August 2009


After I wrote that I thought our 'pond' in the back garden looks pretty nice in the last entry of the July diary I thought it would be nice to show what exactly it looks like right now. The Common Frog (Rana temporaria, Bruine Kikker in Dutch) isn't always present, but today it was again. :)
In the back of our back garden, behind the garage, a couple of Teasel (Dipsacus fullonum, Grote Kaardebol in Dutch) rosettes have grown to very respectable sizes... The Teasel that grew there last year clearly set seed succesfully. 'The Teasel spends one or more winters as a rosette and only forms a flower stem when the diameter of the rosette has reached 30 centimeters' can be read in the Dutch Ecological Flora. Well, the one on the picture below certainly qualifies... It's well over 50 centimeters in diameter, perhaps even a meter!

     



Today was not a very good day for butterflies as it was pretty rainy. Nevertheless, a Comma (Polygonatum C-album, Gehakkelde Aurelia in Dutch) spend a couple of hours out in the open on one of the leaves of the Hop (Humulus lupulus) in our back garden. It was a pretty damaged specimen and just seemed to sit there for a couple of hours, so I doubt it layed eggs on it's food plant it was sitting on.

  



Last year I wrote in the September diary about the sawfly larvae devouring every single leaf of the Grey Willow (Salix cinerea, Grauwe Wilg in Dutch). At that time the willow was just a couple of long twigs. This year however, the plant has grown into quite a tall plant, sprouting several long twigs/branches from the twigs of last year. Again, sawfly larvae are eating from the leaves. This year however, there are so many more leaves that I don't think the larvae will be able to devour every single one of them like they did last year. I'm hoping very, VERY much so that this willow is going to flower next year. The catkins of this species of willow are huge and an important source of pollen or nectar for early flying insects (bumblebees and some species of wild bees).
A couple of things are uncertain though. I'm pretty sure, but not entirely sure, that the plants in our garden are all females. When I planted them I thought that would be great as the females produce lots of nectar. At the moment I'm hoping they're males though. The catkins of males produce pollen, which is a very important food source, for bees especially. I'll just have to wait and see though as there's no way to find out at this moment if there are male of female willows in our back garden. What's much more uncertain now is if this Willow is a Grey Willow or an Eared Willow (Salix cinerea or aurita, Grauwe of Geoorde Wilg in Dutch respectively). These two species are very similar and it might even be a hybrid... I used to be sure they are Grey Willows, but I'm not sure at all anymore today... :/

  



The Hop (Humulus lupulus) plant that I grew out of seed (bought at 'De Hoornbloem' (KNNV Hoorn) grew into a nice plant on the balcony of our house at that time (2007). At that time, we didn't know whether the plant that grew largest was male or female. The plant moved along with us to Beek where it got a nice place in our back garden. It grew into a much bigger plant in it's first year but we didn't spot any flowers. That is, not until autumn. At that time I spotted about 5 dried out hops. No idea how we missed those, they may have been laying on the roof of our shed in between the leaves. Anyway, we were very happy to see the Hop was appearantly a female as only females produce these decorative hops.
This year there will be no way we're going to miss the hops... If all these flowers turn into hops, which I expect, the plant will be absolutely loaded with them! :)

  



The eggs layed by a Pink Lady (Vanessa cardui, Distelvlinder in Dutch) on July 17th seem to have hatched. Several small black and yellow caterpillars are munching away quietly. There's a lot of munching going on in our garden. One of the many Common Ragwort (Senecio jacobeae, Jacobskruiskruid in Dutch) is being eaten by about six small yellow and black caterpillars of the Cinnabar moth (Tyria jacobaeae, Sint-Jacobsvlinder in Dutch). Then there are caterpillars of Small and Great White (Pieris rapae and Pieris brassicae, Klein and Groot Koolwitje in Dutch respectively). The Small White caterpillars can be found on Nasturtium (Tropaeolum majus, Oostindische Kers in Dutch), Perennial Wall-Rocket (Diplotaxis tenuifolia, Grote Zandkool in Dutch) and Black Mustard (Brassica nigra, Zwarte Mosterd in Dutch). I have seen those of Large White on Black Mustard only.
Also ever present in our garden as it seems are Common Frogs (Rana temporaria, Bruine Kikker in Dutch). At the moment a lot of tiny ones are hopping around in the very back of our back garden (it's nice and wet there between the pretty tall grass). The one on the photo below was probably little over 1 centimeter. I suspect these young ones come from the garden of our back neighbours as I heard Common Frogs there in the spring.

           



After the tiny frog of yesterday I photographed a very big one in the 'marsh' in our back garden today. The marsh is a cement tub filled with sand and water. It more or less an experiment to see what will grow in there. I did plant one plant in it though, a Marsh Woundwort (Stachys palustris, Moerasandoorn in Dutch). This big frog (a good 10 cm long) reminds me a bit of a pirate with that one bad eye.
During a walk in the forest today we saw loads of mushrooms and a Lesser Spotted Woodpecker (Dendrocopos minor, Kleine Bonte Specht in Dutch, always a joy to see those) and a very fast Red Squirrel (Sciurus Vulgaris, Eekhoorn in Dutch)! The video below is a bit shaky, it's hard to keep the quality of fast moving videos unfortunately.


Another caterpillar picture! I just wanted to share this one as it shows the spiracles so nicely. The spiracles are the opening in each segment, surrounded by a white circle. Like all insects, caterpillars don't breathe through their mouth but through tracheae, a series of tubes. In case of caterpillars these tubes start at the spiracles (stigma in Dutch).


I went on excursion with the Section Hymenoptera (part of the Dutch Association for Entomology, NEV) today. The Section Hymenoptera studies ants, wasps and bees (Hymenoptera). I've been a member of this section for a while now, thoroughly enjoying their newsletter 'Bzzz', but I had never before went along on an excursion. I'm very glad I could go along this year. It was a very nice day in a beautiful area (the dunes near the small village Schoorl) and very informative. I took a couple of pictures that I've placed on one of the Bees and Wasps pages of the pictures and videos section. Pictures (mainly of the landscape and the excursion group) taken by fellow Section member Raymond Broersma can be found on the photo's page on the website of the Section Hymenoptera.


The caterpillars of the Cinnabar moth (Tyria jacobaeae, Sint-Jacobsvlinder in Dutch) seem to be doing well. Several of them are now eating the ovaries or fresh seeds of the Common Ragwort (Senecia jacobeae, Jacobskruidkruid in Dutch) in our back garden. The distinct black and yellow marking are a warning sign for predators as the caterpillars store the poison of the plant they are eating and are therefore poisonous themselves as well.


Lisette discovered yet another caterpillar species in our garden today! I've been looking around in between the Hop (Humulus lupulus) a couple of times now, hoping to find a caterpillar of Comma (Polygonia c-album, Gehakkelde Aurelia in Dutch), but Lisette found two on the Nettle (Urtica dioica, Grote Brandnetel in Dutch) that stands on our terrace in a flower pot as I used it for an experiment with seeds of Greater Dodder (Cuscuta europaea, Groot Warkruid in Dutch). I just realized I never wrote and entry about that little experiment. I'll do so in a special section on the plants page of the pictures and videos section soon.
Anyway, two caterpillars on the Nettle on our terrace made me curious to see if there really weren't any in the Hop as well. I was in luck, for after only a very short search I found one on the Hop as well! The strange colouration of these caterpillars is meant as a disguise by the way. The caterpillars look like a bit of bird droppings...
The Hop can take some caterpillars eating it. It's quite big and the hops are beginning to show nicely!

     



I knew far from all the caterpillars in our garden would make it into butterflies. Those of Whites especially are targets for for whole armies of ichneumon wasps. I've often read about this and I've seen pictures of it in books and on the internet, but today I found evidence of this in our own garden as well! A caterpillar of Large White (Pieris brassicae, Groot Koolwitje in Dutch) on the Black Mustard (Brassica nigra, Zwarte Mosterd in Dutch) seems to have pretty much exploded. It's covered with the coccoons of an ichneumon wasp. The wasp appearantly had layed eggs in the caterpillar. The larvae have eaten the caterpillar from the inside out, keeping it alive as long as possible. Quite ehm... Cruel? I guess so, but that's how it can work in nature.
Another picture of the caterpillar of Comma (Polygonia c-album, Gehakkelde Aurelia in Dutch) shows this one's doing a lot better. This picture shows the spiracles nicely (I wrote about spiracles in the entry of August 14th as well).
A beautiful bee came to visit one of the Common Ragwort (Senecio jacobeae, Jacobskruiskruid in Dutch) today, as they do pretty much every day. They are usually small dark brown or black bees. I'm not sure about the species, probably Lasioglossum (Groefbijen in Dutch) or Hylaeus (Maskerbijen in Dutch), though I have not seen any markings on the face that are typical for Hylaeus species bees. I'm pretty sure though that the bee on the picture below is a Lasioglossum species bee, possibly Lasioglossum calceatum (Gewone Geurgroefbij in Dutch), a common species in the Netherlands.

     



On my way to work (and back home of cours) I pass a couple of beautiful Jimson Weed plants (Datura stramonium, Doornappel in Dutch). A couple of days ago I noticed something (an insect?) has been eating from the leaves of one of these very poisonous plants. Today I cycled over to these plants to take pictures and look (again) hoping to find what is eating from these plants. The plants give off a very nasty smell when touched (which is why they are also known as Stinkweed in English) and I imagine they taste similar, not to mention that they contain very strong poison. The Dutch Ecological Flora compares it with Belladonna or Deadly Nightshade (Atropa Bella-donna, Wolfskers in Dutch). The name Belladonna means 'beautiful lady' which comes from the use of this plant's poison atropine to dilate the pupils of women as this was seen as something beautiful.
Anyway, the Dutch Ecological Flora says about Jimson Weed that the seeds were used in the past for pharmaceutical purposes and children used to collect them. The contact with the plant alone would dilate the children's pupils.
Dispite my searching I didn't find any sign of what could have eaten the leaves of this plant. As I was sitting there on my knees, turning leaves upside down, my old biology teacher, Willem Pas passed by on his bike. We were talking about plants a bit when I noticed something moving in the gutter behind him. A mole! Willem picked it up to put it down somewhere safer and I was able to take a nice picture. The mole was screaming very loudly and didn't agree with the place Willem had put it back down. It ran back onto the (thankfully very quiet) street, crossed it and disappeared in the tall grass on the other side of the street.
Makes me think back to the mole in our garden on August 17th 2008... :)

  



When I was searching for insects on A Jimson Weed (Datura stramonium, Doornappel in Dutch) the other day, neither of the two plants was flowering. I noticed it was yesterday, so I took along my camera went I went to work today. The light was somewhat poor in the morning, but I took some pictures anyway. I thought I'd give it another try on my way back home. But it seems maybe Jimson Weed flowers don't really like bright sunshine and look much nicer in darker weather conditions? The picture below was taken in the early morning anyway.


In the diary entry of January 3rd I wrote about finding dried out Thistle Broomrape (Orobanche reticulata, Distelbremraap in Dutch) flower stalks. I've went back to that place about 6 times spread over a couple of weeks hoping to find fresh flowering specimens. No luck though. But during the last excursion of this season of the Plant Workgroup last wednesday I heard someone had seen flowering Thistle Broomrapes somewhere else. It'd been a little while since my last visit to last year's growth-place, so I had to go back there as soon as possibly of course! I went there today and started searching. I first searched all along the righthand side of the 'strip' of young shrubs, but found nothing at all. Quite frustrating as there must've been so many Thistle Broomrape plants growing there last year... As I was making my way back to the place where I'd started to search the lefthand side I found them! Right in the middle of where I'd started... There were only a couple of them though. Two that looked pretty nice (which are on the photo below), one very small one that was only just starting to flower so it seemed, and a couple of stalks that had already finished flowering. I'm glad I finally saw them flowering and that I was able to take the picture below. :)
Back in our back garden I was able to photograph an adult sawfly. The larvae of these little insects have been and still are eating from the willow in our back garden (as can be seen on the pictures below). There are larvae of different ages on the willow at the moment. Small green ones that sit with tens on a single leaf, and large green and orange ones that usually take an entire leaf for themselves. The Great Tits (Parus major, Koolmees in Dutch) don't mind, they frequently come to pick a couple of fat ones off the willow, which I don't mind either... :)
I wasn't completely happy with the picture of the parasitized caterpillar I posted in the August 22nd diary entry. The sunlight makes it hard to distinguish seperate wasp-coccoons. I took a new picture today, but unfortunately, the caterpillar is pretty much gone. As I was edditing the picture, I noticed there's probably a little wasp's head on there! It's not very clear, but I think in the middle of the picture below a couple of antennae can be seen.
Also nice for comparison is a new picture of the hops in our back garden. Compare them with the hops on the picture in the August 17th diary entry. There are so many hops on the plant in our garden. It's a really nice sight I think.