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Reproduction in Insects
The majority of insects hatch from eggs, but not all insects lay eggs. The fertilization and development takes place inside the egg, enclosed by shell (chorion). Some species of insects, like the cockroach, as well as juvenile aphids are ovoviviparous. The eggs of ovoviviparous animals develop entirely inside the female, and then hatch immediately upon being laid. Some other species, such those in the genus of cockroaches known as Diploptera, are viviparous, and thus gestate inside the mother and are born alive. Some insects like parasitic wasps, show polyembryony, where a single fertilized egg divides into many and in some cases thousands of separate embryos.
With a few odd exceptions, all insect life begins as an egg. After leaving the egg, insects must grow and transform until reaching adulthood. Only the adult insect can mate and reproduce. The physical transformation of its life cycle to another is called metamorphosis. Insects may undergo gradual metamorphosis, where transformation is subtle or complete metamorphosis, where each stage of the life cycle appears quite different from the others. In some insects, there may be no true metamorphosis at all insects can be divvied into three groups
The most primitive insects, such as spring’s tails, undergo little or no true metamorphosis during their life cycles. Entomologists refer to these insects as Ametabolous, from the Greek for “Having no metamorphosis”. In Ametabolous insects, the immature that emerges from the egg looks like a tiny version of the adult. It will molt and grow until it reaches sexual maturity. Ametabolous insects include silverfish, firebrats, and springtails.
In gradual metamorphosis, three life stages occur:
Insects with gradual metamorphosis are said to be hemimetabolous (hemi = part). This type of transformation is also known as incomplete metamorphosis. Growth happens during the nymph stage. The nymph resembles the adult in most ways, particularly in appearance. Usually, the nymph also shares the same habitat and food as the adults, and will exhibit similar behaviors. In winged insects, the nymph develops wings externally as it molts and grows. Functionally and fully-formed wings mark the stage. Some hemimetabolous insects include grasshoppers, mantids, cockroaches, termites, dragonflies, and all true bugs.
Most insects undergo complete metamorphosis, each stage of the life cycle egg, larva, pupa and adult. They also look different from the others. These insects are called Holometabolous (holo – total). The larvae of Holometabolous insects bear no resemblance to their adult parents. Their habitats and food sources may be entirely different from the adults as well. Larvae grow and molt, usually multiple times. Some insect orders have a unique name for their larval forms: butterfly and moth larvae are caterpillars; fly larvae are maggots; and beetle larvae are grubs.
When the larva molts for the final time, it transforms itself into a pupal. The pupal stage is usually considered a resting, although much activity occurs internally, hidden from view. The larval tissues and organs break down entirely, and then reorganize into the adult form. After the reorganization is complete, the pupa molts to reveal the mature adult with functional wings. Most of the world’s insect species are Holometabolous, including: butterflies, moths, flies, ants, bees, and beetles.
Insects are famous due to for their sporadic nature, as their behaviors are different from each other, because there are many types of insects. Same like that there are different types of flies; there are two types of sex in insects as well as female and male. Now same like that there are different types in male flies, as male fruit flies i.e. Drosophila these flies are very complicated and detailed in preceding to have sex, in our houses there are flies which called houseflies. These flies fly at any type of object for their proper size and then they do copulate with it. According to the researchers these behaviors are may be some of them don’t need male and female courtship. But if we talk about the butterflies and moths, these types of insects wait for the pupa to do copulate with female, it happens immediately when female emerge.
These all are happen due to their different nature, because everything is defined already. These flies are sometimes important for human lives. Because these flies have quality to suck the viruses as well they spread viruses too. According to the research some types of viruses are useful for the human lives. These all are looks false, but when we think about the honey bees these become truth. Sometimes we get knowledge wrong, because the reproduction system is little bit surprising in insects. But when we do to understand the Natures reality which is that, the male insects (flies) their sexual organs are near to their thorax, and as we talked above there are different types of behaviors in insects. This type of copulation not found in other types of insects.
Reproductive system in Male insects
The main reproductive part of the male insects a pair of testes, which placed backside of the insect’s abdomen. And these testes of the insects are having functions which called follicles; the sperms produced in follicles of the insects testes. In testes there are many follicles and these are settled in a parallel shape. The spermatogonia cell is also found in insects’ follicle which is inside of the testes. And these cells are divided into different parts which are called mitosis and mitosis is used to increase the spermatocytes. These change their place during the copulation when it occur during the reproduction system.
Reproductive system in Female insects
As the male reproductive system depends on pair of testes, same like that there is a pair of ovaries in female. Female reproductive system depends on ovaries. When female body is active to reproduce these organs develop eggs and then the abdomen of the female is looks filled which we saw commonly in human beings abdomen, it’s same like in female insects but a little bit change. As we learnt about male reproductive system in male insects, the testes subdivides. The female ovaries are also dividing in function units which called ovarioles. The ovarioles are used to produce eggs, which changes shape in future as a new insect which could be male or female.