Grubs are the immature larvae of various species of beetles: There are endless species of them. This is a mostly invisible pest – living its life cycle in the soil for most of the season.
Grubs of different species tend to look similar except for their overall size
The Adult Beetles
Here in NYC these are a few of the most common adult beetles we see: Black Vine Weevil, Oriental Beetle, European Chafer, Japanese Beetle.
Black vine beetle
Common life cycle
The grubs hatch from eggs laid early during the growing season by adult flying beetles and remain in the soil eating roots and fattening up. Most go dormant in the late Fall and dig themselves lower in the soil column to avoid freezing in winter.
For containerized plants, winter freezing may well destroy much of the population unless the winter is mild or warmer than usual. Most remain as larvae during winter, transforming into pupae in early Spring and emerging as adults a few weeks later.
Most damage is caused by grubs eating roots
The most common symptom of grub damage in trees and shrubs is a general malaise and wilting. They prefer the roots of many sweet sap plants like birch, beech, and maple – but also love evergreens! In lawns, they form patchy dead areas.
On occasion you can spot them immediately after watering, or a heavy rain when the soil becomes saturated and the grubs come up for air. To confirm, it always requires an investigation into the soil to determine if any grubs are present.
Grub damage in lawn
The best time to treat for grubs is late summer through early Fall before the soil freezes. Several treatments may be required to adequately control large populations. Large size species of beetle grubs may also require additional treatments.
Eastern Hercules beetle – Native to Kentucky
and YES !!! – found in a NYC lawn !
If you see any in your garden – Call Plant Specialists TODAY !
We have experts that know what to do !
We have NYSDEC licensed applicators whom can treat them too !!!
Don’t delay – the sooner the better !
GREENING NEW YORK FOR OVER 51 YEARS !
Article written by our Staff Horticulturist, Peter B Morris, BSc, MSc, MBA
All photographs used with permission @SHUTTERSTOCK