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ARLY J O
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APPLIED SCIENCE RESEARCH JOURNAL. 2013. VOL 1 (1): 7 – 21
App. Sci. Res. J
Vol 1(No 1): 7 – 21
Original Research Paper
COLONIZATION AND INVERTEBRATE SUCCESSION
ON MAMMALIAN CARCASSES IN ETHIOPE RIVER, NIGER DELTA,
NIGERIA
Francis O. Arimoro
Department of Biological Sciences,
Federal University of Technology,
P.M.B. 65, Minna, Niger State, Nigeria.
E-mail: francis.arimoro@futminna.edu.ng
Tel +2348035615424
ABSTRACT
Background and aims: Traditionally, forensic entomology has focused on terrestrial
saprophagous insects, and much less is known about biota colonizing corpses in
aquatic environments. This study considered the insect succession on decomposing
remains of the rat (Rattus rattus) in Ethiope River, southern Nigeria to better
understand the colonization of these invertebrates on human corpses.
Methods: The carcasses were held in place by scavenger proof cages at the bottom of
shallow portions of riffles and pools in the river. During this period the ambient
temperature of air and water were monitored every day as well as insect colonizers
until the carcasses were completely decomposed.
Results: A total of four insect orders and eleven (11) taxa of invertebrates were found
colonizing the rat carcasses at the different stages of the decomposition process.
Dipterans were the early colonizers, followed by the Ephemeropterans. Trichopterans
and Hemipterans were only sporadically present at the last stage of the decomposition
process. The total time for decomposition was very rapid not allowing for diverse
invertebrates colonization. The fresh stage of decomposition of the carrion showed
that only representatives of the order Diptera and Chironomus species (>85%) in
particular were found colonizing the carrion. Coleopterans were never found
colonizing the rat carrion. Overall, the abundance of insects increased progressively
with days and with diverse groups at the peak of decomposition.
Conclusions: The invertebrate fauna on the remains, the decomposition and the
feeding patterns do suggest that a better understanding of decomposition in the stream
will be valuable in estimating elapsed time since submergence and in identifying the
environment in which the body has decomposed. Therefore the proper collection and
preservation of invertebrates from bodies immersed in water is imperative to forensic
investigation.
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Keywords: Forensic entomology, Insect succession, Decomposition, colonizers
Macroinvertebrates, Afrotropical stream.
environment in which the body has
decomposed (Chaloner et al 2002;
Fenoglio 2005).
1.0 Introduction
The decomposition of a body on land
and the interaction between the body and
its insect fauna have been well studied,
and predictable insect development and
colonization
patterns
have
been
described
from
many
countries,
geographical regions, habitats and
seasons (Anderson 2009). Colonization
and decomposition of carrions by insects
in water bodies tend to establish
invertebrate population on corpses and
the resulting community frequently
offers clues to victim death and
subsequent postmortem history (Smith
1986; Catts 1982).
To
date,
data
on
invertebrate
colonization of submerged carcasses are
sparse. Some literature available
document the presence of scavenging
macroinvertebrates on dead fish (Schuldt
and Hershey 1995; Chaloner and Wipfli
2002; Chaloner et al 2002; Fenoglio et al
2005), on dead pigs (Grassberger 2004;
Merritt and Wallace 2000; Lopes de
Carvalho and Linhares 2001) and
blowflies using mammalian carcasses
that were submerged but rose to the
surface after gas production by bacteria
(Singh and Greenberg 1994; Merritt and
Wallace 2000). Tomberlin and Adler
(1998) documented larval chironomidae,
ephydridae, and psychodidae on rodents
partially
in
experimental
tubs.
Macroinvertebrates certainly play a key
role in the decomposition of carrion in
stream systems and valuable in
estimating
elapsed
time
since
submergence,
identifying
the
The abundance, richness and species
composition of invertebrate communities
are probably important elements in this
context, but the taxa involved in
decomposition could change in different
stream microhabitats. Few studies have
underlined
the
importance
of
microhabitat
conditions
in
the
decomposition of carcasses. Keiper et al.
(1997) and Merritt and Wallace (2000)
placed adult rat carcasses in stream riffle
and pool during the spring to document
colonization by macroinvertebrates over
time.
The pool and riffle habitats
produce different macroinvertebrate
assemblages, colonization patterns, and
functional feeding-group composition.
Postmortem interval estimates, based on
the biota found on a corpse have
provided supporting evidence for many
criminal investigations (Keiper and
Casamatta, (2001). Haskell et al. (1989)
and Hawley et al. (1989) provided
discussions of invertebrate colonization
and submerged corpses; that is two cases
where murder victims were pulled from
stream and from ponds, respectively.
Each corpse had numerous “red carpet
fiber”
blood
worms
(Larval
chironomidae). The larval were caught
on the clothing of the stream-associated
victims; where as the partially clothed
female extracted from the farm pond had
blood worms adhering to her exposed
back.
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Knowledge
of
the
postmortem
2.0 Materials and Methods
submersion interval (PMSI) defined as
Description of study area
the time between corpse submersion and
The sites were this research was
discovery may be crucial during legal
undertaken is along Ethiope River
investigation.
Entomological
based
located at Abraka, Nigeria which is
estimation is most commonly called the
about 24 km from the river source. River
time since colonization. Based on the
Ethiope is one of the two main tributaries
factors in a particular investigation, this
of the Benin River, the other being the
may, or may not closely approximate the
Jamieson River. From its source at
entire postmortem interval. In either case
Umuaja, it flows a westerly direction for
it is the duty of forensic pathologist or
approximately 100 km through the
coroner to estimate the postmortem
evergreen forest zone and enters the
interval, and forensic entomologist may
Benin River at Sapele (Fig. 1). The river
assist them in providing information on
is tidal only in its lower reaches (Sapele
the time since colonization which can
to Aghalokpe Stretch). Two climatic
ultimately be used to substantiate a
seasons, wet and dry, prevail in the study
portion of the postmortem interval
area. These seasons were defined using
Keiper and Casamatta, (2001).
an Aridity Index (AI). The wet season
This study will help to review the use of
(May-November,
AI
>
30)
is
aquatic biota in forensic investigations,
characterized by high monthly rainfall
providing a cue on how benthic
(range 120 – 350 mm) while the dry
organisms can be useful to determine the
season (December – April; AI < 30) is
time of death of an organism. Thus,
characterized by low precipitation (range
offering new avenues for benthological
0 - 90mm).
research applicable to medicolegal
inquiries of suspicious or mysterious
human deaths. Again, this study would
help to estimate the time of death or
postmortem interval in cases of
homicides, suicide or unexplained death
of organisms especially as it relates to
the tropical Africa region where there is
paucity of research in the field.
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Figure 1. Map of River Ethiope showing the location of the sampling sites. Inset; Map
of Africa showing the location of the study area in Nigeria.
For this study, Rat carcasses (Rattus
rattus) were selected as decomposition
models to ensure adequate replication
and thus sufficient statistical power of
analysis of macroinvertebrate (insect)
succession.
The riparian vegetation at all sites
consists of Symphonia globifena,
Alstonia congesis, Oxystigma manni,
Matrogyna ciliata, Fussiaera repens and
Xylopia sp., Hevea brasiliensis. All the
sites have a very close canopy cover of
>60%. The submerged vegetation in
most sites include Ceratophyllum
submersum, and Salvinia species. It is
about 30 km from the source of the
water; streambed is predominantly
coarse silt and sand. Human activities at
this site include bathing, swimming and
sand dredging. In stream cover is high
here, with poor pool quality and high
riffle quality and gradient.
2.1 Aquatic insect colonization
Sixteen (16) rats were placed in the
Ethiope River on 14 May 2011. Rats
were selected and obtained the day
before placement from the animal culture
laboratory, Delta State University,
Nigeria. The freshly dead rats were
positioned individually in numbered 10
mm mesh envelopes. The envelopes
were fixed with stones and nylon cords.
Eight carcasses were placed in riffle
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environments and the other eight in
sections of the soil surrounding the
pools. The water was 15–30 cm deep in
carcasses were carefully hand sieved for
riffles and 40–60 cm in pools. The
the presence of adult insect taxa and
carcasses were left in place for a
immature specimens, insect larva
maximum of 10 days. Upon setup, time
identification were done with reference
of decomposition and a brief description
to diagnostic keys (Merritt and Cummins
of the deposition site conditions were
1996; Cranston 2000; Epler 2001; Day et
recorded for each day. Sampling of
al. 2002). Ambient temperature of the
insect fauna were conducted daily for 7
surrounding environment water (River)
days. In addition to insect sampling,
and air were taken to check temperature
carcasses were observed daily for
on the decomposition of the carrions by
assessment of the decomposition site of
bacterial activities. The insect larvae
the carcass. Decomposition is a
dislodged from each rat when its body
continuous process that is commonly
was moved were collected with a 250
characterized into discrete stages of
µm mesh net and added to the sample. In
decomposition previously defined as,
the laboratory, all organisms were
fresh, bloat, wet, dry and skeletal (Voss
counted and identified to the genus. The
et al., 2009).
entire set up was repeated again 11 June
2011 and the average of the two readings
For the purpose of this study, the fresh
taken.
stage occurred from the moment of death
to the onset of bloat. Bloat was
2.2 Data Analysis
considered completed upon deflation of
Paired T- test was employed to test the
the carcass. The wet decay stage refers to
statistical significance between the
the period subsequent to carcass
physical and chemical parameters of the
deflation and ends when majority of
surface water at the riffles and pools and
carcass flesh and fluid has been removed
the insect larvae collected from the rat
and only dry constitutes, predominantly
carrion at these two microhabitat using
skin, cartilage commences at this point
'TexaSoft, WINKS SDA Software
and continues until the eventual loss of
(2007).
all remaining soft tissue. The skeletal
stage is defined by the absence of soft
3.0 Results
tissue with only hair and bone remaining.
Ambient temperature of the surrounding
Once removed from the riverbed, each
environment water (River) and air were
carcass was placed in a white plastic
taken to record the temperature required
tray. Insect larvae were carefully
for decomposition of the carrions by
collected with forceps from the mouth,
bacterial activities and varied from 21.0
interiors, external surface and stored in
to 31.0oC with a mean and SE of 25.1 ±
70% ethanol. Insects associated with
1.49 in riffles and 25.0 ± 1.50 in pools
carcasses were sampled through manual
(Table 1). The temperature readings were
collection (paint brush/forceps). In the
not significantly different between the
advanced stages of decomposition,
riffles and pools. As expected, flow
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velocity was significantly higher in the
of 61 Chironomus spp and 15 mayfly
riffles than the pools (p< 0.05). The
individuals attended the carrion of the rat
progression and duration of each
(Rattus
rattus)
throughout
the
decomposition stages (fresh, bloat, wet,
decomposition process. Early colonizers
dry and skeletal stages) of the Rat
arrived during the fresh stage occurring
(Rattus rattus) carrion was rapid and
from the moment of death to the onset of
lasted only for seven days (Table 2).
bloat. Bloat stage consist of persistent
early colonizers which increased
gradually in numbers. As the dry stage
3.1 Insect colonization and succession
A total of four insect orders were found
gave way to the skeletal stage early
colonizing the rat carrion at the different
colonizers became dominant again.
stages of the decomposition process.
Decomposition of carrion was very rapid
Diptera was the most abundant order
as insect succession was also quickly
followed by Ephemeroptera. Trichoptera
encouraged.
and
Hemiptera
only
occurred
sporadically at the last stage of the
decomposition process (Table 2). The
fresh stage of decomposition of the
carrion
showed
that
only
the
representatives of the order Diptera and
Chironomus species in particular were
found colonizing the carrion. On day 2,
one individual of mayfly, Pseudocloeon
sp. was collected from the rat carrion
placed in the riffles. The Chironomidae,
Orthocladius sp. appeared on day 2 and
continued to day 4. It appeared to be
replaced by Tanypus sp. which
disappeared on day 6.
Interestingly, day 5 could be described as
the day different mayfly species
appeared. Pseudocloeon, Cloeon and
Caenis species were found colonizing
the carrion in the riffles. Only one
individual of Caenis species was
however recovered from the carrion in
the pool.
Day 7 witnessed the
appearance of the Trichoptera, Agapetus
sp. and the Hemiptera, Plea sp. although
few individuals were recovered. In all, a
total of 118 species of Diptera consisting
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Table 1. Temperature, flow velocity, dissolved oxygen, pH and Biochemical oxygen
demand (mean ± SD, range) of riffle and pool environments measured during the
sampling period.
Parameters
Riffles
Pools
t-test
p value
25.1 ± 1.49
(21.0 – 30.0)
25.4 ± 0.99
(21.0 – 28.0)
0.53 ± 0.23
(0.32 – 0.81)
6.69 ± 0.34
(5.6 – 8.4)
25.0 ± 1.50
(21.0 – 31.0)
25.2 ± 0.95
(23.0 – 29.3)
0.14 ± 0.07
(0.10 – 0.28)
4.70 ± 0.81
(3.9 – 5.8)
0.85
0.82
0.17
0.86
3.22*
0.009
3.08*
0.014
6.3
(5.8 – 6.9)
Biochemical
oxygen 2.16 ± 0.14
demand (BOD5) mg/l
(1.7 – 2.8)
6.1
(5.8 – 6.3)
2.71 ± 0.13
(2.3 – 3.2)
1.39
0.21
0.42
0.69
Nitrates (mg/l)
2.08 ± 0.01
(1.60 – 2.12)
2.27
0.06
0
Air temperature ( C)
Water temperature (0C)
Flow velocity (m/s)
Dissolved Oxygen (mg/l)
pH
1.07 ± 0.01
(0.08 – 1.40)
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Table 2. Abundance (average number) of invertebrates colonizing rat carcasses in
riffle and pool habitat of Ethiope River.
Day
Order
Genus
Riffle
Pool
Diptera
Chironomus transvaalensis
Chironomus fractilobus
Chironomus transvaalensis
Orthocladius
Pseudocloeon sp.
Chironomus transvaalensis
3
1
2
1
3
1
4
3
6
Total no.
of
species
collected
4
4
4
2
1
9
Orthocladius
Chironomus fractilobus
Chironomus transvaalensis
Orthocladius sp.
Tanypus sp.
Tanypus sp.
Orthocladius
Chironomus transvaalensis
Pseudocloeon sp.
Cloeon sp.
Caenis sp.
Chironomus transvaalensis
Cricotopus sp.
Polypedilum sp.
Orthocladius sp.
Cloeon sp.
Caenis sp.
Chironomus transvaalensis
Cricotopus sp.
Polypedilum sp.
Orthocladius sp.
Crytochironomus sp.
Agapetus sp.
Pseudocloeon sp.
Caenis sp.
Plea sp.
3
2
4
2
1
4
3
1
2
2
3
1
2
2
1
3
3
1
2
2
1
2
2
8
1
4
6
1
3
1
0
2
10
3
2
2
1
0
1
3
2
10
5
2
1
4
10
3
1
3
5
4
1
4
2
1
13
3
4
2
2
2
3
1
3
Total
57
61
118
Stages
of
decomposition
2
Fresh stage
1
Ephemeroptera
Diptera
Bloat
stage
3.
Diptera
Diptera
Wet
stage
4.
5.
Diptera
Ephemeroptera
Diptera
Dry stage
6
Diptera
Skeletal stage
7.
Ephemeroptera
Trichoptera
Ephemeroptera
Hemiptera
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Figure 2 shows the relationship between the midge larvae colonizing the adult rat
carcasses in Ethiope River riffle and pool over time. Chironomidae from six (6) genera
represented >85% of the insects collected. Nonlinear regression illustrates that the
number of midge genera per carcass increased over time (Fig. 2, R2 = 0.60 and 0.57
for riffle and pool carcasses, respectively. Pool and riffle habitats produce slightly
different insect assemblages, colonization patterns and functional-feeding-group
composition. The midge, Chironomus transvaalensis was dominant in the pool
carcasses. Crytochironomus sp. was only recovered from the pool carcasses whereas
Tanypus sp. was only recovered from the riffle carcasses.
No. of chironomid larvae per carcass
18
16
14
12
10
Riffle
8
Pool
Poly. (Riffle)
6
Poly. (Pool)
4
2
0
1
2
3
4
5
6
7
Day
Figure 2. Number of midge larvae taken from rat carcasses submerged in Ethiope
River riffle and pool, with regression lines (solid, heavy) added (2nd-order polynomial
regression line for riffle and pool, respectively: (Y = 0.0525 X2 – 1.044X + 2.714, R2
= 0.60; y = 0.07 X2 – 1.179X + 2, R2 = 0.57).
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carcasses
by
different
4.0 Discussion
This study made use of insect larvae as
macroinvertebrates) and potentially the
evidence to determine the Postmortem
insect fauna attending the carcasses.
Interval of rat carcasses. Insect
assemblages
significantly
differed
4.1 Species Richness
overtime with progression of carcass
In this study, chironomid larvae were the
decomposition in the short period of time
dominant group accounting for over 85%
the experiment lasted (7days). A total of
of the insect larvae colonizing the rat
eleven (11) taxa of invertebrates were
carcasses. This was followed by
documented.
In a similar study
Ephemeroptera with three representative
elsewhere, Vance et al. (1995) reported a
taxa. Trichoptera and Hemiptera were
total of 21 taxa of aquatic insects in baby
represented with only one taxon each. In
pigs in hanging basket samplers within
agreement with this finding, Keiper et al.
the littoral zone of a 12-ha Iowa lake
(1997) reported a total of 21 genera of
between 12 June and 8 July, the most
Chironomidae representing >95% of the
species richness being Ephemeroptera
macroinvertebrates collected during their
and Coleoptera. Similarly, Larval
study to document the colonization by
Chironomidae were the most numerous
macroinvertebrates of adult rat carcasses
macroinvertebrate by the 4th day of
in a woodland stream riffle and pool
submersion. Merritt and Wallace (2000)
during the spring over time. Vance et al.
reported
a
rich
variety
of
(1995) also reported the presence of
macroinvertebrates
colonizing
pig
Ephemeroptera
in
pig
carcases.
carcasses placed in riffle and pool
Coleopterans were not found in this
habitats of an Indiana stream, USA. The
study as compared with the previous
low number of invertebrates recorded in
studies. Again the total time for
this study may be due to the relative high
decomposition was very rapid not
temperature predominant in the study
allowing for diverse invertebrates
site (Afrotropical area) encouraging very
colonization. The high dominance of
rapid decomposition of the rat carcasses
chironomid in this study supports the
that lasted for 7 days only as compared
claims of Keiper and Casamatta (2001)
with other studies carried out in the
who had earlier reported that midge
temperate zone where decomposition of
larvae are probably the most important
carcasses lasted for over a month.
benthic invertebrates to forensic studies
According
to
Anderson
(2009)
because they are numerous and thus
temperature can obviously impact both
likely to colonize a body in appreciable
decomposition and faunal colonization of
numbers after a short period of
mammalian carcasses. Furthermore,
submersion.
differences in carcasses size are known
Levels of dissolved oxygen were
to affect the rate of decomposition (i.e.
between 3.8 and 8.4 mg/L in both the
as bigger carcasses tend to decompose in
riffle and pool habitats. The high
longer time than smaller carcasses thus
dissolved oxygen levels in the riffles
encouraging successive colonization of
must have prompted the colonizing of
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Ephemeroptera which are oxygen loving
geographically
applicable
insect
organisms. Anderson (2009) reported
succession data and information on
that the anoxic conditions of bottom of
colonization
and
postmortem
deep water bodies only permit the
investigation. Knowledge of the effects
colonization of few species as compared
of body submergence is important as
to the shallower portions with much
many homicide victims are disposed of
higher oxygen and higher species
in the streams and rivers in an effort to
diversity.
get rid of the body and a number of
people are lost in the freshwater
environment to drowning and boating. In
4.2 Microhabitat
Pool and riffle habitats produce slightly
all these cases, it is important to the
different
insect
assemblages,
investigators and to family members to
colonization patterns and functional
understand what has happened to the
feeding group composition. The midge,
decedent from the time they were last
Chironomus
transvaalensis
was
seen alive, to the time of discovery. In
dominant in the pool carcasses.
this
study,
Chironomus
spp.,
Crytochironomus sp. was only recovered
Orthocladius sp., Polypedilum sp. and
from the pool carcasses whereas Tanypus
Crytochironomus species are the likely
sp. was only recovered from the riffle
invertebrates’ one could find colonizing
carcasses. The findings of this research
dead corpse in fresh water bodies. These
collaborate well with the account of
species are also dominant species in
Merritt and Wallace (2000) who reported
freshwater systems in the Niger Delta
that carcasses in the riffle habitat
and increase in abundance in organically
supported comparatively more scrapers
polluted streams (Arimoro et al 2007;
and predators, whereas those in the pool
Arimoro 2009; Arimoro et al 2011).
habitat had a larger proportion of
Keiper and Casamatta (2001) had opined
collector-gatherers and shredders. This
that, some taxa (e.g., Orthocladius) are
was further affirmed by Keiper and
cosmopolitan, thereby allowing criminal
Casamatta (2001) who stated that the
investigators to use those organisms as
pool and riffle habitats produce different
indicators of postmortem investigation
macroinvertebrate
assemblages,
over a large geographic area. In addition,
colonization patterns, and functional
Forensic investigators may encounter a
feeding group composition.
mixture of terrestrial and aquatic fauna,
depending on the postmortem history of
a victim. The proportion of each
4.3 Application of the study to corpse
functional feeding group at the time of
decomposition
and
postmortem
carcass collection may provide valuable
investigation
In Nigeria, the use of human remains in
data for PMSI estimates. A corpse could
field based research is legally prohibited.
settle on benthic substrate and become
Animal model, such as Rat (Rattus
colonized by the invertebrates there. If
rattus) used in this investigation are
the corpse then becomes bloated and
available options for the establishment of
rises to the surface, or is partially washed
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up on shore, the exposed portions of the
tissue was left. Nevertheless, the fauna
body may then be used by terrestrial
on the remains, the decomposition and
dipterans (Payne and King 1972;
the feeding patterns do suggest that a
Tomberlin and Adler 1998). Any
better understanding of decomposition in
submerged areas would still remain
the stream will be valuable in estimating
available to aquatic organisms. The same
elapsed time since submergence,
would be true of a victim that dies or is
identifying the environment in which the
disposed of at the edge of an aquatic
body has decomposed. There are infinite
habitat (e.g., beach or other shoreline).
possibilities for the use of insects in
Investigation of bodies near aquatic
forensic investigation since every insect
habitats should include the search for
tells a story about the condition the body
both aquatic and terrestrial forms
has passed through and the places it has
because the presence of both would add
been. At the genus and species level this
information to the cadaver's post-mortem
study identified significant variation in
history. Even fully submerged bodies
the pattern of insect succession on
may support dead terrestrial maggots
decomposing remains. It is essential that
(Singh and Greenberg 1994; Adler 1998)
personnel recognize the importance of
if the victim was exposed to the
this evidence. Preservation of evidence
terrestrial environment after death.
can only occur when it is recognized as
Merritt and Wallace (2000) described a
evidence.
case study in which a submerged car
containing a murder victim was pulled
Acknowledgements
from a river. The car was colonized by
This research was supported by the
black fly (Simuliidae) immatures.
International Foundation for Science,
Analysis of the species composition and
Stockholm, Sweden, through a research
life stages led to an accurate estimate of
grant to F.O. Arimoro A/4934-1. Thanks
submersion
interval,
allowing
to Salami Mercy and Faith Odiase for the
prosecutors to contradict the murder
sorting of samples and assistance in the
suspect's account of the victim's previous
field and laboratory.
whereabouts. The suspect was ultimately
proven guilty. This case study illustrates
References
how aquatic insect colonization of
Anderson, GS (2009). Insect succession
objects other than bodies can also be
on carrion and its relationship to
important during legal investigations.
determining time since death. In:
Byrd JH Castner JL (eds)
Forensic entomology: the utility
Conclusion
In this study, no classic succession of
of
arthropods
in
legal
insect species was observed, in contrast
investigations, 2nd edn. CRC,
with insect colonization in terrestrial
Boca Raton, FL p 201–250.
environments. Most invertebrate fauna
were opportunistic scavengers and fed on
the remains at all times, until no soft
18
APPLIED SCIENCE RESEARCH JOURNAL. 2013. VOL 1 (1): 7 – 21
http://www.ponpublishers.org
Arimoro, FO (2009). Impact of rubber
macroinvertebrate growth and
effluent discharges on the water
standing stock in south-eastern
quality and macroinvertebrate
Alaska streams. Journal of the
community assemblages in a
North American Benthological
forest stream in the Niger Delta,
Society 21: 430–442.
Nigeria. Chemosphere 77: 440449.
Cranston, PS(2000). Electronic guide to
the Chironomidae of Australia.
Arimoro, FO, Ikomi RB and Iwegbue
http://entomology.UCdavis.edu/C
CMA (2007). Water quality
hiro
page.
Assessed
on
changes in relation to Diptera
12/03/2005, 2000.
community patterns and diversity
measured at an organic effluent
Day, JA, Harrison AD, de Moor, IJ
impacted stream in southern
(2002). Guides to the Freshwater
Nigeria. Ecological Indicators 7:
Invertebrates of Southern Africa,
541-552.
Vol. 9. Diptera TT 201/02,
Pretoria:
Water
Research
Arimoro, FO, Nwadukwe FO and Mordi
Commission 200pp.
KI (2011). The influence of
habitat and environmental water
Epler, JH (2001). Identification manual
quality on the structure and
for the larval chironomidae
composition of adult aquatic
(Diptera) of North and South
insect fauna of Ethiope River,
Carolina. Version 1.0 Crawford
Delta state, Nigeria. Tropical
Wille, 53pp.
Zoology 24(2):159-171.
Fenoglio, S, Bo, T, Agosta, P and
Catts, EP (1992). Problem in estimating
Cucco, M (2005). Mass loss and
the postmortem interval in death
macroinvertebrate colonisation of
investigation.
Journal
of
fish carcasses in riffles and pools
Agricultural Entomology 9(4):
of a NW Italian stream.
245-255.
Hydrobiologia 532: 111–122.
Chaloner, DD, Wipfli, MS and Caouette,
JP (2002). Mass loss and
macroinvertebrate colonisation of
Pacific salmon carcasses in
south-eastern Alaskan streams.
Freshwater Biology 47: 263–273.
Grassberger, M (2004). Initial study of
arthropod succession on pig
carrion in a central European
urban habitat.
Journal
of
Medical
Entomology
41
(3):511–523.
Chaloner, DT and Wipfli MS (2002).
Influence of decomposing Pacific
salmon
carcasses
on
19
APPLIED SCIENCE RESEARCH JOURNAL. 2013. VOL 1 (1): 7 – 21
http://www.ponpublishers.org
Haskell, NH, Mcshaffrey, DG, Hawley,
Merritt, RW and Wallace, JR (2000).
DA, Williams, RE, Pless, JE
The role of aquatic insects in
(1989). Use of aquatic insects in
forensic investigations. Pp 173determining submersion interval.
218 in J. H. Byrd and J. L.
Journal of Forensic Sciences 34:
Castner
(editors).
Forensic
622-632.
entomology: the utility of
arthropods in legal investigations.
Hawley, DA, Haskell, NH, Mcshaffrey,
CRC Press, Boca Raton, Florida.
DG, Williams, RE and Pless JE
(1989). Identification of a red
Payne, JA and King, EW (1972). Insect
"fiber":
chironomid
larvae.
succession and decomposition of
Journal of Forensic Sciences 34:
pig carcasses in water. Journal of
617- 621.
the
Georgia
Entomological
Society 7: 153- 162.
Keiper, JB, Casamatta, DA (2001).
Benthic Organisms as Forensic
Schuldt, JA and Hershey, AE (1995).
Indicators. Journal of the North
Effect
of
salmon
carcass
American Benthological Society
decomposition on Lake Superior
20(2): 311-324.
tributary streams. Journal of the
North American Benthological
Keiper, JB, Chapman, EG and Foote, BA
Society 14:259-268.
(1997). Midge larvae (Diptera:
Chironomidae) as indicators of
Singh, D and Greenberg, B (1994).
postmortem submersion interval
Survival after submersion in the
of carcasses in a woodland
pupae of five species of blow
stream: a preliminary report.
flies (Diptera: Calliphoridae).
Journal of Forensic Sciences 42:
Journal of Medical Entomology
1074-1079.
31:757-759.
Lopes de Carvalho, L and Linhares, A
(2001) Seasonality of insect
succession and pig carcass
decomposition in a natural forest
area in southeastern Brazil.
Journal of Forensic Sciences 46
(3):604–608.
Smith, KGV (1986). A manual of
forensic entomology. Cornell
University Press, Ithaca, New
York.
'TexaSoft, WINKS SDA Software, 6th
Edition, Cedar Hill, Texas,
2007.'
Merritt, RW and Cummins, KW (1996).
An introduction to the aquatic
insects of North America. 3rd
edition. Kendall/Hunt, Dubuque,
Iowa.
20
APPLIED SCIENCE RESEARCH JOURNAL. 2013. VOL 1 (1): 7 – 21
http://www.ponpublishers.org
Tomberlin, JK and Adler PH (1998).
Seasonal
colonization
and
decomposition of rat carrion in
water and on land in an open
field in South Carolina. Journal
of Medical Entomology 35: 704709.
Vance, GM, Vandyk, JK, Rowley, WA
(1995). A device for sampling
aquatic insects associated with
carrion in water. Journal of
Forensic Sciences 40: 479-482.
Voss, SC, Spafford, H and Dadour IR
(2009). Annual and seasonal
patterns of insect succession on
decomposing remains at two
locations in Western Australia.
Forensic Science International
193: 26–36.
21