Development and validation of forensically useful growth models for Central European population of Creophilus maxillosus L. (Coleoptera: Staphylinidae)

Abstract

The hairy rove beetle, Creophilus maxillosus (Linnaeus) (Staphylinidae), is recognized for its use in forensic entomology. However, insufficient developmental data exist for the Central European population of this species. Accordingly, we studied the development of C. maxillosus at ten constant temperatures (10-32.5°C). Based on these results, linear and nonlinear developmental models were created and validated. We also studied the effect of different homogenous diets (third-instar larvae or puparia of Calliphora sp. Robineau-Desvoidy or Lucilia sp. Robineau-Desvoidy (Diptera: Calliphoridae) or mix of first-and second-instar larvae of Necrodes littoralis (Linnaeus) (Coleoptera: Silphidae)) on the development and mortality of C. maxillosus. Average total development times ranged between 122.21 days at 15°C and 22.18 days at 30°C. Beetles reached the adult stage in seven out of ten temperatures (15-30°C). No beetles reached the adult stage when fed with larvae of N. littoralis; their development times at first and second larval stage were also significantly longer than in other food conditions. When C. maxillosus larvae were fed with blowfly larvae, the highest mortality was observed at the pupal stage, as compared when they were fed with blowfly puparia-at the first larval stage. While validating thermal summation models, the highest age estimation errors were found for beetles bred at 10 and 12.5°C (between 21 and 43% for all developmental events). Age estimation errors were on average higher for pupation and eclosion than hatching and first and second ecdyses. While validating the models with specimens fed with different diets, the highest errors were recorded for beetles fed with N. littoralis larvae (22% for the first ecdysis and 33% for the second ecdysis) and Lucilia sp. puparia (32% for pupation and 22% for eclosion). Implications for C. maxillosus use in forensic entomology are discussed. Key Points • Development of the Central European population of C. maxillosus was studied at ten constant temperatures and using different homogenous diets. • Thermal summation models were validated with insects reared at different temperatures and fed with different diets. • Total development times ranged between 122 days at 15°C and 22 days at 30°C. Beetles reached the adult stage in seven temperatures (15-30°C). • The highest age estimation errors were found for beetles bred at 10 and 12.5°C (21-43%) and for beetles fed with Necrodes littoralis larvae (22-33%). • The lowest mortality was observed for beetles fed with Calliphora sp. and Lucilia sp. larvae. Estimation errors were generally low for beetles fed with blowfly larvae or Calliphora sp. puparia.

Insect rearing protocols in forensic entomology: Benefits from collective rearing of larvae in a carrion beetle Necrodes littoralis L. (Silphidae)

“…These results revealed a similar temperature pattern as in the previous studies of necrophilous beetles, i.e. a very high mortality at low temperatures [ 9 , 11 , 13 ]. This can be a problem when multiple temperatures need to be studied to create a developmental model.…”

“…In the case of beetles, rearing protocols frequently consisted in monitoring individual insects (both larvae and pupae) that developed in separate containers. For instance, Creophilus maxillosus (Linnaeus, 1758) (Coleoptera: Staphylinidae) larvae were reared separately in 80-ml (1 st instar larvae) and 120-ml (3 rd instar larvae) containers [ 9 ]. In the study of Dermestes undulatus Brahm, 1790 (Coleoptera: Dermestidae) and D .…”

The many elusive pollinators in the genus Amorphophallus

“…For example, Creophilus beetles (Staphylinidae) are reported as exclusive pollinators in A. julaihii. However, Creophilus species are well investigated, as they provide useful forensic information; and Creophilus species are generally predators feeding on copro-necrophagous adult insects and on their larvae (Frątczak-Łagiewska et al 2020). Similar predatory visitors have also been observed in A. titanum (Giordano 1999;Moretto et al 2019).…”

Forensic Entomology in China and Its Challenges

“…In recent years, researchers worldwide have broadened the scope of their research in development biology. Particularly forensically important beetles have been gradually incorporated in their studies [ 70 , 71 , 72 ] as these beetles can be used to extend the estimation range of PMI when primary colonizers are no longer associated with the corpse or have emerged from puparia [ 73 ]. Chinese researchers also carried out temperature-dependent developmental studies on several forensically important beetles (e.g., Creophilus maxillosus (Linnaeus, 1758) [ 73 ], Necrobia rufipes (De Geer, 1755) [ 74 ], Omosita colon (Linnaeus, 1758) [ 75 ], and Dermestes tessellatocollis Motschulsky, 1860 [ 76 ]).…”