Pest Lexicon – Green Guardia

Apple blossom weevil: Recognize flower damage & prevent naturally

The apple blossom weevil is a small snout beetle that can cause significant damage to apple trees in the spring. The larvae destroy the flowers from within, so no fruit is produced. Early detection and targeted, natural measures are crucial.

ⓘAnthonomus pomorum · Apple blossom weevil #Brown buds · Blossom damage · Harvest loss

What is the apple blossom weevil?

The apple blossom weevil (Anthonomus pomorum) is a small, brownish snout beetle. It overwinters as an adult beetle and becomes active very early in the year. Females lay their eggs in closed flower buds. The larva then eats the floral organs – the bud never opens.

Snout beetle Blossom pest Crop failure possible

Important: Damage occurs very early in the year – often before you consciously notice it. Those who only react during flowering are usually too late.

How to recognize an infestation

brown, withered flower buds ("brown heads")
flowers do not open
small puncture hole on the bud
fewer flowers → lower fruit set

Green Guardia Tip: Inspect apple trees very early in the spring (starting when buds swell), especially in sunny, wind-protected locations.

Which plants are affected?

Apple (main host)
rarely ornamental apple

Why does an infestation occur?

mild winters (high survival rate of the beetles)
lack of natural enemies
undisturbed overwintering sites (foliage, bark)

Natural measures & suitable beneficials

1. Mechanical measures (very early!)

Gently shake trees in the morning during cool temperatures
Collect beetles on a cloth/tarp

Recommended beneficial: Nematodes against overwintering beetles

Nematodes (e.g., Steinernema species) can be specifically used to reduce overwintering beetle populations in the soil area.

Why suitable: hits beetles before they go into the buds for egg-laying
Why effective: reduces infestation pressure early on
Important: moist soil & suitable soil temperature required

Promoting natural enemies

Birds (e.g., tits) eat overwintering beetles
Ground beetles hunt on the ground

Why early action is crucial: The apple blossom weevil damages the flower directly – what is destroyed once, cannot be compensated for. Prevention is more important here than "repair."

FAQ about the apple blossom weevil

How many flowers can be destroyed?

A single female can damage dozens of buds. Significant harvest losses are possible in cases of heavy infestation.

Why do I not see any beetles, but many brown heads?

The beetles are active very early and are often well-hidden during the day. The damage remains visible even after the beetles have left.

When is the best time for measures?

Very early in the spring – starting when buds swell, before flowering.

Can the tree recover?

Partially, yes, but heavily damaged flowers are lost permanently – the yield decreases accordingly.