Orange eggs on bottom of tomato leaves?

It's impossible to say for sure what the orange eggs are without more information. Here's what we need to consider:

Possible Scenarios:

* Insect eggs: Many insects lay eggs on plants, and some can be orange. This is the most likely scenario.

* Fungus: Some fungi can produce orange spores that resemble eggs.

* Plant material: Some plants produce orange structures that might look like eggs.

* Something else: There are many possibilities!

To help me figure out what you have, please tell me:

* What kind of tomato plant is it? (e.g., heirloom, cherry, etc.)

* Where are you located? (This helps determine common insect pests in your area.)

* Can you describe the size and shape of the "eggs"? (Are they round, oval, or elongated? How big are they?)

* Do they have any other features? (Are they smooth, bumpy, or sticky? Do they have any markings?)

* Are there any other signs of insects or damage on the plant? (Holes in leaves, webbing, etc.)

Once you provide more details, I can give you a more accurate answer.

In the meantime, it's a good idea to monitor the tomato plant closely for any changes. If you're concerned, you can always contact your local agricultural extension office for advice.