Adult Brown Marmorated Stink Bug (BMSB, Halyomorpha halys)
Why should I monitor for the brown marmorated stink bug?
The brown marmorated stink bug (Halyomorpha halys) is an invasive species of shield bug that has originated from South East Asia. The brown marmorated stink bug (BMSB) is extremely polyphagous and will feed on many crop types including, but not limited to, soft fruit, vegetables, tree fruit and ornamentals. The invasive shield bug has caused significant losses to apple and stone fruit crops in North America and to pear, peach and nectarine crops in Italy.
There have now been several confirmed sightings of Halyomorpha halys adults in the UK. Growers should remain vigilant and monitor their crops for the presence of Halyomorpha halys. It is currently unknown whether the brown marmorated stink bug will become a serious pest in the UK, however early detection of this pest will play a large part in helping to control Halyomorpha halys if it does establish in the UK.
What is the brown marmorated stink bug and what damage does it cause?
The brown marmorated stink bug (Halyomorpha halys) is native to South East Asia but is now considered a globally important pest. The brown marmorated stink bug spread to the United States of America in the late 1990s. It has since become established in many European countries (including Germany, Switzerland, Italy and France), as well as Russia and Georgia. The BMSB can feed on over 100 species of plants and has a wide host range, making it a high impact pest.
Adult and nymph stages of Halyomorpha halys’ life cycle cause damage to crops when they insert their stylet mouthparts into plant tissue for feeding. As they do this, they inject their toxic saliva into the plant tissue which causes marketable produce to become scarred, discoloured and deformed. They particularly favour flower buds and developing fruits on a large variety of crops.
Brown Marmorated Stink Bug (BMSB, Halyomorpha halys) damage to apple
What is Halyomorpha halys’ life cycle?
The eggs of Halyomorpha halys are usually found on the underside of leaves of host plants and are about 1 mm in diameter. The first instar nymphs are around 2.4 mm in length and can often be found around the hatched eggs before they molt and disperse to feed. The Halyomorpha halys’ life cycle has a total of five nymph stages, before becoming an adult.
Adults are larger than most native shield bug species and range from 12 to 17 mm in length. The adults enter diapause in response to the shortening day lengths in autumn and overwinter in large aggregations. They often hide under tree bark or on edges of buildings, where they hibernate overwinter. The brown marmorated stink bug can also become an urban nuisance due to the pest overwintering in buildings.
Halyomorpha halys can have one to two generations per year, however it is anticipated that this species would only have one generation in the UK.
Why should I be concerned about the brown marmorated stink bug in the UK?
Over the past 10 years, the BMSB has been intercepted on goods in the UK on several occasions, however in recent years, a number of adults have been found in the wild in the UK. The first adult was found in Hampshire in 2018 and another adult was found in Hampshire in 2019. The third adult was found in Essex in 2020. Despite these findings, scientists remain unsure as to whether this pest has established in the UK or not, since only adults have been found at present.
Halyomorpha halys can disperse quickly by flight and also as a hitch hiker. The shield bug is thought to establish initially by feeding on exotic plant species in urban centres, however once present it can spread and cause damage very quickly. Researchers have predicted that there is more likely to be a steady build-up of the species in the UK, rather than a population explosion, meaning monitoring with the brown marmorated stink bug trap UK will help to play a big part in how we react to the pest.
If the brown marmorated stink bug successfully establishes in the UK it is expected to only have one generation per year, however severe crop damage has still been caused in other countries where there is only one generation of the BMSB per year.
Why use the brown marmorated stink bug trap UK?
In countries where Halyomorpha halys has been found, serious economic damage has been reported in the same year as the invasive shield bug was first detected. Once established, Halyomorpha halys control is challenging, due to its tolerance to certain insecticides. So far best control of this pest has been achieved by using broad spectrum insecticides, products that are not compatible with IPM (Integrated Pest Management) programmes.
Early detection of this invasive species is key since mitigation strategies are most important during the early stages of an outbreak. Growers can remain vigilant and monitor for the presence of Halyomorpha halys on their sites by using the brown marmorated stink bug trap UK. The clear double-sided sticky traps, combined with the Halyomorpha halys pheromone, provide an effective and cost-effective method for monitoring for this pest.
It is important to note that there are two native species of shield bug in the UK (Dolycoris baccarum and Pentatoma rufipes) that look similar to Halyomorpha halys, meaning that correct identification of this pest is important. The Halyomorpha halys pheromone used with this trap is specific to the brown marmorated stink bug and should help to avoid catches and confusion caused by other shield bug species. It is important to be prepared due to the high potential level of damage that this bug could cause.
How to monitor for Halyomorpha halys using the brown marmorated stink bug trap UK?
Each unit contains one clear double-sided sticky trap and Halyomorpha halys pheromone. The brown marmorated stink bug trap UK should be fixed on to a horizontal tree branch or post, approximately 2.5 m high. One trap is required per site. The Halyomorpha halys pheromone should be fixed next to the trap.
Monitoring for Halyomorpha halys should begin around the end of May and continue until November. The pheromone used is a female pheromone that lasts for 12 weeks. Both the sticky trap and Halyomorpha halys pheromone need replacing after 12 weeks. After November, it is unlikely that adults will still be active in the environment as they will be hibernating.
What crops are most at risk from this invasive shield bug?
Apples and pears are thought to be crops that are most at risk in the UK. However, it is also anticipated that soft fruit, field crops and glasshouse crops including tomato, pepper and brassicas will also be at risk, due to the pests’ broad host range.