[2] Adult flies reflect a metallic blue-green color on their thorax and abdomen and have yellow gena, or cheeks.

[citation needed] Chrysomya megacephala prefer warm climates, and display a correlation between warmer temperatures and higher fecundity.

The majority of Dipteran species that have had a life table constructed have demonstrated a tendency for smaller bodies in the warmer months.

C. megacephala has a relatively[clarification needed] long lifespan as an adult which has helped the species become successful at invading new geographical areas.

These intervals vary depending on geographical location; other environmental factors also can determine how long flies will stay in the larval stage.

[20] The reproduction and survival rates of C. megacephala are closely related to developmental factors, including the amount of available food, and competition from larvae of other species, such as C.

C. megacephala is not predaceous in the adult or larval form, preferring to feed on necrophagous material of any kind, such as fish, cows and humans.

Despite this predation on Chrysomya megacephala, both species had a lower survival rate, lighter adult weight and pupated early.

In many forensic entomology cases either C. rufifacies or Chrysomya megacephala are found on the decaying corpse; mitochondrial DNA is the main method used to determine which subfamily is present.

[26] The species' wide geographical distribution and high fecundity also make it useful in forensic cases; C. megacephala is among the most common blowflies found.

Knowing that, to pupate, larvae move away from the food source to find a safe place to metamorphose, forensic entomologists can accurately calculate a post mortem interval.

Nevertheless, a medical examiner in Hawaii worked on a case in which poisoning by malathion, an organophosphate insecticide,[29] was thought to be the cause of death.

Studying larvae from decomposed remains may provide an effective method of determining the presence of these toxins in a body that is extremely decayed.

[30] Chrysomya megacephala has a beneficial and practical value apart from being significant in forensic investigations; this blowfly is the source of pollination for mangos in the Australian region.

While most areas wish to rid themselves of C. megacephala, Taiwanese farmers have found ways to enhance the population of this blowfly so that more mangos will be pollinated.

[21] Chrysomya megacephala are known to be the source of accidental (secondary) myiasis in humans, where the flies do not pierce the skin but invade an open wound.

[32] The first record of human myiasis caused by C. megacephala and C. rufifacies was in Thailand, where a 53-year-old man had a tumor lesion where the larvae accumulated.