Pien filmed a ‘running grain of cement’, Frans knows what she saw

Forest ranger Frans Kapteijns shares his knowledge of nature on the radio every week. Listeners can submit questions via [email protected]. This time he pays attention to, among other things, a damselfly in a tube, a larva with a rat’s tail and a squeaking moth.
Profile photo of Peter de Bekker

Every Sunday there is also a new episode of the Stuifmail podcast. Listen to it here:

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A running grain of cement
Pien van Dijk sent me a video of an animal. I took an image from that video so I could better see what kind of animal this is. I think this is a caddisfly. This is the larva of a shooting moth. Shooting moths belong to the winged insects. They have an inconspicuous color. They look somewhat like moths, if you look at their body structure. The difference with moths is that the wings of sedge moths do not have scales but are hairy. The larvae are therefore called caddisflies and each tube of such a larva is unique. Sometimes they look like crawling twigs, because the larva has used twigs to make a tube. But the tubes can also be made from other materials that are available there. This can be plant material, but also grains of sand, stones, remains of aquatic animals or combinations of materials.

The rat tail larva of the blind bee (photo: Ben Jansma).
The rat tail larva of the blind bee (photo: Ben Jansma).

Is this strange long-tailed larva the larva of a hoverfly?
Ben Jansma sent me a photo of an animal that he thought was the larva of a hoverfly. I think he’s right. I think this is the rat tail larva of the blind bee. You can see a kind of tail in the animal in the photo, but this is actually a breathing tube. The larvae of blind bees feed on decaying organic matter. You can find them in those kinds of environments.

A blind bee (photo: Saxifraga/Ab H. Baas).
A blind bee (photo: Saxifraga/Ab H. Baas).

Rattail larvae are the larvae of blind bees, but they are not bees but hoverflies. You can read more about the blind bee in the Stuifmail of February 12, 2023.

A polecat (photo: Mara from de Hanevoet).
A polecat (photo: Mara from de Hanevoet).

Seen in the garden
Mara saw an animal in her garden and she thought of a polecat or a ferret. When I look at the beautiful head of this animal, it is clearly a polecat. Polecats belong to the mustelid family. This includes, for example, the weasel, but also the badger. Together with the weasel and the ermine, the polecat is considered one of the smaller mustelids. The maximum length of a polecat is about 45 centimeters and the coat is dark brown. The undercoat is usually light brown in color, but can also be yellowish white or yellow.

A polecat (photo: Saxifraga/Mark Zekhuis).
A polecat (photo: Saxifraga/Mark Zekhuis).

The polecat is a nocturnal predator and is most likely to be found in small-scale landscapes with hedgerows, ditches and ditches. During the day, the polecats sleep in all kinds of holes, but also in heaps of stones, messy sheds, straw and hay bales. Their menu really has everything: from rabbits and hares to birds and reptiles and fruit. Previously, farmers kept polecats as rat catchers.

A death's head butterfly (photo: Remon Veldhuijzen).
A death’s head butterfly (photo: Remon Veldhuijzen).

Is the death’s head butterfly rare in the Netherlands?
Remon Veldhuijzen heard something squeaking and then saw a large butterfly. He recognized the butterfly. The name is death’s head butterfly. Remon wonders if this butterfly is rare. Skull butterflies are large migratory butterflies. They originally occurred in southern Europe. They are rare, but can still be observed anywhere in the country. These butterflies mainly fly at night and then try to enter honey bee nests. Once in such a bee nest, they feast on the honey in the cells. They are not killed in such a bee nest, because the squirrel butterfly fits exactly between two combs and bees are therefore unable to reach the vulnerable abdomen. This is different in honey bee hives, because the combs are further apart and then the honey bees can sting such a butterfly to death. At the moment, death’s head butterflies cannot yet overwinter in our country, but it will not surprise me that this will soon be the case.

Ophion obscuratus species of common parasitic wasp (photo: Marijn Bogaarts).
Ophion obscuratus species of common parasitic wasp (photo: Marijn Bogaarts).

Is this animal a crane fly, a dragonfly or a wasp?
Marijn Bogaarts sent me a photo of an insect. He thought about a crane fly, a dragonfly or a wasp, but it’s none of those three. In Marijn’s photo you see a reddish-brown insect with long antennae, long legs, large eyes and four wings. We are dealing here with the insect ophion obscuratus. This insect does not have a Dutch name. This hymenopteran insect belongs to the common parasitic wasp family. You can often find them on illuminated windows. On the window where Marijn saw the insect, there is a fertilized female of the parasitic wasp. These ladies are mainly active in late autumn: October and November. At night they look for caterpillars of owls from the moth family. Once a caterpillar is found, it is temporarily stunned with one sting. The parasitic wasp then lays one egg in its prey, which regains consciousness after the sting. This egg then develops into a larva in the host and then feeds on the soft interior of the butterfly caterpillar. This larva then pupates and a new normal parasitic wasp emerges from the pupa.

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Death’s head hawkmoth screaming – Insectarea
Remon Veldhuijzen reported that he had found a death’s head butterfly and that it made a squeaking – or something – sound. I have also held skull butterflies in my hand and heard this clearly. In this video, Stuifmail listeners can also hear a squeaking or croaking sound of the death’s head butterfly. So cool! And if listeners want to see or hear more about the death’s head butterfly, then… This English video is highly recommended.

A moth from the pintail family (photo: Veerle Vos).
A moth from the pintail family (photo: Veerle Vos).

Cats caught this creature
Unfortunately, Veerle Vos’ cats had caught an animal. Veerle wonders which animal this is. I think this is a dead moth of the pintail family. I’m thinking of an bindweed pintail. This year, many specimens have been reported to Stuifmail alone, so I think this migratory butterfly will become more and more present in our country. Of course this has to do with the favorable weather conditions. Just like in 2016, when many pintails were reported, the winter of 2022/2023 was also mild. Once again this year, the largest numbers of pintails were seen in August and September. If you would like to read more about the bindweed butterfly, take a look at the link to the Stuifmail of October 1, 2023.

The caterpillar of the queen's page (photo: André van Drunen).
The caterpillar of the queen’s page (photo: André van Drunen).

Eight queen sage caterpillars in the garden, where are the pupae?
Ellen Klaassen-Vaarten had eight caterpillars of the queen’s page in her garden. She now wonders where the dolls from those queen pages have gone. She thought they might have been eaten by snails, but the caterpillars can defend themselves quite well. A kind of extension shoots out from their neck, which is terrifying and at the same time the caterpillar spreads a pungent (pineapple) smell. Many animals find this disgusting and then leave. The caterpillars pupate in the herb layer and not in the soil. Such a pupation can take place on the stem of the wild carrot in Ellen’s garden, but that is not necessary. It may be that the caterpillars have moved further and started looking for an even denser herb layer – more safety. In this video by Ton Vranken you can see how a caterpillar becomes a queen’s page butterfly.

A house sparrow (photo: Pixabay).
A house sparrow (photo: Pixabay).

Tinus wonders where the house sparrows have gone?
Tinus wondered where the house sparrows went. In early September, about thirty to forty came to his strewn food and suddenly he didn’t see any anymore. The fact that the house sparrows have disappeared may be for a short period and that is immediately after the breeding season. The birds then all molt at the same time and are then too weak to fly and too easy to be caught by a bird of prey or predator. The result is that they do not show themselves. If molting is the cause, they will certainly come back. In addition, the winter periods are approaching and then many house sparrows gather and move to safer places and well-sheltered places. They do stay in the Netherlands, because the house sparrow is a resident bird and they do not migrate in the winter. They usually do not move more than a kilometer from their birthplace, but there must be good shelter there. Good shelter during the winter period are evergreen hedges and evergreen climbing plants such as ivy. In addition, barns with straw and hay bales are favorites. Sometimes old nests also provide good places to stay and sleep in colder times.

In the beautiful photos section, this time a photo taken by Maria de Jong.  She made this while cycling home in the early evening (photo: Maria de Jong).
In the beautiful photos section, this time a photo taken by Maria de Jong. She made this while cycling home in the early evening (photo: Maria de Jong).

Beautiful photos section
In the beautiful photos section, this time a photo taken by Maria de Jong. She made this while cycling home in the early evening.

Nature tip
On Thursday, October 19, a mushroom walk will be organized through the landscape of Huis ter Heide near De Moer from ten in the morning to noon. Do you also find mushrooms fascinating? They remain hidden for a year until they suddenly reveal themselves en masse in the fall. They often have beautiful names and come in all kinds of colors and shapes. During this walk you will enjoy all this beauty and discover the important role mushrooms and fungi play in nature.

More information:
• Registration is required and possible through this link.

• Starting point is the parking space at Tussenbaan in De Moer

• Participation costs ten euros, members of Natuurmonumenten pay seven euros.

• This excursion is aimed at adults. Older children are also welcome if accompanied by an adult.

• Wear sturdy walking shoes.

• Wear clothes that suit the weather.

• Always check yourself for ticks afterwards!

• Bring a mirror!

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