Okay, so today is Friday and we have an expression, there is an expression in Brazil that is this

one is sexto because in Portuguese Friday is sexta feira. So what does it mean sexto?

Some people can explain better but I think I'm used to that already. So it means that

it's Friday and usually we are at lunch or at the beginning of the afternoon and we want

to have a beer. I said okay but we still have to work but someone says no sexto so it's

your you have the right to order your beer. So in English it would be it has Friday it

Okay and if I'm not wrong in German it would be it's even regular okay so if you want to

stop start using it feel free. So it's difficult what I mean is that it's not easy to give

a talk on Friday afternoon that's in Brazil is not easy and I guess that here that beer

is even better it is not easy as well but let's go to the point. So the scope of this talk is to

present some models for disease and crop pest control so crop pest I mean a pest that invade

plantations okay and apply different control techniques classical optimal control continuous

time and impulsive feedback stabilization and optimal control on networks okay and comment on

the difficulties when dealing with control affine problems you will see what I mean and other

challenges. So I will present mainly two papers let us say the first one was with Yves DuMont

from Syracuse France and the second one with Lucas Mosquin that now is in Paris-Orbonne but

he's a former student of mine. Okay so the first part is about disease and pest control using sterile

insect technique that I will explain next. So this sterile insect technique involves the use of

radiation to generate male other insects that they then I released into the wild and compete with wild

males that's the idea okay so in the wild the females that mate with sterile male produce no

or less offspring okay so this this female the wild females lose the time of reproduction but

if they mate it with sterile male the eggs are empty that's the idea so they invest the energy

at the time but then they have no offspring. So the aim of the process of releasing sterile insects

is to reduce the size of the insect population okay and that is applied to control diseases

diseases or pests and pests okay so this is the graphical representation of what I said not of

the way they are released so first they are they are captured and then they are radiated in

laboratories okay and then they are released and then they mate they compete with wild males so

these are sterile males and to mate with wild females and the females that mate it with a

sterile insect they have no offspring okay that's the idea so the SIT so SIT is sterile insect

technique has been going around since the since the 50s so it's an old technique and it has been

used against many species sorry many species of insects among them is the this list so I had this

I will name the most famous one I this mosquito that is the responsible for carrying dengue fever

zika yellow fever chikungunya and all these very famous diseases that will get even more famous in

the next years that's why I think Kalex mosquito Anopheles mosquito Anopheles is the responsible

transmission of malaria okay and setse fly that that is responsible for an analysis okay and in

the project that my colleague work if you want he's now based in Lagroup in France that is located

here okay and it's about SIT applied to Aedes albopictus so it's one of the species of the

Aedes mosquitoes sorry and against this fruit fly Bactroceratopsalis so fruit fly because it

eats the fruits in the plantation and it ruins the plantation and it means in a lot in a big

waste of money okay great okay so some considerations about what's going on so first

general what happens is that high levels of radiation are required to achieve full sterility

okay but high radiation has an impact on the fitness of the males and then it has an impact

on the fitness when they are released into the wild they are not very strong to compete with wild

males okay and that's a problem because we want to release males that can do something in the wild

but lower radiation has a reduced impact in fitness but can generate partially fertile males

so males this is this radiated males I released into the wild imagine if you really must it's

like thousands hundred thousands imagine that you release hundred thousand and half of them are

fertile that's a disaster okay so what we wanted to analyze in this work is to propose modern okay

for a site implementation that takes into account batches that have partial sterile it

partial sterility that means that have some residual fertility okay and evaluate possible