Flesh Fly Life Cycle: A Fascinating Journey Through Development

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Flesh flies are intriguing insects, with a life cycle that revolves around consuming decomposing organic matter. These flies belong to the family Sarcophagidae, which derives its name from the Greek words for “flesh-eating.”

The life cycle of flesh flies begins when the female deposits first instar maggots, as opposed to eggs, onto a suitable food source such as a decomposing carcass or excrement. This process, known as larviposition, ensures that the larvae can immediately start feeding and developing.

Flesh Fly Life Cycle

Egg Stage

Flesh flies have a unique method called larviposition in their egg stage. Females engage in larviposition wherein eggs hatch inside the female and are then deposited as first instar maggots on decomposing flesh or excrement1.

Larva Stage

The larval stage lasts for a duration of 5-10 days2. During this time, the maggots infest animal carcasses and start developing. Some features of their larvae include:

  • Gray in color
  • Consuming decomposing flesh
  • Growing rapidly before leaving the carcass

Pupa Stage

Once larvae finish feeding, they leave the carcass and search for a dry place to pupate2. The pupa stage is a transitional phase which allows the maggots to transform into adult flies.

Adult Stage

After completing the pupa stage, flesh flies emerge as adults, ready to repeat the life cycle1. They have a relatively short life span, lasting approximately 23 days from first instar larvae to adult in laboratory conditions1.

Below is a comparison table of each stage in the flesh fly life cycle:

Stage Duration Features
Egg N/A Larviposition, eggs hatch within female
Larva 5-10 days Gray in color, feed on decomposing flesh
Pupa Variable Transitional stage, maggots become adult flies
Adult 23 days Short life span, reproduction

Flesh Fly Identification

Appearance

Flesh flies are a type of fly belonging to the family Sarcophagidae. They have a size range of about 1/4 inch to a 1/2 inch, with large, well-developed wings. Their antennae are relatively short and bristle-like.

Color and Markings

The thorax and abdomen of flesh flies are covered in distinct markings. On the thorax, there are three black longitudinal stripes, while on the abdomen, they have checkered patterns with gray and white or black squares. Some species have golden or yellowish margins surrounding the squares for added contrast.

  • Thorax: Three black longitudinal stripes
  • Abdomen: Checkered pattern with gray and white or black squares, sometimes with golden or yellowish margins

Two well-known species of flesh flies can be compared for their different marking styles:

Species Thorax Stripes Abdomen Pattern Golden/Yellowish Margins
Sarcophaga haemorrhoidalis Black Gray and white squared Yes
Sarcophaga crassipalpis Black Black and white squared No

In conclusion, when identifying flesh flies, it’s important to focus on their appearance and markings. They have unique thorax and abdomen patterns, which can vary between species. By observing these aspects, as well as their antennae and size, you can successfully identify different types of flesh flies.

Flesh Fly Behavior and Habitat

Feeding Habits

Flesh flies (Family Sarcophagidae) are known for their consumption of decaying organic matter, specifically meat and carcasses. They feed on various types of decaying meat, including:

  • Carcasses of dead animals
  • Carrion
  • Garbage containing meat

Adult flies prefer to feed on liquids as they have sponging mouthparts, while their larvae (maggots) consume the decaying meat directly.

Breeding and Infestation

Flesh flies have a unique breeding process, as they lay live maggots rather than eggs on the animal carcass or another suitable habitat. The adult flies are attracted to the scent of decaying organic matter, where they infest and begin the reproduction cycle. The maggots feed on the carcass for 5-10 days before leaving it in search of a dry place to pupate1.

Infestation vs Blow Flies
Both flesh flies and blow flies are attracted to dead animals and decaying matter, but there are some differences:

Flesh Flies Blow Flies
Lay live maggots Lay eggs
Non-metallic color Metallic color on thorax
Feed on carrion Feed on fresh carcasses

Preferred Environments

Flesh flies have a diverse range of habitats, from urban to rural areas. They thrive in environments where decaying organic matter is abundant, such as:

  • Near garbage disposals
  • Livestock farms
  • Animal shelters
  • Near road-killed animals

These flies are adaptable and are not limited to a specific soil type for pupation, although loose soil with good drainage is more favorable2. It is important to maintain cleanliness and proper waste disposal to prevent infestations in both urban and rural settings.

Flesh Fly Prevention and Control

Proactive Measures

To prevent flesh flies, proper sanitation is crucial. Keep garbage areas clean and free of odor. Some tips include:

  • Ensuring dumpsters and trash cans have closed lids.
  • Placing dumpsters at least 50 feet from the building.
  • Regularly removing trash and maintaining a clean environment.

Seal entrances to keep flesh flies outside. Practices include:

  • Using caulk and weather stripping on windows and doors.
  • Installing door sweeps and screens to prevent entry.

Traps and Treatments

For existing infestations, use vacuuming to remove adult flies. Additionally, look for larval breeding sites and remove them. Employing insect light traps can be an effective method.

Two common traps include:

  1. Sticky Traps: Attract flies with odors or ultraviolet light and capture them on adhesive surfaces.
  2. Insect Light Traps: Use UV light to attract flies to an electrified grid, killing them instantly.
Trap Type Pros Cons
Sticky Traps Non-toxic, easy to use Need frequent replacement
Insect Light Traps Efficient, no chemicals Expensive, require electricity

Insecticides are another option for flesh fly control. Different types are available:

Choose a product labeled specifically for flesh flies to ensure effectiveness and safety. Weigh the pros and cons before using insecticides, as they may have negative consequences for beneficial insects and the environment.

Flesh Fly Scientific Classification and Distribution

Family Sarcophagidae and Diptera

Flesh flies belong to the Family Sarcophagidae, which is a part of the order Diptera. Common characteristics include:

  • Six legs
  • Well-developed wings
  • Complete metamorphosis

Their complete metamorphosis consists of four distinct stages:

  1. Egg
  2. Larva
  3. Pupa
  4. Adult

Geographical Range

Flesh flies have a wide geographical range, excluding only the South Pole. Their distribution varies across different species. Key features of their distribution include:

  • Attracted to deceased animals
  • Presence in urban and rural areas
  • Contribution to forensic entomology

Here’s a comparison table showing the differences between Flesh flies (Sarcophagidae) and Blow flies (Calliphoridae):

Feature Flesh Flies (Sarcophagidae) Blow Flies (Calliphoridae)
Taxonomy Family Sarcophagidae Family Calliphoridae
Coloration Mostly dull gray or brown Often metallic blue-green
Larval Feeding Predominantly on dead animals Also on dead and living tissue

In summary, Flesh flies are a distinct group of insects within the Diptera order, known for their unique characteristics and wide geographical distribution. Their role in forensic entomology and preference for deceased animals make them an interesting subject of study in both science and criminology.

Forensic Entomology and Flesh Flies

Flesh Flies in Criminal Investigations

Forensic entomology is a valuable tool in criminal investigations, especially when estimating the minimum postmortem interval (PMI min) and other information related to death circumstances. Flesh flies are one type of insects that are dominant in the early stages of decomposition, and their behavioral patterns can provide critical details during investigations. For example, the larvae are often found on decomposing flesh, which can help forensic experts determine the time of death in certain cases1.

Role in Decomposition Processes

Flesh flies play a crucial part in the decomposition process of vertebrate corpses. They undergo a process called larviposition, where they deposit first instar larvae instead of eggs2. A few main characteristics include:

  • Infesting: Flesh flies infest decomposing flesh in a relatively short period
  • 1st instar larvae: Their larvae go through rapid growth and development during this stage
  • Pupating: Flesh fly larvae eventually pupate, transitioning from maggots into adult flies

Comparison of Flesh Flies and Blow Flies in Decomposition Process

Feature Flesh Flies Blow Flies
Larval deposition Larviposition Egg deposition
Development speed Faster development Slower development
Role in PMI min Crucial in early stages Crucial throughout decomposition

In conclusion, forensic entomology and flesh flies provide essential information for criminal investigations, particularly during the early decomposition process. Understanding their behavior, life cycle, and role in decomposition is critical for investigators to make accurate estimations and conclusions in specific cases.

Flesh Fly Life Cycle Adaptations

Facultative Diapause

Flesh flies, belonging to the family Sarcophagidae, have a unique adaptation known as facultative diapause. This allows them to:

  • Adapt their life cycle to varying environmental conditions
  • Delay their development during harsh conditions or resource scarcity

For example, when temperatures drop or food becomes scarce, flesh fly larvae can enter a facultative diapause, which essentially “pauses” their development until conditions improve. This strategy enables them to survive and reproduce during more favorable conditions.

Longevity and Lifespan

Adult flesh flies have a relatively short lifespan, largely due to their rapid life cycle. Some key features of their life cycle include:

  • Attraction to recently deceased animal carcasses for egg-laying
  • Larval stage lasting around 5-10 days on a carcass
  • Pupation stage occurring in a dry place away from the carcass

The entire flesh fly life cycle, from egg to adult, typically takes around 15-20 days, which means these insects have a quick turnover rate. As a result, their lifespan is often shorter compared to other insects like the house fly.

Comparing Flesh Fly and House Fly Lifespan

Feature Flesh Fly House Fly
Average Lifespan 2-3 weeks 4 weeks
Rate of reproduction Fast Moderate

In conclusion, flesh fly life cycle adaptations such as facultative diapause and their shorter lifespan allow them to thrive in varying environments and adapt to rapidly changing conditions.

Interesting Flesh Fly Characteristics

Diet and Feeding Preferences

Flesh flies, belonging to the family Sarcophagidae, are known for their unique diet preferences. These flies often feed on:

  • Decaying organic matter
  • Animal carrion
  • Feces

Larvae of the flesh fly, for example, infest animal carcasses for 5-10 days before they leave it to pupate.

Unique Behaviors and Habits

Flesh flies exhibit fascinating behaviors and habits, such as:

  • Being attracted to recently deceased animals
  • Invading carcasses in early to advanced stages of decomposition
  • Some species being able to give birth to live maggots

Flesh flies are found in various locations but are more common in temperate climates. They are also valuable to forensic entomologists because they help in determining the time of death.

Comparison table:

Flesh Fly Attribute Example / Instance
Diet Animal carrion, feces
Feeding preferences Decaying organic matter
Habitat More common in temperate climates
Importance in forensics Time of death estimation

Footnotes

  1. red-tailed flesh fly – Sarcophaga haemorrhoidalis (Fallen) 2 3 4 5
  2. Blow and Flesh Flies | Horticulture and Home Pest News 2 3 4

Reader Emails

Over the years, our website, whatsthatbug.com has received hundreds of letters and some interesting images asking us about these insects. Scroll down to have a look at some of them.

Letter 1 – Mating Flesh Flies are not Necrophiliacs!!!

 

Subject: Fly mating with dead fly?
Location: Northeast Florida
June 29, 2014 3:56 pm
I saw this fly (or these flies) today in northeast FL. I thought at first that it was a pair of mating flies and took a few photos. However, it appears that this is a live fly that had been mating with a fly that died, and it was now dragging the dead fly along with it as it walked and flew around. I’ve never seen anything like this before.
Signature: Karen in FL

Flesh Fly matings ends with death of the male!!!
Flesh Fly with dead mate

Dear Karen,
We are positively stunned by your images, which appear to have captured the mating of Flesh Flies in the family Sarcophagidae that ended with the death of one of the partners, from unknown causes.  We can assure you that Flesh Flies do not practice necrophilia, and that for some reason, the individual succumbed while in flagrante delicto, and for yet more unexplained reasons, the sexual bond was not broken after the death.  The red-tipped abdomen is a rather distinctive feature, and upon searching though images on BugGuide, we found at least three genera that have this characteristic:  
SarcophagaOxysarcodexia and Arachnidomyia.  Though they are not necrophiliacs, BugGuide does indicate that:  “Larvae: many species are necrophagous, but some feed in mammalian tissues or parasitize other arthropods (bees, cicadas, termites, grasshoppers/locusts, millipedes), earthworms, or snails(3). Adults feed on various sugar-containing materials such as nectar, sap, fruit juices and honeydew.”  Thanks for providing a very intriguing posting for our site.  Typical Flesh Fly mating should look like this.

Flesh Fly mating ends with death of a partner!!!
Flesh Fly mating ends with death of a partner!!!

Hi Daniel,
I was pretty stunned too when I realized what was going on with that fly! I assumed both flies had been alive when mating began, but I couldn’t imagine what might have killed one partner while leaving the other looking perfectly fine and healthy, except for dragging the dead partner around everywhere it went.
Karen in FL

 

Letter 2 – Mating Flesh Flies we believe

 

More bug love
Location: s. indiana
October 11, 2011 7:33 pm
Found these little guys doing the deed on the hood of my SUV. Are these are regular house flies?
Signature: brian

 

Hi Brian,
These are not House Flies.  We believe they are Flesh Flies in the family Sarcophagidae.  According to BugGuide, they are:  “Similar to blowflies, but generally blackish with gray thoracic stripes (never metallic); 3 black racing stripes on a gray background” and they often have red eyes.

October 13, 2011 5:54 am
You are right these are flesh flies
Signature: brian

Authors

  • Bugman

    Bugman aka Daniel Marlos has been identifying bugs since 1999. whatsthatbug.com is his passion project and it has helped millions of readers identify the bug that has been bugging them for over two decades. You can reach out to him through our Contact Page.

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  • Piyushi Dhir

    Piyushi is a nature lover, blogger and traveler at heart. She lives in beautiful Canada with her family. Piyushi is an animal lover and loves to write about all creatures.

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Tags: Flesh Fly

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