CONSERVATION & ECOLOGY
diameter on the underside of oak leaves in late summer-autumn. The galls are yellowish green or red and often remain attached to fallen leaves. The spring generation forms inconspicuous galls in oak buds.
Acorn or Knopper gall wasp (Andricus quercuscalicis)became established in the UK during the 1970s and is now widespread. Eggs are laid during early summer in the developing acorns of Quercus
robur.Instead of the normal cup and nut, the acorn is converted into a ridged woody structure in which the gall wasp larva develops. The gall is initially yellowish green and sticky, but later comes greyish brown. The next generation forms inconspicuous galls on the male catkins of Turkey oak, Quercus cerris.
Control
Oak gall wasps have little or no impact on the tree’s health and growth is minimal. Control is not necessary nor is any available.
Biology
In general, oak gall wasps alternate between generations that are either asexual (all females) or sexual (males and females). The generation that emerges as adults in summer has both sexes, whereas the generation that develops as adults in late winter-spring is all female. The two alternating generations develop as larvae inside galls that are often markedly different in appearance and often on different parts of the plant.
Female gall wasps insert eggs into the appropriate part of the oak tree, such as vegetative buds, flower buds, acorns or roots. On hatching, the legless wasp grubs begin secreting chemicals that reorganise the oak’s normal growth processes. Instead of producing normal oak tree tissues, the gall structures are created by the plant around the developing grubs.
Most oak galls contain a single larva but some, such as oak apples, contain numerous larvae. Pupation takes place inside the galls. Additional insects may also be found inside some galls. Some of these feed on the gall without actually causing it and are known collectively as inquilines, whilst others are insects which parasitise either the gall-forming insect or the inquilines.
www.rhs.org.uk
Packham’s ‘people’s manifesto’ to save British wildlife
Dog-free nature reserves and a tax on pesticides are among the proposals being released as part of a “people’s manifesto” to save British wildlife. The call is being led by Chris Packham, who says “it’s time to wake up” to the “mass extinction in our own backyard”. Together with seventeen independent wildlife experts, the naturalist and TV presenter has assembled nearly 200 measures to reverse the massive declines that have struck so many of the UK’s animal and plants.
“I think we have normalised these declines that we talk about so freely ... we need to be more terrified about what they actually mean.”
In recent months, experts have warned that Britain is rapidly losing hedgehogs, farmland birds and wildflowers as a result of pesticide use, land conversion and climate change.
“Conservation has become complacent - I think we have normalised these declines that we talk about so freely, and we have lost the ability to see them in any tangible way,” Packham said. “We need to be more terrified about what they actually mean. We are talking about declines of 95, 97, 98 percent, so we are a few percent away from losing these species.”
Among the propsals in the People’s Manifesto to save UK wildlife are:
• Every primary school in Britain to be twinned with a farm to help children understand farming and food growing
• Primary school classes to name and own significant urban trees
• Replant 300,000km of hedgerows destroyed since 1960
• Wildlife ponds for every industrial estate and all municipal parks
• Swift/sparrow/starling boxes to be included in all new-build homes
• Re-wild ten percent of UK uplands
• Ten percent of every farm to be managed for wildlife
• Introduce a pesticide tax and set target for fifty percent reduction in pesticides use
• Make thirty percent of UK waters off- limits to commercial fishing
• Stop seal culling in Scotland
• Make all nature reserves dog-free (except for assistance dogs) and create new dog-walking hotspots
• An independent public service body - Life UK - to oversee all environmental care, free from party politics and government interference
You can download the manifesto by visiting
www.chrispackham.co.ukor by searching People’s Manifesto
More ‘tyresome’ news!
Teams of divers are painstakingly lifting an artificial reef made of tens of thousands of old car tyres from the seafloor south of France after it was found to spread pollution from toxic chemicals.
The operation is costing well over a million euros (£898,000) and is part- funded by the tyre manufacturer Michelin as well as the French state. Fish had been avoiding the area. Local fishing association leader Denis Genovese said that some types of fish swam around the collection of tyres, whilst “no species really got used to it”. Once upon a time it was seen as a
Smooth spangle gall wasp (Neuroterus albipes) PC October/November 2018 127
double solution - a way to get rid of old tyres, whilst creating habitats for marine life and stimulating marine organisms to grow on the rubber.
In 2015, authorities told journalists the tyres were thought to be “completely inert” and to present no risk at the time they were sunk.
Artificial reefs using tyres have also been sunk in other parts of the world. Tens of thousands of tyres have been removed from the seabed at Fort Lauderdale, Florida.
Around Gibraltar, the tyres were washed away by currents. Ships, cars and concrete blocks were later used instead.
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