Entomopathogenic Nematodes: Difference between revisions

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'''Genus''': Steinernema/ Heterohabditis
'''Genus''': Steinernema/ Heterohabditis
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[4]


== Life Cycle ==
== Life Cycle ==
Entomopathogenic Nematodes first start their life cycles at the infective juvenile stage of their life. This is before they infect a host and it's the only free living stage of life that occurs during their life cycle. Then the juvenile finds an insect host to infect by entering through any possible natural opening they can find such as spiracles, the mouth of an insect, the anus, or in some less common cases through intersegmental membranes of the cuticle. About 24-48 hours after the nematode infests its prey the host finally dies while the nematodes mature to and adult stage and then reproduce. The host surprisingly does not die from just being infected by the nematode but dies from the intestinal symbiotic bacteria that is released by the nematodes. Depending on available resources after maturation and reproduction inside the host one or more generations may be able to survive inside a singular host. This whole process from the beginning of the juvenile stage where they spend most of their  life through adulthood and eventually death is approximately 42-56 days.  
Entomopathogenic Nematodes first start their life cycles at the infective juvenile stage of their life. This is before they infect a host and it's the only free living stage of life that occurs during their life cycle. Then the juvenile finds an insect host to infect by entering through any possible natural opening they can find such as spiracles, the mouth of an insect, the anus, or in some less common cases through intersegmental membranes of the cuticle. About 24-48 hours after the nematode infests its prey the host finally dies while the nematodes mature to and adult stage and then reproduce. The host surprisingly does not die from just being infected by the nematode but dies from the intestinal symbiotic bacteria that is released by the nematodes. Depending on available resources after maturation and reproduction inside the host one or more generations may be able to survive inside a singular host[2]. This whole process from the beginning of the juvenile stage where they spend most of their  life through adulthood and eventually death is approximately 42-56 days.  


== Reproduction ==
== Reproduction ==
The reproduction stages of life depends on which family of Entomopathogenic Nematode is being observed. In the Steinernematidae family after the juvenile finds a host whether it is live or dead they will develop into either a male or female. In this family of nematodes multiple nematodes need to infect the same host in order to reproduce but once this occurs, then breeding occurs between one of the males and one of the females and the female will then lay their eggs within the host.  
The reproduction stages of life depends on which family of Entomopathogenic Nematode is being observed. In the Steinernematidae family after the juvenile finds a host whether it is live or dead they will develop into either a male or female. In this family of nematodes multiple nematodes need to infect the same host in order to reproduce but once this occurs, then breeding occurs between one of the males and one of the females and the female will then lay their eggs within the host.  
On the other hand for the Heterorhabditidae family after entering the host they are considered to be self-fertile hermaphrodites. A hermaphroditic nematode has both sex organs that a male and a female would have and therefore does not need to colonize a host with another nematode of the opposite sex. Research shows that this happens more often due to the relative abundance being fairly low for this family so adaptations occurred throughout time.  
On the other hand for the Heterorhabditidae family after entering the host they are considered to be self-fertile hermaphrodites. A hermaphroditic nematode has both sex organs that a male and a female would have and therefore does not need to colonize a host with another nematode of the opposite sex. Research shows that this happens more often due to the relative abundance being fairly low for this family so adaptations occurred throughout time[3].  




== References ==
== References ==
[1] bugsforgrowers.com picture taken by G.B Jagdale, 2015
[1] bugsforgrowers.com picture taken by G.B Jagdale, 2015
----
[2] http://entnemdept.ufl.edu, Author: Nastaran Tofangsaz
[2] http://entnemdept.ufl.edu, Author: Nastaran Tofangsaz
----
[3] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3578460/ Author: Christine T. Griffin
----
[4] https://en.wikipedia.org/wiki/Entomopathogenic_nematode

Revision as of 17:49, 8 April 2021

Entomopathogenic Nematodes (Nematoda Rhabditida)

Overview

second stage juvenile entomopathogenic nematode [1]

There are two different families of Entomopathogenic Nematodes known as Heterorhabditidae and Steinernematidae. Both of these families of Nematodes are considered to obligate parasites of insects meaning that they must parasitize their host to survive and reproduce. Entomopathogenic Nematodes are used as biological insecticides in pest management. These nematodes are considered to be non-toxic to humans and have been very beneficial to the Integrated Pest Management for both agricultural and residential use. They can be found naturally in soils but also can be implemented into almost any soil type and be effective at eliminating pests.

Description

Entomopathogenic Nematodes are soft-bodied, non-segmented roundworms that parasitize their prey and use their body for homes and their bodily fluids for nutrients.

Phenology

Kingdom: Animals


Phylum: Nematoda


Class: Chromadorea


Order: Rhabditida


Family: Steinernematidae/ Heterorhabditidae


Genus: Steinernema/ Heterohabditis


[4]


Life Cycle

Entomopathogenic Nematodes first start their life cycles at the infective juvenile stage of their life. This is before they infect a host and it's the only free living stage of life that occurs during their life cycle. Then the juvenile finds an insect host to infect by entering through any possible natural opening they can find such as spiracles, the mouth of an insect, the anus, or in some less common cases through intersegmental membranes of the cuticle. About 24-48 hours after the nematode infests its prey the host finally dies while the nematodes mature to and adult stage and then reproduce. The host surprisingly does not die from just being infected by the nematode but dies from the intestinal symbiotic bacteria that is released by the nematodes. Depending on available resources after maturation and reproduction inside the host one or more generations may be able to survive inside a singular host[2]. This whole process from the beginning of the juvenile stage where they spend most of their life through adulthood and eventually death is approximately 42-56 days.

Reproduction

The reproduction stages of life depends on which family of Entomopathogenic Nematode is being observed. In the Steinernematidae family after the juvenile finds a host whether it is live or dead they will develop into either a male or female. In this family of nematodes multiple nematodes need to infect the same host in order to reproduce but once this occurs, then breeding occurs between one of the males and one of the females and the female will then lay their eggs within the host. On the other hand for the Heterorhabditidae family after entering the host they are considered to be self-fertile hermaphrodites. A hermaphroditic nematode has both sex organs that a male and a female would have and therefore does not need to colonize a host with another nematode of the opposite sex. Research shows that this happens more often due to the relative abundance being fairly low for this family so adaptations occurred throughout time[3].


References

[1] bugsforgrowers.com picture taken by G.B Jagdale, 2015


[2] http://entnemdept.ufl.edu, Author: Nastaran Tofangsaz


[3] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3578460/ Author: Christine T. Griffin


[4] https://en.wikipedia.org/wiki/Entomopathogenic_nematode