My native datura was grown this year from wild collected seed.  In the depths of summer heat it was producing the most beautiful snow white trumpet shaped flowers.  These night pollinated beauties remain open to greet me in the cool hours of dawn in the desert.

It was over the weekend that I saw the first signs, small black BBs scattered over the ground.  This indicated that moths had been pollinating my datura and night and laid eggs on the branch tips. These hatch out into caterpillar larvae which feed voraciously, then pupates into its final adult moth form.

The BBs are its excrement and I could see where much smaller poops had dropped beneath the point where it first hatched out, then as it grew and worked its way across the plant the poops became proportionately larger.

I looked closely at the entire plant, now about half consumed.  It took my reading glasses and a sharp eye to find the culprit, skilled at camouflaging itself on stems or hiding on the backs of leaves.  It was a huge green worm the size of my index finger.  Icky!!

The size of this worm is enormous, and they can cause widespread damage to nightshade crops such as tomato, eggplant, pepper, my native datura and the South American Brugmansia angel's trumpet.  This fellow was plucked and destroyed, but the plant was already nearly leafless.

The following day his buddy showed up after consuming what green was left on the plant. Its size is shown by the dime, and the poops surrounding it.

The hornworm and the larvae of many butterflies and moths are natural inhabitants of these plants.  Their parents are vital to pollination.  But this is a great example of what's called a "larval food plant", which means when the larvae hatch out they turn around and eat their entire nursery!  So when planting gardens for butterflies and moths, beware that many of their favorite plants are also their favorite meal.

This is also anexample of the important symptom of the caterpillar, our most damaging of all pests.  Whenever you see these pellets, often colored the same as the flower consumed, you know there are caterpillars somewhere in the plant.  And if you don't get busy picking them off, say good-bye to the plant, its flowers and fruits.