Pollen Beetle

Pollen beetles (Meligethes aeneus) are prevalent during Spring and Summer months and are a significant pest of European oilseed rape.  


The adult beetles are up to 2.5 mm long and bronze greenish to blue/black and highly visible against a yellow background. The larvae are creamy-white, 3-4 mm long, with a brown/black head and 3 pairs of short brown legs. The uppersides of the body of the larvae are lightly coloured with dark brown spot


Pollen beetles are a pest of the green/yellow bud stage, adults and larvae feed on developing anther in buds and pollen in flowers. Holes can be found in developing buds where the beetles have eaten through the sepals to reach the stamens. As a result, there may be widespread bud abortion and a reduction in pod-sets and blind stalks. Due to their feeding habits spring oilseed rape can be highly susceptible to the attack of pollen beetles. 

Pollen beetles tend to lay their eggs in flower buds and these hatch after 7-10 days, after this the larvae pupate in the soil. As adults emerge in mid-summer they serve as beneficial pollinators at flowering.


Pollen beetles migrate to winter oilseed rape crops from mid-March and throughout April. Eggs are laid in the flower buds and the larvae (grubs) develop within the flowers. If flowers are not open, beetles bite into and kill buds. Damage to buds declines as the flowers begin to open and pollen becomes more easily obtainable. Egg laying damage to the buds of oilseed rape can cause the flowers to drop off. Both adults and larvae feed on the pollen and nectar in the flowers. Struggling crops may produce fewer side shoots and green buds, meaning lower pollen beetle numbers could be a threat. In recent years, pollen beetles have rarely been abundant enough to warrant treatment: careful monitoring can prevent unnecessary 'insurance' sprays and preserve the efficacy of pyrethroid products.

Control recommendations

Monitor crops from green to yellow bud whenever temperature is 15ºC or higher. Don't panic spray - oilseed rape can tolerate quite a lot of damage by compensatory regrowth. Please check if the AHDB thresholds in the table below have been exceeded. Sample at least 10 plants along a 30 metre transect from the middle of the headland towards the centre of the crop and calculate the average number of beetles per plant. Once pest levels ARE ABOVE THRESHOLD treatment is justified to protect yield - apply a full rate of pyrethroid to minimise the risk of resistance development. If beetles are still active and numbers exceed the threshold three days after treatment try using an insecticide with an alternative mode of action such as indoxacarb. None of these may be used more than once in a crop.

Spraying when pest levels are low increases the risk of resistance evolving in the pest and also may kill natural enemies of the pest or other beneficial insects. Resistance to pyrethroids has been reported since 1999 in mainland Europe and is spreading in the UK.

Do NOT spray after flowering starts: the pollen beetles migrate to open flowers, away from the buds, and become pollinators rather than pests.

Treatment thresholds

Current spray thresholds for winter and spring oilseed rape are:

Plants/sq m

Pollen beetles per plant

< 30








Pollen beetle larvae are attacked by parasitic wasps. 25-50% of larvae are killed by these on unsprayed crops. Where insecticides are used extensively, levels of parasitism can be considerably lower. The parasitic wasps may not be affected by insecticides applied against pollen beetle at green bud, as they arrive in crops during flowering.


Related Links


Monitoring and control of pollen beetle in oilseed rape


Some of the text and image on this page comes from Rothamsted's Croprotect web platform at https://croprotect.com/pests/pollen-beetle



Related Organisations

Content below is from across the PEP community and is not necessarily endorsed by Stewards or by PEP

Connected Content

Integrated Pest Management highlights the growth of a healthy crop with the least possible disruption to agro-ecosystems and encourages natural pest control mechanisms. IPM is one of the tools for low-pesticide-input pest management, and IPM must now be implemented by all professional agchem users.

Oilseed Rape is the most widely grown break crop in the UK. The seed is crushed to produce vegetable oil and the remaining rapeseed meal is a high protein animal feed. 

The Peach-Potato Aphid (PPA) known as Mysus persicae is known to feed on a wide range of plants including several grown as crops.  They are known to transmit viruses to crop plants including Turnips Yellow Virus (TuYV) which can lead to yield reductions in oilseed rape.

Invertebrate pests cause problems in agriculture when the level of injury they cause reaches a point where the crop yield is significantly reduced.   

The IPM Decisions project will create an online platform that is easy to use for the monitoring and management of pests. Access the platform now at https://platform.ipmdecisions.net/  

The Cabbage Stem Flea Beetle (CSFB)  Psylliodes chrysocephala is a key pest on OSR in the UK and across the EU. They are specialist herbivores of plants in the crucifer's family.

Insecticides are a type of agrochemical used to kill, harm or deter insects that either directly infect cultivated plants/animals or that are carriers of disease. In agricultural settings, insecticides may be used in both arable and livestock husbandry situations. The classification of insecticides can occur in various ways: via their biochemical mode of action, their mode of penetration or on the basis of their chemistry. They can also come in various formulations and delivery-systems such as sprays, gels or baits.

App and website dedicated to pest, disease & weed identification and management.

This Topic doesn't yet have a Stewarded summary, but connected groups, content and organisations show below. Click the 'Ask to Join' button if you would like to be a Steward for this Topic and provide a summary of current knowledge and recommend useful resources, organisations, networks and projects. "Like" this Topic if you would like to see it prioritised for providing a wikipedia style summary.

Write whatever you want here - this is the main section. You can add links, add pictures and embed videos. To paste text from elsewhere use CTRL+Shift+V to paste without formatting. Add videos by selecting 'Full HTML' below, copying the 'embed html' from the source page (eg Youtube), clicking 'Source' above and pasting where you want the video to appear.
You can upload an image here. It can be jpg, jpeg, gif or png format.
Upload requirements

You can upload a file here, such as a pdf report, or MS Office documents, Excel spreadsheet or Powerpoint Slides.

Upload requirements
Authors Order
Add Authors here - you can only add them if they already exist on PEP. Just start writing their name then select to add it. To add multiple authors click the 'Add another item' button below.

Please ensure that you have proof-read your content. Pages are not edited further once submitted and will go live immediately.