Département de Biologie, Université de Moncton, Moncton, NB E1A 3E9, Canada.
Food and Agriculture Organization of the United Nations, Manila 1554, Philippines.
Forensic Sci Int. 2022 Jun;335:111288. doi: 10.1016/j.forsciint.2022.111288. Epub 2022 Mar 31.
Although rice production landscapes are often the scene of homicides, vertebrate decomposition and associated arthropods have never been described from rice paddies. Tropical rice landscapes are typically composed of irrigated/non-irrigated rice fields, fallow land (i.e., uncultivated fields), and low earthen levees (bunds) used as access pathways. The specific microclimatic and environmental conditions associated with each subunit of rice field landscapes are likely to impact carcass decomposition as well as the arthropod species associated with carrion. Here, we tested the hypothesis that the combined effects of constraints on arthropod colonization and survival, scarcity of necromass, limited habitat architecture, and recurrent disturbance limit the ability of carrion-related arthropods to colonize corpses and large carcasses in tropical rice-fields. Our results from monitoring pig carcasses in Philippine rice fields indicated that vertebrate decomposition in irrigated fields was slower and incomplete when compared to non-irrigated fields and bunds. Carcasses were colonized by a small complex of carrion-related arthropods that differed in composition and relative species abundance between dry bunds and relatively humid rice paddies. Fire ants (Solenopsis germinata) were observed frequently on carcasses exposed on bunds, rarely in non-irrigated fields, and almost never in irrigated fields. The presence of fire ants was associated with reduced blow fly (Chrysomya megacephala) abundance. Taken together, this indicates that the arthropod fauna associated with carcasses in tropical rice fields is relatively simple in contrast to the generally high arthropod diversity reported for other ecosystems at tropical latitudes. The limited richness of the community also means that an understanding of the development of one abundant calliphorid blow fly, C. megacephala, may be sufficient to investigate deaths and homicides under conditions similar to the ones described in this study.
尽管稻田常常是凶杀案的现场，但脊椎动物分解和相关节肢动物从未在稻田中被描述过。热带稻田景观通常由灌溉/非灌溉稻田、休耕地（即未开垦的田地）和用作通道的低土堤（堤岸）组成。与稻田景观的每个亚单位相关的特定小气候和环境条件可能会影响尸体分解以及与腐肉相关的节肢动物物种。在这里，我们检验了以下假设，即节肢动物定殖和生存的约束、腐肉的稀缺性、有限的栖息地结构以及反复发生的干扰的综合作用限制了与腐肉相关的节肢动物在热带稻田中定殖尸体和大型尸体的能力。我们在菲律宾稻田监测猪尸体的结果表明，与非灌溉田地和堤岸相比，灌溉田地中的脊椎动物分解速度较慢且不完全。尸体被一小群与腐肉相关的节肢动物定殖，这些节肢动物在组成和相对物种丰度上在干燥的堤岸和相对潮湿的稻田之间有所不同。火蚁（Solenopsis germinata）经常在暴露在堤岸上的尸体上被观察到，在非灌溉田地中很少见，在灌溉田地中几乎从未见过。火蚁的存在与减少的丽蝇（Chrysomya megacephala）数量有关。总的来说，这表明与热带地区其他生态系统通常报道的较高节肢动物多样性相比，与热带稻田中尸体相关的节肢动物群相对简单。群落的有限丰富度意味着，对一种丰富的丽蝇（Chrysomya megacephala）的发育的理解可能足以在类似于本研究中描述的条件下调查死亡和凶杀案。
