A key and checklist to the Neotropical forensically important “ Little House Flies ” ( Diptera : Fanniidae )

Fanniidae (Insecta: Diptera) is a relatively small family (ca. 350 spp.) with five genera, of which Fannia Robineau-Desvoidy, 1830 and Euryomma Stein, 1899 have Neotropical distributions. Some of these species are almost always found in forensic studies. Forensically relevant species have been neglected, despite recent forensic studies that suggest their importance for estimating post-mortem interval (PMI). Thus, current and updated keys to identify adults or larvae on carcasses are unavailable for the most important species. While immature stages are important in estimating PMI, evidence suggests that adults (Fanniidae as well as other families) may also be useful for this purpose. Here we provide a key to males of the species of Fanniidae (found on corpses and other decomposing organic matter) with a checklist of species that have been used in forensics in the Neotropical region. The key comprises all 38 species of Fannia and Euryomma that have already been successfully used in forensics, and species that are potentially useful for estimating PMI. These records were found after reviews of the literature and data from entomological collections. Photographs and illustrations of the main characters in the key are provided.

Immature stages of insects are commonly used in the forensic study of PMI, while adults of some species may also provide useful complementary information.In most necropha-

TAXONOMY AND NOMENCLATURE
A key and checklist to the Neotropical forensically important "Little House Flies" (Diptera: Fanniidae)  Paraná. Caixa Postal 19020, 81531-980 Curitiba, PR, Brazil.gous species, adults tend to arrive at carcasses after a predictable PMI (matuszeWski et al. 2010, miChauD & moreau 2009), hence their potential usefulness.These adults also avoid the confusion that may arise due to predation of some fly larvae on others, which may obfuscate the exact time that the first eggs were laid (anDraDe et al. 2002(anDraDe et al. , shiao & yeh 2008)).In South America, during most of the forensic work involving Fanniidae, adults are collected with little attention given to the larvae.Perhaps this is not surprising, as among the newly described species of Fanniidae associated with decomposing flesh, only the third instar larvae of Fannia yunguensis has been described (Quiroga & Domínguez 2010).
We begin to fill this gap in the forensic use of adult necrophagous Fanniidae in South America with this key as a tool that will permit identification using the sometimes difficult diagnostic characters of adult males.The male terminalia are very important because they allow the identification of species when the external structures are morphologically conserved and thus uninformative, especially among Euryomma and some Fannia.In addition to the key to identify adult males we provide a checklist of species with updated distributions.
We include in this study all species reported as associated to decomposing bodies (human or pig), and traps baited with organic decomposing matter (fish, chicken viscera, beef and pork) from available literature as well as from collected material.Forensic references and geographical distributions of the species on the checklist were also obtained from available literature and revision of collections.
A Leica DFC 500 camera was mounted on a Leica MZ16 stereomicroscope from the Rede Paranaense de Coleções Biológicas (Taxonline) to take the photographs, which were assembled using the program Auto-Montage Pro (Syncroscopy).Some of the illustrations presented here appeared previously in grisales et al. (2012a, 2012b).

RESULTS AND DISCUSSION
Six species of Fanniidae were identified by Carvalho & mello-Patiu (2008) as the most common forensic species in South America: F. obscurinervis, F. trimaculata, F. pusio, F. femoralis, F. punctipennis, and F. canicularis.Based on our review of the literature and insect collections, we list a total of 38 species of Fanniidae of actual or potential forensic importance (that may be associated with carcasses or with decomposing organic matter) in South America, of which 29 are in Fannia and nine in Euryomma (see Checklist).
The Fanniidae included here were collected as adults because it is rare to find larval stages in collections, although a few were found.Immature stages were described or illustrated for only eight species (Table 1).Biological cycles and immature stages are unknown for the remaining South American species.Thus, further study of larvae is encouraged.

Table 1 .
Information on immature stages of Fanniidae of forensic importance in South America.