How long does a locust plague last

Reproduction

Grasshoppers differ in their individual development (Ontogenesis) clearly different from other insects such as butterflies, their caterpillars and pupae, as is well known, in no way to the later full insects (Adults) recall. Courtship, mating and egg-laying are still similar:

Courtship

The "singing" or stridulation of the locusts has species-specific tasks for reproduction: It either only serves to set the female in tune with the male or to set the mutual attunement to mating. Even females who do not sing themselves, like female birds, know the species 'own song, so they only react to the courtship of the species' own males, so that mismatches are ruled out.
In most grasshopper species, however, the females also sing; this creates a loud and physical stimulus-reaction chain between the partners: The male exerts a species- and function-specific stimulus with his song, which the female grasshopper in turn also responds to appropriate (ie species and situation-specific) singing reacts, because this signals to a partner of the same species that he is right with her and should continue singing and getting closer. The male then responds with suitable singing and approach and thus ultimately stimulates the female to mate.

pairing

The mating is initiated by the male chants, to which the females react differently:

  • Females of the long-antennae terrors ready to mate (Ensifera)let themselves be attracted by the chants of the males and finally climb them. Depending on the species, the males stay with their partner or they change their position by e.g. B. turn backwards or even turn upside down. The partner then grasps the abdomen with a pair of fine thorns (the so-called. Cerci) the abdomen of the partner, secretes a whitish gelatinous Spermatophores and sticks them to the female genital opening. The couple then split up again - the pairing only lasts a few minutes.
    Immediately after the separation, the female begins to eat the jelly, which can take several hours. Meanwhile, the sperm migrate from the inside of the jelly into the female's genital opening and fertilize her eggs.
  • The females of the short-antennae terrors (Caelifera) behave much more passively: If you are unwilling, you defend the male with the rear rails (Tibia) from. On the other hand, they signal their willingness to couple by "singing" on their part and in interplay with their partner (see above). Stimulated in this way, the male finally ascends and guides the tip of the abdomen on the female abdomen (Abdomen) and grabs its tip from below. Then the male often lets himself fall back on his back and dragged along by the partner. Such pairings can take a long time (20 minutes to several hours).

Egg laying

A few days after mating, the eggs begin to lay. The female sinks her eggs in the ground or in above-ground media such as cracked tree bark, plant stems or leaves (some leaf locusts = Tettigoniidae); a few species of field horror lay their eggs at the base of grasses or in leaves that have been folded up for this purpose (small golden insect = Chrysochraon brachyptera).

The females of the long-feeler terrors (Ensifera) drill their conspicuously long laying tube into the respective nest substrate and lay their eggs individually or in small groups; the short-lived fright (Caelifera) however, the tip of their abdomen sinks into the ground, and so do the field locusts (Caelifera Acrididae) lay their eggs in a quickly hardening, foamy secretion. The eggs of most species overwinter, so that the next generation does not appear until the next spring.

Larval development

The larvae of most species only hatch after the winter dormancy in spring - only the crickets (Gryllidae) and thorn horror (Tetrigidae) overwinter in one of the larval stages. What is so astonishing for insects is that the larvae already resemble the later adult locusts in the first stage. Cricket larvae sometimes go through more than 10 stages, the larvae of the grasshopper (Ensifera Tettigoniidae) at least 5–7 and the short-feeler terrors at least 4 or 5.

The wing systems are at first tiny and only clearly recognizable as lobes in the last two stages. The rear wings are already spread out here, but folded over the front ones, and both (front and rear wings) are often slightly offset next to each other. The forewings of the last, that is, the imaginal phase, on the other hand, completely cover the folded rear wings, provided that it is a short-winged form; long-winged, airworthy forms have elongated wings.
The long ovipositor of the leaf horror (Tettigoniidae) develops similar to the wings and parallel to the larval stages.

The individual stages are not roughly distinguished on the basis of their sizes, but rather precisely through regular events, namely the moulting between them. While the abdomen (Abdomen) Constantly enlarged in the course of growth through stretching of the skins between its segments, the front two sections of the locust's body remain the same size between the skins and only enlarge during a molt. The skin is not peeled off in parts, rather the larva or the Imago the whole old shell (Exuvia).


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