The anatomical structures of the first, second and third instars of Chrysomya rufifacies (Macquart) were examined by light microscopy. Observations were documented on the three main characteristics; the cephalopharyngeal skeleton, anterior spiracle and posterior spiracle. The first instar larva bore cornuae of fairly pigmented delineation with slim hypostomal sclerite and distinct dental sclerite. First instar did not have obscured anterior spiracle but posterior spiracles were obscured with thin lining of opened peritreme. Intersegmental spines were evident. The second instar larva displayed a prominent anterodorsal process approaching closer to hypostomal sclerite while upper margin of the dorsal cornua was slightly pigmented. Each anterior spiracle consisted of nine to ten papillae, arranged in a single row. Peritreme of the posterior spiracle thick, opening at the end of peritreme was not wide and confined to two spiracular slits. The third instar larva showed a prominent arch of the ventral cornua with broad and bold appearance. It approached the dorsal cornua and became narrow at the incision median. The anterior spiracle consisted of a single row of nine to ten papillae while intersegmental spine could be identified with one to three dark pigmented tips. A dark pigmented and wide periterime was observed confining three short and thick spiracular slits while button was poorly pigmented. The most distinctive feature of this second and third instar larva was the slender, thorn-like tubercle with numerous spined tips on the middle line segment of the body. These findings provide identification features of C. rufifacies larvae instars.

Forensic entomology is defined as knowledge about insect and its relationship with a decomposed human body. With this knowledge, post-mortem interval (PMI) can be estimated. PMI can be determined by taking into consideration the insect species and the developmental stage of the insects. Identification of the insect species requires the insect to develop into adulthood. Since this will take a relatively long time, the objectives of this study were to optimize temperature and humidity for the growth of Chrysomya megacephala larvae to adults. C. megacephala larvae were transferred into a rearing container and put inside a special incubator with temperature adjusted to 27, 30, 33, 36 and 39°C separately. Once optimum temperature for larvae growth was determined, optimum relative humidity was determined then for the length of time taken for C. megacephala larvae to develop into adults. To achieve this, the larvae of C. megacephala were incubated in a special incubator and the relative humidity set at 54.2, 57.6, 76.0 and 67.5% (control) separately. The developmental stages of C. megacephala for both temperatures and humidity levels were recorded accordingly. Results obtained indicated that C. megacephala developmental stages grew much faster in 33oC than other temperatures. The optimum relative humidity level for the species was 76.0%. By utilizing the appropriate temperature and relative humidity the development of C. megacephala, from eggs to adults could be reduced from 8 to 9 days to 5 days.