USE OF LARVAL LENGTH AND WEIGHT OF NATIVE BLOWFLIES (DIPTERA: CALLIPHORIDAE) AS TOOLS TO ESTIMATE DEATH TIME IN FORENSIC ENTOMOLOGY

ACOSTA, X; ANDREA XIMENA GONZÁLEZ-REYES; CENTENO, N D; MEJÍA-MONTAÑO E; PALACIOS E; FLORES V; CORRONCA JA

Otro; XXXIX Reunión Científica Anual de la Sociedad de Biología de Cuyo; 2021

Blowflies (Diptera: Calliphoridae) are usually the first to colonize a corpse and flies of the genus Lucilia are among the most important forforensic entomology for estimating the Interval Postmortem (IPM). The objective of this work was to construct forensic methods usinglarval body size (length and weight) of L. ochricornis and L. purpurascens that allows estimating a more precise IPM in forensic expertise.The temperature, humidity and light were recorded in an outside environment in the four seasons of the year in the province of Salta in2018. With the average values of these variables the brood chamber was calibrated: autumn: 13.4 °C, 74.9 %, 1035:1325 h (L:O) and 1916lux; winter: 15.1 °C, 63.4 %, 1052:1308 h (L:O) and 2292 lux; spring: 23.6 °C, 69.9 %, 1315:1045 h (L:O) and 2276 lux; and summer: 22.3°C, 76.0 %, 1225:1135 h (L:O) and 1985 lux. Adult flies of L. ochricornis and L. purpurascens were captured in the town of La Caldera(Salta, Argentina). The larvae obtained were distributed in three replicates of 250 larvae for each species and culture temperature. Oncethe larvae hatched, 10 larvae were sacrificed every 12 h from each replica to which length and weight were measured at each instar (I, IIand III). With these data, MANOVA analyzes were performed and isomegalen diagrams and growth models were constructed. There aredifferences in the length (F=29.747, p=0) and mean body weight (F=30.963, p=0) between species. When analyzing the effect of thedifferent temperatures by larval instar for each species, there were no differences in length (L) and weight (W) to L. ochricornis (FL=2.266,pL=0.053; FW=1.543, pW=0.190), or L. purpurascens (FL=2.291, pL=0.051; FW=1.026, pW=0.448). Studies on larval body size are scarceand less frequent are those that assess body weight. Numerous studies have considered that larval length and weight are the best estimatorsof the time of death while the larvae are feeding. Isomegalen diagrams are the most commonly used developmental models to representbody size data and the PMI estimates through its use is reliable. The logistic growth model is adequate and coinciding with that registeredfor other species of Calliphoridae. The use of information from different sources as length and weight increases the range of possibilitiesto obtain an accurate and reliable PMI in forensic cases.