They appear to be some sort of a scarab beetle. They will leave of their own accord- I would not spray any more poison. It will do no good, because they are coming out of the ground and crawling around looking for food. I'm surprised the exterminator didn't tell you that.

I'm certain this is a temporary phenomenon and they will disappear the same way that they appeared.

Do you have a compost pile near your garage? They love compost. Has any area of your yard been flooded lately? Sometimes they come up for air when the soil is too wet.

If you had not sprayed, I would recommend scooping them up in a container to feed to the local scrub jays or someone's chickens. One Gardenwebber calls them "compost shrimp". In any case, they don't do any harm, and will probably crawl right out of your garage again.

Renee

We have five bird baths, some on both sides of the house, most filled four times a day with my irrigation timers. Anything as tasty as a nice juicy grub, lasts about a minute above ground. We enjoy everything from hummers to turkeys. Al

Hi. These are Japanese Beetle grubs, and the Calif. Dept. of Food and Agriculture lists them as serious and extremely invasive pests. I hate them because they always seem to dive-bomb me directly every summer...don't know why, maybe they know I don't like them..but they always fly directly at me!

Sorry, got sidetracked. They can be controlled to a good extent with something called "Milky Spore Powder" that is non-toxic to animals, people and the environment in general. You can get it online or at Lowe's or Home Depot. You spread it over your lawn (or in your case, at the inside/outside edges of your garage), which is where (usually) they like to lay their eggs at the end of their summer life-cycle season--this is why you are experiencing so many right now. They all ended their cycles a couple of weeks ago, layed their eggs and now the grubs are starting to grow.

The Milky Spore Powder is composed of spores--"offspring"--of a bacteria that the grubs love to eat. The grubs act as a host to the bacteria, which then starts growing inside the grub's tummies and eventually kills them before they mature--next summer--into flying beetles.

Part of the problem is that since almost everyone has a lawn here in California, you can spread the powder around, but if your neighbors aren't doing it, then it's not going to help much...but it does help, and if you start using it now you will definitely see a decrease next summer/fall. Good luck!

Here is a link that might be useful: CA Dept F&A Japanese Beetle section

I hate those things,for the first time in over 40 year they are under our lawn and the stupid skunks/racoons have shredded our backyard trying to dig them out.Dh and i went to Lowes saturday and got 5 bags of spectracide and spread it all over our yard,front and back.We have no animals,so no worry there.
Kathi

They are probably not Japanese Beetles. They have not established a beachhead in CA. They are fig beetle larvae, a large, metallic green scarab that flies at your face as Phil says. They do very little damage as grubs, and the adults do very little damage to fruit. Japanese Beetles are much smaller.
Renee

Fig beetle grubs. You could put them all in a tub they cannot crawl out of, and leave them out for the birds. You will have happy birds. Or if you have a friend with chickens, you would have a happy friend with happy chickens.

not japanese beetle grubs

Definitely NOT Japanese beetle grubs.
But as has been said, grub of the fig beetle, aka green fruit beetle.