The following is a prediction of the stage of development of several species of insects, based on the blooming of bridal wreath spirea or Vanhoutte spirea (Spiraea x vanhouttei). This information is from Coincide by Donald A. Orton. The 190-page book published in 1989 is available from the Labor of Love Conservatory, 468 S. President, Suite 103, Carol Stream, IL 80188-2894; (630)668-8597.

Phenology information is listed for scouting and identifying potential problems. It helps you know when to look for certain pests. It should not be used as a biological calendar spray schedule.

Full bloom:

Birch leafminer young larvae

Elm leaf beetle young larvae

European pine sawfly feeding larvae

Gypsy moth feeding larvae

Pine needle scale crawlers (first generation)

Full to late bloom:

Lilac (ash) borer newly hatched larvae

Oystershell scale (brown) crawlers

Finishing bloom:

Bronze birch borer newly hatched larvae

Most blossoms brown, a few still white:

Flat-headed appletree borer larval hatch

Peach tree borer newly hatched larvae

Viburnum borer newly hatched larvae

Bloom finished:

Oystershell scale (gray) crawlers