From Fruit Flies to Green Bottles – A Guide to Feeding Your Growing Regal Jumping Spider

So, you’ve just welcomed a tiny i4 Florida Regal Jumping Spider into your home! At this stage, they are curious, bold, and incredibly fun to watch—but as any new "spider parent" knows, the biggest question is always: "What’s for dinner?"

While your sling might be small now, these Florida giants grow fast. Transitioning them to the right prey at the right time is the key to a healthy, vibrant spider. Here is everything you need to know about moving from fruit flies to Green Bottle flies.

Stage 1: The Fruit Fly Era (i4 to i5)

At the i4 (4th instar) stage, your spider is roughly the size of a large garden pea. Their world is small, and their prey should be too.

We start all our slings on Drosophila hydei (large fruit flies). These are flightless, easy for the spider to catch, and provide the perfect amount of nutrition for these early molts.

• Frequency: Offer 2–3 flies every 2–3 days.
• Tip: If you see your spider’s abdomen looks nice and plump (like a little teardrop), they are well-fed!

Stage 2: The "In-Between" (i6)

As your spider reaches its i6 molt, you’ll notice they are becoming much more athletic. They might start "taking down" multiple fruit flies at once. This is your signal that they are ready for a challenge. This is the perfect time to introduce Green Bottle Flies or small house flies as a stepping stone.

Stage 3: Graduation to Green Bottle Flies (i7+)

Once your Florida Regal hits the i7 stage (juvenile), it’s time for the "gold standard" of jumping spider feeders: Green Bottle flies (Lucilia sericata).

At the Bug Hub, we use Green Bottles for all our older juveniles and adults, and here is why:

1. Natural Enrichment

Green Bottles are fast, erratic fliers. Watching a Regal Jumping Spider track, stalk, and "teleport" onto a fly in mid-air is incredible. It provides vital mental stimulation and physical exercise that you just don't get with slower prey.

2. Safety First

Unlike crickets or mealworms, Green Bottle flies cannot bite or harm your spider. If your spider is in "pre-moult" and doesn't want to eat, a fly can be left in the enclosure without any risk to the spider’s safety.

3. Superior Nutrition

Florida locales are known for their impressive size. Green Bottles are packed with the protein and moisture needed to support those big, successful molts and to keep those famous iridescent chelicerae looking vibrant.

How to Make the Switch: A Step-by-Step Guide

If your spider has only ever seen a fruit fly, a buzzing Green Bottle might be a bit of a shock! Here is how to transition them smoothly:

1. The "Pupae" Method: Instead of trying to catch a fast-moving fly, place a Green Bottle pupae (the little brown casters) at the bottom of the enclosure. When the fly emerges a few days later, it will be fresh, "gut-loaded," and ready for your spider to hunt.
2. The Cooled Fly: Chill your Green Bottles in the fridge for 10 minutes to slow them down, then offer one fly to your spider, giving it a little more time to react without the buzzing.
3. Monitor the Reaction: Some spiders are "braver" than others. If your spider retreats to its hammock when the fly buzzes, it might not be quite big enough. Offer a fruit fly instead and try the Green Bottle again after the next molt.
4. Hydration is Key: Always ensure there are fine water droplets on the side of the enclosure. A hunting spider is an active spider, and they need to stay hydrated!

A Final Note on Moulting

Regardless of what you are feeding, never feed a spider that is in "heavy premoult." If your spider has built a thick, opaque silk hammock and hasn't come out for a few days, stop offering food. Once they have shed their skin, wait 4–7 days for their new fangs to harden before offering their first post-moult Green Bottle.

Ready to start your journey with a Florida Regal? [Browse our current i4 Slings here] – and don't forget to grab a Starter Kit to ensure you have the perfect habitat for your new friend!