Cranberry Insect Pests: How To Treat Pests On Cranberries

Damage From Pests On Cranberry Plant
cranbery pest
(Image credit: Scott Tunnock, USDA Forest Service,

Cranberries are wonderful fruits that not many people think they can grow at home. For a lot of us, cranberries come as a gelatinous can shape at Thanksgiving. For more of us, they’re a strange aquatic thing grown in faraway bogs by men in waders. Both of these are somewhat true, but they can also be grown in your own garden, even without the bog. If you’re one of the lucky few with your very own cranberry vines, you might be devastated by the sudden invasion of insects. Keep reading to learn more about cranberry pest management and how to treat bugs that eat cranberries.

Cranberry Pest Management

First of all, it’s important to clear up which kind of cranberries we’re talking about. This article is about cranberry vines (Vaccinium macrocarpon), which are often confused with cranberry bush (Viburnum trilobum). With that in mind, here are some of the most common bugs that eat cranberries and their methods of control: Cranberry Tipworm – Maggots feed on leaves, creating a cupping effect. Apply insecticide during the growing season’s first hatch period, usually in mid to late spring. Cranberry Fruitworm – Larvae eat fruit from inside out, leaving an entrance hole covered with webbing. Spray with insecticide or hand pick and dispose of fruitworms. False Armyworm – Larvae eat new growth, blossoms, and fruit. Late season flooding is good for control. Black-headed Fireworm – These pests link leaves and vine tips together with webbing and cause browning in uprights. Spring flooding and insecticide can be used for control. Cranberry Weevil – Larvae hollow out flower buds before opening. Some chemical control is effective, but weevils are continually building up resistance to it. Cranberry Flea Beetle – Also called the red-headed flea beetle, adults skeletonize leaves during high summer. Like many flea beetles, they can be managed with certain insecticides. Spanworm – Green, brown, and big cranberry spanworms are all active pests of cranberries. The larvae feed on leaves, blossoms, hooks, and pods. Most insecticides are effective. Cranberry Girdler – Larvae feed on roots, runners, and stems, turning foliage brown in late summer. Best treated with insecticides in late summer to early autumn. While rarely a problem, aphids will occasionally feast on cranberry plants and their honeydew can attract ants as well. By eliminating the aphids, you’ll take care of any ant problems.

Liz Baessler
Senior Editor

The only child of a horticulturist and an English teacher, Liz Baessler was destined to become a gardening editor. She has been with Gardening Know how since 2015, and a Senior Editor since 2020. She holds a BA in English from Brandeis University and an MA in English from the University of Geneva, Switzerland. After years of gardening in containers and community garden plots, she finally has a backyard of her own, which she is systematically filling with vegetables and flowers.