Larval internal morphology of the introduced blowfly Chrysomya megacephala (Fabricius, 1794) (Diptera: Calliphoridae)

Abstract

The blowfly Chrysomya megacephala (Diptera: Calliphoridae) colonizes different environments and is found in many global regions. Its importance includes its involvement in the decomposition of organic matter, forensic entomology, maggot therapy, bioprospecting, source of biodiesel, industry, stabilization of heavy metals in soil, pollination, and as a vector of diseases and causing secondary myiasis. Internal morphological studies contribute to understanding insect's function and provide basic data for applied areas with interest in this specie. The objective of this study was to describe the internal morphology of C. megacephala larvae. Post-embryonic development occurred over 240 h, equally divided into larval and pupal stages. After hatching, the larvae averaged <1 mm in length and 0.02 mg in weight, growing to 13.83 mm and 50.4 mg in the third instar. We utilized whole, third-instar larvae to perform histology. Sensory organs were observed in the cephalic region, antennae, maxillary palps, and ventral organ. The alimentary canal comprises a foregut, midgut, and hindgut, including tracheal insertions and accessory organs, such as salivary glands. The midgut is the largest organ of the alimentary canal and fat body are present in body cavity and intersegmental space. Thus, our data about the internal morphology of C. megacephala larvae describe the structure and position of the alimentary canal, salivary gland, sensory organs, and fat body.