Blue-green Bottle Fly

Appearance

Like all green bottle flies in its family, the ''Lucilia coeruleiviridis'' adult is a metallic blue-green bodied fly. The facial region is white with large red compound eyes.

There are also bristles present as well as plumose aristae. The thorax also contains bristles, all of which are evenly paired. Just behind the head, the anterior spiracle is black in color, as is the thoracic posterior spiracle. The meron, just below the wing, is bristled.

The venation of the wings is “incomplete” in that it does not reach the wing edge. The basicosta of the wing, or the “shoulder” area, is yellow in coloration, and the calypters—the scale-like structures just below the wing base—are white and of unequal size.

The legs of the adult are usually brown to black in color. Like most flies, it also has tarsal pulvilli, soft pads at the end of each foot used to “stick” to surfaces; in this species they are slightly yellow in color. As with all insects, coloration is very important in identification of a species, as is the presence of bristles.

Sometimes, the presence of a pair of bristles on the thoracic plate is the only reliable way to distinguish one species from another.

Naming

''L. coeruleiviridis'' was first discovered by French entomologist Pierre-Justin-Marie Macquart in 1855.

Distribution

''Lucilia coeruleiviridis'' has a Nearctic distribution, which means; of, relating to, or being the biogeographic subregion that includes Greenland and North America north of Tropical Mexico and is very ubiquitous in the southern United States.

This particular blowfly is probably even the most preponderate of all species of blowflies in the southeastern United States during the spring and fall and will remain active during mild winters.

Reproduction

The white-bodied larvae of ''L. coeruleiviridis'' develop in three stages, called instars. In each instar, the larva grows larger and larger. Its only function in this stage is eating until the final growth stage to adult fly.

The marked differences between each instar are seen in the spiracles of the maggot on the posterior end. During the first instar, the larva has “Y-V” shaped spiracles.

The second instar can be characterized by the shape of the spiracles increasing in size as well as number in that the “Y-V” orientation becomes 2 distinct slits on each side.

Likewise, the third instar larva has 3 larger spiracular slits on each side. It has also been seen that the larval stages of ''Lucilia coeruleiviridis'' are very similar to those of ''Lucilia eximia'', though no sufficient data has been collected.

Uses

It has been found that the maggots of the green bottle fly prefer necrotic tissue and will leave living tissue alone, so they are often used in maggot therapy, or Maggot Debridement Therapy. This therapy is the intentional introduction of disinfected maggots raised to clean out wounds that will not heal, typically larger wounds.

However, ''Lucilia sericata''— the common green bottle fly— is the preferred species. The maggots have three primary duties: to clean out wounds by eating dead tissues, kill off the bacteria, and encourage healthy tissue growth.

Cultural

There is a fable that says ''Lucilia'' species can predict death and show up before it occurs. This idea may have originated much in the same way the theory of Spontaneous Generation came about around two millennia ago, based on how Calliphorids are typically the first insects to arrive on a carcass. The theory was a supposed process that life would come from sources other than seeds or parents. Understanding this makes understanding how this cultural fable may have come about much easier.