to 4 day old eggs in either modified TC-100 or ExCell 400 medium. From these initial cultures, one, originally isolated in the Ex-Cell medium, produced sufficient cell growth to allow subcultivation and eventually led to the establishment of two cell strains, one that forms multicellular vesicles in suspension and one consisting of tightly attached epithelial-like cells. The strains were compared to an extract from E. kuehniella eggs by isozyme analysis and shown to be from the same species. Both strains were inoculated with various insect viruses, including nucleopolyhedroviruses from Autographa californica, Anagrapha falcifera, Anticarsa gemmatalis, Galleria mellonella, Heliothis armigera, Helicoverpa zea, Lymantria dispar, Plutella xylostella, and Rachoplusia ou. Both strains were highly susceptible to most of the nucleopolyhedroviruses (with the exception of the viruses from Helicoverpa zea and Lymantria dispar which did not show cytopathology to either cell strain) with large numbers of occlusion bodies produced in most of the inoculated cells. Our results suggest these new lines can be useful in biocontrol research. Abbreviation: / NPV: nucleopolyhedrovirus, the prefix M or S refers to multiple or single nucleocapsids Ek-x4T: an attached cell line from E. kuehniella Ek-x4V: a vesicular cell line from E. kuehniell

Placenta-Like Structure of the Aphid Endoparasitic Wasp Aphidius ervi: A Strategy of Optimal Resources Acquisition

Aphidius ervi (Hymenoptera: Braconidae) is an entomophagous parasitoid known to be an effective parasitoid of several aphid species of economic importance. A reduction of its production cost during mass rearing for inundative release is needed to improve its use in biological control of pests. In these contexts, a careful analysis of its entire development phases within its host is needed. This paper shows that this parasitoid has some characteristics in its embryological development rather complex and different from most other reported insects, which can be phylogenetically very close. First, its yolkless egg allows a high fecundity of the female but force them to hatch from the egg shell rapidly to the host hemocoel. An early cellularisation allowing a rapid differentiation of a serosa membrane seems to confirm this hypothesis. The serosa wraps the developing embryo until the first instar larva stage and invades the host tissues by microvilli projections and form a placenta like structure able to divert host resources and allowing nutrition and respiration of embryo. Such interspecific invasion, at the cellular level, recalls mammal's trophoblasts that anchors maternal uterine wall and underlines the high adaptation of A. ervi to develop in the host body

An Expressed Sequence Tag collection from the male antennae of the Noctuid moth Spodoptera littoralis: a resource for olfactory and pheromone detection research

<p>Abstract</p> <p>Background</p> <p>Nocturnal insects such as moths are ideal models to study the molecular bases of olfaction that they use, among examples, for the detection of mating partners and host plants. Knowing how an odour generates a neuronal signal in insect antennae is crucial for understanding the physiological bases of olfaction, and also could lead to the identification of original targets for the development of olfactory-based control strategies against herbivorous moth pests. Here, we describe an Expressed Sequence Tag (EST) project to characterize the antennal transcriptome of the noctuid pest model, <it>Spodoptera littoralis</it>, and to identify candidate genes involved in odour/pheromone detection.</p> <p>Results</p> <p>By targeting cDNAs from male antennae, we biased gene discovery towards genes potentially involved in male olfaction, including pheromone reception. A total of 20760 ESTs were obtained from a normalized library and were assembled in 9033 unigenes. 6530 were annotated based on BLAST analyses and gene prediction software identified 6738 ORFs. The unigenes were compared to the <it>Bombyx mori </it>proteome and to ESTs derived from Lepidoptera transcriptome projects. We identified a large number of candidate genes involved in odour and pheromone detection and turnover, including 31 candidate chemosensory receptor genes, but also genes potentially involved in olfactory modulation.</p> <p>Conclusions</p> <p>Our project has generated a large collection of antennal transcripts from a Lepidoptera. The normalization process, allowing enrichment in low abundant genes, proved to be particularly relevant to identify chemosensory receptors in a species for which no genomic data are available. Our results also suggest that olfactory modulation can take place at the level of the antennae itself. These EST resources will be invaluable for exploring the mechanisms of olfaction and pheromone detection in <it>S. littoralis</it>, and for ultimately identifying original targets to fight against moth herbivorous pests.</p

Kairomonal Stimulation of Oviposition into an Artificial Substrate by the Endoparasitoid \u3ci\u3eMicroplitis croceipes\u3c/i\u3e (Hymenoptera: Braconidae)

Preparation of an artificial oviposition substrate (AOS) from agarose and host hemolymph for oviposition by a parasitic wasp, Microplitis croceipes (Cresson), is described. Natural hosts for this endoparasitoid are larvae of Heliothis spp. Infusion of hemolymph from Heliothis zea (Boddie) into a drop of solidified agar induced females of M. croceipes to oviposit into the material. Ovipositional response to dilution of host hemolymph was determined. The factor or factors that stimulated oviposition were moderately heat sensitive, dialyzable, and unaffected by treatment with protease or pancreatic trypsin or hexane extraction. Hemolymph from Manduca sexta (L.) was less effective than H. zea hemolymph. The AOS will facilitate in vitro efforts to rear M. croceipes, because dissection of host larvae is no longer necessary and many eggs can be collected easily

Corrected Species Identification of the Predator Orius Pumilio (Heteroptera: Anthocoridae) in a Research Colony

Our laboratories have reported on the predatory minute pirate bugs (Family Anthocoridae) in a research colony that was obtained in Dec 2002. The species was originally thought to be Orius insidiosus (Say) (Ferkovich & Shapiro 2004a, 2004b, 2007; Ferkovich & Shapiro 2005a, 2005b, 2005c; Ferkovich et al. 2007). However, specimens from the colony were identified as O. pumilio (Champion) by T. Lewis (USDA, ARS, Wapato, WA) in Apr 2008, not O. insidiosus as previously reported in the publications listed above