The SVB (Squash Vine Borer) is a moth that resembles a wasp, it lays eggs that hatch into larvae which look like/are maggots. Below are some pics of the adult borer and it's larvae.

https://www.google.com/search?q=squash+vine+borer&sxsrf=ALeKk02TMZUciVKAzZtq1DMelfk2_FI32A:1617890452476&source=lnms&tbm=isch&sa=X&ved=2ahUKEwjSvdHN5-7vAhXdKVkFHWazA2MQ_AUoAXoECAEQAw&biw=1280&bih=606

Use some sort of row cover. That can impede all manner of flying insects from invading vegetable gardens.

I've never heard of SVBs laying eggs inside of squash fruit. They are vine borers, and specifically go after hollow vines. Why would an SVB take the trouble to bore a hole in a squash fruit when there is a vine conveniently nearby? Pickleworms do that, but they come from a moth-like bug.

Thanks for the great information guys! I’ll try catching a picture of the bug, but I don’t see it unless one of my squash is growing :/

Like Dan posted, SVBs prefer summer squash plants (zukes, yellow necks, even pumpkins), but if Butternut is the only squash plants available they may have nowhere else to lay their eggs?

My vote would also be for Pickle worm http://entnemdept.ufl.edu/creatures/veg/pickleworm.htm particularly if you are in a hot humid climate. Row covers are a pain but effective against flying insects.

My butternuts have been regularly killed by SVBs. The vines are a little harder to penetrate, and Moschata are thereby considered somewhat "resistant" to SVBs in that respect, but it hardly means that they are immune. That "somewhat" is exactly that. The SVBs can get through if they try hard, and they do. But again, SVBs don't mess with fruit.

If you can get a pic of the wasp it may turn out to be a real wasp and they are generally good as a pest predator. If it was/is a real wasp it may have been on the hunt for those larvae or eggs recently laid. Farmerdill and Dan are pulling me in the pickle worm direction ;-)

Actually, a good picture of the larvae themselves would help. Pickleworm larvae are pretty distinctive - light green with dark spots.

These are the only pictures I have of the maggots - they were yellow with a brown tip

Well, a brown tip does sound like a squash vine borer larvae. A little hard to believe, but ...

My attempt to protect my just pollinated baby whilst waiting for the covers to come. Praying it works!!

@dan, can you think of any other bugs that have larvae similar to the SVB?

I grew Buttercup squash in 2018. The SVB egg-laying period was unusually long that year, and along with infestation of the vines, quite a few of the squashes themselves were infected. That happened only once before, when SVB bored into Queensland Blue squashes about 15 years ago & caused many of them to rot from the inside. I'm really surprised to see Butternut squash infected so young, though.

@zeedman oh noo that sounds horrible! I haven’t seen any sort of rotting at the base or stems of the plant, which makes me think it’s not SVB. I’m currently living in the UAE and SVB isn’t native here. It also looks like the squash was injected? It had a hole / multiple holes. I’ve been racking my head trying to figure out what it is hahah but all the suggestions have been really great and helpful 💚🙏🏽

That's pretty extraordinary to hear about SVBs damaging a squash fruit. Thank you, zeedman, for your observation. Also, I believe that SVBs are native to North America. Not clear that they are anywhere else. I think fruitworms are endemic in the Gulf, but they too have moth-like progenitors. FWIW, I believe that corn borer larvae have that brown tip. Also moth-like, but they are truly international. Then again, they are really just considered a grain pest.

Concur: always possible you have critters in the middle east that we are unaware of. Many of us turn to our regional Agricultural Universities.. May be worth a try. College of Food and Agriculture (uaeu.ac.ae)

Thanks farmerdill, I hadn’t thought of that. I’ll definitely try contacting them 👍🏽

Hello everyone, an update:

I have been covering my squash fruits as gardengal suggested, which has been going great as the culprit insect doesn’t lay it’s eggs in the fruit. Here’s a picture of the squash that’s currently the biggest.

The culprit was a moth, not a wasp haha and I found spraying my leaves with a natural deterrent helped keep them away. Though I did find this little guy flying around - very cute!