Brood XIX Updates from Virginia - Days 3 and 4.

Brood XIX Updates from Virginia - Days 3 and 4.

The last two days have been pretty hectic here in Viriginia. While you were probably enjoying cookouts and parties on Memorial Day, your's truly spent the day in the car with the windows open driving mile after mile listening for the sounds of calling periodical cicadas and mapping their distribution in and around Williamsburg, VA.. I think I must've added at least 75 data points to the distribution map.

Positive and Negative Data

Its not enough to record positive sightings of periodical cicadas. Its also just as important to record negative sightings as well. This negative data helps in defining the boundaries of the area of emergence for periodical cicadas. This information can then be analyzed in order to determine if boundaries have expanded or contracted or to determine overlap zones between different brood boundaries. Not to mention while we solicate the public's help with reporting their sightings it is still difficult to reach everyone and the public has a tendancy to only record positive sightings and not negatives. Afterall negatives aren't as much fun but they are just as important.

Species concentrations around Williamsburg, VA

The predominant species here seems to be Magicicada tredecim. Specimens of this species are easily obtainable pretty much wherever you go because they like to be down low as well as high in the trees. Magicicada tredecassini has been found in great numbers in Ashland, VA and in small concentrated pockets northwest of Williamsburg just as you cross the Chickahominy River on Route 5 (John Tyler memorial highway).

Single calling M. tredecassini males have also been noted in other areas along with Magicicada tredecim but not everywhere.

In addition and this came as a surprise to me but I also discovered a small pocket of Magicicada tredecula also north and west of Williamsburg along Route 5 on the southern side of a small town called rustic. I almost caught one yesterday but was ultimately unsuccessful. Like M. tredecassini, these little guys also call high up in the trees. I will eventually return to this spot and hopefully have better luck.

Determining edges around Williamsburg

So far I have managed to map to the edges of the brood's extent in Williamsburg around three sides. I have indicated the edges with red pips which also indicate negative sightings. I still need to come to the end of the broods range to the north of Williamsburg. I hope to get that done tomorrow.

Surveying south of Williamsburg

Today, while you were back at work I spent yet another day in the car collecting and recording a whole boatload of negative data. This time however, I went south. I drove through the towns of Newport News, Suffolk, Chesapeake and Virginia Beach stopping every mile to take a negative data point and I ended up going all the way to the North Carolina border. Unfortunately I didn't have a chance to map Norfolk but hopefully I'll have time to get to it. Besides, its probably all going to be negatives anyway.

The Great Dismal Swamp

One of the hightlights of my long journey was stopping and having a look at parts of the Great Dismal Swamp. A wet marshy area in southeastern Virginia and northeastern North Carolina. It is approximately 111,000 square acres and was believed to have formed when the continental shelf shifted thousands of years ago. There is even a lake at the center of the swamp known as Lake Drummond. It is believed that this lake was created during a meteor strike producing a crater that eventually filled with water from the surrounding swamp. Pretty interesting stuff.

I drove along the eastern edge of the Great Dismal Swamp from Chesapeak, VA all the way into North Carolina. I did stop at several points along the way to snap these meager photos.

Well, that's about all I have for you during this update. I admit that I haven't collected many cicada specimens or taken many photos during this trip so far so I apologize for the. I hope to remedy that in my future updates.