How to Hatch Blue Bottle Fly Pupae | SpoodFood
Blue bottle flies are one of the most useful flying feeders for jumping spiders, mantises, chameleons, and other insectivores that respond strongly to moving prey.
SpoodFood Blue Bottle Fly Pupae are intended for customers who want to skip the spike or maggot stage and move more quickly toward adult flies.
Our pupae may range from newly pupated to approximately a couple of weeks into development, so they will not necessarily hatch at the same time. Some may emerge relatively quickly, while newer pupae may take longer.
That variation is normal and can be useful because it may provide a more gradual supply of adult flies instead of having the entire batch emerge at once.
Guide Credit: This article is adapted from fly-hatching guidance originally shared by Spood Oddities on Facebook, based on their extensive hands-on experience hatching Blue Bottle, Green Bottle, and House Flies. SpoodFood has updated the process to reflect our current Blue Bottle Fly Pupae product, since our customers receive pupae rather than spikes.
You can visit Spood Oddities here:
https://www.facebook.com/profile.php?id=100092238757744
How Long Do Blue Bottle Fly Pupae Take to Hatch?
Blue bottle flies can take approximately 10–20 days from the beginning of the pupal stage to adult emergence.
That does not mean every SpoodFood order will require another 10–20 days after arrival.
Because our pupae may already be partway through the pupal stage when shipped, some may hatch considerably sooner.
The most important thing to remember is:
Developmental age matters more than the number of days since your package arrived.
A newly formed pupa may need considerably more time than a dark, mature pupa that is approaching emergence.
What You Need
A simple hatching setup works well.
You will need:
- A well-ventilated container
- Paper towel
- Water for lightly moistening the paper towel
- A warm location in your home
- An escape-resistant container for the adult flies
- Food for adults, such as a small amount of honey, bee pollen, or an appropriate reptile or insect feeding jelly
Good ventilation is important throughout the process.
Step 1: Examine the Pupae
Blue bottle pupae naturally darken as they develop.
More mature pupae generally become dark brown as they approach adult emergence.
Because your order may contain pupae of different developmental ages, expect some variation in color and hatching time.
Do not assume that lighter or newer pupae have failed simply because darker pupae hatch first.
Step 2: Prepare a Lightly Damp Paper Towel
Place the pupae on a lightly damp paper towel inside a well-ventilated container.
The towel should provide humidity without being soaking wet.
The goal is to prevent the pupae from becoming excessively dry while still maintaining good airflow.
Replace or refresh the lightly damp paper towel regularly as needed.
Step 3: Keep Them Warm
Place the hatching container somewhere warm in your home.
Possible locations include:
- A warm shelf
- On top of a refrigerator
- A consistently warm animal or insect room
- Near, but not directly against, a safe heat source
Warmer conditions generally accelerate development, while cooler temperatures slow it.
Avoid excessive heat or direct sunlight.
Step 4: Maintain Humidity Without Soaking Them
Humidity is important during the final stages of development.
The lightly damp paper towel provides much of the needed moisture.
As the pupae become very dark brown and appear close to emergence, a light mist on one side of the container can provide additional humidity.
Do not saturate the pupae or create standing water.
The goal is a lightly humid, well-ventilated environment.
Step 5: Be Patient
Blue bottle flies do not always hatch according to a precise schedule.
Some pupae may emerge before others, particularly when the batch contains pupae at different developmental ages.
It is normal for emergence to extend over a period of time.
Not every pupa will necessarily complete development successfully, so keep that in mind when determining how many feeders you need.
If you require a consistent supply of flies, maintaining multiple small hatching containers started at different times can be more reliable than depending on a single batch.
What Happens When They Hatch?
Once adult flies begin emerging, transfer or maintain them in a well-ventilated, escape-resistant container.
Adult blue bottle flies are strong fliers, so prepare the enclosure before opening the hatching container.
Once hatched, provide the flies with both food and moisture.
Possible food sources include:
- A small drop of honey
- Bee pollen
- An appropriate reptile or insect jelly
For water, lightly misting one wall of the enclosure allows flies to drink droplets without creating excessive moisture.
Based on the experience shared in the original Spood Oddities guide, adult Blue Bottle Flies may remain useful as feeders for approximately 8–10 days when provided with food and water.
Temporarily Chilling Adult Flies for Feeding
Adult Blue Bottle Flies can be temporarily slowed by refrigeration, making them easier to transfer into feeding enclosures.
The Spood Oddities method uses approximately 8 minutes of refrigeration for adult Blue Bottle Flies.
The goal is to place the flies into a short period of reduced activity, not to freeze them.
Work quickly after removing them from refrigeration because they will become active again as they warm.
Should I Refrigerate the Pupae?
Cool temperatures slow insect development.
However, the original Spood Oddities guide specifically notes that Blue Bottle Fly pupae do not remain viable in refrigeration as reliably as spikes once they have already entered the pupal stage.
Their reported 4–5 week refrigerated shelf life applies to Blue Bottle spikes, not Blue Bottle pupae.
Because SpoodFood sells pupae specifically to provide a faster route to adult flies, we recommend treating them primarily as ready-to-hatch feeders rather than assuming they can be stored as long as spikes.
If you are not ready to hatch them immediately, cooler conditions can slow development, but extended storage may reduce eventual hatch success.
Why Buy Pupae Instead of Spikes?
Blue Bottle Flies are commonly sold as spikes, which are the larval or maggot stage.
Those larvae must first complete development and pupate before adult flies can emerge.
SpoodFood Blue Bottle Fly Pupae have already completed the larval stage.
That means:
- No waiting for spikes to pupate
- No managing the larval stage
- A cleaner and simpler hatching process
- A potentially much faster path to adult flying feeders
- Pupae at different developmental ages may provide staggered emergence
For customers primarily interested in adult Blue Bottle Flies, pupae remove an entire developmental stage from the process.
Common Reasons Hatching Takes Longer Than Expected
The pupae are relatively new
Newly pupated flies naturally require more time before emergence.
The room is cool
Lower temperatures slow development.
The pupae are drying out
A completely dry environment can reduce successful development. Maintain light humidity while preserving good airflow.
You are expecting the whole batch to hatch together
Because pupae can be at different developmental ages, staggered emergence is normal.
Some pupae do not complete development
Live biological products naturally have some variability. Not every individual necessarily reaches adulthood.
A Simple Blue Bottle Fly Hatching Routine
For an easy routine:
- Place pupae in a well-ventilated container on a lightly damp paper towel.
- Keep the container in a consistently warm location.
- Maintain light humidity without soaking the pupae.
- Replace or refresh the damp paper towel as needed.
- Watch for pupae becoming very dark brown.
- Allow adults to emerge naturally.
- Provide newly emerged flies with food and water.
- Use brief refrigeration when needed to temporarily slow adult flies for feeding.
Final Tips
Do not get discouraged if your first batch does not hatch all at once.
Blue Bottle Flies are living feeders, and temperature, humidity, developmental age, and individual variation all influence emergence.
Once you establish a routine, hatching pupae can provide a simple way to maintain a supply of highly active flying feeders.
For jumping spiders in particular, flies provide movement that can stimulate natural stalking and hunting behavior and make feeding much more engaging.
Source & Credit
Special thanks to Spood Oddities for sharing their fly-hatching methods and practical experience with the feeder community.
This article was adapted from their original fly-hatching guide and updated by SpoodFood to reflect customers receiving Blue Bottle Fly pupae rather than spikes.
Visit Spood Oddities on Facebook:
https://www.facebook.com/profile.php?id=100092238757744