Tag Archives: insects

Wildlife-friendly UK farms help Duke of Burgundy butterfly numbers take flight

Duke of Burgundy photo by Charlie Jackson under creative commons

The Guardian reports this is the time of year when the Duke of Burgundy, a small jewel of a butterfly named after an unknown aristocrat, takes to the wing.

Ten years ago, it was Britain’s rarest butterfly, living in tiny colonies on scrubby chalk or limestone grassland. Now it has bounced back, its population surging by 25% over the decade.

Last spring, one of the biggest colony of Dukes in the country was discovered by Martin Warren, the author of Butterflies: A Natural History. This was a chance find but the thriving population on chalk downland in Dorset is no accident.

Wasps may be hated – but they’re actually one of our most valuable species, study finds

Wasp photo by Pictoscribe under creative commons

iNews reports wasps may be the most hated creature in the garden but they are actually among the most valuable species around, a study has found. Researchers have conducted a major investigation into the 33,000 species of wasp and concluded they are the most unfairly maligned insects in the back yard. They conclude that wasps deserve to be just as highly valued as other insects, such as the much loved species of bees, because they play a key role as pollinators and as predators – keeping the insects they eat further down the food chain in check…

Government agrees to release parasite wasps to kill invasive pests attacking sweet chestnut trees

iNEWS reports thousands of parasite wasps are set to be released in England in an effort to kill an in invasive pest attacking sweet chestnut trees. The Government has granted approval for Torymus sinensis, a type of parasite wasp, to be introduced in order to attack the invasive Oriental Chestnut Gall Wasp.

Concern has been mounting about the fate of England’s sweet chestnut trees after the Oriental Chestnut Gall Wasp was first spotted in Kent in 2015. The wasp’s larvae causes abnormal growths – known as ‘galls’ – on the leaves of sweet chestnut trees. Large infestations can weaken the host tree, making it more vulnerable to pests and diseases.

A good year for UK butterflies but third of species still in decline

Red Admiral Butterfly

The Guardian, and Daily Mail report last year was the third good summer in a row for butterflies and the 10th best since records began, but one-third of Britain’s species are still in long-term decline.

Conservation scientists warned against overstating the butterfly boom, saying perceptions of a “good” year have lowered in the light of plummeting insect numbers. “Perhaps because of the sunny spring weather last year and the fact that more people were enjoying nature as part of their day-to-day activities, butterflies seemed more numerous,” said Richard Fox, of Butterfly Conservation.

Box-tree moth, Agapanthus gall midge and Gypsy moth arrive in Normandy – Gardeners Beware!

Species that have been introduced into areas outside their natural range through human actions and that pose a threat to native wildlife, are known as invasive non-native species.  Sadly some have made their way to Normandy, affecting our native wildlife.  However, you can help, by recognising them and reporting them, and even taking measures to control them. Read these details, from FNW Committee member, Bill Stanworth, on three such species to look out for.

The box-tree moth (Cydalima perspectalis) has been recorded for the first time in Normandy at Springhill garden. Adult moths were attracted to a mercury vapour lamp in July 2020 and later in the year larvae were found on its foodplant, box (Buxus sempervirens) growing in the same garden. The moth is a native of the Far East and so its arrival in Europe (in 2006) is thought to have been from imported box plants – ugh.

The first record of the moth in the U.K. was from Kent in 2007 but a year later it was found in Weybridge, Surrey. Since then the moth has been gradually increasing and from distribution maps the moth may have been in our area for a year or so. Papers about the moth and its distribution can be found on the RHS website.

The adult moth, shown below is large and very distinctive. Its markings are variable and even a brown form exists. The stripy green caterpillar is also quite distinctive and is shown resting below on its foodplant. It creates silk strands that tie leaves together forming a lair from which it can feed and retreat into, in times of danger.

Box-tree moth
Box-tree moth catepillar

You can see from the photos below that even in less than one season they can seriously damage the plant. Feeding signs and frass are shown on the left and serious defoliation on the right. If you see this happening to your box bushes please check with the RHS and other websites for control methods (preferably using the non-pesticide methods).

We urge you to control this species as box is a native plant in southern England and it could have a serious effect on our best-known native boxwood at Box Hill, Surrey and other sites in the county and country. If you see the box-tree moth the RHS would like to know, you can submit your records on their website via their box-tree moth survey.

Box bush damage
Box bush damage

The second pest to look out for is the Agapanthus gall midge, which was also found in Springhill garden for the first time in 2020. It’s another devastating pest (if you grow Agapanthus in your garden!), a fly this time, that lays its eggs on the young Agapanthus flower buds. The tiny, creamy-yellow larvae develop and cause the flower bud to become distorted, go brownish and most fail to open. A photograph of the affected buds (here detached from the plants) is shown below.

According to the RHS the midge causing this was new to science and only discovered in 2014, this time at Wisley but it is probably a native of southern Africa, home of the plants. Control methods are given on the RHS website. Agapanthus flowers are popular with some native pollinators; an example shown here is probably a melanistic garden bumblebee (Bombus hortorum) from Springhill garden. This one spent a lot of time on this white flowered variety! Sadly many Agapanthus flowers at Springhill were ruined this year.

The RHS are asking for help from gardeners who have seen agapanthus gall midge or damaged flowers and request you send photos of symptoms on the flowers and buds, plus opened buds showing larvae where possible, to entomology@rhs.org.uk on their website.

Agapanthus flower buds
Bumble bee on Agapanthus flower

Another invader and potential pest is the gypsy moth (Lymantria dispar). The male shown below was attracted to a mercury vapour lamp at Springhill garden on 7 August 2020. On mainland Europe the moth can be a serious pest, stripping broadleaved trees (particularly apple, plum and willows; oaks and poplars in forests) and bushes.

Look out for patches of eggs covered with yellow/brown hairs on trunks and walls over winter or for large dark grey/black hairy caterpillers with reddish spots from April to June/July. Apparently the hairs don’t cause irritation of the skin unlike the oak processionary moth. The RHS website says ‘whilst a single defoliation from this caterpillar even early in the season, should not affect the vigour of a host plant, repeated defoliations can have an adverse effect’ and advice is given with regards control. They also very sensibly say ‘where possible tolerate populations of caterpillars’.

This moth (not mentioned/recorded in ‘The Larger Moths of Surrey’ [Graham A. Collins] published by SWT in 1997) was a former resident in the East Anglian fens but it lived on bog-myrtle and creeping willow and so wasn’t considered a pest. The European strain was accidentally introduced and has spread rapidly in the London area. Hopefully, as the large bodied females are mostly flightless, we won’t be troubled for a while.

There is no statutory requirement to notify sightings of gypsy moth to the plant health authorities but you can report serious damage to the government’s ‘Forest Research’ website: TreeAlert (their on-line pest reporting tool).

Gypsy moth

2018 saw the first arrival of the oak processionary moth (Thaumetopoea processionea) to Normandy (see our previous article). No moths were seen in Normandy in 2019 as far as we know but you may have seen that the Forestry Commission have erected posters warning the public to be alert for them and report them when seen. In addition at least one team has been seen on Normandy Common searching for evidence of their presence. This year three males were attracted to the mercury vapour lamp at Springhill so please stay vigilant.

Britain’s moths decline by a third in 50 years, study finds

The Guardian and iNEWS report moths in Britain have declined in abundance by a third over the past 50 years, according to a study. The declines of 39% in the abundance (relative representation in an ecosystem) of larger moth species over southern Britain and a 22% fall across northern Britain add to the picture of calamitous declines in flying insects in the industrialised world.

Among the most rapidly declining of Britain’s 900 larger moth species are the stout dart (-81% over an average 10-year period), the golden plusia (-58%) and the garden dart (-54%). 

UK scientists confirm arrival of brown marmorated stink bugs

Brown marmorated stink bug photo under creative commons

The Guardian, and iNEWS report it is brown, stinky and will strike fear into the hearts of apple and other fruit growers. Scientists have now confirmed that the brown marmorated stink bug (Halyomorpha halys), a small flying insect that emits an unpleasant almond-like odour, has arrived in Britain, after most probably hitching a ride on packaging crates. 

Traffic noise is making female crickets less picky

Bog Bush-Cricket (Metrioptera brachyptera) female – Creech Heath, Dorset
Photo by Will Atkins under creative commons

iNews reports traffic noise makes female crickets less picky when choosing a mate, a new study from Anglia Ruskin University suggests, threatening their long-term survival. Male crickets perform courtship songs to attract a female by rubbing their wings together. Females will generally pick the male with the best serenade. But road noise is making it harder for female crickets to distinguish between a top notch song and an off-key performance, the researchers said. 

Pesticide set for return in UK despite EU ban ‘stops bees sleeping’

The Independent reports neonicotinoids, linked to collapse in insect pollinator populations, knock bees’ and flies’ behavioural rhythms out of sync. Almost all living creatures require sleep in some form to function properly, and insects are no exception. But new research warns exposure to a common insecticide, banned in the EU but set for reintroduction to the UK, impacts the sleep of bumblebees and fruit flies, and “may help us understand why insect pollinators are vanishing from the wild”.