As the lab has been gearing up for mosquito intensive work, this past week winded down on field work. Preparation, explanation, and identification were major themes this week.
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| Wells Reserve, sunrise 7/2/24 |
Mosquito Identification
Starting off, my Monday was almost exclusively focused on mosquito identification. In doing so, I was able to assist a research assistant in the lab in IDing mosquitos collected from CDC light traps. Of the mosquitos I looked at, there was a different purpose in identification then typical, reference specimen. Over time training and reference specimen used by the lab may lose distinguishable body parts including scales, legs, abdomen, and even heads. This makes it difficult to practice skills and use these mosquitos as a reference when identifying specimen to send to the state for testing. The majority of mosquitos I sorted were Coquillettidia perturbans which is a vector for West Nile virus (WNV). In the sample sorted there was 75 mosquitos with 47 that were Cq. perturbans. Other mosquitos identified were Aedes (Ochlerotatus) cantator (3), Ae. Canadensis (3), Ae. provocans (1), Ae. fitchii (4), Ae. excrucians (12), and Ae. intrudens (5).
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| Sorted reference mosquitos |
These mosquitos were all collected in June so if they were used for testing, we would primarily be for positive results of Jamestown Canyon virus (JCV). While at the time of writing this, I do not have the species of JCV concern on hand, the species sent out for testing changes depending on the time of year. Moving forward into specimen collected in July, we will submit further species to the Maine Health and Environmental Testing Laboratory (HETL) for testing of JCV, WNV, and Eastern Equine Encephalitis (EEE/triple E). Since these will be used as reference mosquitos, it was a good step to reestablishing an adequate inventory.
Bird Banding
Tuesday was spent bird banding again, and this time I was able to be a part of this from start to finish. Arriving on the site at 5 am, the mist nets were set up and ready to capture birds by around 6 am. For the next 4 hours we collected, processed, and released birds until it was too hot to continue (for bird safety). As the summer has pushed forward, we have had many visitors stop by to learn from Patrick Keenan. This week there were multiple summer camps that stopped by to watch and indirectly I have been able to learn further about why certain measurements are made, or why this work is impactful. Patrick often informs the kids stopping by that while we are processing the birds, it's much like a checkup at the doctor’s office. It may not be the birds favorite experience, but it certainly does not hurt them. And before you know it the bird is released (often by one of the kids) back into the wild.
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| Chestnut Sided Warbler caught in mist net |
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| Grey Catbird with missing leg due to scaly leg mites |
In the photo above, Patrick identified a recaptured Gray Catbird that has been suffering from scaly leg mites. We knew this was a recapture because if you look closely, this bird has a band on its right leg. On that same leg there is also visible jagged/unusual scales due to scaly leg mites. You may also notice that the left leg is missing. That is because scaly leg mites burrow in the birds leg and feeds on keratin. This caused a the leg to deteriorate and is a very detrimental condition that will likely lead to this birds early death. While it still has one leg, it can still perch (somewhat), and grab food, but once that leg is lost - and it will be, the bird will be doomed. While this internship has introduced myself to various disease and conditions that tick and mosquitos may cause, I thought this was extremely interesting.
Pesticide Resistance Project
Going forward into the week, I had more opportunity for mosquito ID practice, assisting with ID of ticks, and learning more about the pesticide resistance project I will be working on. What this boils down to is that there have been previous studies that have shown that species of Culex mosquitos are more likely to oviposit in water that has been infused with hay. In particular this study will use Bermuda hay, lactalbumin hydrolysate, brewer’s yeast, and water. This mixture is put into what is called a gravid trap and encourages mosquitos to lay egg rafts.
There will be about 5 traps placed once a week at a single site on a Thursday and picked up the following Friday morning. Each lab member involved in this project has a list of sites and will follow this process weekly. In past years multiple sites were surveyed weekly with one trap at each, but it was determined that this procedure will be more beneficial, given that they are placed at the right time, when mosquitos that are desired are present. Culex restuans are present in the early summer (June) and Cu. pipiens congregate starting around July with their peak in August. There is a bit of an overlap in July when both these species are present and could oviposit in the gravid trap, but Cu. pipiens are desired for this study. So in theory, if Cu. restuans are still abundantly active when we place these traps in the coming weeks, the one site per week could render undesired results with limited sample collection. Or if Culex activity trends as it has historically, Cu. pipiens eggs rafts may be collected in larger amounts than previous years.
New Section on This Blog
In other news, I thought it may be beneficial to try to create a pictorial guide for tick reference on this blog. I have talked in length of tick species and their medical importance, so I have decided to try to show aspects of what I am talking about. If you are interested, the banner section of my blog now has a section labeled “Tick Pictorial Identification Guide”. While this is still a work in progress, I have included dorsal and ventral images of ME tick species that I have taken on my phone. All of the specimen pictured were either collected by me or identified by myself in the lab. Hope you enjoy!
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