Synchronization of life cycles of three mermithids (Nematoda) with their chironomid (Diptera) hosts and some observations on the pathology of the infections

1971 ◽  
Vol 49 (7) ◽  
pp. 975-982 ◽  
Author(s):  
William M. Hominick ◽  
H. E. Welch
Keyword(s):  
Life Cycles ◽  
Fourth Instar ◽  
New Hosts ◽  
Limited Period

The life cycles of three mermithid species were synchronized with those of the chironomid hosts. Hydromermis palustris overwintered as an advanced parasite in Cladotanytarsus sp., emerged in early May, and infected new hosts throughout the summer. Gastromermis deltensis overwintered as an early parasite, mainly in Harnischia sp., emerged in late May, and also infected new hosts throughout the summer. Hydromermis conopophaga probably overwintered as an egg, infected new hosts in spring, and emerged from Polypedilum simulans and Harnischia sp. in late June. It had only one generation per year. The chironomids overwintered as third instars. Cladotanytarsus sp. was the first to molt to the fourth instar in the spring, Harnischia sp. was second, and P. simulans last. Both Cladotanytarsus sp. and Harnischia sp. emerged throughout the summer; P. simulans had a limited period of emergence in the summer. The sex of the mermithids was correlated with their number per host. Intersexes in parasitized adult Harnischia sp. are described and illustrated.

Observations on the Effect of Exposure to a Low Temperature on Laemophloeus minutus (Ol.) (Col. Cucujidae)

1954 ◽  
Vol 45 (2) ◽  
pp. 351-359 ◽  
Author(s):  
Gwyneth C. Williams
Keyword(s):  
Low Temperature ◽  
Adult Male ◽  
Developmental Stages ◽  
Instar Larva ◽  
Fourth Instar ◽  
Fourth Instar Larva ◽  
Atmospheric Humidity ◽  
Larval Instars ◽  
Limited Period

Experiment showed that all developmental stages of Lacemophloeus minutus (Ol.) can survive exposure to a temperature of + 2°C. for a limited period which varies with the instar.The egg was more susceptible to such exposure than any other stage, followed by the first, second and third larval instars and the adult, which did not differ significantly from each other, and then by the fourth-instar larva and pupa which can also be grouped together.The adult male proved 1·21 times more susceptible than the female to the effects of exposure.Atmospheric humidity did not influence the mortality of eggs or adults. Previous starvation did not affect the mortality of adults subsequently exposed to + 2°C.

scholarly journals Emergence timing and voltinism of phantom midges, Chaoborus spp., in the UK

2019 ◽  
Author(s):  
R. Cockroft ◽  
W.R. Jenkins ◽  
A. Irwin ◽  
S. Norman ◽  
K.C. Brown
Keyword(s):  
First Generation ◽  
Adult Emergence ◽  
Great Majority ◽  
Experimental Period ◽  
Life Cycles ◽  
Fourth Instar ◽  
Separate Experiment ◽  
Cycle Times ◽  
Group 5 ◽  
The Uk

AbstractAfter introduction of overwintered fourth instar larvae (2027 in total), emergence timing of adult Chaoborus spp. (Diptera: Chaoboridae) was investigated in four outdoor freshwater microcosms in the UK in 2017. Adults started emerging on 13 April and emergence reached a peak on 2 May. The majority of emergence was completed by 3 June. Emergence rates for each microcosm ranged from 51.4% to 66.2% with a mean of 60.9%. The great majority of emerged adults were C. obscuripes (99.68%). Males appeared to emerge slightly earlier than females. The results indicated that for overwintered C. obscuripes larvae, the adults emerged en masse in spring (rather than emerging gradually over the course of spring and summer). In a separate experiment at the same location, the number of Chaoborus spp. life-cycles occurring per year was determined using six replicate groups of microcosms, each group containing four microcosms. Each microcosm contained 200 L of water and was enclosed within a ‘pop-up’ frame covered with ‘insect-proof’ mesh (1 mm2 aperture). The first microcosm in each group was ‘seeded’ with egg rafts (first generation) of Chaoborus spp. Following adult emergence, as soon as the first egg rafts were laid in each microcosm these were removed and transferred to the second microcosm in that group, and so on. The larvae sampled from the second and subsequent generations in the microcosms were all C. crystallinus. C. crystallinus produced up to four discrete generations within the experimental period, and life-cycle times from egg-to-egg ranged from 14 days (replicate group 5, first generation) to 56 days (replicate 3, second generation). These two experiments, indicated that i) adult C. obscuripes arising from overwintered larvae emerged en masse in the spring, and ii) up to four generations of C. crystallinus occurred; i.e. C. crystallinus exhibited a multi-voltine life history under the temperate conditions of this UK study.

scholarly journals Mechanisms behind the Madness: How Do Zombie-Making Fungal Entomopathogens Affect Host Behavior To Increase Transmission?

mBio ◽  
2021 ◽  
Author(s):  
Charissa de Bekker ◽  
William C. Beckerson ◽  
Carolyn Elya
Keyword(s):  
Complex Traits ◽  
Life Cycles ◽  
Host Behavior ◽  
Crucial Step ◽  
Fungal Entomopathogens ◽  
New Hosts

Transmission is a crucial step in all pathogen life cycles. As such, certain species have evolved complex traits that increase their chances to find and invade new hosts.

scholarly journals Production of Larval Tanypodinae (Insecta: Chironomidae) in the Mud at Loch Leven, Kinross

1976 ◽  
Vol 75 (3) ◽  
pp. 157-169 ◽  
Author(s):  
W. Nigel Charles ◽  
Kenneth East ◽  
Thomas D. Murray
Keyword(s):  
Life Histories ◽  
Dry Weight ◽  
Common Species ◽  
Average Density ◽  
Life Cycles ◽  
Fourth Instar ◽  
Individual Species ◽  
Seasonal Patterns ◽  
Loch Leven ◽  
Two Generations

SynopsisLife histories and production of the five common species of Tanypodinae (Pentaneura monilis, Procladius simplicistilus, P. crassinervis, P. choreus and Psilotanypus rufovittatus) in the mud at Loch Leven were measured from March 1971 to March 1972. The methods used to identify each species of larva are described. All were univoltine except Pentaneura monilis which had two generations per year, but the seasonal patterns of the life cycles were different. The average density of third and fourth instar Tanypodinae was 3100/m2 and densities of individual species exceeded 2500/m2 for short periods in Procladius crassinervis and P. choreus. Net annual dry weight production by this subfamily was 2·6 g/m2(57 kJ/m2), with individual species ranging from 1·1 g/m2 (P. crassinervis) to 0·16 g/m2 (Pentaneura monilis). These results are discussed briefly and compared with production estimates for other zoobenthos.

TAXONOMIC AND BIOLOGICAL OBSERVATIONS ON STREPTOCARA CALIFORNICA (GEDOELST, 1919) GEDOELST AND LIÉGEOIS, 1922 AND THE GENUS STREPTOCARA (NEMATODA: ACUARIIDAE)

1964 ◽  
Vol 42 (5) ◽  
pp. 773-783 ◽  
Author(s):  
George G. Gibson
Keyword(s):  
Life Cycles ◽  
Fourth Stage ◽  
Melanitta Perspicillata ◽  
Mergus Serrator ◽  
Bucephala Islandica ◽  
Aythya Valisineria ◽  
New Hosts ◽  
Aythya Marila ◽  
Clangula Hyemalis ◽  
Highly Evolved

A detailed redescription is presented for adults of Streptocara californica (Gedoelst, 1919) Gedoelst and Liégeois, 1922 based on specimens from under the gizzard lining of a common scoter, Oidemia nigra (L.), from Vancouver, Canada. Adult S. californica are here reported from the type host, Melanitta deglandi (Bonap.), and from the following new hosts near Vancouver: Anas platyrhynchos L., Aythya valisineria (Wilson), Bucephala islandica (Gmelin), Clangula hyemalis (L.), Melanitta perspicillata (L.), and Mergus serrator L. A description of the fourth-stage larvae is presented, based on specimens from Aythya marila (L.), Melanitta perspicillata (L.), and Mergus merganser L. from the same region. Yseria californica Gedoelst, 1919; Korjakinema gusi Oschmarin, 1950; Streptocara dogieli Belopolskaya, 1952; and Skrjabinobronema californicum (Gedoelst, 1919) Yamaguti, 1961 are considered synonyms of Streptocara californica. A comparison of the prevalence of S. californica with that of S. crassicauda charadrii Skrjabin, 1916 seems to indicate rather different life cycles for the two species. It is suggested that the genus Streptocara may be more highly evolved than the other genera of the Seuratiinae.

scholarly journals Sexual Development in Non-Human Parasitic Apicomplexa: Just Biology or Targets for Control?

Animals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2891
Author(s):  
Teresa Cruz-Bustos ◽  
Anna Sophia Feix ◽  
Bärbel Ruttkowski ◽  
Anja Joachim
Keyword(s):  
Sexual Reproduction ◽  
Sexual Development ◽  
Current Knowledge ◽  
Life Cycles ◽  
Complex Life Cycles ◽  
Transmission Blocking ◽  
New Hosts ◽  
Sexual Stages ◽  
New Generation ◽  
Effective Transmission

The phylum Apicomplexa is a major group of protozoan parasites including gregarines, coccidia, haemogregarines, haemosporidia and piroplasms, with more than 6000 named species. Three of these subgroups, the coccidia, hemosporidia, and piroplasms, contain parasites that cause important diseases of humans and animals worldwide. All of them have complex life cycles involving a switch between asexual and sexual reproduction, which is key to their development. Fertilization (i.e., fusion of female and male cells) results in the formation of a zygote that undergoes meiosis, forming a new generation of asexual stages. In eukaryotes, sexual reproduction is the predominant mode of recombination and segregation of DNA. Sex is well documented in many protist groups, and together with meiosis, is frequently linked with transmission to new hosts. Apicomplexan sexual stages constitute a bottleneck in the life cycle of these parasites, as they are obligatory for the development of new transmissible stages. Consequently, the sexual stages represent attractive targets for vaccination. Detailed understanding of apicomplexan sexual biology will pave the way for the design and implementation of effective transmission-blocking strategies for parasite control. This article reviews the current knowledge on the sexual development of Apicomplexa and the progress in transmission-blocking vaccines for their control, their advantages and limitations and outstanding questions for the future.

scholarly journals Alternative bacteriophage life cycles: the carrier state of Campylobacter jejuni

Open Biology ◽  
2014 ◽  
Vol 4 (3) ◽  
pp. 130200 ◽  
Author(s):  
Patcharin Siringan ◽  
Phillippa L. Connerton ◽  
Nicola J. Cummings ◽  
Ian F. Connerton
Keyword(s):  
Campylobacter Jejuni ◽  
Pathogenic Bacteria ◽  
Carrier State ◽  
Life Cycles ◽  
Enteric Disease ◽  
New Host ◽  
Complex Life Cycles ◽  
Phenotypic Changes ◽  
Poultry Products ◽  
New Hosts

Members of the genus Campylobacter are frequently responsible for human enteric disease, often through consumption of contaminated poultry products. Bacteriophages are viruses that have the potential to control pathogenic bacteria, but understanding their complex life cycles is key to their successful exploitation. Treatment of Campylobacter jejuni biofilms with bacteriophages led to the discovery that phages had established a relationship with their hosts typical of the carrier state life cycle (CSLC), where bacteria and bacteriophages remain associated in equilibrium. Significant phenotypic changes include improved aerotolerance under nutrient-limited conditions that would confer an advantage to survive in extra-intestinal environments, but a lack in motility eliminated their ability to colonize chickens. Under these circumstances, phages can remain associated with a compatible host and continue to produce free virions to prospect for new hosts. Moreover, we demonstrate that CSLC host bacteria can act as expendable vehicles for the delivery of bacteriophages to new host bacteria within pre-colonized chickens. The CSLC represents an important phase in the ecology of Campylobacter bacteriophage.

THE CONCEPT OF AUTONOMOUS SYSTEMS IN INDUSTRY 4.0

2019 ◽  
Vol 12 (1) ◽  
pp. 77-87
Author(s):  
György Kovács ◽  
Rabab Benotsmane ◽  
László Dudás
Keyword(s):  
Industry 4.0 ◽  
Intelligent Systems ◽  
Autonomous Systems ◽  
Essential Element ◽  
Industrial Sector ◽  
Life Cycles ◽  
Multi Agent Systems ◽  
New Paradigm ◽  
Intelligent Machines ◽  
Digital Network

Recent tendencies – such as the life-cycles of products are shorter while consumers require more complex and more unique final products – poses many challenges to the production. The industrial sector is going through a paradigm shift. The traditional centrally controlled production processes will be replaced by decentralized control, which is built on the self-regulating ability of intelligent machines, products and workpieces that communicate with each other continuously. This new paradigm known as Industry 4.0. This conception is the introduction of digital network-linked intelligent systems, in which machines and products will communicate to one another in order to establish smart factories in which self-regulating production will be established. In this article, at first the essence, main goals and basic elements of Industry 4.0 conception is described. After it the autonomous systems are introduced which are based on multi agent systems. These systems include the collaborating robots via artificial intelligence which is an essential element of Industry 4.0.

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