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 conquest of England by the Planuncuses
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.
Another photo from a girl also from southern England shows the same nymph, but with a clearly visible division between a dark, almost black abdomen and a light brown pronotum:
Therefore, the differences in the color of the abdomen and pronotum in such cockroaches should be treated as normal color variations within a single species.
Count stripes and sleep well
It’s important to note that, due to the transverse white stripe, harmless planuncus cockroaches can be confused with brown-banded cockroaches — a typical British pest that can not survive in the UK outdoors and can only inhabit houses and apartments here. Such roaches cause damage similar to German cockroaches: spoil food, contaminate furniture and interior items with their droppings, and carry bacteria on their legs. Although brown-banded cockroaches are much less likely to cause such serious infestations as German cockroaches, they are a common pest in apartments and require immediate extermination upon detection.
The photo below shows a Planuncus nymph on the left, and a brown-banded cockroach nymph on the right:
We can see that these insects are clearly distinguished by the number of white stripes: a Planuncus nymph has one, while a brown-banded cockroach nymph has two. Therefore, if you encounter one of these white-striped arthropods in your apartment, don’t panic, but count the number of stripes: if it has only one, don’t worry — it’s just a harmless forest cockroach. But if the cockroach in your home has two such stripes (as well as two longitudinal black stripes on the pronotum), call pest control.
The woman with the nymph in the previous photo wrote that she often encounters these cockroaches in her garden, but she only started to worry when she found one in her house. So, if you live in the UK, be prepared for a similar situation.
Interestingly, despite their highly successful march across Europe, the planuncus cockroaches haven’t yet made it to North America — unlike the ectobius cockroaches, which have long since established themselves in the New World. In another video, I showed photos of forest cockroaches sent to me from New York — I haven’t yet received any nymph with a white transverse stripe, which will clearly indicate this type of roaches, from there.
This is further confirmation of the harmlessness of these cockroaches: they haven’t yet become so accustomed to the human-modified environment that could cross the ocean with cargo or simply by transport. But, apparently, their conquest of America is only a matter of time: perhaps the ectobius cockroaches established themselves there earlier simply because they had previously mastered life in European port cities, albeit outside human house. Planuncus cockroaches became closely associated with humans much later, so they will also cross the Atlantic later as well (if they haven’t already, simply by staying out of researchers’ sight). So it is quite possible that we should expect small discoveries of small forest cockroaches from the New World.
At the same time, Ectobius cockroaches themselves remain quite common, background wild roach species in Britain. And because of this commonness, they end up in apartments and houses just as often (if not more often) than Planuncus cockroaches.
For example, this photo shows a cockroach from a house in Oxford, the fourth one a girl has caught in one month:
Although it’s an adult female, its light coloring and the uniform color of its pronotum and elytra identify it as a tawny cockroach Ectobius pallidus. However, it differs less from both Planuncus cockroaches and its relatives in the genus Ectobius than from German cockroaches.
It’s ironic that this girl caught all four cockroaches in her house at different times of day. Here’s an excerpt from her letter:
I’ve attached a photo of the last one I found, which was found dead on the kitchen counter. The other three were all alive still and found in different places and at different times of day, respectively:
in the morning on a sideboard in the living room
in the evening on the bed in one bedroom
late at night on the wall in the other bedroom
This, by the way, can also be considered one of the signs of the randomness of such migrations of forest cockroaches into apartments and houses in England: they do not keep any kind of daily rhythm typical for their species in the wild, but behave as if in a peculiar extreme situation, trying to find shelter or an exit to their natural environment.
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.
