Invasive species have been know to be organisms that do not naturally live in a given region or habitat but find their way into such a new habitat. They come into their host community with a deleterious effects. The consequence of their presence leads to disruption of the normal activities withing such community. They seem to have a goal which is to eliminate the existing species that are aboriginal to the invaded community. They do not meant well for the original inhabitants of the community they have invaded. Economy sabotage, negative impact on the environment and adverse effect on human health are just few of their accomplishments.

Recently, towards the tail end of year 2019, in the United states, the Pacific Northwest received an unusual guest from Asia. The uninvited guest find its way to an apiary. Damages was done at the apiary by the invading guest. The farmer got to his farm late enough that he couldn't save his bees from the predator.

The invaders ensure that the whole bees in the hive were completely destroyed with their head torn apart from their body. All that the farmer saw was carcase of the severed bees body on the ground. The invader has completely annihilate the bees in the hive visited. All thanks to the invaders Asian giant hornet.(Vespa mandarinia)

What is Vespa mandarinia

CC BY 2.5 commons wikipedia

Vespa mandarinia known as Asian giant hornet,(AGH) is the known largest specie of hornet that originate from the Eastern Asia most especially the temperate and Tropical eastern Asia. They predominantly dwell in the low mountains and as well as in the forest. It is also well adapted to this same conditions in the Pacific Northwest of North America, more reason why it could survive there possibly after it has been introduced there deliberately or unknowingly through shipment to the United States. They can hardly be found in the high mountains and plains.

This insect belongs to the order

![1920px-Male_Vespa_mandarinia.DSC_1515.jpg](

^{Male_Vespa_mandarinia CC BY-SA 4.0,}

hymenopterans which also include other insects such as bees, (its main prey),sawflies, wasp and ants. Most of the insects in this group are very useful as pollinator and pest control.
Vespa mandarinia is a social hornets, that uses its stingers for defence (the females). The social hornets are very aggressive and intimidating. However, in spring (using northern meteorological season) time like this,when flower blooms and trees reproduce, they are not very aggressive because food is readily available. The case is not the same in late summer when the weather is dry, and there is high request for protein to feed their larvae.

Vespa mandarinia Weapon

The weapon of destruction possessed by Vespa mandarinia is called stinger which is about 6mm in lenght. The stinger is peculiar to all hymenopterans. Its a modified ovipositor which its primary function is for laying eggs. So obviously, it is possessed by females alone. The stinger in them, better known as ovipositor is used to plopped egg into their prey. This ovipositor when used to attack, it completely immobilize the prey especially human with the feeling of hot nail driven into the body.

Effect of stinger on human

Asian giant hornet does not really sting human without proper warning. The insect minds its own business especially when on the search for food. They only attack human when the latter comes near their nest to disturbed them. The insect always try to avoid human. Before they descend on human, man would have deliberately ignored sound made by the insect mandible. Interestingly,the venom of honey bee is more toxic when compared to that of giant hornet, but the difference between the two is that honey bee only sting once while giant hornet can sting several times, and the effect of the venom could be life threatening.

Venom composition and effect on human

The venom of this insect has been studied to contain acetylcholine (a neurotransmitter) and a compound which mediate itching better known as histamine. Another component is kinins a polypeptides of –18 amino-acid residues which is a neurotoxin in the insect venom. A component of interest again is mastoparan a polypeptide and an enzyme phospholipase. All these component are in the venom and work together to suppress human immune system and thereby giving way for quick spread of the inflammation caused by the sting. Blood and muscle cells are seriously attacked as a result of synergetic action of all the chemicals present in the venom. Kidney failure, respirative failure and liver dysfunction are all imminent when an individual is sting. Japan annually experience 30-50 death as a result of Asian giant hornet sting. Though the death always result because of anaphylactic reactions rather than toxicity. Some of the reactions may include, itching rash on skin, swollen throat or tongue,light headedness and many more. All these could be experienced withing minutes or hours after sting. These hornets can attack several times, which means they can deposit large dose of the venom in the human body when they attacked. On United States social media , they called Asian giant hornet as murder hornet Further reading on effect of AGH sting on human click here

Attack on bee colony

The attack of giant hornet on honeybee colony is a coordinated attack. It is an assault on the bee colony that leads to colossal loss of an entire colony. The attack can be said to be a three stage coordinated one.

stage one

A lone attack where just one giant hornet goes to a nearby honeybee hive between 2km-7km distance from their own colony. On reaching the honeybee colony, it will attack a single bee worker at the entrance of the hive, ripe off its head at the thoracic segment into a paste and head back to its own nest to feed their own larvae. Since they are social insect, they communicate and head back to where the one that carry out the lone attack came from to carry out a major slaughter phase.

stage two.

At stage two, a group of 20-30 giant hornet carry out what is called slaughter. They destroy thousands of honey bee workers who are defenceless against the attackers. They rip off their heads one after the other until they are done with the workers manning the beehive entrance.

stage three

Pupae of drones CC BY-SA 3.0

Once the hive is open to invasion, the abandoned honeybee larvae and pupae becomes bee-brood paste in the mouth of the invasive hornet. Withing hours a beehive which was once full of activities becomes a ghost town

Its so pathetic that the western honeybee Apis mellifera ligustica lacks defense mechanism unlike the Japenese honeybee Apis cerana japonica which has evolved to developed defense method against the Asian giant hornet and other invading insect.
The Japanese honeybee forms what is called Hot defensive ball against the invader. How do they do this? As soon as the invading hornet enter the hive, the bees quickly form a ball around the hornet.

Honey bee ball thermal defence CC BY-SA 3.0

They generate heat up to 46°C with the aid of their flight muscles. This they normally do to heat up their hive during cold. So they form ball round the hornet. The formation of the ball also elevate the amount of carbon iv oxide withing the ball. The hornet withing the ball can't survived the two conditions while the horneybee surrounding it can survive both increase in the amount of carbon iv oxide and temperature raise up to 50°, although some of the horneybee may not survive as they also die along, but they are able to prevent the invader from achieving its mission.

The history of Asian giant hornet into North America will not finish without mentioning where they were first sighted which is the British Columbia's Vancouver island in Canada pacific coast in mid-August 2019. Three of the Asian giant hornets were first sighted there. The government agency raised an awareness about the invasion of the hornets. They warned that the number might increase by spring when the queen will appear. The warning was sounded so that proactive measure would be taken to contain the number of the hornet.

## Conclusion The consequence of the increase in the number of **_Murder hornet_** could affect the safety of human life and also reduce the honey yield annually in the affected part of the country.