Biodiversity and decomposition - Qatar University

Qatar Biodiversity Newsletter [No. 12, April 2009] [A scientific newsletter issued periodically concerning the different aspects of Qatari biodiversity and sponsored by the department of Biological and Environmental Sciences, Qatar University]

Editor: Dr. Mahmoud M. Kardousha

Editorial board: Dr. Roda F. Al Thani, Dr. Nobuyuki Yamagushi Department Of Biological and Environmental Sciences Qatar University

Qatar Biodiversity Newsletter ‫اع اي – ﻥ! ة دوری‬

No. 12, April 2009

Welcom e… th

…In this 12 issue of the newsletter Professor Philip Watson write on how insects can play a very interesting role in revealing mysteries in Forensic medicine. Dr. Watson is a Professor of Biology at Ferris State University, coordinator of the forensic biology program and international coordinator of the An Giang university Vietnam/Ferris university exchange.

Biodiversity and Decomposition By Phillip L Watson PhD Professor/Fulbright Fellow at Qatar University Department of Biology and Environmental Sciences Professor Phillip L Watson

Introduction Now, Professor Watson, is a Fulbright fellow at Qatar University, Dept of Biology and Environmental Sciences and contributing in teaching and research activities.

For most people, the finding of a dead animal is something to avoid because of the unpleasant sight and smell. But for unique group of organisms (saprosarcophagous or necrophilous), a dead animal is an ephermeral patch resource (EPR) which they will attempt to exploit. These decomposers and those that feed on those decomposers will colonize the resource quickly, take want they need and depart the resource in a predictable pattern. This predictable pattern of colonization is used in time of death estimation which is useful in forensic cases. (Catts & Haskell 1990) In a resource rich environment, the time it takes for this succession to occurs depends upon the climate and can take be completed in a week or two, in a resource poor environment both colonization and succession is believed to occur in a much shorter time frame. Kelly in 2006, described succession patterns and the diversity of necrophilous insects in the Great Karoo in South Africa. These successional stages were temporally much quicker and the overall diversity lower than have been found in similar temperate zone studies (Watson 03, 09). But the literature and data remains limited on EPR in resource poor

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Newsletter, No. 12, April 2009 Page 2 of 9

environments such as deserts. My few trial experiments in Qatar have Back issues: not yet been fully analyzed but they indicate similar patterns to Kelly Vol. 1, No.1 (October 2007). (Serial in 2006. But the timing or arrival and departure of each stage of No. 1). “A glance at biodiversity of Qatar” by Mahmoud M Kardousha. succession in decomposition and the aggressiveness of that colonization seems to be accelerated in the desert from these pilot Vol. 1, No. 2 (November 2007). studies. A temporal increase in species diversity could be due to this (Serial No. 2). “Research on Cyanobacteria of Qatar” by Roda accelerated pace of decomposition. Al Thani and Malcolm Potts.

Vol. 1, No. 3 (December 2007). (Serial No. 3). “Fish diversity in Qatari waters” by Mohsen Al Ansi Vol. 2. No. 1 (January 2008). (Serial No. 4). “Molluscs of the state of Qatar” by Jassim A. Al Khayat Vol. 2. No. 2 (February 2008). (Serial No. 5). “Ostrich breeding future in Qatar-a worthy step in conservation” by Atef M. Kamel Vol. 2. No. 3 (March 2008).(Serial No. 6). “Harmful algae species of Qatari waters” by Abdulrahman AlMuftah Vol. 2. No. 4. (April 2008). (Serial No. 7). “Diversity of parasitic plants in Qatar” by Gamal M. Fahmy Vol. 2. No. 5 (May 2008). (Serial No. 8). “Marine biodiversity and impacts of human activities on coastal ecosystems” by Fahed Al Jamali No. 9 (January 2009). “Basic ecology of Ethiopian hedgehog , Paraechinus aethiopicus in Qatar: when do they hibernate and breed? By Nobuyuki Yamaguchi.

Dead Bird at Qatar University Farm, 09-photo by Dr Nobuyuki Yamaguchi How many species do you see?

In general the diversity of necrophilous or saprosarcophagous insects No. 10 (February 2009). “DNA and their predators and parasites follow a predictable succession baracode promotes plant biodiversity pattern. In general the pattern of succession on a dead animal is research” by Talaat A. Ahmed. 1) discovery and colonization by blow flies No. 10 (March 2009). “Wastewater 2) discovery and colonization by flesh flies wetlands can creating an attractive 3) discovery and exploitation by carrion beetles habitats for wildlife” by Mahmoud M. Kardousha 4) discovery by predator beetles 5) exiting of blow flies 6) exiting of flesh flies

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7) exiting of carrion and predatory beetles 8) discovery by dried organic matter feeders such as moths, dermestid beetles and skin beetles 9) Exit of all necrophilous insects.(Catts & Haskell 90) Of course these successional events overlap each other on the EPR. This accounts for the species diversity on the EPR at any one particular time. This successional event is also complicated by vertebrate scavengers (Watson 09) Flies are the earliest colonizers and have four stages in their life cycle as is seen in the house fly life cycle below.

Death is usually first followed by discovery of the EPR by blow flies of the family Calliphoridae. These are the irredescent green, blue and black flies and are the earliest necrophilous insects. In my temperate zone studies, this family arrives at the EPR within 10 minutes of the death of the animal. The olfactory cue is not known, but the blowflies will congregate on the site in an oviposition (egg laying) frenzy. Several blowfly species will attempt to oviposit on the EPR but generally one species will out compete the others and dominate the EPR. The blowflies eggs will hatch within a few hours depending upon

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the ambient temperature and the larvae (maggots) will feed. In the temperate zone, the blowfly will typically feed for a few days, depending upon temperature and depart to pupate in the soil and metamorphoses into adult flies. This growth of the larvae and the resulting metamorphosis is temperature dependent. In general, the higher the temperature, the more rapid the egg to adult development occurs. Two of many blowfly species that compete for the EPR in Qatar are shown below.

Calliphora macellaria (Left ) and Lucilia illustris (right) Overlapping the blow flies successional pattern is the arrival and colonization of the EPR by the flesh flies of the family Sarchophagidae. These large grey flies arrive later but make up for their tardiness by laying larvae rather than eggs (larvaipositing). These flies will consume the EPR and also the blow fly larvae in an attempt to dominate the EPR.

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Unlike the blowflies, the flesh flies can not be used to predict time of death as accurately. Their presence does indicate the stage of decomposition succession of the EPR which can be used to predict time of death in a forensic case. Flesh flies resemble house flies except many of the species have checkered abdomens.

Editorial board: Dr. Mahmoud M. Kardousha (Biodiversity and Parasitology) Dr. Roda F. Al Thani (Microbiology and Mycology) Dr. Nobuyuki Yamaguchi (Wildlife conservation and environmental sciences).

The next to arrive are the carrion beetle family Silphidae. These beetles may begin to consume the resource, lay eggs on the resource and have their larvae consume the resource or eat the fly larvae. I have not seen these beetles in Qatar yet nor have I found them in the literature or in the reference insect collections at the biology museum at QU. These beetles are usually recognized by their colorful markings and antenna. Their nocturnal habits may have prevented their observation by me in Qatar.

All rights reserved For correspondence: Dr. Mahmoud M. Kardousha Lecturer of Parasitology and Biodiversity Department of Biological & Environmental Sciences Qatar University POB. 2713, Doha, Qatar [email protected] Newsletter website:

The next family of beetles to come to the EPR and have been collected in Qatar are the rove beetles or Staphylinidae

www.qu.edu.qa/qu/colleges/arts_sciences/ cas_bio_newsletter.html

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These species are predators and will attack the fly larvae at the EPR. Many of the fly larvae are consumed by them and never leave the EPR to pupate and metamorphose into adults. Finally are a group of beetles and moths from various families that attack the drying remains of the EPR. These specimens have also not been collected by me or found in the QU Biology Museum collection. I know they must exist ecologically but they also have cryptic behaviors that may have allowed them not to be captured. I have collected several death watch beetles however that may fit this ecological niche. Species diversity and decomposition research has not been in Qatar. Forensic use of data from future research in Qatar could be valuable if a time of death determination would ever be needed. The QU biology museum is a good resource for specimen records that can be used to determine endemic EPR species.

Now, look again at fig 1, do you see the five species?

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Selected References: -Byrd JH, Castner JL. 2001. Forensic entomology: Insects in legal investigations. Boca Raton, FL: CRC Press. -Catts EP, Haskell NH, eds. Inc. 1990. Entomology and death: A procedural guide. Clemson, SC: Joyce’s Print Shop. -Kelly JA. 2006. The influence of clothing, wrapping and physical trauma on carcass decomposition and arthropod succession in central South Africa. PhD Thesis, University of the Free State -Smith KGV. 1986. A manual of forensic entomology. Ithaca, NY: Cornell University Press. -Watson, Carlton CE. 2003. Spring succession of necrophilous insects on wildlife carcasses in Louisiana. J Medical Entomology 40(3): 338-47 -Watson. P.L et al. 2009 (in prep) Effects of clothing on decomposition. -Watson PL et al 2009 (in prep) Effects of scavengers on decomposition succession. Appendix: Computing Post Mortem Interval (PMI) or time of death Species diversity is not needed to use the colonization rate to predict time of death. What is needed in general is: 1. Identification of the insect to species level. This is usually done on the adult because the larvae are very difficult to identify to species. 2. Interpretation of local weather data and computation of degree days or heat units per day. 3. Entomological analysis—computation of identified fly species to available degree day computation 4. Computation of the time of death 2 Methods 1 Accumlated Degree Days (ADD) CDD or ADH ( Hour) • Accumulation of heat units above some threshold temperature for a day or an hour • A thermal constant must be known for the insect or minimum threshold ( i.e. 12 degrees C)

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2. •

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Degree Day (DD) = Average temperature - Thermal Constant ( TC) of insect Estimate average temperature ( most widely used method) = _Max temp + Min Temp DD = 2 - TC Example blowfly TC = 7 degrees C Max temp on one day = 20 ; Min = 8 14 - 7 = 7 degree days If max temperature = 36 and min = 30 then =66 /2 = 33 - 6 = 27 degree days So the warmer the faster, the cooler the slower and if no ADD or CDD then development stop In practice,larvae are collected at the scene. Larvae are observed until they reach the adult stage. Laboratory temperature are used with outdoor temperature records to determine time of oviposition or time of death Successional based PMI Baseline data is collected--- experiments are done to determine the kinds of organisms that are present at any one time. Members of EPR fauna are collected and identified to species EPR taxa are matched to baseline taxa The lower and upper PMI limits corresponds to the 1st and last day of co-occurrence Succession data should be incorporated into a database so when a forensic entomologist needs to access the data, it is available to be used to get an estimate of the time of death. Succession and species diversity data is very site specific. Data generally is not used from one location to make estimates.

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