Search results for "Wolbachia."

Low Levels of Mitochondrial DNA and Symbiont Diversity in the Worldwide Agricultural Pest, the Greenhouse Whitefly Trialeurodes vaporariorum (Hemipte…

2015

Trialeurodes vaporariorum, the greenhouse whitefly, is a cosmopolitan agricultural pest. Little is known about the genetic diversity of T. vaporariorum and the bacterial symbionts associated with this species. Here, we undertook a large phylogeographic study by investigating both the mitochondrial (mt) diversity and the infection status of 38 T. vaporariorum collections from 18 countries around the world. Genetic diversity of T. vaporariorum was studied by analyzing sequence data from the mt cytochrome oxidase I, cytochrome b, and NADH dehydrogenase subunit 5 genes. Maximum-likelihood (ML) phylogeny reconstruction delineated 2 clades characterized by limited sequence divergence: one clade c…

PARASITES AND SEXUAL REPRODUCTION IN PSYCHID MOTHS

2004

Persistence of sexual reproduction among coexisting asexual competitors has been a major paradox in evolutionary biology. The number of empirical studies is still very limited, as few systems with coexisting sexual and strictly asexual lineages have been found. We studied the ecological mechanisms behind the simultaneous coexistence of a sexually and an asexually reproducing closely related species of psychid moth in Central Finland between 1999 and 2001. The two species compete for the same resources and are often infected by the same hymenopteran parasitoids. They are extremely morphologically and behaviorally similar and can be separated only by their reproductive strategy (sexual vs. as…

Diversity and composition of the microbiome associated with eggs of the Southern green stinkbug, Nezara viridula (Hemiptera: Pentatomidae).

2022

Although microbial communities of insects from larval to adult stage have been increasingly investigated in recent years, little is still known about the diversity and composition of egg-associated microbiomes. In this study, we used high-throughput amplicon sequencing and quantitative PCR to get a better understanding of the microbiome of insect eggs and how they are established using the Southern green stinkbug Nezara viridula (L.) (Hemiptera: Pentatomidae) as a study object. First, to determine the bacterial community composition, egg masses from two natural populations in Belgium and Italy were examined. Subsequently, microbial community establishment was assessed by studying stinkbug e…

How do Wolbachia Symbionts Increase the Proportion of Females in Their Hosts?

2001

Genetic variation in the primary sex ratio in populations of the intertidal copepod, Tigriopus californicus, is widespread on Vancouver Island.

2011

Hypothesis: Genetic variation for the primary sex ratio is widespread in a copepodwith polygenic sex determination. Cytoplasmic sex ratio distorters (e.g. Wolbachia andmicrosporidians) influence the primary sex ratio in this copepod. Organism: The intertidal copepod, Tigriopus californicus; six populations from VancouverIsland, British Columbia. Study site: Quantitative genetics experiment in the laboratory. PCR and antibioticsexperiment to test for the presence of cytoplasmic sex ratio distorters. Results: Genetic variation for the primary sex ratio was found in five of the six populationssurveyed. The primary sex ratio was paternally transmitted. There was no evidence thatWolbachia or mic…

External and internal elimination of supernumerary larvae in the whitefly parasitoid Eretmocerus mundus Mercet (Hymenoptera: Aphelinidae)

2008

Abstract The solitary parasitoid Eretmocerus mundus Mercet (Hymenoptera: Aphelinidae) is one of the key biological control agents of the whitefly Bemisia argentifolii Bellows & Perring, also known as B. tabaci (Gennadius) B-biotype (Homoptera: Aleyrodidae). We present new information on its biology, and particularly about larval elimination during the first instar in cases of superparasitism. For the first time, physical elimination of supernumerary larvae was observed, both outside and inside the host. These findings are documented with confocal microscopy images and video recordings. We observed more than 350 B. argentifolii nymphs, parasitized with one, two or more than two larvae. Physi…

Contrasting effects ofWolbachiaon cytoplasmic incompatibility and fecundity in the haplodiploid miteTetranychus urticae

2002

Recent studies on Wolbachia-induced incompatibility in haplodiploid insects and mites have revealed a diversity of cytoplasmic incompatibility (CI) patterns among host species. Here, we report intraspecific diversity in CI expression among four strains of the arrhenotokous mite Tetranychus urticae and in T. turkestani. Variability of CI expression within T. urticae ranged from no CI to complete CI, and included either female embryonic mortality or male conversion types of CI. A fecundity cost attributed to the infection with the high-CI Wolbachia strain was the highest ever recorded for Wolbachia (−80 to −100% decrease). Sequence polymorphism at a 550-bp-portion of Wolbachia wsp gene reveal…

Zoonotic Dirofilaria immitis and Dirofilaria repens infection in humans and an integrative approach to the diagnosis

2021

Abstract Dirofilariosis by Dirofilaria immitis and Dirofilaria repens is endemic in dogs from countries of the Mediterranean basin. Both species may infect humans, with most of the infected patients remaining asymptomatic. Based on the recent description of the southernmost hyperendemic European focus of heartworm disease in dogs from the Pelagie archipelagos, we performed a serological and molecular survey in human population of that area. Human blood samples were collected in the islands of Linosa (n=101) and Lampedusa (n=296) and tested by ELISA and molecular test for the detection of D. immitis and D. repens. Samples were also screened for filarioid-associated endosymbionts, Wolbachia s…

To B or Not to B: Comparative Genomics Suggests

2018

Insect lineages feeding on nutritionally restricted diets such as phloem sap, xylem sap, or blood, were able to diversify by acquiring bacterial species that complement lacking nutrients. These bacteria, considered obligate/primary endosymbionts, share a long evolutionary history with their hosts. In some cases, however, these endosymbionts are not able to fulfill all of their host's nutritional requirements, driving the acquisition of additional symbiotic species. Phloem-feeding members of the insect family Aleyrodidae (whiteflies) established an obligate relationship with Candidatus Portiera aleyrodidarum, which provides its hots with essential amino acids and carotenoids. In addition, ma…