The mystery of the bird poop caterpillar
Master Gardener Laura Simpson also helps a reader with a yard fungus that looks like scrambled eggs and shares a reader suggestion on how to deter critters from the yard.
Q: Have gardened most of my life but have never seen one of these characters. Caught him eating on my navel orange this morning.
A: You sent a couple of good photos of a weird-looking caterpillar. I was stumped, as I had never seen one of these before, so I forwarded your photo to some folks at University of California. Monique Rivera at UC Riverside tells us that it looks like a bird poop caterpillar.
The bird poop caterpillar, Papilio cresphontes, can be found in plain sight because it’s cleverly disguised as, well, bird poop. Birds like to eat caterpillars, but not bird poop, so they usually escape attention. Sometimes they have a pair of bright red horns to dissuade predators who might have figured out that they are edible. It is the juvenile version of the giant swallowtail butterfly, so if it doesn’t eat too many leaves off of your orange tree you probably want to let it be.
Q: Laura, I have a wood burning cast iron stove on our deck to take the chill off and for ambience. After several fires I empty the ashes into my vegetable garden and till it in. Am I doing good or bad things to my soil?
A: Wood ash is a fine addition to your garden soil or compost pile. It is rich in phosphorus, but not much else. It may raise the pH of your soil, making it slightly more alkaline, but probably not enough to do anything to your plants.
Q: About a year ago we had a tree removed from the front yard and the stump cored out. In the area where the soil is maybe 50-50 sawdust and ground, a mysterious yellow blob, I assume it is mold of some kind, has recently appeared about four or five times. It looks like bright yellow scrambled eggs. It is a bit mushy when it first appears overnight. When I remove it, I find it is full of what I figure are black spores. Any suggestion on how to prevent the yard being full of scrambled eggs?
A: That yellow stuff is most likely dog vomit fungus, which is technically a slime mold. This is commonly found in shady, moist areas and it grows on mulch, rotting leaves, dead tree trunks, and in this case sawdust from a dead tree stump. If the area has poor drainage, you probably want to correct that to prevent further fungus issues. It will likely go away on its own with the arrival of hot dry weather.
Here’s a great bit of advice from one of my readers:
For your reader with an animal eating the grass, here’s another thing to try. I had an animal (skunk?) tearing up my lawn to get to grubs. I bought a roll of 4-foot-wide Tenax multi-purpose plastic net (stiff fabric, unlike bird netting, which is like handling a spider web) and laid it down around the edges of my lawn. The animals freak out when they try to walk on it and leave the lawn alone. You can pick it up to mow the lawn and use it over and over.
Have questions? Email gardening@scng.com.
Looking for more gardening tips? Here’s how to contact the Master Gardener program in your area.
Los Angeles County
mglosangeleshelpline@ucdavis.edu; 626-586-1988; http://celosangeles.ucanr.edu/UC_Master_Gardener_Program/
Orange County
ucceocmghotline@ucanr.edu; 949-809-9760; http://mgorange.ucanr.edu/
Riverside County
anrmgriverside@ucanr.edu; 951-683-6491 ext. 231; https://ucanr.edu/sites/RiversideMG/
San Bernardino County
mgsanbern@ucanredu; 909-387-2182; http://mgsb.ucanr.edu/