Biology of the Chalcid Wasp, Megastimus wachtli, and Its Relationship to Colonization of Cypress Seeds by .. Insetti del Cipresso III. A Specific Male Olfactory Sensillum Detects Behaviorally Antagonistic Hairpencil Odorants open access. Request PDF on ResearchGate | Relationships between the olive fly and la stessa specie somministrata agli insetti adulti (vedi quanto sopra discusso). . antagonistic interactions between microbes and larval density . Insects or Insecta (from Latin insectum) are hexapod invertebrates and the largest group within The higher level relationship of the insects is unclear.
The first three pairs of ganglia are fused into the brain, while the three following pairs are fused into a structure of three pairs of ganglia under the insect's esophaguscalled the subesophageal ganglion. This arrangement is also seen in the abdomen but only in the first eight segments. Many species of insects have reduced numbers of ganglia due to fusion or reduction.
Some insects, like the house fly Musca domesticahave all the body ganglia fused into a single large thoracic ganglion. At least a few insects have nociceptorscells that detect and transmit signals responsible for the sensation of pain. The larvae reacted to the touch of the heated probe with a stereotypical rolling behavior that was not exhibited when the larvae were touched by the unheated probe. These macromolecules must be broken down by catabolic reactions into smaller molecules like amino acids and simple sugars before being used by cells of the body for energy, growth, or reproduction.
How to raise useful insects in the farm with ecological and economic advantages
This break-down process is known as digestion. It should be emphasized that there is extensive variation among different orderslife stagesand even castes in the digestive system of insects . This is the result of extreme adaptations to various lifestyles. The present description focus on a generalized composition of the digestive system of an adult orthopteroid insect, which is considered basal to interpreting particularities of other groups.
The main structure of an insect's digestive system is a long enclosed tube called the alimentary canalwhich runs lengthwise through the body. The alimentary canal directs food unidirectionally from the mouth to the anus. It has three sections, each of which performs a different process of digestion. In addition to the alimentary canal, insects also have paired salivary glands and salivary reservoirs. These structures usually reside in the thorax, adjacent to the foregut.
The salivary ducts lead from the glands to the reservoirs and then forward through the head to an opening called the salivarium, located behind the hypopharynx. By moving its mouthparts element 32 in numbered diagram the insect can mix its food with saliva. The mixture of saliva and food then travels through the salivary tubes into the mouth, where it begins to break down.
Insects using extra-oral digestion expel digestive enzymes onto their food to break it down. This strategy allows insects to extract a significant proportion of the available nutrients from the food source. It can be divided into the foregutmidgut and hindgut. Foregut[ edit ] Stylized diagram of insect digestive tract showing malpighian tubulefrom an insect of the order Orthoptera The first section of the alimentary canal is the foregut element 27 in numbered diagramor stomodaeum.
The foregut is lined with a cuticular lining made of chitin and proteins as protection from tough food. The foregut includes the buccal cavity mouthpharynxesophagus and crop and proventriculus any part may be highly modifiedwhich both store food and signify when to continue passing onward to the midgut. As the salivary glands produce fluid and carbohydrate-digesting enzymes mostly amylasesstrong muscles in the pharynx pump fluid into the buccal cavity, lubricating the food like the salivarium does, and helping blood feeders, and xylem and phloem feeders.
From there, the pharynx passes food to the esophagus, which could be just a simple tube passing it on to the crop and proventriculus, and then onward to the midgut, as in most insects.
How to raise useful insects in the farm with ecological and economic advantages -
Alternately, the foregut may expand into a very enlarged crop and proventriculus, or the crop could just be a diverticulumor fluid-filled structure, as in some Diptera species. Note the contraction of the abdomen to provide internal pressure Midgut[ edit ] Once food leaves the crop, it passes to the midgut element 13 in numbered diagramalso known as the mesenteron, where the majority of digestion takes place. Microscopic projections from the midgut wall, called microvilliincrease the surface area of the wall and allow more nutrients to be absorbed; they tend to be close to the origin of the midgut.
In some insects, the role of the microvilli and where they are located may vary. For example, specialized microvilli producing digestive enzymes may more likely be near the end of the midgut, and absorption near the origin or beginning of the midgut. Envaginations at the anterior end of the hindgut form the Malpighian tubules, which form the main excretory system of insects.
Excretory system[ edit ] Insects may have one to hundreds of Malpighian tubules element These tubules remove nitrogenous wastes from the hemolymph of the insect and regulate osmotic balance. Wastes and solutes are emptied directly into the alimentary canal, at the junction between the midgut and hindgut. Insect reproductive system The reproductive system of female insects consist of a pair of ovariesaccessory glands, one or more spermathecaeand ducts connecting these parts.
The ovaries are made up of a number of egg tubes, called ovarioleswhich vary in size and number by species. The number of eggs that the insect is able to make vary by the number of ovarioles with the rate that eggs can develop being also influenced by ovariole design. In fact, however, as we know it today, it has its roots in studies on the biology and the ethology of living organisms conducted by naturalists in the seventeenth and eighteenth centuries.
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Insect - Wikipedia
Genduso and others have dealt with this matter with very interesting results and unfortunately, still today, little applied. In a nutshell, biological struggle is a technique that exploits antagonistic relationships between living organisms to contain the populations of harmful ones.
In short, these are techniques that tend to restore agronomic errors by exploiting the rules and principles of the ecosystem. To make examples very simple and easy to understand, for those who are not interested in ecological dynamics and their feedback, it means: In fact, it is good to underline that thanks to the technique of biological control, the use of chemical pesticides and of those substances, which, although natural, kill both harmful and useful insects, is eliminated or at least reduced.
Among these plants, to make this contribution extremely applicative, we remember some of them: Dandelion — It is a plant with a thousand qualities including that of attracting ladybugs.
Therefore, using its applications and its uses, you can think of inserting hedges or agglomerates of this plant into your farms to balance some of our agronomic errors.