Editing Forensic entomology (section)

==Factors==

=== Moisture levels ===
Both the decomposition and insect activity on a corpse are significantly influenced by humidity. Elevated humidity can hasten the decomposition process by fostering microbial proliferation, which facilitates the breakdown of tissues. Additionally the odors and gases produced by this microbial activity draw insects to the body. These smells are particularly attractive to insects like blowflies and flesh flies, which may quickly populate a body in humid conditions.<ref>{{cite journal | vauthors = Campobasso CP, Di Vella G, Introna F | title = Factors affecting decomposition and Diptera colonization | journal = Forensic Science International | volume = 120 | issue = 1–2 | pages = 18–27 | date = August 2001 | pmid = 11457604 | doi = 10.1016/S0379-0738(01)00411-X }}</ref>

Low humidity, on the other hand, can impede the breakdown process. Mummification rather that breakdown may result from the body losing moisture more quickly in arid settings. Given that many insects need damp atmosphere to survive, this may discourage their activity. Nonetheless, some insects, like dermestid beetles, can survive in dry environments and can still be found on a body.<ref>{{cite web | url = http://www.clt.uwa.edu.au/__data/page/112507/fse07_forensic_entomology.pdf | title = Forensic entomology: use of insects to help solve crimes | archive-url = https://web.archive.org/web/20120119175704/http://www.clt.uwa.edu.au/__data/page/112507/fse07_forensic_entomology.pdf | archive-date=19 January 2012 | work = Uwa.edu.au | date = 20 March 2008 }}</ref><ref>{{cite book | vauthors = Vilet MH, Richards CS, Midgley JM | date = 2010 | chapter = Contemporary precision, bias and accuracy of minimum post-mortem intervals estimated using development of carrion-feeding insects. | veditors = Amendt J, Campobasso CP, Goff ML, Grassberger M | title = Current concepts in forensic entomology. | location = Heidelberg | publisher = Springer | pages = 109–137 }}</ref>

The existence of standing water next to a body can also affect the activity of insects. Aquatic insects, such as water beetles and some fly species, may be drawn to bodies near water sources. These insects can colonize the body and hasten its decomposition. Furthermore, because different insect species have distinct preference for habitats, the presence of water might influence the kinds of insects that inhabits the body.

All things considered, the rate and pattern of a corpse's decomposition and insect colonization are greatly influenced by its humidity. To estimate the postmortem period and reconstruct the circumstances around a death, forensic entomologists can benefit from an understanding of how humidity levels affect decomposition.<ref>{{cite journal | vauthors = VanLaerhoven SL, Anderson GS | title = Insect succession on buried carrion in two biogeoclimatic zones of British Columbia | journal = Journal of Forensic Sciences | volume = 44 | issue = 1 | pages = 32–43 | date = January 1999 | pmid = 9987868 | doi = 10.1520/JFS14409J }}</ref>

===Submerged corpses===
M. Lee Goff, a noted and well respected [[forensic entomologist]], was assigned to a case involving the discovery of a decomposing body found on a boat half a mile from shore. Upon collection of the maggot mass, only one insect, ''[[Chrysomya megacephala]]'', was discovered. He concluded that the water barrier accounted for the scarcity of other flies. He also noted that flies will not attempt to trek across large bodies of water unless there is a substantially influential attractant.

In addition, the amount of time a maggot mass has been exposed to salt water can affect its development. From the cases Goff observed he found that if subjected for more than 30 minutes, there was a 24‑hour developmental delay. Not many more studies have been conducted and thus a specific amount of delay time is difficult to estimate.<ref name="Goff, M. L 2000">{{cite book | vauthors = Goff ML | title = A Fly for the Prosecution. | location = Cambridge, Massachusetts | publisher = Harvard University Press | date = 2000 }}</ref>

The main focus of a study accomplished by Payne and King<ref>{{cite journal | vauthors = Payne JA, King EW |date=1972 |title=Insect succession pattern on decomposing pig carcasses in water |journal=Journal of the Georgia Entomological Society |volume=7 |pages=153–162}}</ref> using fetal pigs, was the insect succession regarding carcass decomposition in an aquatic setting. Their results concluded that in the early floating stages of the cadaver, eggs were laid by blowflies. Moreover, by the bloating stage, most of the exposed flesh was absent and maggots migrated from the body. Many of the latter were present below the water line and fed on the carcass; with only their [[Spiracle (arthropods)]] protruding the surface.

===Sun exposure===
"Because insects are cold-blooded animals, their rate of development is more or less dependent on ambient temperature."<ref>{{cite book | veditors = Catts EP, Haskell NH | title = Entomology & Death: A Procedural Guide | location = Clemson, SC | publisher = Joyce's Print Shop, Inc. | date = 1990 | page = 5 | isbn = 978-0-9628696-0-0 }}</ref>
Bodies exposed to large amounts of sunlight will heat up, giving the insects a warmer area to develop, reducing their development time.
An experiment conducted by Bernard Greenberg and John Charles Kunich with the use of rabbit carcasses to study accumulation of degree days found that with temperature ranging in the mid 70s to high 80s the amount of developmental time for maggots was significantly reduced.<ref>{{cite book | vauthors = Greenberg B, Kunich JC |year=2002 |title=Entomology and the Law: Flies as Forensic Indicators |publisher=[[Cambridge University Press]] |location=Cambridge, United Kingdom |isbn=978-0-521-80915-3}}</ref>

In contrast, bodies found in shaded areas will be cooler, and insects will require longer growth periods. In addition, if temperatures reach extreme levels of cold, insects instinctively know to prolong their development time in order to hatch into a more accepting and viable climate in order to increase the chance of survival and reproduction.

Furthermore, insect activity and colonization patterns can also be influenced by the length and intensity of solar exposure. Because the increasing temperature speeds up their development, insects are more likely to be active and colonize a body more quickly in places exposed to direct and extended sunlight. In comparison to shaded locations, this may result in a quicker succession of insect life and disintegration stages. On the other hand, because of the lower temperatures, shaded areas might have slower rates of insect activity and decomposition, which would delay the processes of insect colonization and decomposition.<ref>{{cite journal | vauthors = Hall RD |date=2005 |title=Entomology and the Law-Flies as Forensic Indicators |journal=Journal of Medical Entomology |volume=42 |issue=5 |pages=922|doi=10.1603/0022-2585(2005)042[0922:EATLAF]2.0.CO;2 |doi-broken-date=1 November 2024 }}</ref>

===Air exposure===
Air exposure can have a significant impact on insects and the determination of postmortem interval (PMI). Hanged bodies can be expected to show their own quantity and variety of flies. Also, the amount of time flies will stay on a hanged body will vary in comparison to one found on the ground. A hanged body is more exposed to air and thus will dry out faster, leaving less food source for the maggots.

The presence and behavior of insects on hanging bodies can vary. As the body begins to decompose, a compilation of fluids will leak to the ground. This area is where most of the expected fauna can be found. Also, it is more likely that rove beetles and other non-flying insects will be found here instead of directly on the body. Fly maggots, initially deposited on the body, may also be found below.<ref name="Goff, M. L 2000"/>

===Geography===
According to [[Jean Pierre Mégnin]]'s book ''La Faune des Cadavres'' there are eight distinct faunal successions attracted to a corpse. While most [[beetle]]s and [[fly|flies]] of forensic importance can be found worldwide, a portion of them are limited to a specific range of habitats. It is forensically important to know the geographical distribution of these insects in order to determine information such as post mortem interval or whether a body has been moved from its original place of death.

[[Calliphoridae]] is arguably the most important family concerning forensic entomology given that they are the first to arrive on the corpse. The family can be found worldwide. ''Chrysomya rufifaces'', the hairy maggot [[Calliphoridae|blow fly]], is a forensically important member of the family Calliphoridae and is widespread, however it is not prevalent in the Southern [[California]], [[Arizona]], [[New Mexico]], [[Louisiana]], [[Florida]], or [[Illinois]] regions.<ref>{{cite journal | vauthors = Whitworth T |title=Keys to Genera and Species of Blow Flies of America North of Mexico |journal = Proceedings of the Entomological Society of Washington | volume= 108 |issue=3 |year=2006 |page= 710 |url=https://www.biodiversitylibrary.org/page/30254115 }}</ref>

[[Flesh fly|Flesh flies]] fall under the family Sacrophagidae and generally arrive at a corpse following Calliphoridae. Unlike Calliphoridae, however, members of this family are able to fly in heavy rain. This key advantage enables them to occasionally reach a body before Calliphoridae, affecting the maggot mass that will be discovered. Flesh flies are globally distributed including habitats in the United States, Europe, Asia, and the Middle East.<ref>{{cite book | vauthors = Pape T | chapter = Catalog of the Sarcophagidae of the World. | title = Memoirs on Entomology | location = Gainesville, FL | publisher = Associated | date = 1996 | pages = 288–289 }}</ref>

Beetles are representative of the order [[Coleoptera]] which accounts for the largest of the insect orders. Beetles are very adaptive and can be found in almost all environments with the exception of [[Antarctica]] and high mountainous regions. The most diverse beetle fauna can be found in the tropics. In addition, beetles are less submissive to temperatures. Thus, if a carcass has been found in cold temperatures, the beetle will be prevalent over Calliphoridae.

===Weather===
Various weather conditions in a given amount of time cause certain pests to invade human households. This is because the insects are in search of food, water, and shelter.
Damp weather causes reproduction and growth enhancement in many insect types, especially when coupled with warm temperatures. Most pests concerned at this time are [[ant]]s, [[spider]]s, [[cricket (insect)|cricket]]s, [[cockroach]]es, [[ladybug]]s, [[yellowjacket]]s, [[hornet]]s, [[mouse|mice]], and [[rat]]s.
When conditions are dry, the deprivation of moisture outside drives many pests inside searching for water. While the rainy weather increases the numbers of insects, this dry weather causes pest invasions to increase. The pests most commonly known during dry conditions are [[scorpion]]s, ants, [[pillbug]]s, [[millipede]]s, crickets, and spiders. Extreme drought does kill many populations of insects, but also drives surviving insects to invade more often.
Cold temperatures outside will cause invasions beginning in the late summer months and early fall. [[Box elder bug]]s, [[cluster fly|cluster flies]], ladybugs, and [[silverfish]] are noticed some of the most common insects to seek the warm indoors.<ref name="arabicking">{{cite web | url = https://www.arabicking.com/get-rid-of-a-dead-rat-and-dead-rat-smell/ | title = Dead rat tips | archive-url = https://web.archive.org/web/20110916143650/http://www.terminix.com/Information/Weather/ | archive-date=16 September 2011 | work = Terminix.com | date = 19 March 2008 }}</ref> In general, insects are poikilothermic animals; thus meaning their level of activity is substantially depended upon their surrounding environmental conditions. An increase in the temperature will result in an accelerated metabolism of the insect; hence resulting in an increased activity.<ref>{{cite journal | vauthors = Jaworski T, Hilszczański J |date = December 2013 |title=The effect of temperature and humidity changes on insects development their impact on forest ecosystems in the expected climate change |journal=Forest Research Papers |volume=74 |issue=4 |pages=345–355 |doi=10.2478/frp-2013-0033 |s2cid=53992457 |issn=2082-8926 |doi-access=free }}{{Dead link|date=October 2022 |bot=InternetArchiveBot |fix-attempted=yes }}</ref>