Blue Bottle Fly Pupae vs. Spikes | SpoodFood
Blue Bottle Fly Pupae vs. Spikes: Which Is Better for You?
Blue bottle flies are a favorite feeder for jumping spiders, mantises, chameleons, and other insectivores that respond strongly to active flying prey.
But when you buy Blue Bottle Flies, you may see them offered in two different forms:
- Spikes — the larval or maggot stage
- Pupae — the developmental stage immediately before the adult fly emerges
Both can eventually produce adult Blue Bottle Flies, but they are not the same product and they are not equally convenient for every keeper.
If your goal is simply to get adult flies hatching as quickly and easily as possible, pupae may be the better choice.
What Are Blue Bottle Fly Spikes?
“Spikes” are Blue Bottle Fly larvae.
They are still in the feeding and growing stage of development and must complete that stage before they can transform into pupae.
That means the process looks roughly like this:
Spike → Pupa → Adult Fly
When you purchase spikes, you are starting earlier in the fly's development.
This can be useful if you want a product that can potentially be stored longer under appropriate conditions or if you are comfortable managing the larval stage before pupation.
The tradeoff is time.
You must first wait for the spikes to finish developing and pupate before the adult hatching process even begins.
What Are Blue Bottle Fly Pupae?
Pupae have already completed the larval stage.
The fly is developing inside the pupal case and preparing to emerge as an adult.
The process is therefore much shorter:
Pupa → Adult Fly
SpoodFood Blue Bottle Fly Pupae may range from newly pupated to approximately a couple of weeks into development.
Because of that range, some individuals may be much closer to adult emergence than others.
This also means you should expect staggered hatching rather than every fly emerging at exactly the same time.
The Biggest Difference: How Quickly You Get Adult Flies
For many keepers, this is the deciding factor.
If you purchase spikes, they first need to:
- Finish their larval development.
- Enter the pupal stage.
- Complete pupal development.
- Emerge as adult flies.
If you purchase pupae, the first two steps have already happened.
You're starting much closer to the feeder you actually want.
That makes pupae especially attractive to people who:
- Do not want to maintain spikes
- Do not want to deal with the maggot stage
- Want adult flies sooner
- Prefer a cleaner and simpler hatching setup
- Mainly use adult flying prey rather than larvae
Are Pupae Faster to Hatch?
Usually, yes — because you are starting later in the developmental cycle.
Blue Bottle Flies may take roughly 10–20 days from the beginning of the pupal stage to adult emergence, but that does not mean a SpoodFood order will necessarily take another 10–20 days after delivery.
Some of the pupae may already be well into that period.
A darker, more mature pupa may hatch relatively soon, while a newly formed pupa naturally requires more time.
This is why the age of the pupa matters more than the number of days since your package arrived.
Why Would Someone Choose Spikes?
Spikes still have advantages for certain keepers.
Longer potential storage
The original fly-hatching guidance shared by Spood Oddities notes that Blue Bottle spikes can remain useful under refrigeration considerably longer than pupae.
That can make spikes attractive if you want to keep a larger quantity on hand and hatch smaller batches over time.
More control over when pupation begins
Since spikes are at an earlier stage, you have more of the developmental cycle ahead of you.
For experienced keepers who already have an established fly-hatching routine, that may be useful.
Some animals may eat the larvae
Depending on the animal being fed, the larval stage itself may also be usable as a feeder.
If your only goal is adult flying prey, however, this advantage may not matter.
Why Would Someone Choose Pupae?
Pupae are primarily about convenience and speed.
No maggot stage to manage
The larval stage is already over.
Less waiting
You are closer to adult emergence from the moment the order arrives.
Simpler setup
There is no need to wait for spikes to convert into pupae before beginning the hatching process.
Cleaner handling
Many keepers simply prefer working with dry pupal cases instead of larvae.
Staggered emergence
Because SpoodFood pupae may arrive at different developmental ages, adults may emerge over a period of time instead of all at once.
For some keepers, this creates a more useful feeder supply.
Which Stores Better?
This is one area where spikes and pupae are meaningfully different.
Based on the practical experience shared in the original Spood Oddities fly-hatching guide, the longer refrigerated storage period associated with Blue Bottle Flies applies primarily to spikes.
Once Blue Bottle Flies have entered the pupal stage, extended refrigeration can be less reliable.
For that reason, SpoodFood Blue Bottle Fly Pupae are best considered ready-to-hatch feeders, not long-term refrigerated inventory.
If your priority is long storage before beginning the hatching process, spikes may be the better choice.
If your priority is producing adult flies sooner, pupae are generally the more convenient option.
Hatching Pupae Is Simple
A basic Blue Bottle Fly pupae setup requires very little equipment.
Place the pupae in a well-ventilated container on a lightly damp paper towel.
Keep them somewhere warm and maintain light humidity without soaking the pupae.
As they mature, the pupae generally become darker.
Adult flies will emerge naturally once development is complete.
Because different pupae may be at different developmental stages, do not assume that the batch has failed just because some hatch before others.
What About Hatch Rate?
Blue Bottle Fly pupae are living biological products.
Not every individual will necessarily complete development successfully.
Temperature, humidity, developmental age, storage history, and handling can all affect emergence.
For that reason, it is a good idea to hatch more pupae than the exact number of adult flies you expect to need.
For a continuous feeder supply, using multiple smaller batches can also be more reliable than depending on one large hatch.
Pupae vs. Spikes at a Glance
| Blue Bottle Spikes | Blue Bottle Pupae | |
|---|---|---|
| Developmental stage | Larvae | Pupae |
| Maggot stage involved | Yes | Already completed |
| Time to adult flies | Longer | Generally shorter |
| Must wait for pupation | Yes | No |
| Handling | Live larvae | Dry pupal cases |
| Refrigerated storage potential | Generally better | More limited |
| Best for | Longer-term storage and experienced hatchers | Faster, simpler adult-fly production |
Which Should You Choose?
Choose spikes if you:
- Want greater refrigerated storage potential
- Are comfortable managing the larval stage
- Want control over more of the developmental cycle
- May also use larvae as feeders
Choose pupae if you:
- Primarily want adult flying feeders
- Want to skip the spike stage
- Prefer simpler handling
- Want adult flies sooner
- Do not want to manage larvae before pupation
For many jumping spider keepers, pupae are the more straightforward option because the goal is usually the same: get to an active adult fly as efficiently as possible.
A Note About SpoodFood Blue Bottle Fly Pupae
SpoodFood Blue Bottle Fly Pupae are supplied at varying points within the pupal stage.
They may range from newly pupated to approximately a couple of weeks into development.
That means hatching time will vary within an order.
Some may emerge relatively quickly, while others will naturally require more time.
This variation is expected and can provide a more gradual supply of adult flies.
Source & Credit
Special thanks to Spood Oddities for sharing their practical fly-hatching experience with the feeder community.
Information about Blue Bottle Fly development, refrigeration, and hatching in this article was informed in part by their original fly-hatching guide and adapted by SpoodFood to reflect our Blue Bottle Fly Pupae product.
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