No. 8/June 14, 2016
Modified Growing Degree Days (Base 50°F, March 1 through June 9)
Insect development is temperature dependent. We can use degree days to help predict insect emergence and activity. Home, Yard, and Garden readers can use the links below with the degree day accumulations above to determine what insect pests could be active in their area.
Slime Molds in Turf
Temperatures jumped in the last week and rain has fallen or is predicted across most of the state. With warm, wet weather comes the possibility of slime molds, one of the stranger organisms we encounter in the Plant Clinic.
Gypsy moth larvae are becoming fully grown and migrating to pupation sites. They become very noticeable descending tree trunks, crawling across sidewalks, and crawling on fences and buildings seeking cracks and crevices in which to pupate. This is when many people first notice them, especially if the infestation is too low to cause obvious tree defoliation.
The hot, dry weather we are experiencing is conducive for sod webworms in non-irrigated turf. High temperatures result in shorter generation times, allowing more generations and higher population numbers. Dry soils reduce the infection rate of naturally-occurring microsporidia that usually help keep larval numbers low. All of this allows more individuals to mature faster resulting in high sod webworm numbers.