Hymenoptera is a large order of insects that includes bees , saw bees , mud bees , ants , and a variety of predatory and parasitic bees. Among the hymenoptera insects that are still alive on Earth, more than 150,000 species have been discovered and described. In addition, more than 2,000 long-extinct species have been identified from fossils and amber. According to the constriction of the abdomen of such insects with the thorax of the body node (with or without the ventral stalk, that is, the "waist"), the order is divided into two suborders: slender-waisted suborder and broad-waisted suborder. As for the time when hymenoptera insects appeared on Earth, the earliest dates back to the Triassic Period, 235 million years ago.
A digger wasp, translated as the earth-digging bee
Females of hymenoptera are special, often laying their eggs deep within or elsewhere in the host animal or plant. Therefore, their ovipositors have also undergone corresponding adaptive changes, such as saws, needles, spines, etc., and some types of ovipositors are specialized as stinging needles. Hymenoptera are all-metamorphic insects that undergo the growth and development and change of four insect states, including eggs, larvae, pupae and adults, in their lifetime.
"Hymenoptera" is derived from the ancient Greek "ὑμήν (hymen)" that is, for "membrane(membrane)", and "πτερόν (pteron)", which is "wing(wing)", which is translated as hymenoptera in Chinese. "hymenopteran" refers to hymenoptera insects.
[Evolution] Based on a comparative analysis of morphological structures, genes, and proteins, it is believed that hymenoptera insects originated from an evolutionary branch. In the evolutionary branching diagram of insects , hymenoptera insects are closely related to other endopteran insects ( such as diptera , lepidoptera moths and butterflies) .
The evolutionary relationship between hymenoptera insects and some other endopteran insects (Note: due to illness and hands not listening to commands, the drawing and writing are very irregular. The same applies below. ）
Hymenoptera insects originated in the Triassic period, about 235 million years ago, and the oldest fossil species found today belongs to the family Apiaceae. The social hymenoptera appeared during the Cretaceous period, between about 145 and 0.66 million years ago.
Evolutionary branching diagram of Hymenoptera
A bumblebee ( ) is sucking on nectar with its long beak
【Morphology】The size of hymenoptera insects varies greatly, from small to large species. Usually has 2 pairs of membranous wings. The mouthpiece is suitable for chewing the outer mouthpiece, and the upper jaw is developed and powerful. Many types of mouthparts extend forward such as beaks, called beaks, which can be used to suck on liquid substances such as nectar. They have a pair of large and prominent compound eyes and 3 small single eyes on their heads.
There are some hook hairs on the leading edge of the hindwings of hymenoptera insects, called wing reins, which can chain the hindwings tightly to the forewings, making them a whole and facilitating flight. Insects of the order Lepidoptera have only 2 to 3 fins per hindwing, but there can be many of them in the large species. Compared to some other winged insects , the vein order on the wings of hymenoptera insects is simpler , especially in small species.
The more ancient primitive hymenoptera insects, the females of the gentry are blade-shaped or saw-shaped, and this ovipositor evolved because they cut through the plant tissue and lay eggs in it when they lay eggs. However, the egg laying apparatus of most species of female insects is needle-shaped and suitable for direct penetration into the host body during egg laying. Some types of oviposiforms are also particularly long, which can be several times as long as the body. Some of the ovipoters become stingers and completely lose their spawning function. Spawning is laid by its base, rather than being excreted from the tip. So what are these stinging needles used for? It turns out that when they catch prey, they use it to drain venom to anesthetize the prey, paralyzing it and unable to move or resist. But in some bees and bees, stinging needles are mainly used for defense.
The larvae of Hymenoptera insects clearly have three individual segments of head, thorax and abdomen, 3 thoracic segments, and 10 abdominal segments. Some of the larvae of the broad-winged suborder are very similar in appearance to the larvae of Lepidoptera. They feed on the leaves of plants, so they have a pair of well-developed palates suitable for chewing. There is a pair of feet under each thoracic segment. Also, the abdomen also has 6 to 8 pairs of gastropods, or protopods. But unlike Lepidoptera larvae, the broad-winged suborder larvae have no toe hooks (spinous protrusions used to grasp the surface of objects) on their gastropods, and the antennae degenerate with only a little stumps. However , the borer larvae in the broad-winged suborder Not only do they lack gastropods and pectoral feet , but are generally smaller than non-drill moth larvae.
The larvae of the slender-waisted suborder are footless, maggot-like, and relatively soft and tender. Therefore, they often live in the small room in the host body or in the nest, so that they can be well protected, and the larvae living in the nest room can also be cared for by adult individuals. The head of the parasitic wasp larvae is also very degenerate, some of which are also indented into the chest or chest, and many organs are degenerated or underdeveloped, such as no single eye, no antennae (some are also very short), degenerate mouth organs, incomplete digestion and excretion systems, etc. The larvae of the pintail of the slender-waisted suborder have 10 pairs of valves or breathing holes on the body, while the larvae of the parasitic wasps have 9 pairs.
【Food】Different species of hymenoptera insects, the types of food they use for feeding and using vary greatly. The vast majority of primitive types of species are plant-eating, feeding on the leaves of plants, including the coniferous species. Predatory peaks use their stinging needles to inject venom into their prey, paralyzing them from moving, and then carrying them back to their nests to feed the young bees. They themselves feed on nectar or pollen. Parasitic bees lay their eggs in the host, where the hatched larvae feed. For example, in an endangered species, the natural parasitism rate of Homer butterfly ( ) is as high as 77 %, most of which are parasitic wasps of the order Hymenoptera. Some parasitic wasps have their own hosts as parasitic insects, called heavy (pronounced chóng) hyperparasitoids. Between plant-feeding and parasiticity, there are also some intermediate types of species. They inhabit galls or nests of other insects, stealing their food and eventually killing them for consumption.
【Classification】
The rose trilobite ( ) has no bee waist and is a saw bee of the broad-waisted suborder
The German wasp (germanica) has a thin waist between the thorax and abdomen, and belongs to the suborder Slender Waist
Depending on whether there is a shrunken waist (also called a bee waist or ventral stalk) between the thorax and abdomen, hymenoptera insects are divided into two suborders, namely the waistless broad-waisted suborder and the slender-waisted suborder.
The broad-waisted suborder may be an adjunct taxon, and they can all be commonly referred to as sawflies. The suborder Slender-waisted suborder may have evolved from the orussidae in the broad-waisted suborder Orussidae. The broad-waisted suborder sawfish does not have a thin waist-like ventral stalk between the thorax and abdomen. Their larvae are free-living plant-eating insects, resembling Lepidoptera larvae (cockroach larvae) with a pair of true feet under each thoracic segment, but unlike most sawfish larvae, which have a pair of protopods on each abdominal segment and no toe hooks at the ends of the feet.
The first segment of the abdomen of the slender-waisted suborder is healed with the thorax, called the thoracic-abdominal segment. Between the 1st and 2nd abdominal segments, it is constricted to form a thinner "waist", called a bee waist or ventral stalk (wasp-waist, or petiole). Such insects include a variety of bees, predatory bees and parasitic wasps. Their larvae are maggot-shaped, no chest feet, no gastropods, and no single eyes. In many species, in the larval stage, the hindgut is closed, and the feces formed after food digestion are stored in the body. After completing the growth and development of the larval stage, the anus does not open.