If you saw ants, it's possible you may have an aphid infestation. Ants will farm aphids for their honeydew and even store the aphid eggs for use in the springtime.
Aphid infestations will causes yellowing, stunting, mottling, browning, and curling of leaves, just like what appears in your picture. Look on the underside of some of the leaves for tiny little green specks moving around. Also look for little webs made on the underside of the leaves as well, these are spidermites, another pest.
The cheapest cure for aphids is to spray the hell out of the plants with a blast from the hose. Just let em have it! It knocks them off the plant and they usually can't find it again. You can kill aphids by spraying, especially under the leaves, with a solution of 2 tsp mild dish or laundry soap to a bottle of luke warm water. The soap washes off the aphid’s protective waxy coating and causes dehydration. You can also mix three parts luke warm water to one part vegetable or horticultural oil and a couple drops of dish soap. This mixture can be sprayed on to clog the respiratory spiracles of aphids. Spray once a week taking turns between solutions.
Oh yea, and if you see a bunch of
these don't kill them like I did a few years ago. They're ladybug larvae, and really good for your plants.
