Have you ever seen a walking stick insect, maybe in a museum display or at an entomology demonstration? They look just like twigs and are fascinating creatures. This makes them popular as pets in classrooms and homes. However, if pet walking sticks are accidentally or purposefully let out of their cages, they can become pests in the landscape.
The Indian walking stick, native to India, has established itself in coastal California landscapes after escaping from captivity. While they look cool, these insects feed on a wide variety of plant species like ivy, privet, rose and even some vegetable plants. They are mostly a nuisance although walking stick insects can defoliate plants.
the first official finding occurred in San Diego County in 1991 and soon after in San Luis Obispo County. The most northerly extent of its current range in California is Humboldt County with verified finds in 2021. Indian walking stick populations are confined to the coastal regions of California where the mild conditions allow for their survival in the wild.
Indian walking stick insects can produce viable eggs without mating, and their eggs are hard to distinguish from their droppings. This means that you can unwittingly release them into the landscape when you clean their cages. Owners of walking stick insect pets must be responsible for understanding the biology of these organisms and caring for them properly.
For more details on the biology of this insect, identification, and how to manage the spread of the Indian walking stick, see the newly revised Pest Notes: Indian Walking Stick by authors Dr. David Headrick from Cal Poly SLO and UC IPM's Karey Windbiel-Rojas.
This article is from the UC Integrated Pest Management Program's Pests in the Urban Landscape blog.