Coelomomyces infection of the adult female mosquito Aedes trivittatus (Coquillett) in Manitoba

1980 ◽  
Vol 58 (7) ◽  
pp. 1215-1219 ◽  
Author(s):  
B. W. Taylor ◽  
J. A. Harlos ◽  
R. A. Brust

Adult females of Aedes trivittatus collected near Winnipeg, Manitoba, were found to be infected with a Coelomomyces sp. The level of infection, as expressed by the formation of sporangia within the haemocoel of the adult, was as high as 56% in blood-fed female mosquitoes. No sporangia were found in females or males that were fed only carbohydrates. Mature sporangia were visible through the abdominal wall of the infected adult at time of death. None of the infected females was able to reproduce. Coelomomyces infection was found to be initiated during the fourth larval instar and (or) pupal stage in artificial pools. Two species of copepods were present in the pools; however, the role of these organisms in the life cycle of the Coelomomyces sp. is not known at this time.

1992 ◽  
Vol 49 (11) ◽  
pp. 2291-2299 ◽  
Author(s):  
Geert van Urk ◽  
Frans C. M. Kerkurm ◽  
Henk Smit

Along a gradient of contamination in Lake Vossemeer (where contaminated sediments from the River Rhine are deposited out), Chironomus cf. plumosus larvae occurred at lower population densities and with higher frequencies of deformities as the contamination levels increased. At the least polluted sites, the frequency of larval deformities was elevated only slightly compared with reference levels. At these sites, C. cf. plumosus had a bivoltine life cycle and overwintered in the fourth larval instar stage. At moderately contaminated sites, the percentage of prepupal larvae was significantly lower in spring and the development of pupae delayed by 2 wk. At heavily contaminated sites, larval densities were strongly reduced and no pupae were observed at all. Under such conditions, population density seems to be a suitable additional indicator of toxic stress. The frequency of deformed larvae was higher from November to April than from July to October. Maximum frequencies were observed during emergence of the overwintering generation, suggesting that the period between February and April may be the most suitable period for the assessment of this parameter.


1969 ◽  
Vol 94 (1-2) ◽  
pp. 165-174
Author(s):  
Alejandro E. Segarra-Carmona ◽  
Irma Cabrera-Asencio ◽  
Luisa E. Flores-López ◽  
Luis Morales-Collado

The arrival of the invasive Asian lime swallowtail, Papilio demoleus L., in Puerto Rico has prompted the need for a better understanding of its life cycle, and its control options under local citrus-producing conditions. Our results show that P. demoleus has a life cycle of approximately 30 days. From oviposition, eggs hatch in three days. Larval instar durations are 3, 2, 3, 3, and 5 d for larval stages 1 to 5, respectively. Pupal stage lasts approximately 12 days. Head capsule measurements for instars 1 to 4 are similar in males and females. Last instar females tend to be larger than males. Our data suggest that 12 or more generations are possible under local conditions. Acute stomach toxicity tests on third instar larvae indicate that spinosad and Bacillus thuringiensis subs, kurstaki cause 100% mortality in most concentrations tested. Other insecticides were not effective. Possible advantages of using these products are discussed in light of initiatives to use reduced risk pesticides and biologically-based pesticides.


Author(s):  
Petar Halachev ◽  
Victoria Radeva ◽  
Albena Nikiforova ◽  
Miglena Veneva

This report is dedicated to the role of the web site as an important tool for presenting business on the Internet. Classification of site types has been made in terms of their application in the business and the types of structures in their construction. The Models of the Life Cycle for designing business websites are analyzed and are outlined their strengths and weaknesses. The stages in the design, construction, commissioning, and maintenance of a business website are distinguished and the activities and requirements of each stage are specified.


2021 ◽  
Vol 9 (6) ◽  
pp. 1242
Author(s):  
Loganathan Ponnusamy ◽  
Haley Sutton ◽  
Robert D. Mitchell ◽  
Daniel E. Sonenshine ◽  
Charles S. Apperson ◽  
...  

The transovarial transmission of tick-borne bacterial pathogens is an important mechanism for their maintenance in natural populations and transmission, causing disease in humans and animals. The mechanism for this transmission and the possible role of tick hormones facilitating this process have never been studied. Injections of physiological levels of the tick hormone, 20-hydroxyecdysone (20E), into part-fed (virgin) adult females of the American dog tick, Dermacentor variabilis, attached to the host caused a reduction in density of Rickettsia montanensis in the carcass and an increase in the ovaries compared to buffer-injected controls. This injection initiates yolk protein synthesis and uptake by the eggs but has no effect on blood feeding. Francisella sp. and R. montanensis were the predominant bacteria based on the proportionality in the carcass and ovary. The total bacteria load increased in the carcass and ovaries, and bacteria in the genus Pseudomonas increased in the carcass after the 20E injection. The mechanism of how the Rickettsia species respond to changes in tick hormonal regulation needs further investigation. Multiple possible mechanisms for the proliferation of R. montanensis in the ovaries are proposed.


2021 ◽  
Vol 22 (9) ◽  
pp. 4438
Author(s):  
Jessica Proulx ◽  
Kathleen Borgmann ◽  
In-Woo Park

The ubiquitin (Ub) proteasome system (UPS) plays a pivotal role in regulation of numerous cellular processes, including innate and adaptive immune responses that are essential for restriction of the virus life cycle in the infected cells. Deubiquitination by the deubiquitinating enzyme, deubiquitinase (DUB), is a reversible molecular process to remove Ub or Ub chains from the target proteins. Deubiquitination is an integral strategy within the UPS in regulating survival and proliferation of the infecting virus and the virus-invaded cells. Many viruses in the infected cells are reported to encode viral DUB, and these vial DUBs actively disrupt cellular Ub-dependent processes to suppress host antiviral immune response, enhancing virus replication and thus proliferation. This review surveys the types of DUBs encoded by different viruses and their molecular processes for how the infecting viruses take advantage of the DUB system to evade the host immune response and expedite their replication.


2021 ◽  
Vol 22 (2) ◽  
pp. 643
Author(s):  
Xiao Li ◽  
Fen Wang ◽  
Yanyan Xu ◽  
Guijun Liu ◽  
Caihong Dong

Hydrophobins are a family of small secreted proteins found exclusively in fungi, and they play various roles in the life cycle. In the present study, genome wide analysis and transcript profiling of the hydrophobin family in Cordyceps militaris, a well-known edible and medicinal mushroom, were studied. The distribution of hydrophobins in ascomycetes with different lifestyles showed that pathogenic fungi had significantly more hydrophobins than saprotrophic fungi, and class II members accounted for the majority. Phylogenetic analysis of hydrophobin proteins from the species of Cordyceps s.l. indicated that there was more variability among the class II members than class I. Only a few hydrophobin-encoding genes evolved by duplication in Cordyceps s.l., which was inconsistent with the important role of gene duplication in basidiomycetes. Different transcript patterns of four hydrophobin-encoding genes during the life cycle indicated the possible different functions for each. The transcripts of Cmhyd2, 3 and 4 can respond to light and were related with the photoreceptors. CmQHYD, with four hydrophobin II domains, was first found in C. militaris, and multi-domain hydrophobins were only distributed in the species of Cordycipitaceae and Clavicipitaceae. These results could be helpful for further function research of hydrophobins and could provide valuable information for the evolution of hydrophobins.


Insects ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 42
Author(s):  
Samy Sayed ◽  
Sayed-Ashraf Elarrnaouty ◽  
Saad AlOtaibi ◽  
Mohamed Salah

This study aimed to estimate the virulence of an indigenous Beauveria bassiana on all developmental stages of two indigenous coccinellids; Coccinella undecimpunctata and Hippodamia variegata through three application methods; direct spray, contact method, and feeding on aphids treated with the fungus (ingestion). Also, indirect effect on all developmental stages resulted from 1st larval instar treated with these application methods. All treatments were done with a concentration of 1 × 105 which was recommended in previous studies for different aphid species with a control of 0.02% Tween 80 (v/v). The mortality of 1st larval instar of both H. variegata and C. undecimpunctata and pupal stage of C. undecimpunctata were significantly increased with spray method only. Also, contact method achieved significantly higher mortality on 1st larval instar of C. undecimpunctata only. Regard to indirect effect, except of mortality of 1st larval instar of both predators and 2nd larval instar of H. variegata, other developmental instars/stages of both predators were not affected by B. bassiana through the three tested application methods in the mortality, duration, survival, cumulative survival male and female longevity, and fecundity. Therefore, both tested predatory coccinellids could be compatible with this indigenous isolate of B. bassiana where, in general, there are no negative effects of the fungus on both predators.


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