Emergence has occurred over most of the eastern two-thirds of Kentucky as of May 30. While all of a county with reported cicada activity is colored blue, it often is limited to specific areas in and around woodlots and forests.
Management recommendations for periodical cicadas in fruit This Kentucky Pest News article covers use of insecticides to prevent damage to fruit trees, small fruits and grapes.
Protecting Landscape Trees and Woody Shrubs from Damage
Periodical cicadas are potential pests of many trees and woody ornamentals, with the exception pines and other species that produce gummy substances when damaged. These insects can cause problems in orchards, vineyards, nurseries, home and commercial landscapes. Physical injury or “flagging” occurs after females slit twigs to insert batches of eggs. Twigs break at these weak spots and are left to dangle, turn brown and die. This “pruning” is not a serious problem for large trees but can adversely affect the developing structure of small trees. A more subtle impact can occur several years later as growing nymphs remove sap from roots.
- New orchard or landscape plantings should be delayed until after periodical cicada activity has ended for the season.
Young trees can be covered with netting or cheesecloth to protect the tender twigs. This should be done when the first male singing is heard. Secure the covering around the trunk to prevent cicadas from climbing up to the limbs. The netting should be removed at the end of June or when cicada activity stops.
If practical, cicada nymphs can be prevented from feeding on roots of young trees by pruning out twigs with egg slits. This needs to be done within a three weeks after egg laying has ended. Although a time consuming process, it may be a viable alternative considering the production life and long term value of backyard fruit trees. Feeding by large numbers of nymphs over several years can reduce the vigor of small trees.
- Insecticide applications generally are of limited use in protecting trees from damage, especially where cicadas are very abundant. Repeated treatment will be needed to deal with new arrivals. Orchards under a routine spray schedule should be treated about twice a week during peak cicada activity. Spray requirements will vary according to intensity of the outbreak, which can range from a few cicadas in some areas to massive numbers in other areas.
Some cats and dogs are intrigued by cicadas and may eat enough of them to cause an upset stomach but cicadas are not toxic and cannot sting.
Periodical cicadas will fly to things that produce noise at some frequencies so they may appear to "attack" weedeaters and lawnmowers. Being somewhat ungainly in the air, these insects may crash into people or machinery but it is unintentional.
Here are a few significant dates from a study of the emergence of this brood in 1991 at Robinson Forest by Dr. Paul Kaliz, UK Forestry Dept.
- Emergence began on May 4, about 10 days earlier than 2008.
- Widespread emergence by May 10, 1991. Males begin to call and form groups that chorus as they attract females for mating. Adults will use their piercing sucking mouthparts to feed on plant sap.
- The last nymph caught leaving the soil on May 31, 1991
- The last adult heard calling on June 16
Keep us up to date by sending your observations, pictures, etc. of Kentucky cicada activity to: Lee.Townsend@uky.edu.
Species in Brood XIV
Kalis found the periodical cicada population is his study to be comprised of three species. Links will take you to information about them and examples of their songs. Magicada septendecim (85%), M. septendecula (13%), and M. cassini (5%).
University of Michigan Museum of Zoology Periodical Cicada Page
Here is a regional map of emergence sightings.
Periodical cicadas in Kentucky (Entfact 446) This fact sheet list has information on the life cycle of cicadas and the broods of periodical cicadas that occur in Kentucky.
This page is maintained by Lee Townsend, Department of Entomology, University of Kentucky.
Please send questions or suggestions to: Lee.Townsend@uky.edu