scholarly journals Effects of Host Age on the Parasitism ofPachycrepoideus vindemmiae(Hymenoptera: Pteromalidae), an Ectoparasitic Pupal Parasitoid ofBactrocera cucurbitae(Diptera: Tephritidae)

2013 ◽  
Vol 96 (2) ◽  
pp. 451-457 ◽  
Author(s):  
Hai-Yan Zhao ◽  
Ling Zeng ◽  
Yi-Juan Xu ◽  
Yong-Yue Lu ◽  
Guang-Wen Liang
Keyword(s):  
Host Age ◽  
Pupal Parasitoid

scholarly journals Host-age effects and the efficiency of the pupal parasitoid Dirhinus giffardii (Silvestri, 1913) (Hymenoptera: Chalcididae) against the melon fly Bactrocera cucurbitae (Coquillett, 1849) (Diptera: Tephritidae)

2018 ◽  
Vol 87 (2) ◽  
pp. 177-190 ◽  
Author(s):  
Shahid Mehmood ◽  
Kamran Sohail ◽  
Muhammad Qasim ◽  
Shupeng Xu ◽  
Haiyang Geng ◽  
...  
Keyword(s):  
Age Effects ◽  
Host Age ◽  
Bactrocera Cucurbitae ◽  
Pupal Parasitoid ◽  
Melon Fly ◽  
Emergence Rate ◽  
Different Ages ◽  
Biological Aspects

Abstract Dirhinus giffardii is an efficient and aggressive pupal parasitoid of tephritid flies, including Bactrocera cucurbitae. Here we report on the various biological aspects of Dirhinus giffardii, mainly host-age preference, potential as well as the survival of this parasitoid from the pupae of different ages and its in vivo release against Bactrocera cucurbitae. The emergence rate of parasitoids was higher in old pupae than in fresh pupae. Similarly, the lifespan and potential of parasitoids emerged from older pupae were higher than those emerged from younger ones. The parasitoids reared on older pupae significantly controlled melon fly infestation in vivo. These findings suggest that parasitoids reared on older pupae of B. cucurbitae have a greater potential regarding fecundity, parasitism performance and survival, as these parasitoids effectively suppressed populations of B. cucurbitae under greenhouse conditions.

scholarly journals Exposure Time and age Links Parasitism, Emergence and Development of Pupal Parasitoid Dirhinus giffardii Against Bactrocera zonata

2020 ◽  
Vol 8 (3) ◽  
pp. 104-107
Keyword(s):  
Biological Control ◽  
Exposure Time ◽  
Artificial Diet ◽  
Fruit Fly ◽  
Developmental Time ◽  
Host Age ◽  
Laboratory Rearing ◽  
Pupal Parasitoid ◽  
Percent Parasitism ◽  
Bactrocera Zonata

The parasitism, emergence and development of pupal parasitoid, Dirhinus giffardii (Silvestri) was assessed against the pupae of the fruit fly, Bactrocera zonata (Saunders), under laboratory conditions. The fruit fly and D. giffardii were reared in glass cages on the artificial diet, and a known number of different 1-hour (fresh), 1-day, 2-day, 3-day and 4-day old pupae were offered to the respective parasitoids for a period of 6, 12, 18 and 24 hours. It was noted that the parasitism was increased gradually with an increase in pupal age and exposure time. The highest parasitism occurred on 3-day old pupae followed by 4-day, 2-day, 1-day and 1 hour (fresh) old pupae. The studies also manifested that exposure time and host age have a significant effect on the oviposition, per female parasitism, percent parasitism, emergence and development of pupal parasitoid, D. giffardii. The average developmental time of parasitoid was recorded significantly longer in 1-hour (fresh) old pupae than in the older pupae. The study revealed that D. giffardii is a virtuous candidate for the biological control of B. zonata and the pupae of B. zonata might be the perfect host for laboratory rearing of this parasitoid.

scholarly journals Identification of Epidemiological Traits by Analysis of SARS−CoV−2 Sequences

Viruses ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 764
Author(s):  
Bohu Pan ◽  
Zuowei Ji ◽  
Sugunadevi Sakkiah ◽  
Wenjing Guo ◽  
Jie Liu ◽  
...  
Keyword(s):  
Clustering Analysis ◽  
Phylogenetic Trees ◽  
Sequence Similarity ◽  
Host Age ◽  
Hierarchical Clustering Analysis ◽  
Genome Sequences ◽  
Geographic Patterns ◽  
Rapid Spread ◽  
Pairwise Sequence Similarity ◽  
Sequence Similarity Analysis

Severe acute respiratory syndrome coronavirus 2 (SARS−CoV−2) has caused the ongoing global COVID-19 pandemic that began in late December 2019. The rapid spread of SARS−CoV−2 is primarily due to person-to-person transmission. To understand the epidemiological traits of SARS−CoV−2 transmission, we conducted phylogenetic analysis on genome sequences from >54K SARS−CoV−2 cases obtained from two public databases. Hierarchical clustering analysis on geographic patterns in the resulting phylogenetic trees revealed a co-expansion tendency of the virus among neighboring countries with diverse sources and transmission routes for SARS−CoV−2. Pairwise sequence similarity analysis demonstrated that SARS−CoV−2 is transmitted locally and evolves during transmission. However, no significant differences were seen among SARS−CoV−2 genomes grouped by host age or sex. Here, our identified epidemiological traits provide information to better prevent transmission of SARS−CoV−2 and to facilitate the development of effective vaccines and therapeutics against the virus.

scholarly journals Sheep nemabiome diversity and its response to anthelmintic treatment in Swedish sheep herds

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Peter Halvarsson ◽  
Johan Höglund
Keyword(s):  
Species Richness ◽  
Diversity Index ◽  
Nematode Species ◽  
Abundant Species ◽  
Anthelmintic Treatment ◽  
Host Age ◽  
Larval Culture ◽  
Nematode Parasites ◽  
South Central ◽  
Nematode Diversity

Abstract Background A novel way to study the species composition and diversity of nematode parasites in livestock is to perform deep sequencing on composite samples containing a mixture of different species. Herein we describe for the first time the nematode community structures (nemabiomes) inhabiting Swedish sheep and how these are/were affected by host age and recent anthelmintic treatments. Methods A total of 158 fecal samples were collected (n = 35 in 2007 and n = 123 in 2013–2016) and cultured from groups of sheep on 61 commercial farms in the south-central part of the country where most animals are grazed. Among the samples, 2 × 44 (56%) were paired collections from the same groups pre- and post-treatment with anthelmintics such as macrocyclic lactones, benzimidazoles or levamisole. Samples were analyzed for their nemabiome using the PacBio platform followed by bioinformatic sequence analysis with SCATA. Species richness and diversity were calculated and analyzed in R. Results Nematode ITS2 sequences were found in all larval culture samples except two, even though the fecal egg counts were below the McMaster threshold in 20 samples. Sequencing yielded, on average, 1008 sequences per sample. In total, 16 operational taxonomical units (OTU), all with ≥ 98 % identity to sequences in the NCBI database, were recognized. The OTUs found represented nematode species of which ten are commonly associated with sheep. Multiple species were identified in all pre-anthelmintic treatment larval culture samples. No effects on nematode diversity were found in relation to host age. On the other hand, recent anthelmintic treatment lowered species richness, especially after use of ivermectin and albendazole. Interestingly, despite zero egg counts after use of levamisole, these samples still contained nematode DNA and especially H. contortus. Conclusions Our findings provide evidence that nemabiome analysis combined with diversity index analysis provides an objective methodology in the study of the efficacy of anthelmintic treatment as both high and low abundant species were detected.

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