Doesn’t sound like a typical activity, does it? Yesterday I actually tried. What drove me to do that? The sun was shining, I wanted to use the macro lens and I think I even dreamed of a hoverfly – very motivating. Whatever – armed with an umbrella, I visited the airfield in Freiburg. I shook a few branches with little success. From a blackberry I shook a nursery web spider (Pisaura mirabilis).
When I shook the branch of a mountain pine (Pinus mugo mugo), an unknown bug from the Pentatomidae group fell into the umbrella. After some photos I put it back into the tree. What a surprise when I tried to identify it at home: It seemed to be Holcogaster fibulatus. In Germany, this species has been detected only once before (in Nordrhein-Westfalen; Hamers, 2018).
Typically, it occurs further south but it is said to be nowhere common (Sauer, 1996). Due to the global warming, more and more species from the Mediterranean are reaching Germany. And Freiburg is located close to the Belfort Gap, through which various southern species have reached Germany in recent years. Nevertheless, it remains a surprise and it is a pleasant result for an hour of nature observation on the outskirts of the city.
Hamers, B. (2018): Nachweis von Holcogaster fibulata (GERMAR, 1831) in Nordrhein-Westfalen. Heteropteron 51:14-15.
Sauer, F. (1996) Wanzen und Zikaden, Fauna-Verlag, Karlsfeld
During my stay on Scharhörn I wondered which insects made the jump to this island. It’ s only 15 km to the mainland – but this is a distance that many insects cannot cover without help.
For sure, many insects were transported by chance from the mainland. But even if they made the jump to Scharhörn, it is not easy to survive: Salt everywhere, only a very small number of plant species grow and storm surges can flood most of the island at any time of the year. A species of sawflies made the jump and reproduced in the European Searocket (Cakile maritima – Europäische Meersenf) were i found some larvae.
There are also few species of bugs which occurs on Scharhörn:
Lygus maritimus is adapted to feed in various plants of the salt marshes and I found individuals on Sea Wormwood (Artemisia maritima – Strand-Beifuß) and Tripleurospermum maritimum (Echte Strandkamille). Of course there is a parasite which larvae lives in these bugs – Phania funesta.
There’s always a parasite in nature….. For example, owl moths (Noctuidae) have also made it to the island, as have parasites of them – Ophion obscuratus as well as Netelius sp. which probably live in the caterpillars of moths as well.
Surprisingly, I found no spiders and very few beetles. The most interesting of these was Broscus cephalotes (Kopfkäfer) – a nocturnal, predatory ground beetle.
In sum, I found just little more than 30 species of insects on the isle. Well, it was very stormy and by far to late in the season for many species. Maybe, there will be a next time to have a closer look earlier in the season.