My understanding is that this type of bug hatches after one or two big rains come (as the rainy season here is just getting in full swing), and have a very short life span. I'm not sure they have much purpose except for providing a food source for other bugs, lizards, chickens, and whoever else would choke one down. Here, some ants are cleaning up some leftovers the next morning on our porch.
And of course, a few chickens let themselves into our yard and helped themselves to some delicious, wingless bugs....just waiting to be eaten. Yum!
Rain! And lots of it lately.