Leek show to go ahead on 25th July 2020
LEEK & District Show – Staffordshire Moorlands’ premier agricultural event for more than half a century – is to go ahead after all in July 2020….and beyond.
The news comes just three months after organisers took the ‘extremely reluctant and sad’ decision to discontinue the long-standing show, following falls in attendance and revenues during the last two years.
Now, funding to enable this year’s event to be held has been secured – and a five-year plan put in place to ensure the Show’s survival well into the new decade.
“The strength of feeling locally that the Show must not be allowed to die has been overwhelming” said Acting Show Chair Rachel Torr.
“Soon after we announced last year that it had become financially impossible for the Show to continue, we were contacted by three members of the local agricultural community who were determined that couldn’t and shouldn’t happen.
“Thanks to their dedication and hard work, and the support of sponsors old and new, the Leek & District Show will now go ahead on Saturday 25th July 2020 – and for the foreseeable future!”
The three businessmen – Kenneth Carr, Bruce Daniel and Ed Simms – have between them considerable experience and expertise in organising and running agricultural events, and have already ensured that sufficient resources are in place for this year’s Show.
“We began by trying to determine what had gone wrong in previous years, and it became clear that the Show needs to be run as a business, on a firm and sustainable financial footing,” said Mr Daniel, who has been involved with Manifold Valley Agricultural Show for 40 years.
“We’ve got the full support of the agricultural community and suppliers, and a five-year plan in place, backed by sponsorship pledges. We don’t want the 2020 Leek & District Show to be a one-off ‘stay of execution’; we want the whole community to ‘own’ it, be prepared to pay to go in, and to continue to invest in its future.”
Mr Daniel and his colleagues are expected to be co-opted onto the Show Committee at a special meeting convened for later this month, and are looking forward to working with existing members to ensure the event’s continued success.
Added Mr Daniel: “We certainly don’t want people to think we’re moving in and taking over; we simply want to contribute our own collective experience and ideas to bolster the strength of the existing committee.”
Leek United has been main sponsor of the Show for the past six years, and has confirmed that its support for the event will also continue.
Andrew Healy, the Society’s Chief Executive, said: “We are absolutely delighted that, with the help of our own sponsorship, Leek & District Show can continue this year and beyond. As main sponsor, we look forward to working closely with organisers to help ensure that the Show is a successful summer highlight for local businesses and families alike in the Staffordshire Moorlands.”
- Thousands expected to flock to Leek and District show
- From our Obsession
- Allium (Onion) Leafminer
- Allium leaf miner update: 09/20/19
- Pest Alert – Allium Leafminer
- Host Plants and Damage Symptoms
- Life History
- Monitoring and Management
- Allium Leafminer Known Range
- Reporting a Possible Detection
- Selected References
- Allium Leaf Miner
- Allium Leaf Miner Phytomyza gymnostoma
- Allium Leaf Miner Distribution
- What is Allium Leaf Miner?
- Life cycle of the Allium Leaf Miner
- How to Tell You Have Allium Leaf Miner
- Control of the Allium Leaf Miner
- Pests and diseases
- Pests and Diseases
Thousands expected to flock to Leek and District show
The 56th annual Leek and District Show will take place at Birchall Playing Fields on Saturday, July 28.
Starting at 8am, the event is sponsored by Leek United Building Society for the fifth year running.
The show committee has planned a wide range of fun and entertainment for the whole family.
There will be the livestock classes, for which the show is well known, from cattle and sheep to goats and shires. There will be a 94 class unbenched dog show, horse and pony section with qualifiers for the Olympia first and second round qualifier and championship show 2018.
There will be classes and competitions in horticulture, WI and flower design for adults and children alike.
The two ever popular craft marquees was quickly booked up with a wide range of crafts and gifts.
The Ladies section is once again holding a baby competition by Pure Photography, who will this year be joined by TinyTalk High Peak and Leek Baby Signing.
Main ring entertainment includes the Field Gun Display Team, Horses in Harmony Dressage Team and the Dog and Duck Show.
There will be a large number of trade stands where show-goers can meet up with friends and colleagues, have fun trying to win prizes or even milk a cow, while supporting local businesses and charities.
Livestock events are a key feature of the annual event (Image: Leanne Bagnall/StokeonTrentLive)
There will be Punch and Judy shows in the small entertainment ring plus music courtesy of the Florence Brass Band.
Popular attractions include the farriers, who will once again be showing their skills in the production of horseshoes.
Again this year, free wifi will be available on the showground so show-goers will be able to invite their friends and family along to join in the fun and entertainment.
If you fancy something a bit geeky call into the Internet Connections marquee to see the games they have available to play.
If you’re feeling peckish, there will be numerous catering outlets to tempt even the fussiest of eaters.
This year, as a trial, the show committee is offering local musicians and artistes the opportunity to showcase their skills on a music stage. Taking to the stage from 11am will be Rebecca Jayne, Timothy Hoar, Mark Wright, Kayleigh Knight, Megan Barnes, Dominic ‘Chuck Berry’ Cooper, Jack
Porteous and the Tony and Jaxx Duo.
A free park and ride will be available from Ornua, The Mount and Leek Bus Station.
The annual event attracts thousands of people to Birchall playing fields (Image: Leanne Bagnall/StokeonTrentLive)
Check the show website for timings.
Ticket prices have been frozen, with advance tickets available from Leek United Building Society’s Head Office and local branches, the show website and the Tourist Information Centres in Leek and Hanley.
Alternatively, why not support the Moorlands’ premier rural event by becoming a member of the Leek and District Show. Benefits include entrance
to the show and reserved areas along with a vehicle pass either for the Co-Op car park or the showground.
Prices are: single membership £8, double membership £15,vice president £20, patron £25.
Please contact Allan Pickering on 07834 707073 for further information.
Dogs are welcome on the showground but please keep them on a lead, don’t let them worry the animals and clean up any mess.
- A full 32-page supplement about Leek show is available in this week’s (Wednesday July 25) Leek Post & Times and Cheadle Post & Times.
From our Obsession
Future of Finance
New technology is upending everything in finance.
If you suddenly found yourself in a chat group where Chinese investors buy and sell cryptocurrencies, chances are high that you’d get frustrated quickly, even if you can read the language.
Why are people enthusiastically talking about the prices of pancakes and egg tarts? Why the hell is someone trying to buy a concubine? Is this some kind of hipster community that is obsessed with avocados?
While crypto enthusiasts in the West have created a lexicon of their own, a parallel slang is flourishing in the crypto trading community in China, a country that once dominated global bitcoin trading before authorities cracked down on local exchanges in September.
Chinese crypto investors are still trading peer-to-peer on services like WeChat and encrypted apps like Telegram, and discussing trades on online forums like 8btc.com. The jargon helps avoid further government intervention by obscuring their intentions from prying eyes. They probably won’t thank us for this, but here’s a glossary to help demystify what’s going on.
币圈 (Bì quān) — Literally “coin circle.” Refers to the crypto space.
大佬 (Dà lǎo) — “Boss.” Refers to a trader with a lot to invest. The equivalent to a “whale” in Western crypto slang.
狗庄 (Gǒu zhuāng) — “Dog banker.” From gambling and stock-market parlance: retail investors use the term to refer to big-time traders who can easily move the market and burn them. Typically used in complaints.
韭菜 (Jiǔcài) — “Leek.” Also borrowed from stock markets: It’s a metaphor for newbie investors who get “harvested”—that is, they follow the lead of seasoned investors but often end up losing their money. Fortunately, they can grow back when other naive newcomers spring up to replace them.
老韭菜 (Lǎo jiǔcài) — “Old leek.” By extension, a longtime retail investor who routinely gets burned by whales over time.
币妈 (Bì mā) — A shorthand for biquan dama, which means “coin-circle aunties.” Dama refers to middle-aged Chinese women who are hungry for new assets but lack basic investment knowledge and skills (pretty much the same gendered concept as the bitcoin grandma featured in one well-known business paper). The term was first floated when middle-aged investors rushed to buy physical gold in 2013, pushing up global gold prices. Then they flocked to local stock markets amid a historic bull run—followed by an inevitable meltdown—in 2015. Crypto appears to be the “aunties’” newest playground.
囤币 (Tún bì) — “Hoarding coins.” To stay invested in cryptos and buy more of them over time. The Western equivalent of “hodl.”
糖果 (Tángguǒ) — “Candy.” Refers to free token giveaways in exchange for signing up for ICO projects. Roughly the same as “airdrop” in Western slang.
薅羊毛 (Hāo yángmáo) — “Pulling out the wool.” From financial markets: refers to the activity of investors who try to make money in the long run by hunting for bonuses offered by banks and other financial institutions. In the crypto space, hunting for candy, for example, is one way to “pull out the wool.”
割韭菜 (Gē jiǔcài) — “Cutting leeks.” Pretty much what it sounds like.
搬砖 (Bān zhuān) — “Moving bricks.” The slang term for arbitrage, the simultaneous buying and selling of the same asset in different markets in order to take advantage of different spreads offered by brokers. For example, arbitrage traders buy cryptos in open markets like Japan, and sell them at a premium in banned markets like China.
梭哈 (Suōhā) — The transliteration of “Show Hand,” a variant of five-card stud poker made popular by Hong Kong gambling films. Here, it means “all in.” One popular but sexist meme in the Chinese crypto community goes, “Show Hand, Show Hand, all Show Hand. If win, order young models at clubs. If lose, go and do farm work.”
Some other trading terms to get familiar with:
There’s a slang term for every major crypto coin. And as you can tell, they are predominantly named after food that sounds similar:
|Slang||Refers to…||Pinyin||Literally means…|
|大饼||Bitcoin||Dà bǐng||Big pancake|
|小饼||Bitcoin cash||Xiǎo bǐng||Little pancake|
|大姨太||Ethereum||Dà yítài||Big concubine|
|小姨太||Ethereum classic||Xiǎo yítài||Little concubine|
|辣条||Litecoin||Là tiáo||Spicy stripe|
Posted by Rosemary Gordon|August 5, 2016
Photo credit: N. Sloff, Dept. of Entomology, Penn State
The allium leafminer, also known as the onion leafminer, was first spotted in Lancaster County, PA, in December 2015, making it the first confirmed infestation in the western hemisphere. The pest was seen targeting onions, leeks, garlic, chives, shallots, as well as green onions, with leeks being described as the most damaged host.
Shelby Fleischer, Professor of Entomology at the University of Pennsylvania, discusses the symptoms of infestation, how to identify the newly spotted pest, and control measures.
One of the first symptoms you will notice on plants is wavy, curly, and distorted leaves, which Fleischer says may be mistaken for damage from herbicide residue. However, upon closer inspection, you will be able to see puncture marks along the sides of the leaves toward the distal end.
“This is something the female does with their ovipositor, so both females and males can feed on the plant exudates,” he explains.
The fly larvae mine the plant leaves and move toward the bulb and leaf sheaths where they pupate. Exactly where they pupate in the plant may vary depending on bulb and leaf size, Fleischer says. To check for larvae, the plants must be pulled out of the ground and the leaves pulled back.
Damage from feeding can create entry routes for bacterial and fungal pathogens, and Fleischer has already seen bacterial rot brought in on several specimens.
Spotting the adult flies is harder due to the fact they are small and fly fast. “Seeing the damage is the first symptom; next you look at the leaves for puncture wounds; and then finally, you peel back the leaves to look for pupae,” he explains.
Adult allium leafminers are less than 3 millimeters (mm) in length, are grey or black in color, have a distinctive yellow or orange patch on the top and front of their heads, and have yellow “knees.” Yellow also can be seen on the sides of the adult fly’s abdomen, and the wings are situated horizontally over the abdomen when at rest.
The eggs are white, tiny (only 1/2 mm long), and slightly curved. The larvae are white, cream, or yellowish in color, are headless, and up to 8 mm long at their final instar. The pupae are dark brown, 3.5 mm long, with a pair of posterior spiracles with 18 to 20 bulbs per spiracle.
There are an estimated 1,090 degree days from egg-to-adult development using a 41.2°F threshold, or 1,225 degree days using a 37.8°F threshold.
Monitoring And Behavior
The allium leafminer overwinters as pupae in plant tissue or in surrounding soils and emerge as adults in late winter into spring.
Because the pest is new to the U.S., most information on its life cycle has been gathered from Europe. According to Fleischer, current research indicates the pest has a pretty distinct flight pattern early on in the season beginning from March until the beginning of May, where all flight activity stops.
“Another series of flight activity starts up later, but exactly how much later we don’t know yet. The flight timing may influence which crops get damaged. But with some luck, hopefully flights will wait until September,” Fleischer explains.
Using yellow sticky traps also has been effective in trapping adults and monitoring flight patterns, he says.
One of the first ways Fleischer suggests protecting your crop from allium leafminer is to time your plantings to avoid emergence, flight activity, and adult oviposition. If you’ve successfully assessed flight timing, using row covers during flight time also may be used as a control measure.
For chemical control, systemic and contact insecticides can be used as long as they are labeled for use on allium crops. Products labeled for leafminers that may be effective on allium crops include Aza-Direct (Gowan), TriGard (Syngenta), Scorpion (Gowan), Warrior II (Syngenta), and Radiant (Dow AgroSciences), among others.
Rosemary Gordon is editor of American Vegetable Grower, a Meister Media Worldwide publication. See all author stories here.
Allium (Onion) Leafminer
The allium leafminer Phytomyza gymnostoma (also known as the onion leafminer) has recently been detected and confirmed from infested leeks in Lancaster County, PA. This is the first confirmed infestation in the Western Hemisphere.
The allium leafminer has been reported to infest species in the genus Allium. Leeks (A. porrum) tend to be described as the most damaged host, which may be influenced by the timing of the second generation and the planting of leeks. Infestations have also been reported in onion (A. cepa), garlic (A. sativum), chive (A. schoenoprasum), shallot (A. cepa), and green onion (A. fistulosum). There are many ornamental species of Allium, and at least one endangered Allium (A. munzii in California). The full host range is unknown.
Adult females make repeated punctures in leaf tissue with their ovipositor, and both females and males feed on the plant exudates. These punctures may be the first sign of damage. Larvae mine leaves, and move towards and into bulbs and leaf sheathes. Both the leaf punctures and mines serve as entry routes for bacterial and fungal pathogens. High rates of infestation have been reported: from 20 to 100 pupae per plant, and 100% of plants in fields. The literature suggests organic production and market garden production systems tend to be most at risk, perhaps due to insecticidal control in conventional production systems.
Adults: Small (~ 3 mm) long grey or black flies with a distinctive yellow or orange area on the top and front of head (fig.1). Wings are held horizontally over abdomen when at rest, white halters. Legs have distinctive yellow “knees”. Although adults are fairly distinctive, male genitalia are required to confirm ID.
Eggs: White, 0.5 mm long, and slightly curved.
Larvae: White, cream, or yellowish maggots, headless, up to 8 mm long at their final instar.
Pupa: Dark brown, 3.5 mm long, with a pair of posterior spiracles with 18-20 bulbs per spiracle.
Allium leafminers overwinter as pupae in plant tissue or surrounding soil. Adults emerge in late winter (March) into spring (throughout April, perhaps into May), and lay eggs at the base of plant stems. Larvae mine leaves, and move downward into the base of leaves or into bulbs, where they pupate. Pupae may
move into soil. These 1st generation pupae undergo a diapause or aestivation period which lasts throughout the summer, and develop into adults that emerge in the autumn (September / October). This 2nd generation of adults lay eggs into Allium spp., which develop through the larval and into the pupal stage. These 2nd generation pupae will overwinter. Egg-to-adult development is estimated to require 1,090 degree-days using a 5.1o C threshold, or 1,225 degree-days using a 3.2o C threshold.
Adults have been captured using yellow sticky cards or yellow plastic bowls containing soapy water.
Cultural Control: Covering plants in February, prior to the emergence of adults, and keeping plants covered during spring emergence, can be used to exclude the pest. Avoiding the adult oviposition period by delaying planting (after mid-May we think) has also been suggested to reduce infestation rates. Covering fall plantings during the 2nd generation flight can be effective. Growing leeks as far as possible from chives has been suggested.
Organic Chemical Control: Azadirachtin (Aza-Direct or other formulations) or spinosad (Entrust or other formulations) follow label instructions for leaf miner.
Synthetic Chemical Control: Systemic and contact insecticides can be effective. EPA registrations vary, however, among Allium crops. Check labels to ensure the crop is listed, and for rates and days-to-harvest intervals. Options that may be effective include cyromazine (Triguard), dinotefuran (Scorpion), spinetoram (Radiant), lambda-cyhalothrin (Warrior II or other formulations), and abamectin (Agri-Mek or other formulations).
Allium leaf miner update: 09/20/19
Allium Leaf Miner
Allium leaf miner (ALM) feeding/egglaying scars were detected in chives and scallions near Princeton (Mercer Co.), NJ on Friday of this week. This indicates that the second (fall) flight of these flies is now underway, and damage is occurring.
Photo: Sabrina Tirpak. Allium leafminer oviposition scars on onion
Growers should consider initiating the control method of their choice at this time. Affected crops include chives, scallions, garlic, onions and leeks.
Floating row covers, kept on until the second flight ends will help minimize access to plants. Insecticide applications targeting adults may be helpful as well, although frequency of applications is uncertain. Spinosyn materials (Radiant, Entrust (OMRI approved)), pyrethroids (Mustang Maxx, Warrior), and pyrethrin materials (Pyganic (OMRI approved)), neonicotinoids (Scorpion, Venom) and the insect growth regulator Trigard are labeled for miner control.
Adult activity and observations of feeding will be reported on in the IPM Update as they occur. At this time, all growers should respond to the second adult generation. We will attempt to identify the end of the second flight so that growers know when the risk of infestation has abated.
Pest Alert – Allium Leafminer
Host Plants and Damage Symptoms
The allium leafminer (Phytomyza gymnostoma Loew) has been reported to infest species in the genus Allium. Leeks (A. porrum) tend to be described as the most damaged host, which may be influenced by the timing of the second generation and the planting of leeks. Infestations have also been reported in onion (A. cepa), garlic (A. sativum), chive (A. schoenoprasum), shallot (A. cepa), and green onion (A. fistulosum). There are many ornamental species of Allium, some wild species are common weeds, and at least one species is endangered (A. munzii in California). Current literature varies in reporting damage in ornamental and wild Allium spp. The full host range is unknown.
Wavy, curled and distorted leaves from the allium leafminer. Photo: L. Donovall.
Adult females make repeated punctures in leaf tissue with their ovipositor, and both females and males feed on the plant exudates. Leaf punctures arranged in a linear pattern towards the distal end of leaves may be the first sign of damage. Leaves can be wavy, curled and distorted. Larvae mine leaves, and move towards and into bulbs and leaf sheathes where they pupate. Leaf mines are most evident in species with thin leaves (chives). In species with larger leaves, it is often necessary to peel back the leaves to find the insect. Both the leaf punctures and mines serve as entry routes for bacterial and fungal pathogens. High rates of infestation have been reported: from 20 to 100 pupae per plant, and 100% of plants in fields. The literature suggests organic production and market garden production systems tend to be most at risk, perhaps due to insecticidal control in conventional production systems. Leafminers as a pest in Allium crops has rapidly increased following introduction of allium leafminer.
Allium Leafminer pupa embedded in leaf tissue from a field in Lancaster PA. Photo L. Donovall.
Feeding punctures along side of leaf
The allium leafminer was first described in 1858 from Poland, and is native to Poland and Germany. Recently, the geographic range has been rapidly expanding. It is now present throughout Europe, reaching the United Kingdom in 2004. It has recently been reported in Asia, Turkey, and parts of Russia and Turkmenistan.
- Adults: Small (~ 3 mm) long grey or mat-black colored flies with a distinctive yellow or orange patch on the top and front. Yellow color also present on side of abdomen. Wings held horizontally over abdomen when at rest. Legs with distinctive yellow “knees” (at femur-tibia junction). White halteres. Although adults are fairly distinctive, male genitalia are required to confirm identity.
Adult Allium Leafminer
- Eggs: White, 0.5 mm long, and slightly curved.
- Larvae: White, cream, or yellowish maggots, headless, up to 8 mm long at their final instar.
- Pupa: Dark brown, 3.5 mm long, with a pair of posterior spiracles with 18-20 bulbs per spiracle.
Allium Leafminer pupa. Photo by Donovall.
Allium leafminers overwinter as pupae in plant tissue or surrounding soil. Adults emerge in late winter (March) into spring (throughout April, perhaps into May), and lay eggs at the base of plant stems. Larvae mine leaves, and move downward into the base of leaves or into bulbs, where they pupate. Pupae may move into soil. These 1st generation pupae undergo a diapause or aestivation period which lasts throughout the summer, and develop into adults that emerge in the autumn (September / October). This 2nd generation of adults lay eggs into Allium spp., which develop through the larval and into the pupal stage. These 2nd generation pupae will overwinter. Egg-to-adult development is estimated to require 1,090 degree-days using a 5.1°C/41.2°F threshold, or 1,225 degree-days using a 3.2°C/37.8°F threshold.
Monitoring and Management
Adults have been captured using yellow sticky cards or yellow plastic bowls containing soapy water.
Covering plants in February, prior to the emergence of adults, and keeping plants covered during spring emergence, can be used to exclude the pest. Avoiding the adult oviposition period by delaying planting (after mid-May in Poland) has also been suggested to reduce infestation rates. Covering fall plantings during the 2nd generation flight can be effective. Growing leeks as far as possible from chives has been suggested. Continuous cultivation of Allium species (such as chives) provides the pest with a continuous food source.
Systemic and contact insecticides can be effective. EPA registrations vary, however, among Allium crops. Check labels to ensure the crop is listed, and for rates and days-to-harvest intervals. Options labelled for leafminers or dipteran leafminers that may be effective include azadirachtin (Aza-Direct or other formulations), cyromazine (Trigard), dinotefuran (Scorpion), lambda-cyhalothrin (Warrior II or other formulations), spinetoram (Radiant), spinosad (Entrust or other formulations), and zeta-cypermethrin (Mustang or other formulations). Other materials labelled for Liriomyza leafminers or thrips that may be effective include abamectin (Agri-Mek or other formulations), acetamiprid (Assail), and cyantraniliprole (Exirel). Among these, the Entrust formulation of spinosad is allowable for certified organic production if allowed by your certifying organization.
- Scientific Name: Phytomyza gymnostoma Loew (Family Agromyzidae)
- Common Names: Allium leafminer, onion leafminer
- Recent Synonyms: Napomyza gymnostoma Loew
Allium Leafminer Known Range
Reporting a Possible Detection
If you suspect you have observed damage or a life stage of the allium leafminer outside of the known range, please contact a plant inspector in the regional Department of Agriculture office or an Extension Educator or Diagnostic Laboratory in the local Cooperative Extension Office. In Pennsylvania, contact the plant inspector in your regional office of the Pennsylvania Department of Agriculture or an Extension Educator in the local Penn State Extension office.
Insecticides labelled for leafminers
Collins, D. and M. Lole. 2005. Phytomyza gymnostroma Loew (Diptera: Agromyzidae), a leaf mining pest of leek and onion new to Britain. Entomologist’s monthly magazine 141: 131-137.
Coman, M. and I. Rosca. 2011. Biology and life-cycle of Napomyza (Phytomyza) gymnostroma Loew., a new pest of Allium plants in Romania. Southwestern Journal of Horticulture, Biology and Environment 2 (1): 57-64.
Coman, M. and I. Rosca. 2011. Allium crop protection plant management for Napomyza gymnostroma Loew pest. Scientific papers series management, economic engineering in agriculture and rural development. 11(2).
CSL Pest Risk Analysis for Phytomyza gymnostoma. 2007. 13 pp.
Kahrer, A. 1999. Biology and control of the leek mining fly, Napomyza gymnostoma. Integrated control in field vegetable crops. IOBC Bulletin 22 (5): 205-211.
Simoglou. K. B., E. Roditakis, M. Martinez and N. E. Roditakis. 2008. First record of Phytomyza gymnostoma Lowe (Diptera: Agromyzidae) a leaf mining pest of leeks in Greece. Bulletin OEPP/EPPO 38: 507-509.
Global Pest and Disease Database. Pest record created February 6, 2009, reviewed March 20, 2009. Accessed 3/11/2016
USDA APHIS. 2016. New Pest Advisory Group (NPAG) Report. Phytomyza gymnostoma Loew: Onion leafminer. 7 pp.
Plantwise Knowledge Bank. Accessed April 2, 2016.
Authors: This pest alert was written by Shelby Fleischer, Department of Entomology, Penn State, University Park, PA, and Tim Elkner, Penn State Extension, Lancaster County. Edited by D. Gilrein, Cornell Cooperative Extension of Suffolk County. April 11, 2016.
It is stubbornness on my part, but I refuse to give up leeks. The allium leaf miner is a pesky thing that has taken up residence around here and likes to shred anything in the allium family, though it seems especially partial to garlic, leeks and bulbing onions.
I’ve given up on onions, but I can’t bring myself to give up leeks and garlic. I cover everything I grow with fine mesh netting from March onwards. The leaf miner lays its eggs in two periods, March-April, then that lot hatch and lay eggs in October and November, making overwintering leeks very vulnerable. It’s tiny, only 3mm long, and thus often finds cracks and holes to make its way to its progeny’s favourite dinner. Garlic can soldier on, but I find the leeks are often in tatters and then rot over the winter.
This year I am going to employ a different method. I’m going slim and small. I’m going to successionally sow leeks and pick them when they are a little fatter than my thumb, but not much more. This is an excellent trick for small gardens regardless of miners: you can fit many skinny baby leeks in where spacing for mature leeks would be prohibitive, and they taste heavenly – delicate with not a hint of toughness.
Rather than sow leeks now for transplanting out just when the miner is on the wing, I’m going to sow in situ (leeks germinate best in soils at 10-15C) from the third week of April into June; I’ll sow them in wide drills, aiming to get the seed 1cm apart, with 15cm between rows. I’ll pull the leeks when they are 15-20cm high (after about 13 weeks).
I’m hoping to miss the majority of flies, and even if I do get a few infestations, they will be pulled before the second generation can take hold. Of course, if you don’t have leaf miner, sow a batch indoors now and be eating leeks by June. Choose fast-growing, early varieties such as ‘Nipper’, ‘Bulgaarse Reuzen-Lincoln’ or ‘Sprintan’ F1.
You don’t have to limit yourself to baby leeks: beetroot and turnips are far superior when picked small and sweet. Space the seed 2.5cm apart in rows 20cm apart, or patches or blocks with the seed 5cm apart in every direction. Thin to 7.5-10cm apart for perfect small beet and turnips. You should get about 30 plants per 30cm2 and be ready to pick within 9-12 weeks. If you give them a little wider spacing, say 15cm between plants, you can encourage very rapid growth indeed.
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Allium Leaf Miner
Allium Leaf Miner Phytomyza gymnostoma
The allium leaf miner has fast become a serious pest affecting all of the alliums – onion family. It’s primarily a problem with leeks which are its preferred host but it will go for onions, garlic, chives and shallots. It can be devastating to the crop. Allium leaf miner actually became No. 7 in the RHS “Top Ten” list of pests in 2015!
The Allium Leaf Miner was first noted in Poland in 1858 but it’s only in recent times that it has become a significant pest. Possibly a result of climate change providing more hospitable conditions for the pest.
Allium Leaf Miner Distribution
It has spread quickly, being noticed as a problem in Hungary in 1986. By 1990 it was in Slovenia and Croatia moving across into Serbia by 1992. Come 1994 it was in Germany, Austria and Slovenia. In 2002 / 2003 it appeared in Switzerland, France and Britain. It is also in the USA (Pennsylvania and Maryland especially but spreading quickly)
In Britain is was initially picked up in the West Midlands but has now spread widely covering all of the Midlands and South of the country. It has been detected in all of Wales as well. It’s moving north and climate change seems to be aiding its spread.
Initially it was just a garden and allotment pest in Britain but now it’s becoming a problem for commercial growers. According to the RHS there are no chemical controls currently approved for its control available to home growers. Derris (rotenone) and pyrethrin were mentioned as being controls in 2007 by FERA but Derris is now delisted. However, both Derris and pyrethrins are unlikely to be effective due to the lifecycle of the pest. Farmers have access to systemic insecticides that would be effective.
What is Allium Leaf Miner?
The adult is a very small fly with a body just 3 mm long. It is grey / black in colour with a yellow forehead and yellow on the abdomen. The legs are also black except for yellow knees.
The adult lays eggs which hatch into maggots. These are pale yellow in colour, tapering to an eyeless pointed head with a pair of brownish hooks. When fully developed they are about 6 mm long. These burrow through the host plant, leaving tunnels behind.
When fully developed, the maggot pupates. The pupae are are reddish brown in colour and 3 to 4 mm long. These are found near the surface of the host plant inside the leaf tissues. The fly hatches from these and starts the cycle again.
Life cycle of the Allium Leaf Miner
There are two generations a year with summer and winter rests. The fly overwinters as pupae sat within the plant tissues of its host plants.
In the spring, from March to the end of May, adults (from the 2nd generation of the year
previous) emerge from the pupae. Timing of the emergence seems to be temperature dependent.
Mating occurs within 48 hours after the adults hatch. The adults feed from the leaves leaving distinctive small white / yellowish spots in vertical lines on the leaves. The droplets of sap that appear at these bite marks allow the adults to recognize and select the host plant necessary for them. This is a characteristic behaviour of leafminers.
The adult females then lay eggs, inserting them into the leaves. This is the starting point of the first generation of the current year. The eggs hatch into the maggots which eat tunnels inside the plant. They head down towards the roots. Once fully grown, they pupate with the brown pupae at the base of the hole they’ve eaten in the plant.
The flies do not hatch out usually between the end of May until September, this is to protect them from hot summers. It appears this behaviour is controlled by day length rather than temperature and is, therefore, quite consistent.
The adults of the first generation of the current year leave at the end of August and through September, following the same process as above.
How to Tell You Have Allium Leaf Miner
- The pest only attacks members of the onion family. Leeks and chives being the primary host but garlic, shallots and onions are very much at risk
- The distinctive track marks on the leaves indicate eggs are being laid
- Sometimes the leaves will show tracks from the tunnels (galleries) eaten by the maggot
- The leaves will curl and collapse
- Maggots can be found inside vertical tunnels inside the leaves and flesh of the plant
- Small brown pupae are found at the base of the tunnels near the surface but inside the plant. The tracks may be easier to spot.
- To avoid confusion, onion fly maggots are larger and found in the soil beside the plant.
Control of the Allium Leaf Miner
The only practical control is to cover the crop, especially in the danger periods of March to June and September to November, with insect protective mesh or fleece.
If the infestation is detected in the crop, affected plants should immediately be uprooted and burned. Do not compost infested plants, the pupae will still be able to hatch spreading the infection.
If you are growing on an allotment or with neighbours growing vegetables, make them aware of the problem and how to handle it. This will, at least, reduce the fly population and threat.
Allium Leaf Miner Feeding Spots – First Sign of the Problem
Allium Leaf Miner Damage – Distorted, collapsing leaves and track marks in the leaves.
Allium Leaf Miner Tracks in Harvested Leeks 1 – Thanks to Stewart Jones for Image
Tracks in Harvested Leeks 2 – Thanks to Stewart Jones for Image
Allium Leaf Miner Pupa – Thanks to Philip Surridge for the Image
Leek, Allium ampeloprasum, also known as Allium porrum, is a biennial vegetable in the family Liliaceae, grown for its edible bulb and leaves. The plant is a slightly developed bulb attached to a cylindrical stem formed by the overlapping thick, flat leaves. The plant can produce clusters of white, pink or purple flowers and blue-black seeds in the second year. The plant can reach 0.6–0.9 m (2–3 ft) and can be grown as an annual, harvested after one growing season or as a biennial with two growing seasons. Although modern leek does not grow wild, it was likely domesticated from wild ancestors in the Mediterranean region.
Leek scape (flower bud)
Leek blossom ‹ ×
Leeks are consumed as a vegetable after cooking and are incorporated into many dishes.
Basic requirements Leeks grow very well in cool climates and can be successfully grown in most soils as long as they are rich and well draining. Leek will grow optimally in a well-draining loam with a pH between 5.5 and 7.0. Leek will grow optimally at temperatures between 18-21˚C (65-70˚F) with 8 hours of bright sunlight. Propagation In areas with short growing seasons, leeks should be planted from transplants started indoors. Seeds should be planted at a depth of 0.6-1.3 cm (0.25-0.5 in) leaving 7.5-10 cm (3-4 in) between plants and allowing 20-40 cm (8-16 in) between rows. The soil should be moist to a depth of (18 in) and have reached a minimum temperature of 7˚C (45˚F) for successful germination. Transplants should be planted 5-8 cm (2-6 in) apart in rows spaced 30-90 cm (12-36 in) apart. In order to produce large stalks either plant the leek in a depression 7-10 cm (3-4 in) deep and gradually fill to the leaves. Alternatively, the leeks may be planted at ground level, with soil being added around the stalk throughout the season. General care and maintenance Leeks require regular watering for optimum development and should be provided with water once a week by soaking the soil to a depth of around 18 inches. Blanching leeks encourages the production of long white stalks. Blanching is achieved by gradually mounding the soil around the stalk to leaves. Blanching should not be carried out until the plants have reached an appropriate size – roughly that of a pencil. Leeks will benefit from the addition of nitrogen fertilizer throughout the growing season. fertilizer should be applied as a side dressing. Keep leek beds weed free by carefully cultivating around the plants taking care not to damage the leek roots. Harvesting Leeks develop slowly and take about 100 and 120 days to reach maturity. Leeks are ready for harvest when the stalk has reach 3.5 cm (1 in) in diameter. Harvest by carefully loosening the plant with a garden fork and pulling from the soil.
Anderson, C.R. Leeks. University of Arkansas Division of Agriculture. Available at: http://www.uaex.edu/publications/pdf/FSA-6070.pdf. Free to access. Drost, D. (2010). Leeks in the garden. Utah State Cooperative Extension. Available at: http://extension.usu.edu/files/publications/publication/HG_2004-04.pdf. Free to access. MacKenzie, J. (2008). Leeks. University of Minnesota Cooperative Extension. Available at: http://www.extension.umn.edu/garden/yard-garden/vegetables/leeks/doc/M1230.pdf. Free to access.
Pests and diseases
Pests and Diseases
Within this section of the website we have tried to address some of the common issues gardeners face when it comes to pests and diseases. If there is something you require advice on please email [email protected] and we’ll ask our horticulturalist, Aaron Hickman to help.
Slug and Snail control: to some the presence of slugs and snails on the plot are a nuisance while to other they are just part of nature. To read more about controlling slugs and snails
Leek Problems: allium leek miner and leek moth
Many gardeners are now having serious problems with the allium leaf miner and leek moth attacking their crops. Up until a few years ago these two pests were mostly confined to the southern and eastern counties but now they are progressively working their way across the country. To read more click here
Potato and tomato blight
This is a common and serious disease that attacks potatoes and tomatoes whether they are grown outdoors or under protection. The disease is much more damaging to a crop in wet seasons and can be less of a problem in dry summers. To read more click here
A common disease that affects brassicas grown on allotment plots, to read more click here