Search results for " Insect"
showing 10 items of 280 documents
Antimicrobial and Insecticidal: Cyclic Lipopeptides and Hydrogen Cyanide Produced by Plant-Beneficial Pseudomonas Strains CHA0, CMR12a, and PCL1391 C…
2017
Particular groups of plant-beneficial fluorescent pseudomonads are not only root colonizers that provide plant disease suppression, but in addition are able to infect and kill insect larvae. The mechanisms by which the bacteria manage to infest this alternative host, to overcome its immune system, and to ultimately kill the insect are still largely unknown. However, the investigation of the few virulence factors discovered so far, points to a highly multifactorial nature of insecticidal activity. Antimicrobial compounds produced by fluorescent pseudomonads are effective weapons against a vast diversity of organisms such as fungi, oomycetes, nematodes, and protozoa. Here, we investigated whe…
New records of gall-inducer and inquiline insects in a few mediterranean countries, with biological notes
2014
An annotated list of some gall-inducing and inquiline insects found on herbaceous plants and trees in Italy and in other few Mediterranean countries is reported. Among the gall-inducer species, Phanacis phoenixopodos (Mayr, 1882) is new for the Italian peninsula, Callirhytis rufescens (Mayr, 1882), Andricus quercusramuli (L., 1761) and Plagiotrochus amenti Kieffer, 1901 (Cynipidae: Hymenoptera) are new for Sicily; the latter was previously cited from Italy without collecting data. Oecocecis guyonella Guenée, 1870 was found in Libya and Amblypalpis olivierella Ragonot, 1886 (Gelechiidae: Lepidoptera) in Jordan, Libya, Northern Yemen, and the United Arab Emirates. In addition, Saphonecrus gal…
Horizontally transmitted parasitoid killing factor shapes insect defense to parasitoids
2021
Protection from parasitism by a virus Parasitoid wasps have developed myriad systems to overcome the defense mechanisms of their hosts as they lay their eggs in the bodies and eggs of targeted species. Gasmi et al . report how the host can fight back when infected by a virus that expresses a protein conferring resistance to the parasitoid. When members of the butterfly and moth family are targeted by wasps, a protein family has evolved that is horizontally carried by viruses—and sometimes is incorporated into the host genome—and impairs the ability of parasitoid offspring to fully develop and emerge. Characterizing the ability of this protein to protect hosts against specific parasites, the…
Sequence and evolution of the gene for the monomeric globin I and its linkage to genes coding for dimeric globins in the insect Chironomus thummi.
1995
We isolated genomic clones containing sequences encoding globins I and IA from a Chironomus thummi thummi genomic library. Three clones contain globin IA (ctt-1A) genes, while one contains a globin I (ctt-1) gene. The coding regions of the four genes are identical except for the single base substitution accounting for the globin I/IA polymorphism. The noncoding DNA flanking the coding region is more than 98% similar, confirming a previous hypothesis that the globin ctt-1 and ctt-1A genes are alleles. Hemoglobins I and IA are monomeric in the insect hemolymph. Earlier in situ hybridization studies suggested that monomeric and dimeric globin genes are clustered at different chromosomal loci. …
Chromosomal variation and genome size support existence of cryptic species of Triatoma dimidiata with different epidemiological importance as Chagas …
2006
Summary The wide geographical distribution of Triatoma dimidiata, one of the three major vectors of Chagas disease, ranges from Mexico to northern Peru. Since this species occupies a great diversity of artificial and natural ecotopes, its eradication is extremely difficult. In order to assist control efforts, we used chromosome analyses and DNA amount as taxonomic markers to study genetic variability in populations of T. dimidiata from Mexico, Guatemala, El Salvador and Colombia. We differentiated three groups or cytotypes defined by characteristic chromosome C-banding patterns and genome size measured by flow cytometry. The three cytotypes are restricted to different geographic locations. …
Cryptic biodiversity loss linked to global climate change
2011
Climate impacts on biodiversity are usually assessed at the morphospecies level. An analysis of the distribution and mitochondrial DNA variability of nine montane aquatic insect species in Europe suggests range contractions will be accompanied by severe loss of genetic diversity. These results imply that morphospecies-scale assessments may greatly underestimate potential biodiversity losses from climate change.
Divergent Evolution of an "Orphon" Historic Gene Cluster in Chironomus
1993
The histone genes of the midge Chironomus thummi thummi are organized in tandemly repeated gene groups, each containing the four core histone genes plus an H1 gene. These repetitive gene groups are found at five different loci, linked on one chromosomal arm. In addition to the clustered gene groups an isolated histone gene group exists which is found spatially separated on a different chromosome ("orphon" gene group). These orphon genes have been cloned and analysed in detail. Nucleotide sequence and in situ hybridization data suggest that the orphon gene group was established early during chironomid speciation, possibly by a transposition-like mechanism. This allowed the genes to be moved …
Molecular Evolution of the Globin Gene Cluster E in Two Distantly Related Midges, Chironomus pallidivittatus and C. thummi thummi
1998
We have studied the evolutionary dynamics of a cluster of insect globin genes by comparing the organization and sequence of the gene group in two distantly related species, Chironomus pallidivittatus and C. t. thummi. Although the general architecture of the globin gene cluster has been conserved, we have found an additional, previously undescribed gene (named Cpa F) in C. pallidivittatus which shows signs of accelerated sequence evolution at nonsynonymous codon positions. This new gene is clearly functional, as demonstrated by Northern analysis. Comparison of paralogous and orthologous genes reveals patterns of intraspecific sequence homogenization. The head-to-head-oriented globin 3 and 4…
Molecular evolution of P transposable elements in the Genus drosophila. II. The obscura species group.
1998
A phylogenetic analysis of P transposable elements in the Drosophila obscura species group is described. Multiple P sequences from each of 10 species were obtained using PCR primers that flank a conserved region of exon 2 of the transposase gene. In general, the P element phylogeny is congruent with the species phylogeny, indicating that the dominant mode of transmission has been vertical, from generation to generation. One manifestation of this is the distinction of P elements from the Old World obscura and subobscura subgroups from those of the New World affinis subgroup. However, the overall distribution of elements within the obscura species group is not congruent with the phylogenetic …
Influence of Bacterial Secondary Symbionts in Sitobion avenae on Its Survival Fitness against Entomopathogenic Fungi, Beauveria bassiana and Metarhiz…
2022
The research was focused on the ability of wheat aphids Sitobion avenae, harboring bacterial secondary symbionts (BSS) Hamiltonella defensa or Regiella insecticola, to withstand exposure to fungal isolates of Beauveria bassiana and Metarhizium brunneum. In comparison to aphids lacking bacterial secondary symbionts, BSS considerably increased the lifespan of wheat aphids exposed to B. bassiana strains (Bb1022, EABb04/01-Tip) and M. brunneum strains (ART 2825 and BIPESCO 5) and also reduced the aphids’ mortality. The wheat aphid clones lacking bacterial secondary symbionts were shown to be particularly vulnerable to M. brunneum strain BIPESCO 5. As opposed to wheat aphids carrying bacterial s…