Next you will find out:
- how many cockroaches hatch from one egg;
- how cockroach eggs and egg capsules look (so-called oteca) and how many eggs are contained in one such capsule;
- how and where the process of laying eggs and the subsequent appearance of young cockroaches take place;
... as well as other interesting facts concerning the "birth" of cockroaches from eggs.
It may seem strange to someone, but only one tiny larva hatches from one cockroach egg, which later, after several molts, turns into an adult insect. This is fundamental: there is only one cockroach in one egg.
It is easy to explain: a greater number of larvae simply cannot fit here, and the egg itself is a developing egg cell that can turn into only one embryo.
On the photo - cockroach eggs:
On a note
Purely theoretically, two twin larvae can develop from one cockroach egg, like in other animals. However, such cases are very rare, and, in general, it is almost always one cockroach that develops from one egg.
It is important not to confuse the egg directly and the special egg capsule, or oteca, which houses many of these eggs. By the way, precisely because of the compact swelling that the “pregnant” female of the red cockroach carries with it, many people believe that there are many future pests in one cockroach egg - they confuse the capsules with the eggs themselves.
Let's touch on this point in more detail and see how many cockroach eggs are in the pool and how such a capsule is arranged.
Cockroach Egg and Egg Capsules
Eggs of almost all species of cockroaches are still in the body of the female “packed” in a special shell, which quickly hardens in air and forms a characteristic capsule.
Such a capsule is called an oteca (from the Greek “oo” - egg, “tekos” - storage) and serves to protect vulnerable eggs from the effects of adverse environmental factors.It provides the high survival rate of cockroaches both in nature and in human habitation.
On a note
Ooteka also exists in other species of invertebrates: in addition to cockroaches, for example, it is characteristic of praying mantis and mollusks.
Oroteka cockroaches can have different shapes, sizes and colors, depending on the type of insect. For example:
- The black cockroach ooteca has a dark brown color, about 12 mm long, about 6 mm wide and a well-marked ridge on the surface;
- The edema of the black beetle is red, about 8 mm in length, with clearly visible transverse constrictions;
- In the Madagascar cockroach, the ooteka is strongly elongated, has a light yellow color, and measures about 25x4 mm.
The photo below shows the appearance of the Prusak library:
And in the next photo you can clearly see what the oothek looks like. madagascar hissing cockroach:
Despite the relatively high strength and hardness of the wall, the oteca allows the developing embryos to breathe, resembling these bird egg shells.
How many eggs are in each edeka is determined by the type of cockroach. For example, at red cockroaches in each such capsule there are on average 20-30 eggs, rarely up to 50. They lie very closely to each other in 4 even rows - two in height and two in width.
The eggs themselves are tiny in size - about 1 mm long and a few tenths of a millimeter wide. They are light yellow or white, translucent, and through their shell you can even make out the embryo with a magnifying glass.
The photo below shows what cockroach eggs look like inside the library:
Formed during the period of laying eggs cockroach. In a special chamber in the abdomen of a female, a large amount of sticky secretion is secreted, which literally dip eggs from a special organ.
When the process of the formation of eggs ends, the secret stands out for some time, closing the swelling from the inside. At this point, in most species of cockroaches, the capsule for a significant part of its length leaves the body of the “pregnant” female and remains attached to the end of the abdomen for some time.
In this capsule, cockroach eggs develop from 30 to 75 days. Development proceeds most rapidly under conditions of high temperature (above 30 ° C) and humidity, but when the temperature drops below 15 ° C, their development stops, resuming with the return of heat. This allows populations to survive the cold.
It is interesting
An adult Prusak dies at a temperature below -5 ° C and above + 45 ° C, while its ejecta normally tolerates short-term cooling to -10 ° C and overheating to + 55 ° C. In addition, insecticides have little effect on the oteca (and many of them have almost no effect). For example, in Prusaks, whose females drag a capsule at the end of the abdomen until the end of the development of larvae, if the mother is killed by the insecticide, the eggs in the oteke continue to develop, and later from them young nymphs hatch anyway.
Different species care for the eggs and their protective capsule differently.
For example, females of black cockroaches lay their edemas, and, thus, leave their eggs to fend within 3-4 days after the ooteca is fully formed. Then, for almost two more months, the capsule develops without any protection. If predators or parasites find such a source at this time, they will destroy the eggs. In many ways, this is why red cockroaches everywhere black out the black ones - they just eat their eggs.
The Prusaks themselves, as well as various exotic species, for example, ash and Madagascar cockroaches, show a certain care for the offspring.The females of the red cockroaches wear a hole in the end of the abdomen until the larvae hatch, and from danger they can at least carry it away.
And for the same Madagaskar people, the eurea develops in the body cavity, and only a few times a day does a “pregnant” cockroach expose it outside for airing. The larvae also hatch inside the mother's body, but at almost the same moment they leave the brood chamber. The observer of this process creates the feeling that the cockroach is giving birth (that it is supposedly viviparous), although in fact, without exception, cockroaches lay eggs, just in some species the development of eggs to the larval stage takes place inside the abdomen of the mother.
The photos below show how the female Madagascar hissing cockroach "gives birth":
Depending on the type of cockroach, the number of “pregnancies” and the streaks given by the female in her entire life vary. Thus, the female of the prusak can produce up to 9 capsules in its life (of which “born” in the amount of more than 250 larvae), although usually the “average” female produces about 3–4 otek per life.
At the same time, in the female of the Prusak, the library is clearly visible, and in large tropical species, in which the capsule is hidden in the body, it may not be clear that the female is in an interesting position.
How does the process of hatching cockroaches from eggs
Cockroach embryos constantly move inside the egg, absorbing fetal fluid and nutrients. When they reach such dimensions that they no longer fit in the egg, they tear up its shell and begin to gnaw the crest of the ooteca.
In those species, the females of which lay capsules, after the larvae leave the oteca, a strong outer shell remains. For those whose dwelling develops inside the body of the female, its shell is very soft, and by the time the larvae appear, it bursts completely, and the offspring leaves the mother's body in a free state, after which the female gets rid of the rest of the capsule.
On the video at the end of the article you can see how cockroaches are “born”.
In large species, up to 60 young larvae can spawn at a time, but in general, the normal number of young individuals is 25-35 pieces. The same number of young cockroaches hatch from the library of ordinary domestic species.
Further on the photo you can see how the black cockroach’s oteoca and newborn larvae look around it:
As a rule, the whole process of "birth" of cockroaches lasts from several minutes to several hours. After birth, the larvae are usually very light, almost white, but then - as the chitinous cover hardens - they darken.
Are there viviparous cockroaches?
Cockroaches are not viviparous creatures. The terms "egg-breeding" and "egg-laying" are used to these insects.
If the embryo develops in the egg and does not receive nutrition from the maternal organism in the process of development, but it is in the female's organism, then this method of reproduction is called egg production.
Those cockroaches, whose females simply leave their beaver to the mercy of fate, are typical egg-laying insects. The same species in which the eggs develop inside the body of the female, and the nymphs hatch simultaneously with the exit from the brood chambers, which are egg-breeding.
Therefore, the terms “pregnant cockroach” and “viviparous cockroaches” are not quite correct - only live-bearing animals are truly pregnant.
From a scientific point of view, the expression “cockroaches give birth” is not quite correct. This process is not called childbirth, but rather is hatching.
The photo shows a female Madagascar cockroach with nymphs emerging from its abdomen:
Features of the appearance of the larvae
For the most part, cockroaches show no concern for offspring. Even in the well-known red cockroaches after the larvae emerge from the oteca, they are just near her for a while, and, therefore, near the female, but for an hour or two they run away and hide in convenient shelters.
Considering that the female tries to lay the oteca in a place that is secluded and remote from the main shelter of other adult insects, the larvae have little contact with other individuals for the first few days.
In some tropical species, females take care of the newly emerged larvae. In the same Madagascar cockroaches, babies gather under the belly of their mother, who continues to guard them for several hours, hisses as the enemy approaches, and can even make frightening attacks. However, by the end of the first day after hatching, the young cockroaches were creeping apart, and the female’s mother’s concerns ended there.
On a note
Only relict cockroaches show special care for kids. They live in small colonies with a rudimentary hierarchy, and their offspring is wooed as carefully as in the nests of termites.
Given the fact that the nymphs of cockroaches can eat immediately after hatching, they do not need long-term care, and they quickly become regular equal members of the family.
Interestingly, the larvae of cockroaches immediately after their birth into the world often try to eat their own edeka. They need it as a source of protein in the first hours of life.
Where do cockroaches lay egg capsules?
The female cockroach is trying to lay a capsule with eggs in the most secluded and safe places. In nature, this space under the stones, fallen trees, deep under a layer of rotted leaves, and in some species - even in the ground or in dry wood.
Similarly, in the apartment - cockroaches and then lay eggs in the safest places, for example:
- in the cracks between the walls of the furniture;
- under the bedside tables;
- between the sink and the nightstand under it;
- for plinths;
- in the ventilation passages;
- under the bathroom;
- on the shelves in the pantry.
Sometimes, when cleaning the owners of an apartment, dry shells of Prusacks can come across their eyes - they are already empty, and they can simply be thrown into the trash can. But if a large source of black cockroach was discovered, it is useful to destroy it, because several dozens of future pests can hatch from it.
Do not expect that if you make a raid in search of "eggs" of cockroaches and destroy a few capsules, then this will remove the cockroaches from the apartment completely. Those capsules that can be found are likely to be already empty, but the number of undetected ones will be significantly larger (red-haired cockroaches carry them with them).
And even the search for etek even in the case of the fight against black cockroaches is a very laborious and ineffective exercise. It is much more reliable to remove pests simply by disinsection in the room.
Interesting video: Madagascar cockroach "gives birth" (fast playback)
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