Biological Response of Chrysomya putoria (Wiedemann, 1818) (Diptera: Calliphoridae) Pupae After Submersion in Freshwater

Abstract

Forensic Entomology uses arthropods to aid in legal investigations. This study checked the biological response of Chrysomya putoria pupae to submersion in fresh water for up to 6 d, evaluating the critical submersion time, survival rate, and development time of the flies. Adults were collected using fish baits in two typical traps. Seven hundred and twenty fourth-generation pupae with 2 d of development were used and separated into submergence intervals: 24, 48, 72, 96, 120, and 144 h. An additional 120 pupae were used as a control. Each treatment was done in triplicate, consisting of 40 pupae distributed in four tulle-sealed test tubes containing 10 pupae each. All tubes of each treatment were co-adhered in test tube racks and were submerged in mineral water in a container with constant oxygenation, except those of the control group, which were not submerged. The tubes were removed from the water according to their respective submersion interval, until 144 h was completed. The control group had a survival rate of 90%, while the 24-h treatment had 85% and the 48-h treatment had 35.8%. The critical submersion time for pupae was 72 h, with 100% mortality by 144 h. The average development time for the control group was 3.2 d, while the 24- and 48-h treatments developed in 4.3 and 6.3 d, respectively. The longer the individuals were submerged, the lower the survival rate was, while the development time increased. The data obtained in this study have potential in applications to estimate the interval of submersion of a cadaver.

Keywords: Calliphoridae; aquatic environment; forensic entomology; pupae.