Search results for "moths"
showing 10 items of 129 documents
Defense strategies used by two sympatric vineyard moth pests.
2014
8 pages; International audience; Natural enemies including parasitoids are the major biological cause of mortality among phytophagous insects. In response to parasitism, these insects have evolved a set of defenses to protect themselves, including behavioral, morphological, physiological and immunological barriers. According to life history theory, resources are partitioned to various functions including defense, implying trade-offs among defense mechanisms. In this study we characterized the relative investment in behavioral, physical and immunological defense systems in two sympatric species of Tortricidae (Eupoecilia ambiguella, Lobesia botrana) which are important grapevine moth pests. …
No evidence of an immune adjustment in response to a parasitoid threat in Lobesia botrana larvae.
2017
5 pages; International audience; Immune function is a key determinant of an organism's fitness, and natural insect populations are highly variable for this trait, mainly due to environmental heterogeneity and pathogen diversity. We previously reported a positive correlation between infection prevalence by parasitoids and host immunity in natural populations of the vineyard pest Lobesia botrana. Here, we tested whether this correlation reflects a plastic adjustment of host immunity in response to the local presence of parasites. To this end, we measured immunity of non-parasitized L. botrana larvae exposed, respectively, to one of the two most common species of parasitoids in vineyards, over…
A haplotype-resolved, de novo genome assembly for the wood tiger moth (Arctia plantaginis) through trio binning
2020
ABSTRACT Background Diploid genome assembly is typically impeded by heterozygosity because it introduces errors when haplotypes are collapsed into a consensus sequence. Trio binning offers an innovative solution that exploits heterozygosity for assembly. Short, parental reads are used to assign parental origin to long reads from their F1 offspring before assembly, enabling complete haplotype resolution. Trio binning could therefore provide an effective strategy for assembling highly heterozygous genomes, which are traditionally problematic, such as insect genomes. This includes the wood tiger moth (Arctia plantaginis), which is an evolutionary study system for warning colour polymorphism. F…
Geographic mosaic of selection by avian predators on hindwing warning colour in a polymorphic aposematic moth
2020
AbstractWarning signals are predicted to develop signal monomorphism via positive frequency-dependent selection (+FDS) albeit many aposematic systems exhibit signal polymorphism. To understand this mismatch, we conducted a large-scale predation experiment in four locations, among which the frequencies of hindwing warning coloration of aposematic Arctia plantaginis differ. Here we show that selection by avian predators on warning colour is predicted by local morph frequency and predator community composition. We found +FDS to be strongest in monomorphic Scotland, and in contrast, lowest in polymorphic Finland, where different predators favour different male morphs. +FDS was also found in Geo…
Lobesia botrana larvae develop faster in the presence of parasitoids.
2013
3 pages; International audience; To combat parasitism hosts often rely on their immune system, which is the last line of defense. However, the immune system may not always be effective, and other non-immunological defenses might be favored to reduce the cost of parasite infection. Here we report that larvae of the moth Lobesia botrana can rapidly accelerate their development and reach maturity earlier in response to cues perceived at a distance from parasitoids. Such a phenotypically plastic life history shift, induced by the perception of deadly enemies in the environment, is likely to be an adaptive defensive strategy to prevent parasitoid attack, and has important implications in host-pa…
Different food sources elicit fast changes to bacterial virulence
2016
Environmentally transmitted, opportunistic bacterial pathogens have a life cycle that alternates between hosts and environmental reservoirs. Resources are often scarce and fluctuating in the outside-host environment, whereas overcoming the host immune system could allow pathogens to establish a new, resource abundant and stable niche within the host. We tested if short-term exposure to different outside-host resource types and concentrations affect Serratia marcescens —(bacterium)'s virulence in Galleria mellonella (moth). As expected, virulence was mostly dictated by the bacterial dose, but we also found a clear increase in virulence when the bacterium had inhabited a low (versus high) re…
The relative abundance of hemocyte types in a polyphagous moth larva depends on diet.
2016
7 pages; International audience; Hemocytes are crucial cells of the insect immune system because of their involvement in multiple immune responses including coagulation, phagocytosis and encapsulation. There are various types of hemocytes, each having a particular role in immunity, such that variation in their relative abundance affects the outcome of the immune response. This study aims to characterize these various types of hemocytes in larvae of the grapevine pest insect Eupoecilia ambiguella, and to assess variation in their concentration as a function of larval diet and immune challenge. Four types of hemocytes were found in the hemolymph of 5th instar larvae: granulocytes, oenocytoids…
Insecticidal spectrum and mode of action of the Bacillus thuringiensis Vip3Ca insecticidal protein.
2016
The Vip3Ca protein, discovered in a screening of Spanish collections of Bacillus thuringiensis, was known to be toxic to Chrysodeixis chalcites, Mamestra brassicae and Trichoplusia ni. In the present study, its activity has been tested with additional insect species and we found that Cydia pomonella is moderately susceptible to this protein. Vip3Ca (of approximately 90 kDa) was processed to an approximately 70 kDa protein when incubated with midgut juice in all tested species. The kinetics of proteolysis correlated with the susceptibility of the insect species to Vip3Ca. The activation was faster to slower in the following order: M. brassicae (susceptible), Spodoptera littoralis (moderately…
Insecticidal Activity and Synergistic Combinations of Ten Different Bt Toxins against Mythimna separata (Walker)
2018
The oriental armyworm (OAW), Mythimna separata (Walker), is a destructive pest of agricultural crops in Asia and Australia. Commercialized Bt crops have performed very well against their target pests
Synthesis and biofilm formation reduction of pyrazole-4-carboxamide derivatives in some Staphylococcus aureus strains
2016
The ability of several N-phenyl-1H-pyrazole-4-carboxamide derivatives and other pyrazoles opportunely modified at the positions 3, 4 and 5, to reduce the formation of the biofilm in some Staphylococcus aureus strains (ATCC 29213, ATCC 25923 and ATCC 6538) were investigated. All the tested compounds were able, although to a different extent, to reduce the biofilm formation of the three bacterial strains considered. Among these, the 1-(2,5-dichlorophenyl)-5-methyl-N-phenyl-1H-pyrazole-4-carboxamide 14 resulted as the best inhibitor of biofilm formation showing an IC50 ranging from 2.3 to 32 μM, against all the three strains of S. aureus. Compound 14 also shows a good protective effect in vivo…