SAN DIEGO — Over the years I have worked to keep my garden as organic as possible, without pesticides and using as few chemical fertilizers as possible. The garden now has a wonderful ecosystem that teems with life — ladybugs, lacewings, earthworms, bees, spiders, butterflies, dragonflies, hummingbirds, birds, opossums, lizards and praying mantises are all welcome and beneficial. One insect that is not welcome is the Indian walking stick (Carausius morosus), and I have been battling them for a few years now, just like many of my fellow California gardeners. For years, these non-native insects have been sold on the Internet as pets, even thought it is illegal to keep them in the United States without a permit. Many websites still sell them and some post warnings about the dangers of releasing the insects into the wild, since they can become an ecological problem. Theory has it that the invasion we are now experiencing is due to many of these so-called “pets” being released into the wild after the owners tire of them or disposed of their eggs or dead carcasses improperly. Appropriately named for their sticklike appearance, the Indian walking stick blends in very well with its surroundings and until it moves, one would never suspect it is there. If in danger, the insect can lie motionless for hours. Belonging to the same order of insects as the cricket, grasshopper, praying mantis and cockroach, there are several thousand different species of walking sticks that can be found all over the world. Many do not eat plants. The Indian walking stick is defiantly plant eating and is fast becoming an ecological pest, having adapted itself quite nicely to our environment and garden offerings. One of the reasons this insect’s population is growing so fast is the fact that the female Indian walking stick can reproduce without a male and can produce hundreds of eggs in her lifetime. Unfertilized eggs will hatch into only female insects that mature and repeat the process. The tiny hatchlings molt (shed their skin) several times over their approximate one-year lifespan and grow to a length of about 4 inches. Their eggs are also very difficult to find. The natural enemies of the walking stick are birds, rodents, reptiles, spiders and other insects. Since using pesticides is out of the question for me, I decided to introduce praying mantises into my garden last year in the hope that they would put a dent in my thriving walking stick population. We showed a few walking sticks to the praying mantises and several were devoured, while others escaped the uninterested mantis. By the end of this summer, I will have a better idea if the mantises are helping rid my garden of these unwanted pests. Even if they do not, I have enjoyed watching the mantises in my garden and hope they will continue to flourish there. One way I have been getting rid of these pesky insects is with water and a strong stomp of my foot. Walking sticks hate water, and when I hose down the vines and shrubs where I know they are hiding, they quickly emerge trying to escape the strong surge of water. When fleeing the water, they can run quite fast. Then, with my garden gloves in place, I pick them up and — I’m sure you get the picture. So far, this has been my most effective method of annihilating them. Since walking sticks belong to the same insect family as grasshoppers, it would appear that any insecticide that kills grasshoppers might kill them, but for the time being, I am going to “stick” with my hose, foot and nature in the hope that I can keep their population in balance. If you have any tips on how you are dealing with this problem, I will be happy to share your ideas with readers in an upcoming column later this spring. E-mail your comments to [email protected]. — Linda Marrone is a local Realtor with Coldwell Banker who specializes in historic and architecturally designed homes. She is a co-founder of the Secret Garden Tour that will take place this coming spring for the 11th consecutive year. The owner of a historic home and garden in La Jolla’s Barber Tract, you will find her working in her garden every chance she gets. Take a tour of Linda’s garden on: www.LindaMarrone.com.