HORNED CATERPILLARS ON THE RANGE

I was sent some photos of a strange striped caterpillar found out in out range land here in Eddy County, and as a cattle grower they want to know what they were eating because there were lots of them. This insect is scientifically classified as Hyles lineata, white lined sphinx moth, a species in the Order Lepidoptera (moths & butterflies) and the Family Sphingidae (sphinx moths, hummingbird moths, hornworms). This moth must first develop as a caterpillar, which is the major feeding form. The caterpillars have many color forms, from a bright yellow-green with black spots or stripes on the back, to almost entirely black with only glimpses of yellow breaking up the black. Each caterpillar has a posterior horn as decoration. This horn is flexible and sometimes brightly colored, but it is NOT a stinger. These caterpillars are not poisonous, but if too many were eaten one might get an upset stomach. It is quite interesting to now learn that the Tohono Oodham a native American tribe in Arizona many years ago would harvest these larvae, dry and braid them and use them for food. Also when one learns the nutritional value of insects; they serve many peoples better than fast foods of today. In Eddy County, we do not know how many generations may occur in a year, but it is typically the July-August brood of caterpillars that are most noticed. As the monsoon season draws towards a close, we start to notice in different desert regions a massive movement of caterpillars. These caterpillars have fed on a multitude of plants found in the desert, and when they do wander into a residential neighborhood, they may feed a bit on landscape plants, but will have little effect on those plants. Why do these caterpillars pick a certain area? Good question for which we have no answer. Do they pick the same area year after year? It doesn't seem to be that, way, probably because plant communities’ change year to year and the adults may go to another food source to lay eggs, and thus the caterpillars will be in a new place next time. It may seem whimsical but the patterns of use may have real but undetected characteristics. It is random distribution, the luck of the draw! The adult moths also present an interesting sight. The moths have a very streamlined look, with forewings gray with various white stripes and bands breaking up the outline, and with smaller hind wings that are dominated by pink. These moths are seen both day and night hovering around many of our desert plants, especially four o'clocks and Desert Willows here in Eddy County, where they appear like a multitude of hummingbirds. The moths have a long tongue (proboscis) coiled beneath head, that unfurls when they approach a plant. They dip this tongue into the nectaries and drink the sweet fluids. These moths are some of the most important pollinators of desert plants here in Eddy County. Enjoy don't fear this fantastic display by the insects. Nature is a wonder always if one can just rekindle the interest and enthusiasm for all kinds of life. These insects are not harmful, and represent wildlife that is extremely important to the success and survival of the Sonoran Desert. This is one of the great wonders of living in the desert, the rancher who sent me the photos live here their whole life and this is the first time they have seen them in such numbers. So expect to see lots of sphinx moths in the near future or we don’t know this late in the season they may burrow in the soil and over winter to next spring and emerge as moths then. Subscribe to Eddy County Ag news at: http://nmsueddyag.blogspot.com/ Eddy County Extension Service, New Mexico State University is an equal opportunity/affirmative action employer and educator. All programs are available to everyone regardless of race, color, religion, sex, age, handicap, or national origin. New Mexico State University, U.S. Department of Agriculture, and the Eddy County Government Cooperating.