1. Insects that transmit infectious pathogens between organisms are called vectors. Mosquitoes transmit many diseases like dengue, yellow fever, and zika. 2. Identification of potential virus-transmitting vectors like mosquitoes involves taxonomic and morphological identification. 3. Factors influencing a vector's ability to transmit pathogens include molecular, behavioral, and structural factors that allow pathogens to enter a host during feeding.

1. Name: AADAR NALSE Student id: 20-1-01237
MEDICAL ENTOMOLOGY
INSECTS AS VECTORS
Any agent that carries and transmits an infectious pathogen to another living organism is
referred to as a vector. A vector-borne disease is a structural or functional disorder in a human,
animal, or plant that is transmitted by a vector.
To find the potential virus-transmitting vectors, which are mostly mosquitoes, a step-by-step
taxonomic approach is applied. The specific mosquito is identified with the use of this
morphological identification.
The information regarding insects, such as their presence in a certain region and illness, is found
in the next phase in order to determine whether they are harmful to humans. Aedes albopictus,
for example, has been discovered to be a vector for a variety of diseases, including dengue fever,
yellow fever, and zika. During an epidemic, the most important thing to know is how to stop it
from spreading; this should be recognised as soon as the first patient appears, otherwise there
will be a massive loss.
Toxins, venoms, allergic reactions, parasite infections, and other non-vector illnesses are also
produced by phylum arthropoda species. Mosquitoes infect and kill approximately 725,000
people per year. This also demonstrates a significant impact on society and the economy.
Not all vectors are insects, and not all insects are vectors. For example, order Diptera, Acari,
Hygrophila, and so on.
Being a vector is a homoplastic trait which means this trait evolves independently multiple times.
Holometabolous life cycle shows complete metamorphism and consists of different stages like
egg, larva and pupa or adult (example: butterfly). Hemimetaboly shows incomplete
metamorphosis which includes the egg, nymph and adult or imago (example: grasshopper).
Various patterns can be seen in vector-borne diseases, such as:
Animals/insects that eat blood and spread illnesses are known as hematophagists. Their mouth
parts have evolved to make feeding easier for them.

2. Zoonosis is a disease spread by animals to humans. Rabies, Ebola, Swine Flu, and other diseases
are examples. A reservoir is a long-term host for an infectious disease pathogen.
Malaria is not a zoonosis since humans serve as reservoirs for the parasites that cause it, and it is
not transmitted by animals.
Vector Competence: Not all insects are capable of acquiring, maintaining, and transmitting a
pathogen. As a result, mosquitoes do not transmit all diseases since not all pathogens can
multiply and enter the human body when the mosquito bites and suckes.
The time it takes a mosquito to pick up a pathogen and the time it takes for the infection to
spread/release it is critical since pathogens can only stay in the vector for a limited amount of
time, which is known as bite twice.
The time it takes for pathogens to show symptoms is known as the incubation period. Extrinsic
(time spent exhibiting in vector) and intrinsic (time spent donating the pathogen) incubation
periods are used.
The gonotrophic cycle is the reproductive cycle that includes seeking for a blood meal, eating,
digestion, and egg development, among other things.
Many cases are endemic to a certain place because the reservoirs are only found there. Consider
the case of Lyme disease.
Factors that influence vector competency include:
1. Molecular factor: For example, receptors, pathogens have specific molecular proteins that
can recognize particular receptors of skin.
2. Behavioural factor: Mosquitoes are specific about their targets so they require particular
behavioural factors in order to reach a specific host.
3. Structural factors.
1.Molecular factor: Receptors and infections, for example, have specialised molecular
proteins that can recognise specific skin receptors.
2.Behavioral factor: Mosquitoes are quite specific about their targets, thus they need
specific behavioural elements to reach them.
3. Structural Factors :
Types of pathogen transmissions:
Vertical: For example, mom to child.
Transstadial: For example, This resembles a holometabolous cycle which means transmissions
are unidentical.

3. Horizontal: From species to species.