This is a nymph of a cockroach of the genus Planuncus, which a viewer of my channel photographed in the kitchen of his house in Essex, England. These nymphs are very recognizable by the light transverse stripe under the pronotum.
The man writes that in a few weeks he has already found three or four such individuals. And several more times he came across adult winged specimens, very similar to the usual German cockroaches.
He assumed that these were Ectobius vinzi, and was a little surprised to find such cockroaches in England, north of London – in a climate not very favorable for these insects.
In fact, there is nothing surprising about this. These cockroaches are very abundant in England and they regularly get into houses here. But it was not always so…
Typical feral cockroaches in UK homes
Really, the photos show an adult cockroach and a nymph of a species from the genus Planuncus. This genus today includes the species Planuncus vinzi – the same one that was formerly called Ectobius vinzi. This species is referred to as the complex Planuncus tingitanus, also known as the variable cockroach – cockroach specialists have not yet decided how to distinguish several species within this complex and whether they should be distinguished at all. Perhaps they are all one species.
Here is a photo of another adult female Planuncus tingitanus, also from England, but this time from London:
Note its black ootheca with eggs:
Species of the genus Ectobius have brown oothecae, while cockroaches of the genus Planuncus have black ones.
However, females of this species without ootheca, are difficult to distinguish from females of species of the genus Ectobius, and therefore it’s not always possible to say with certainty which forest cockroach has found its way into your home.
One more female forest cockroach in a home in Essex
For example, this is how most forest cockroaches found in apartments in England look like:
From this specimen we can definitely say that this is a female and this is not a German cockroach. Since distinguishing between females of different forest British cockroach species is generally quite difficult, it’s impossible to say with certainty that this is a Planuncus, not the Ectobius, especially since it lacks an ootheca.
However, one thing is certain: its pronotum is a uniform reddish color, without the black stripes characteristic of croton bugs. Therefore, further identifying the species is not particularly important: it’s enough to know that this cockroach is not a pest and will definitely not breed in an apartment.
A woman found four such cockroaches over the course of several summer weeks in her home in Essex. Two were already dead, two were still alive. All four were found under the dishwasher and microwave. I suspect it was the sheer number of cockroaches and the frequency with which they were found that led the homeowner to suspect that they weren’t just stray outdoor insects, but actual household pests. Fortunately, her suspicions were wrong: such British cockroaches, occasionally found in homes, especially in summer and early autumn in Essex, are completely normal and completely save. Moreover, here in England, they are becoming more numerous every year and are colonizing more and more new areas.
The Planuncuses campaign of conquest of England
And it is Planuncus tingitanus that has become a peculiar phenomenon in the last 20-25 years. Since the beginning of the millennium, it has been rapidly spreading from Algeria, Morocco and southern Europe to the north and in just a few years has populated Germany, France and England. Scientists are studying this dispersal as one of the striking examples of an exceptionally rapid invasion of a species into new habitats.
Presumably, such a victorious march to the north may be associated with global warming and the formation of such conditions in England and Germany that are suitable for these cockroaches: winters here are becoming milder and cockroach eggs can survive the cold. And during a longer and warmer summer, the insects that hatch from these eggs in the spring have time to grow up, mature and lay their own eggs. This is exactly the way of life that the dusky cockroaches have been leading here for a long time, and Planuncus tingitanus are now beginning to compete with them for habitats:
Jackals, which were found only in southern Europe half a century ago, are spreading northward in approximately the same way, and today they are already observed in Belarus and the Baltic countries. But cockroaches do this at a truly dizzying speed: if the jackal invasion lasts for more than half a century, then cockroaches have managed to capture half of Europe in just a couple of decades.
So, when we see these cockroaches in England, we are witnessing a grand tectonic shift in entire faunas on our continent. And this shift is largely human-induced. Planuncus tingitanus are significantly tied to the anthropogenic landscape: they live mainly in dense shrubs in parks in cities, small towns and villages, there are a lot of them in hedges near houses. In England, with lots of old walls, parks, bushes and ornamental plantings, these cockroaches have found a comfortable habitat for themselves.
Can these cockroaches get into apartments and cause harm here?
It is not surprising that, actively running between the bushes, these England cockroaches can climb the walls of houses and sometimes even get inside the premises. Fortunately, they are not dangerous here: they do no harm, do not breed inside houses and do not spoil food supplies. They can not find food indoors and therefore, can not live in apartments for a long and, even more so, cannot reproduce here. In fact, their impact on an apartment is no different from that of ladybugs or moths that occasionally fly in. Therefore, there’s no need to be afraid of them or worry when encountering them in your home. It is only important not to confuse them with German cockroaches, to which they are very similar. I was explaining how to distinguish them from German cockroaches for sure:
Interestingly, that Planuncus nymphs differ from those of other cockroaches — both wild forest cockroaches and domestic German cockroaches — to the same extent that adult females of this species resemble females of the genus Ectobius.
Another wild cockroaches from England
Here’s, for example, another cockroach, a photo of which was sent to me by a viewer from England:
It’s a dead ringer for the cockroach in the first photo. And its most noticeable feature is the transverse white stripe on the upper part of the abdomen, just below the pronotum. This stripe is the specifical feature of a nymphs of the genus Planuncus, and it’s by this stripe that these cockroaches are most easily distinguished from both their German relatives and from Ectobiuses.
The next nymph’s white stripe is even more noticeable and contrasting due to the overall darker color of its abdomen:
The man photographed this roach in a house on the south coast of the UK and wrote that he regularly came across these small nymphs and slightly larger specimens in the garden near the house and inside the house itself.
We can see that these nymphs are much darker than the specimens in the previous photographs — their base color is almost black. This is normal: the smallest nymphs of these cockroaches are darker than those that have already molted several times. Moreover, even today, scientists have not yet decided whether Planuncus tingitanus cockroaches are considered a single species or a group of closely related species. Accordingly, differences in nymph coloration may, among other things, be determined by species-specific characteristics. These subtleties are still under scientific debate, but the main fact remains: if a cockroach caught in Britain has a transverse white stripe down the middle of its back, it’s a Planuncus, nowadays very common in England. Whether it’s Planuncus tingitanus or Planuncus vinzi is a matter for entomologists to sort out.
It’s noteworthy that this same guy from the south coast of the UK, along with photos of black nymphs, sent a photo of a similarly belted nymph, but light-brown:
This means he has cockroaches of both colors in his garden and in his house. Therefore, they can be treated equally — as occasional, harmless visitors from the surrounding area.
So if you meet such insects in your home, just throw them out the window: let them develop new territories and open a new page in the evolution of life in Europe.
And if you could not identify your cockroaches, then send me their photos and videos. I think together we will definitely identify their species.
And if you have identified your cockroaches after reading this post and know for sure that they are not pests, you can thank me with a cup of coffee. It will be warming my soul when I will be preparing a new article or video about your neighbors in apartments.
