The Caliphoridae family is one of the largest and most diverse families of flies. Up to 1500 species in 97 genera of this family have been identified so far (1–4), which are distributed in neotropical regions and a large number of them in Africa and southern Europe (5). From Iran, 20 species of three subspecies, Calliphorinae, Chrysomyinae, and Luciliinae have been reported so far (6).
This family have been considered by many researchers in the field of medical sciences, forensic medicine, veterinary medicine, pharmaceutical and biomedicine due to the possibility of easy and fast breeding, ability and growth of this insect on cheap materials, the rapid output of the target product, the non-toxicity of the target product, and the stability of the physiological parameters of the insect during the biotechnology process (7). Also, many studies are still being done on this family (8–10).
Lucilia sericata belongs to the Calliphoridae family (8). This species is mostly distributed in hot and humid regions of the world, although they are also present in areas with dry climates (11). It is a domesticated species and has a high adaptability (12). Lucilia sericata has a complete metamorphosis (Holometaboluse). Life cycle of this species includes egg stages, three larval stages (1, 2, and 3), pupa, and adult. The eggs are placed in clusters of about 2000-3000 on animal carcasses and excrement. About 18 to 24 hours later, they will be opened and entered the larval stage. The larvae are milky, conical in shape with anterior and posterior spirals, and after 4 to 5 days, they turn into pupae. Pupae usually have a hard, brown and black coating, and finally, after 6 to 14 days, they turn into adult flies (13). These flies are capable of mass production in the standard environment and conditions of the insectarium. Adults are mostly metallic green. The antenna is tripoded and aristate, and the RS rifle is branched out twice. Frontal sutures are well visible and calypters have been grown well in them. The average lifespan of an adult is usually 7 days (14). One of the nutritional habits is that it feeds on corpse and dead tissues; therefore, it has a special place in medical sciences, veterinary medicine, and forensic medicine (9, 12, 15, 16). One of the useful and practical uses of the larvae of L. sericata is in the field of Maggot therapy (17). Maggot therapy is a useful, effective and controlled method using sterile larvae of L. sericata to treat a variety of acute and chronic wounds (18). This method was approved by the US FAD in 2004 with the approval of K033391 (19). This method is also used to treat wounds, which are caused by bed sores, traumatic skin injuries, and burns.
It is also effective in chronic diabetic ulcers, osteomyelitis, and ulcers created after cancer surgery (20, 21). Chronic wounds, which are primarily associated with severe and prolonged inflammation, stop the proliferation of cells and cause the extracellular matrix to be regenerated incompletely. Excessive ECM overexpression temporarily and its ineffective removal from the wound surface usually stop the healing of chronic wounds (22). Necrotic tissue is also a good place for the accumulation of various pathogens and the production of biofilms, which in turn cause the infection of dead cells and wounds. (23, 24).
Traditional treatments for chronic wounds include surgery, enzymatic debridement, and rinsing (25). The most important drawbacks of these methods are pain, mechanical damage to healthy tissues, and human error. Maggot therapy can be used as an alternative, classical and controlled method instead of the mentioned methods to treat wounds (26, 27). Important advantages of this method include cleaning the wound surface, disinfecting and accelerating wound healing (28).The mechanical movement of larvae on the wound and the production and secretion of various digestive enzymes by them are two very important factors in accelerating wound healing (29). Maggot excretions / secretions contain a variety of digestive enzymes, including carboxypeptase A, B (carboxypeptidase A, B), collagenase-amino peptidase (aminopeptidases collagenases), aspirin and serine protease (aspart), trypsin- and chymotrypsin-like ones., and metalloproteases, which are active in a wide range of pH. In larval secretions, by breaking down fibronectin and converting it into biological active components, fibroblasts are multiplied and migrated (12, 30). Today, with the advancement of biotechnology, new research is being done on the use of flies products in the pharmaceutical industry, and the production of recombinant proteins from some Lucilia members is being developed and evaluated (31, 32). As briefly mentioned above, due to the importance of this species in various fields and sciences, accurate identification of members of this subfamily requires the necessary accuracy and precision. Blow flies have a wide variety of species and their morphological diagnosis is confusing and difficult (31), and due to the similarity of the species, errors in morphological diagnosis may occur. However, the accurate identification of this species of insect can be done by experts and experienced people (33). Due to the importance of accurate identification of species, the use of molecular methods to accurately identify and confirm morphological methods is recommended (34). In general, for molecular identification, a variety of nucleotide and mitochondrial loci and different gene markers are used to accurately identify species. The CO1 Cytochrome c oxidase has a high degree of nucleotide diversity and it is considered by many specialists to identify species. It was first proposed by Harbor and it is well established that this barcode can be used as a suitable marker for identification. Different species of humans, birds, and insects has been considered by many biotechnologists and molecular entomologists as a marker that has been successful in differentiating two species (31). We also decided to use this method to identify the species of Lucilia sericata in the maggotarium of Shiraz School of Health due to the specificity of this marker.