Part 5

Biology/Behavior. In most of the southern area of its range, the puss caterpillar is thought to have two generations per year. The first generation develops in the spring and early summer, while the second generation develops in the fall. After emerging from a cocoon and mating, the female moth lays her eggs on a suitable host plant. In a few days the eggs hatch into larvae, which develop by feeding on the leaves of a wide range of trees and shrubs. The natural enemies of the puss caterpillar usually keep its numbers under control; however, every 4 or 5 years the caterpillars become more numerous, and the number of envenomizations associated with them increases.

Avoidance/Control. Always wear protective clothing such as gloves and a long-sleeved shirt when working in areas heavily infested with puss caterpillars. During periods of M. opercularis abundance, children should be instructed to stay away from infested trees and shrubs and not to handle caterpillars. If necessary, heavy puss caterpillar infestations may be treated with an appropriate insecticide.

Envenomization Reaction/Treatment. (See appendix.)

c. SADDLEBACK CATERPILLAR (Sibine stimulea)

Identification. The saddleback caterpillar is easy to recognize since its brown sluglike body is covered mid-dorsally with markings that resemble a brown or purplish saddle sitting on a green and white saddle blanket. Upon close examination, stout spines can be observed along the caterpillar’s lateral body margin and on its four tubercles. Many of these spines are hairs that are connected at their bases with individual poison glands. Just prior to pupation and subsequent development into a moth, the caterpillar is 2-3 cm (0.8-1.2 in) long.

Distribution. In general, the saddleback caterpillar in the United States is distributed southeast of a diagonal line drawn from Massachusetts through the middle of Texas.

Biology/Behavior. From May to November, Sibine stimulea caterpillars may be found feeding on the leaves of a large variety of trees, shrubs, and other plants. Envenomization usually occurs when the victim accidentally contacts vegetation infested with these caterpillars. At the instant the victim’s skin contacts the caterpillar, the spine tips break off, thus allowing toxin to flow out of the hollow spines and into or onto the skin.

Avoidance/Control. When working in infested areas, wear gloves, a long-sleeved shirt, and long pants to prevent accidental envenomization. During periods of local heavy infestations, children should be instructed to avoid trees, shrubs, and other vegetation commonly infested with these caterpillars. Local entomologists may be contacted to obtain information on the most effective insecticide for saddleback caterpillar control in a given area.

Envenomization Reaction/Treatment. (See appendix.)

BIBLIOGRAPHY

General

1. Barnard, J.H. Cutaneous responses to insects. JAMA 196:3 (1966).

2. Borror, D.J., and D.M. DeLong. An introduction to the study of insects, 2d ed. New York: Holt, Rinehart and Winston, 1964.

3. Dodge, N.N. Poisonous dwellers of the desert. Popular Series No. 3, Southwestern Monuments Assoc., Box 1562, Globe, Ariz., 1955.

4. Frazier, C.A. Diagnosis and treatment of insect bites. Clin Symp 20:75-100 (1968).

5. Frazier, C.A. Insect allergy: Allergic reactions to bites of insects and other arthropods. St. Louis: Warren H. Green, Inc., 1969.

6. Frazier, C.A. Treatment guide: Common biting and stinging insects and other arthropods. West Point, Pa.: Merck Sharp & Dohme, 1972.

7. Frazier, C.A. Cutaneous manifestations of insect allergy. Cutis 13:1038-1047 (1974).

8. Horen, W.P. Insect and scorpion sting. JAMA 221:894-898 (1972)

9. Infections and bites: Parasites, arthropods and animals, Section 18. In D.J. Demis et al. (eds.). Clinical dermatology, vol. 4. Hagerstown, Md.: Harper & Row, 1974.

10. James, M.T., and R.F. Harwood. Herm’s medical entomology, 6th ed. London: Collier-MacMillan, 1970.

11. Lyon, J.B. Insect bites and stings. Practitioner 200: 670-677 (1968).

12. Micks, D.W. Insects and other arthropods of medical importance in Texas. Tex Rep Biol Med 18:624-635 (1960)

13. Millikan, L.E., and R.S. Berger. Clinical and laboratory diagnosis of arthropod bites. CRC Crit Rev Clin Lab Sci 5:201-225 (1974).

14. Parrish, H.M. Deaths from bites and stings of venomous animals and insects in the United States. Arch Intern Med 104:198-207 (1959).

15. Parrish, H.M. Analysis of 460 fatalities from venomous animals in the United States. Am J Med Sci 245:129-141 (1963).

16. Perlman, F. Insects as allergen injectants: Severe reactions to bites and stings of arthropods. Calif Med 96:1-10 (1962).

17. Riley, W.A., and O.A. Johannsen. Medical entomology, 2d ed. New York: McGraw-Hill, 1938.