They arrive just after the month of May, billions of them, and now they’re gone. Did they migrate somewhere else, or did they all die off? And if they died off, where to they generate from next season? They only live for what seems a very short period of time (days, weeks?), it makes me wonder how they come back.
Among vertebrates, the tendency is for relatively rapid growth through childhood and adolescence, arriving at physiological maturity and remaining in a relatively stable state for numerous years. (Yes, there are big distinctions between 25 and 45, but they are nowhere like that between 5, 10, and 15, and similarly for dogs, cats, and horses, ceteris paribus.) The state of sexual maturity is also the state when productive, efficient use of the environment for nourishment of self and dependents is common.
Insects will use the above strategy but also a wide range of other strategies. One extremely common one is a robust, environment-exploiting larval stage that lasts for most of the individual lifespan. Metamorphosis to adult (imago) form and mating is something that one does at the end of one’s life. Customarily the entire annual crop metamorphosizes together, increasing the likelihood of finding a mate and minimizing the likelihood of being consumed by a predator before mating. Since we tend to regard the imago stage as “the insect” and ignore the larval stages, this leads to ephemeral presences from the insects which adopt this strategy, including the periodical cicadas, the mayfly, and the june bug.
The fat white grubs about an inch long and three eight inch wide in the soil when you plant in the spring are June Bug larva. They help to attract the moles that dig up you lawn.