Weston Logo

The Caterpillars are Coming!

The Caterpillars are Coming!

It’s time for battle!


Winter Moth and Gypsy Moth are invasive species that will decimate foliage, and in recent years their number and destructiveness have been on the rise. Apple, ash, basswood, birch, cherry, crabapple, elm, maple, and oak are particularly susceptible to Winter Moth & Gypsy Moth caterpillars; fortunately most shrubs (with the exception of blueberries) are mostly exempt from destruction. However, if there’s a many of them and they are hungry, they will eat just about anything!


Early Spring is prime time for caterpillars, so you should be prepared.


Proactive treatment is your best control. Throughout the Winter & early Spring, go hunting and check around your property for eggs; liberally apply Bonide’s All Seasons Horticultural Oil to inhibit hatching and kill emerging larvae. Winter Moths lay their eggs in protected crevices, such as tree bark & cracks in wood & siding. Gypsy Moth egg masses look like beige or white cottony tufts and are often tucked into protected nooks under lichen and debris.
In early April, around the time that buds begin to swell, the Winter Moth eggs will begin to hatch into inchworm larvae. The tiny larvae spin threads of silk and drift up into the tree canopies – this is known as “ballooning”. They’ve also been known to crawl across the ground towards the shadow-line of trees and shrubs, so a few well-placed sticky traps will help on that front.


Once the young Winter Moth caterpillars are up in the canopy they will burrow into tree buds and devour them from the inside out, and horticultural oil will be of no help. Apply Bonide Thuricide to emerging leaves (Bt, aka Bacillus thuringiensis kurtstaki) to active feeding areas; this bacteria-based product essentially causes a disease epidemic and kills them at the source once it is ingested.

More mature Winter Moth larvae are not as vulnerable to Bt, so you will need to switch tactics and use a spinosad based product, such as Captain Jack’s Dead Bug Brew. With any product, always be very careful of spraying in areas where butterflies & beneficial moths may be active – evening is an excellent time to apply these pesticides.


In May things become more complicated, as the Gypsy Moth caterpillars begin to emerge. This is the most active feeding time. Keep spraying Captain Jack’s, or switch things up with a pyrethrin-based contact insecticide like Bonide Eight, which works well on Gypsy Moth in particular. Water damaged trees once a week so that they can recover.


June: The feeding frenzy should be mostly over, and the caterpillars will retreat into the soil to pupate and become adult moths.

July: Take a nap in your hammock and congratulate yourself on your victory! Unfortunately, your yard may be a little less shady than before, but continue watering any damaged trees and shrubs- this extra care and attention will help them recover.

Share Via:

Facebook
Twitter
LinkedIn
Email
Print
WESTON NURSERIES

Weston Nurseries is committed to being a center for horticultural knowledge. Enjoy!

SEARCH TOPICS
Generic selectors
Exact matches only
Search in title
Search in content
Post Type Selectors
Search in posts
Search in pages
SHOP

Shops Trees, Shrubs, & Perennials – in stores and online.

EXPLORE MORE
PLANT CARE
SOCIAL
SEARCH BY MONTH
Archives
EVENTS & CLASSES

Online Shopping at Weston Nurseries

We are excited to offer two unique opportunities to shop online at Weston Nurseries.

Farm To Door™

WN Online Shopping icons_Ship to Door
Plants shipped directly to you!

Browse our online inventory for a huge selection of plants available to ship directly from the farm to your home! Anywhere in New England!*

Shop Our Garden Centers

WN Online Shopping icons-02
Great for large plants and larger orders!

Shop your local store for plants, garden supplies, soil, mulch and more. Then pick up your order at the garden center or arrange for local drop off!

If you are interested in ordering gift cards, please click here!
*Some restrictions may apply to certain states.

FLASH SALE

Memorial Day Weekend Flash Sale On Hydrangeas!

25% off all Hydrangeas this weekend only!

Saturday, May 25th – Monday, May 27th! 

Hydrangeas are a classic and beautiful sign of summer. Celebrate Memorial Day Weekend by sprucing up your yard with some new hydrangeas. Discount applies at all locations.

*Sale Fine Print:

For “Cash and Carry” transactions only. Offer good while supplies last.

No open orders or deliveries for future dates. All Flash Sale products must be taken the same day. Not valid on previous orders. No transfers allowed between stores on any sale items.

Skip to content