Sunday, 19 April 2015

Rosemary beetle (Chrysolina americana) and Pyrethrum

Rosemary beetle
      My daughter had bought me the full dvd set of 'Dad's Army' series and I'd taken to watching one a day in my study while I ate lunch. This was very handy because each episode was exactly lunch length. On this particular day I was due to visit the doctor for some minor surgery at 2pm, so I went to the door a few minutes before the story ended, with a view to getting ready. That was when the trouble started, because it wouldn't open. The handle turned but the spigot, latch, or whatever that thing is called that goes into the door frame, didn't move.

      When you're abroad and you don't speak the lingo, you raise your voice and shout your gibberish, indignant that the blasted natives haven't bothered to learn English. So it is when a door lock doesn't work - you shake it harder. Unfortunately the success rate is the same.

      I looked out of the window but it didn't give an option - there is a steeply sloping roof immediately under it, subtended by a drop of about twelve feet. For a moment the old opening credits of Starsky and Hutch came to mind - the bit where they jump from a first storey window and land backside first on the roof of a car. If we could just get the Toyota under the window..... But no, it'd put a hell of a dent in the car roof. I've a feeling that's why Starsky did it on someone else's car.

      "I can't get out", I shouted to my wife, while I hammered on the door, bitterly anticipating the inevitable comments about old ladies and lavatories. After a few minutes of shouting, I heard her come up the stairs. She grabbed the handle and rattled it.

      "It's stuck", she said after a long period of rattle.

      "I know it's bloody stuck," I bellowed, "I had noticed", and with some difficulty I  resisted the temptation to  display my expertise in sarcasm by enquiring as to the Pope's religion. "I've got to get to the doctor's. Maybe if I could unscrew the handle?"

      There followed a long period of getting a screwdriver into the room. It wouldn't go under the door, so we had to be creative: eventually she got some garden twine from the greenhouse and pushed it under the door to me. I then lowered this  from the window and she tied the screwdriver on the end. Having then unscrewed and removed the handle the position wasn't greatly improved because there was just a small hole with a square bar of metal sticking through it. The bar turned easily but still didn't move the latch. Things were getting desperate. My appointment time was getting closer and I needed to set out.

      "Don't panic Mr Mannering", came the voice of Jones the butcher from behind me. That really helped my blood pressure.

      John Wayne suddenly sprang to mind.- on numerous occasions  I'd seen him put is shoulder to a door and burst into some cowboy cabin. I didn't want to damage the door but we'd run out of alternatives.

      "You'll have to throw yourself at the door and bust it open", I shouted. temporarily missing the point that  John Wayne's height of six foot six against a film set balsa wood door didn't compare well with my wife's five foot two against solid pine.

      There was a short silence followed by a sigh, a thump as the door bulged slightly. then another bang indicating that she'd bounced off the door and hit the banister surrounding the top of the stairs. Thank God she hadn't gone over the top - I could have starved to death in there.


      "What's up?"

      "I've hurt my shoulder".

      So much for the human battering ram.

      "Go and get Terry", I shouted, saving the sympathy for later. He's a bloke who lives across the road. He  isn't exactly John Wayne but he's quite big. I watched from my eyrie as she crossed the road holding her shoulder, only to determine that Terry wasn't in.

      "We're all doomed - doomed I say", came the sepulchral Scottish tones of Private Frazer, with startling appropriateness.

      "I'll see if Bert (name changed to protect the innocent) 's in" she shouted, heading next door.

      Bert usually worked away but, by a miracle, on this occasion he was in. However, when he came to the other side of my imprisoning door his first words were: "unfortunately, I've got a bad shoulder"

      'Christ', I thought viciously, 'the next person she gets to 'help''ll probably be in an iron lung or a wheelchair.

      "But I could try this", he continued after a moment's thought. There was a short silence, then the door, plus a piece of the frame, suddenly shot into the room closely followed by Bert, moving backwards. It seemed he'd employed the technique of bending suddenly and applying his not inconsiderable bum to my B&Q budget pine. Luckily, the door just missed making contact with me, otherwise the minor surgery at the doc's could have become  major.

      I suppose that if there is a moral to this story it is that, to save bothering neighbours, one should marry a seventeen stone woman.
Rosemary beetle damage
      And as if I didn't have enough problems with the door, I discovered the following day that my rosemary plant had suffered a severe attack by some tiny (8mm long) insects. These were rosemary beetles, a relatively new pest probably brought in on plants from their native habitat in southern Europe. They also attack lavender, sage, thyme and a few other plants and the common factor seems to be scented leaves. According to the RHS they do most damage between late summer and spring and the plant recovers early on with new growth, only to have it eaten back later on. I think this is because in the spring they are too busy having sex to bother with eating. Most of the ones I came across were doing it, unless they just enjoy playing piggy-back. The larvae (baby beetle) is slug-like with a dark stripe along the side and it also feeds on the leaves until full up, when it falls to the soil, where it pupates for the winter.

      The RHS are doing a survey of the spread of the beetles and would appreciate people filling in a short questionnaire if you come across them. If you can help, just Google 'rosemary beetle RHS'.

      The beetles can be killed using something like Provado Ultimate Bug Killer but care should be taken not to spray when the plant is in flower as bees will also suffer. It's also a not good idea  to use this if the leaves are to be used for culinary purposes, unless you have a death wish for someone in the family. Pyrethrum, on the other hand, is an organic pesticide extracted from Chrysanthemum cinerariifolium. Working on contact, it is soon washed off the plant and, in any case, has little toxicity for humans. It can be used to kill caterpillars, beetles, scale insects, leaf hoppers, thrips, whitefly and others. However, in the case of the rosemary beetle the RHS think it only effective against the larvae. A good organic compromise therefore is to place newspaper under the plant, shake the adult beetles onto this, stamp on them, then spray Pyrethrum to get rid of the larvae.

Rosemary beetles mating amongst the wreckage of the plant