Morphology successfully separates third instar larvae of Muscina

Area of Science:

• Entomology
• Forensic Science
• Dipterology

Background:

• The muscid genus Muscina (Diptera: Muscidae) comprises species of significant medical, veterinary, and forensic importance.
• Accurate identification of third instar larvae is challenging due to contradictory literature data, often requiring rearing to the adult stage.

Purpose of the Study:

• To provide detailed morphological redescriptions of third instar larvae of Muscina levida, Muscina prolapsa, and Muscina stabulans.
• To revise and discuss the taxonomic value of third instar larval morphology for species identification.
• To identify reliable morphological characters for differentiating these three Muscina species at the larval stage.

Main Methods:

• Detailed morphological examination of third instar larvae using light microscopy.
• High-resolution imaging of larval morphology via scanning electron microscopy.
• Analysis and comparison of morphological features, including spinulation patterns and spiracular distance.

Main Results:

• Emden's spiracular distance factor (SDF) was found to be unreliable for identifying third instar Muscina larvae due to variable ratios and overlap between species.
• Significant differences in the spinulation patterns of abdominal segments were identified as key characters for discriminating between Muscina levida, Muscina prolapsa, and Muscina stabulans.
• Comprehensive redescriptions of the third instar larval morphology for the studied species are provided.

Conclusions:

• Spinulation patterns of abdominal segments offer a reliable method for the identification of third instar larvae of Muscina species.
• Relying on adult identification can be circumvented by utilizing specific larval morphological features.
• This research enhances the accuracy of forensic entomology by providing robust criteria for Muscina larval identification.