Post‐embryonic development of Chrysomya putoria (Diptera: Calliphoridae) in swine and bovine tissues in South America: implications for forensic entomology

Abstract

Necrophagous diptera are used in forensic entomology to measure the post-mortem interval (PMI) of cadavers. PMI estimates based on fly larvae, however, can be inaccurate when larval development is retarded, or accelerated, by the nutritional composition of the cadaveric tissue. We compared the post-embryonic development of Chrysomya putoria (Wiedemann, 1830) on different tissues of pigs and cows. Forty newly hatched fly larvae per treatment were placed on 60 g of the following swine tissues: liver (T1), swine lung (T2), swine heart (T3), swine muscle (T4), bovine heart (T5), bovine lung (T6) and bovine muscle (T7). There were four replicates/treatment. Experiments were conducted in controlled conditions (28°C day/26°C night, RH 70% ± 10% and 12 h of photophase). Fly larvae reared on swine liver took longer to develop (5.2 days) than flies reared on other substrates (from 3.5 to 4.5 days), and this difference was statistically significant. The total duration of development on swine liver (T1) was significantly slower (8.7 days) when compared to the other treatments. Larvae reared on swine lungs (T2) were significantly heavier in the third instar (x = 61.2 mg) than larvae reared on swine liver (T1), swine muscle (T4), bovine lung (T6) and bovine muscle (T7). Total larval survival was high (above 76%) in all treatments except for T1 (66%). There was no deviation from the expected adult sex ratio, and the percentage of abnormalities remained within the expected range. These results reinforce the idea that, to achieve greater accuracy in PMI estimates, the type of tissue on which the larvae develops needs to be taken into account.

Diets of animal origin and their influence on the development of the immatures of Chrysomya albiceps (Diptera: Calliphoridae): implications for forensic entomology

“…Animal-based diets are the natural substrate of these necrophagous insects and need to be employed. This finding corroborates studies that observed that the time of larval development and the rate of assimilation of nutrients are factors that together influence larval weight gain (Ribeiro & Milward-de-Azevedo, 1997;Salazar-Souza et al, 2017). The results presented here confirm the suitability of swine and bovine meats as larval substrates.…”

“…This is reflected in the faster development and greater body mass gain of insects reared on the former. This finding corroborates studies that observed that the time of larval development and the rate of assimilation of nutrients are factors that together influence larval weight gain (Ribeiro & Milward‐de‐Azevedo, ; Salazar‐Souza et al ., ).…”

Development time, body mass and length of immatures of Paralucilia fulvinota (Bigot, 1877) (Diptera: Calliphoridae) reared under natural conditions in a Central Amazon forest

“…Pujol-Luz et al (2006) used pork in the rearing of P. fulvinota, while the present study used beef. For example, larvae of Chrysomya putoria (Wiedemann, 1830) (Calliphoridae) needed more time to develop when reared with swine liver compared to bovine liver (Salazar-Souza et al, 2019).…”