Berries Production Guide

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Miscellaneous Pests

This section was updated - 13 July 2021


Birds can cause serious crop losses by eating or “pecking” the fruit before harvest. Understanding the birds’ feeding behavior can help when planning a control strategy. The use of scaring devices is regulated by the “Farm Practices Protection (Right to Farm) Act”. For more information on birds and their control, and on the regulations, refer to “Birds” in "General Berry Pests" in this guide.

Calyx Contaminants


The incidence of calyx contaminants is very low in the Fraser Valley. However, berries harbouring calyx contaminants can be downgraded or rejected by buyers.


The major contaminants of blueberry calyxes are the egg sacs of spiders (dwarf and comb-footed), and pupae of lacewings and syrphid flies. Contaminants usually appear as a white, “furry” mat in the calyx end of the fruit.

Life History

Spiders and lacewing and syrphid larvae eat or parasitize other insect pests and are considered “beneficials”. Contaminants appear in calyxes of blueberries, from mid-June until early August. Studies have not found a pattern of occurrence linked to time of season, location in the field or on a plant, plant variety, vegetation management or insecticide use.


Cultural control

The best way to manage this problem is to try and remove contaminated fruit on the grading lines.

Chemical control

Control sprays are not recommended. Sprays against the egg sacs or pupae found in calyxes are usually ineffective, and may result in outbreaks of thrips, mites, aphids and caterpillars.


Snails are slug-like creatures with protective shells. The shells can be up to 2 cm in diameter and have yellow and brown rings. Snails climb into the blueberry bushes and eat the moss and lichens on the branches. Occasionally they eat the leaves and berries. Their protective shells allow them to stay in the bushes during the day. Snails can end up with the picked berries, especially when mechanically harvesting. Snails that are the size of blueberries cannot be removed mechanically and can end up in the pack.

Cultural Control

Control weeds and keep cover crops mowed as tall grasses and weeds provide protection and may attract these pests.

Chemical Control

If present in large numbers, control snails in the spring before they climb into the plants. When the pests are active and conditions dry, apply in the evening at the base of plants or to the headlands.

Sluggo or Ferramol (0.76% ferric phosphate) slug and snail bait at 25 to 50 kg/ha (10 to 20 kg/acre) scattered by hand or granular applicator between the rows and near the base of the plants when snails are detected. Apply the highest rate if infestation is severe. Re-apply at least every two weeks if snails continue to be a problem. Do not place in piles.

Note: ferric phosphate is not harmful to pets, birds or wildlife.

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