Larvae, Pupae, and Vero Cells

Earlier this week, we hatched our eggs, separated them into groups of 250 larvae per tray, fed them, and let them develop. After sorting all the larvae, we ended up with 24 trays of each mosquito population resulting in a grand total of 12,000 mosquitoes! These pictures are all of the larval rearing trays that we currently have in the rearing room.

Under ideal temperature conditions and with adequate food, this is about the time we should start seeing pupae. Sure enough, when I came to the lab this morning, I was greeted by hundreds and hundreds of pupae! A good portion of the morning was spent transferring the pupae from the larval rearing trays into small cups. These cups were then placed in a cage with sugar water. Within the next 1-2 days, these pupae will be adult mosquitoes.

This weekend, in preparation for the experiment, we also had to seed our flasks with Vero cells. Vero cells are a lineage of cells that are used in cell culture and these are cells that we will eventually infect with our virus. However, before we can infect the cells, we must first know how many cells are in each flask. This is where the process of seeding comes in. Seeding is spreading a defined amount of cells into the flask. The cells that we distribute in the new flask are pulled from an existing cell culture. After a few steps, the cells are dislodged and present in a cell suspension (video below – ignore the mosquito stuck somewhere in the microscope). From here, we calculate how much cell suspension is needed to get 21.6×10^6 cells per flask, add some media, and allow the cells to incubate for a few more days.

The major task this week will be picking pupae, but on Thursday, Friday, and Saturday, we will also be inoculating our cells with Zika virus. One step closer to our infectious bloodfeeding!

And so it begins…

Today marked the beginning of an experiment that I have been preparing for months. This experiment will consume a majority of my thoughts, time, and energy for the next 2-3 months, and I could not be more excited!

First off, if you are wondering what you are looking at in the picture below, that is THOUSANDS of mosquito larvae that I hatched this morning. Believe it or not, this is only half of the mosquitoes that will be hatched for this project! They will be used in an experiment evaluating the potential for two populations of Aedes aegypti (the yellow fever mosquito) to vertically transmit Zika virus to their offspring. Vertical transmission is the transmission from the mother to her offspring.

In the coming weeks, we will infect these mosquitoes with Zika virus in the laboratory, allow them to lay eggs, hatch those eggs, and test the progeny for the presence of Zika virus… That’s the simplified version, anyways! Over the next few months, I will share the progress of the experiment and the methods we use to investigate something like the vertical transmission of an arbovirus.

From this point forward, everything is on a very strict and planned schedule. Many people will spend many hours on various aspects of the study from bloodfeeding, to sorting mosquitoes, to RNA extractions and PCR. For this week, we are focusing on getting these immature mosquitoes to their adult form to be used in the study. Tomorrow, we will hatch more eggs, separate the larvae into more rearing trays (so they aren’t crowded and have plenty of room to develop), and make final preparations for the study. Stay tuned for more updates!



My name is Casey and this is my new website! I am an early-career scientist currently located at the Florida Medical Entomology Laboratory in Vero Beach, FL. My current research is on mosquitoes, insecticide resistance, and vector competency. I also have been conducting extension research in elementary schools and underserved communities in Florida.

Please explore my page and stay tuned for updates! I am getting ready to start some experiments that look at the vertical transmission potential of Zika virus in Aedes aegypti and the extrinsic incubation period of Zika virus in Aedes aegypti. I will be sure to post updates!