Forensic Science International 166 (2007) 182–189 www.elsevier.com/locate/forsciint Succession pattern of carrion-feeding insects in Paramo, Colombia Efrain Martinez, Patricia Duque, Marta Wolff * Grupo interdisciplinario de Estudios Moleculares (GIEM). Universidad de Antioquia. AA, 1226 Medellı´n, Colombia Received 8 April 2004; accepted 10 May 2006 Available online 21 June 2006 Abstract The minimum postmortem interval can be estimated based on knowledge of the pattern of insect succession on a corpse. To use this approach requires that we take into account the rates of insect development associated with particular climatological conditions of the region. This study is the first to look at insect succession on decomposing carcasses in the high altitude plains (Paramo) in Colombia, at 3035 m above sea level. Five stages of decomposition were designated with indicator species identified for each stage: Callı´phora nigribasis at the fresh stage; Compsomyiops verena at the bloated stage; Compsomyiops boliviana during active decay; Stearibia nigriceps and Hydrotaea sp. during advanced decay and Leptocera sp. for dry remains. A succession table is presented for carrion-associated species of the region, which can be used for estimating time since death in similar areas. Compsomyiops boliviana is reported for the first time in Colombia. # 2006 Elsevier Ireland Ltd. All rights reserved. Keywords: Forensic entomology; Paramo; Insect succession; Neotropics 1. Introduction change drastically over short distances. In any study of this type we would expect to find a similar process of insects being Forensic entomology is a frequently used tool to estimate the involved in the recycling of cadavers, but the occurrence of the time interval between death and the discovery of the body. This species involved in this process should vary throughout period is known as the postmortem interval or PMI. For different climactic regions. To date most of the neotropical intervals greater than 72 h, forensic entomology can be more studies have been done in warm tropical conditions, and none accurate in determining PMI than traditional techniques, and has looked at the process at high altitudes. sometimes is the only available method [1]. This study addresses our lack of knowledge in this area as The carrion-feeding invertebrate fauna is principally made part of a larger ongoing effort to identify the carrion-feeding up of insects and the estimation of PMI using the succession of entomofauna and associated insect succession patterns at insects on cadavers and age necrophagous larvae has been used altitudes ranging from 0 to >3000 m above sea level. extensively [2–8]. The first records of applied forensic entomology occurred in China in the 13th Century [9]. 2. Materials and methods Forensic entomology was used for the first time as a legal instrument in a court of law in France in 1850 [10]. Since then The study was carried out in the Paramo region of Chingaza the number of studies carried out in this field has increased National Park, located in the Eastern range of the Colombian significantly, particularly in Europe, United States, Canada and Andes, (738300 to 738550W; 48200 to 48500N) at an altitude of in some parts of the subtropics [1,2,10,11–16]. 3035 m above sea level. Average annual temperatures fluctuate In the Neotropics, relatively few studies have been carried between 4.5 and 21.4 8C and the annual relative humidity is out [17,18,3,4,19,6,20–22]. In countries such as Colombia, above 80% [23]. The landscape of the Paramo is characterized by environmental conditions and regional climatic conditions can the presence ‘‘ fraylejones’’ (Espeletia spp.), ‘‘chuscales’’ (Chusquea tessellate) and ’’pajonales (Calamagrostis spp.) [24]. Three pigs (Sus scrofa L.) were used as models. Each pig * Corresponding author at: Instituto de Biologı´a, Universidad de Antioquia, weighed approximately 10 kg and was killed by cardiac puncture A.A. 1226, Medellı´n, Colombia. Tel.: +57 4 210 5662; fax: +57 4 233 01 20. on September 12, 2002. Immediately after death, the pigs were E-mail address: [email protected] (M. Wolff). placed in individual metal cages (60 cm  40 cm  40 cm) 0379-0738/$ – see front matter # 2006 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.forsciint.2006.05.027 E. Martinez et al. / Forensic Science International 166 (2007) 182–189 183 Table 1 Succession of insects associated with exposed carcasses on Paramo. Ecological Order Family Species Fresh Bloated Active Advanced Remains category ALEALEALEALPALP Necrophagous Diptera Calliphoridae Calliphora xxxxxxxxxxxxxxx nigribasis Compsomyiops xxxxxx boliviana Sarconesiopsis xx magellanica Compsomyiops x xxxxxxx xxxxx verena Sarcophagidae Helicobia sp. x x Microcerella sp x Unident x Predators Diptera Tachinidae Unident x x x x Coleoptera Histeridae Neopachylopus sp. x x x x Carabidae Carabus sp. x x x x Staphylinidae Lathropinus sp. x x x x Dianous sp.xxxxx Anacyptus sp. x Stenus sp. x Melyridae Dasyrhadus sp. x x x x Dytisidae Copelatus sp. x x Predators/ Hymenoptera Sphecidae Unident x x x x parasitois Ichneumonidae Unident x x x Braconidae Unident x Encyrtidae Unident x Chalcididae Unident x Predators Dermaptera Forficulidae Unident x x x x Hemiptera Enicocephalidae Unident x Reduviidae Unident x x x Saprophagous Diptera Piophilidae Stearibia xx xx nigriceps Muscidae Azelia sp. xxxx (probably) Dasymorellia xxxx seguyi Fannia sp. x x Helina sp. x Hydrotaea sp. x x x x x Limnophora sp.xxxxx Syllimnophora xxxx atroviatta Muscina x x xx xx stabulans Sphaeroceridae Leptocera sp.xxxxxx Phoridae Beckerina sp. x x x Dohrniphora sp. x x Metopina sp. x x x Diploneura sp. x Borophaga sp. x Unident x x Sepsidae Orygma sp. x x Drosophilidae Drosophila sp. x x Mycetophilidae Speolepta sp. x Coleoptera Ptillidae Actinopteryx sp.xxxxx Omnivorous Hymenoptera Vespidae Unident x x x Dyctioptera Blattellidae Unident x x Incidental Diptera Anthomyzidae Ischnomyia sp. x x Camillidae Unident x x Ceratopogonidae Unident x Chamaemyiidae Unident x x 184 E. Martinez et al. / Forensic Science International 166 (2007) 182–189 Table 1 (Continued ) Ecological Order Family Species Fresh Bloated Active Advanced Remains category ALEALEALEALPALP Chloropidae Meromyza sp. x x x Dolycopodidae Unident x x Otitidae Cephalia sp. x x Psycodidae Psychoda sp. x x Sciaridae Unident x x x Sciomycidae Unident x Syrphidae Eristalis sp.xxxx Tabanidae Tabanus sp. x x x Coleoptera Cantaridae Cantharis sp. x Chrysomelidae Unident xxxxx Coccinelidae Unident x Curculionidae Unident x Lampyridae Pollaclasis sp. x x Photuris sp. x x Lycidae Unident x Melolontidae Unident x Nitidulidae Conotelus sp. x x Oedemeridae Unident x Hemiptera Cercopidae Unident x Cicadelidae Unident xxxxx Lygaeidae Unident x x Miridae Unident x x x Pentatomidae Unident x Pyrrhocoridae Unident x A: Adult; L: Larvae; E: Eggs; P: Pupe. made with 2 cm  2 cm wire meshing. This allowed access to The taxonomic identification of the adults and larvae was the carcasses by insects while preventing disturbance by carried out using the following keys; Greenberg and Szyska vertebrate scavengers [6]. The three cages were placed 50 m [18,21], Borror et al. [27], Carvalho [28], Dear [29], Liu and from each other. Greenberg [30], Mariluis [31], Mc Alpine et al. [32,33], The cadavers were observed for 8 h immediately following Queiroz and Carvalho [34], Smith [2,35], Stehr [36], Wells sacrifice. Subsequently, the process of decomposition was et al. [37] and White [38]. When necessary, the larvae were observed during daylight hours from September 12 to December cleared with KOH and permanently mounted in Canada balsam. 4 2002. Samples were taken three times a day (7.00, 13.00 and All the specimens were deposited in the Universidad de 19.00) for the first eight days; twice a day (at 11.00 and 17.00) for Antioquia Entomological Collection. the next eight days and subsequently once a day (at 12.00) until the dry remains stage had been reached 83 days after death. At 3. Statistical analysis each sampling time, arthropods flying over or perched on the carcass were collected with an entomological net before the This study was designed to evaluate the succession pattern of carcass was moved. Then, insects in natural cavities (eyes, nose, insects during the decomposition of the three cadavers, and was mouth, anus) and the cardiac puncture wound were collected. not designed for a quantitative analysis. However, insect Finally, three times a day the insects were collected underneath species were assigned a number and the presence or absence of the carcass and in the soil to a depth of 10 cm. Immature each species on each cadaver on each day was recorded and the specimens were fixed in 80% alcohol and the adults were killed data analysed with a Kruskal–Wallis test P > 0.05. with ethyl acetate and mounted with entomological pins. Ambient and body (rectal) temperature were taken at the same 4. Results time as collecting the specimens. Observations were made on the physical changes of the carcass over time (colour, degree of Flies (dipterans) and beetles (coleopterans) constituted swelling, discharge of liquids and gases, etc). The carcass was 99.6% of the individuals collected. There were no significant weighed once a day with a scale [25]. differences between the three cadavers used with respect to the The first eggs mass founded, the colonising species, were presence and absence of species on each day (Kruskal–Wallis identified by collecting eggs from the carcasses. These were test, P > 0.05). The data then were combined to define the placed in plastic containers (three per pig) containing succession pattern. approximately 200 g of raw pig liver. The containers were In total, 36,892 individuals were collected (larvae, nymphs immediately covered with muslin and placed in styrofoam and adults) belonging to 6 orders, 53 families, 42 genera and 98 boxes.