Brood XIV Periodical Cicadas Latest Stuff
News Category: Cicada Missions
Brood XIV Periodical Cicadas Latest Stuff
Hi Folks, I apologize for the lack of updates. So I thought I'd head this update with a little bit of cicada humor. I've just been totally busy with the whole Brood XIV event. It looks like Cape Cod is now in full swing regarding the emergence. You can look for the emergence to start to wind down over the next couple of weeks. I would suggest you go out and experience it while you still can because they won't be around again for another 17 years.
Distribution Maps have been updated.
Even though it looks like the site hasn't been updated in a while, the stream of user-submitted data points is ongoing. Due to the massive amounts of sightings being reported, I have been concentrating a lot of my efforts in providing accurate and updated distribution map information. As I write this message, more reports are piling in. So I am a bit behind again with the new data points!
Last Weekend's Survey.
I spent most of my time in the extreme western portions of the Cape. I visited the towns of Bourne, Monument Beach, N. Pocasset, Pocasset, Cataumet, W. Falmouth, E. Falmouth, N. Falmouth and of course Mashpee to see my friend Lisa. As you can see by the map as of 6/8/08 there are a lot of "yellow pips" where I noted no Periodical Cicadas at all. While this may change as more reports come in, it shows that the emergence is very "patchy" at best.
Speaking of "Patchy Emergences".
One of the places I stopped was in Pocasset on Clubhouse Dr. Just off of County Road (see map). The Periodical Cicadas were singing away. I found many cicadas in low-lying bushes and surrounding trees and even in the middle of the road and tons of exuvia. The chorussing I'd say was loud but not like it was during the Brood XIII periodical cicada emergence last year.
However, as I continued along Clubhouse Dr. which runs along the Pocasset Golf Club there was absolutely no signs of periodical cicadas! No calling no signs of exuvia, nothing. Continuing further on to the end of the road, there was still nothing.
Many Deformed Cicadas
I decided to head back the way I came and stopped to take some photos on the upper end of Clubhouse Dr. While there were a lot of nice-looking periodical cicadas that seemed to survive the eclose (molting) process. Some were still extremely deformed and others just never completed the process.
People often ask me what are the causes of these extreme deformations. I have theorized after talking with many people that there can be several causes.
1). During the mass-exodus from the ground, the periodical cicada's number one priority is to get to a vertical surface to molt. During this process sometimes they can fall after taking several hours to climb to a nice secluded spot. Once they fall, they have to start their climb all over again. Unbeknownst to them, they injure themselves. Most often-times there may be some "internal bleeding" going on. What I mean by "internal bleeding" is the spaces between the outer hard nymphal casing and the pre-molted cicada can collect a clear fluid which some consider to be an insect's blood. By the way, cicadas do have blood like most other insects but they do not have an enclosed circulatory system like you and I. An insect's blood is known as "Hemolymph".
Once the cicada gets injured, the "Hemolymph" can sometimes dry or harden making the cicada nymph appear black. Once this happens, it's fate is pretty much sealed. It will be forever stuck inside it's nymphal casing. While falling can be one form of injury, a cicada nymph may injur itself in other ways.
2). Sometimes when there isn't enough surface area due to overcrowding, one periodical cicada who was happily molting and minding its own business may often times get injured by other periodical cicadas also looking for a place to molt. Any time during the eclose process, if a periodical cicada teneral is in the way of other cicada nymphs looking for spots for molting these tenerals may often get walked on or trampled on by other nymphs causing deformed wings as indicated by the picture on the right. Click the thumbnail to enlarge.
3). Finally, maybe environmental factors play a roll. For instance, the use of plant fertilizers and insect repellants may have an affect on a genetic level which can cause deformities. More research needs to be done in this area.
An Unusual Deformity.
However, there are some deformed cicadas which I just cannot explain, especially during the molting process. There is a definite sequence of events that must take place during the normal process of molting. First along the back of the thorax of a mature nymph's skin a "split" appears and the cicada teneral pushes through the opening thorax first. Then soon after the upper part of the abdomen appears along with the pronotum followed by the head.
Eventually the cicada will wiggle its legs out of its nymphal skin extending itself backwards and will be held in place inside the skin by its lower abdomen. The cicada will stay in this position for about 45 minutes. During this time the cicada's legs will harden enough for it to support its own weight. It will then do a big "sit-up" grabbing the old nymphal skin with its legs and pull out its abdomen. Once that is completed the wings will fully expand, then fold in "roof-like" over the body.
This whole process can take up to an hour and a half. The thumbnail above and to the left is a brief slide-show pieced together from various periodical cicadas during the molting process. It isn't all that long but if you view it you will get a general idea of the normal process.
As previously indicated there are times when this process goes horribly awry. The thumbnail to the right, is of a cicada with its legs and most of its head still encased within its nymphal shell but it still managed to pull out its abdomen and the wings formed perfectly!! I really wish I was there because I really cannot explain this one! This cicada will live in this state for many days. Hopefully it will get eaten by a predator thus putting it out of its misery.
Periodical Cicada Experiments.
I collected around 20 male and 20 female cicada specimens the last day of May. As of this writing most of them are still alive. The females seem to be a bit "hardier" than the males. Out of the 20 males I collected only around 1/2 are still alive. Whereas out of the females only one has died so far.
I have intentionally kept females and males separated from each other for experimentation purposes.
Male Periodical Cicada Calling Song.
I was curious as to how loud the sound would be with just 20 male cicadas in a mesh bag. Since I brought these cicadas back from Cape Cod to my neighborhood in North Chelmsford, I was curious as to how loud the sound could be without extraneous background noise from other non-captive cicadas. If you click on the video to the left you will see with the use of immitation calling followed by a fake female wing flick response I managed to get a number of the cicadas in the mesh bag to call. The fake wing flick response to a male cicada's call is paramount to getting the cicadas to start calling because it signals that there is a female nearby. Unlike non-captive periodical cicadas which set up aggregations (grouping together of multiple males) trying to get them to call in captivity is sometimes difficult. As you can hopefully hear, the sound gets pretty loud and with just 20 cicadas it sounds like a full chorus. Credit for this method goes to John Cooley and David Marshall of the University of Connecticut at Storrs for teaching me this method.
Female Wing Flick Response.
I was curious to see what would happen when I conducted a male simulated call to the group of females kept in a separate mesh bag. I was happy to discover that after calling the females responded with wing flicks signalling their readiness and willingness to mate. I don't know if this has ever been recorded before but take a look for yourself. Click the thumbnail above and to the right to watch this response.
It is often said that male cicadas can mate more than once while the females mate only one time. After mating, the males deposit what is known as a "sperm plug" in the female thus preventing all other males from mating with her. Hopefully with future experiments that I intend to conduct, I want to witness the entire mating behavior of a single male and female from start to finish.
That is listen for the male calling and the female's wing flick response, this will set up second and third stage calling responses in the male and eventually they will mate. I'd be interested in seeing the actual mechanics of how this comes about. Once the pair has mated, I will use the same male and see if he will mate with additional females. So stay posted for future videos.
Massachusetts Cicadas In the Media.
Below are more links to some newspapers where I was interviewed by the media. Thanks to them for helping spread the word about Periodical Cicadas here in Massachusetts.
WGBH Greater Boston Talk Show with Emily Rooney - Click here.
Boston Globe - Cape Cod is Again Abuzz - Click here.
So What'd I Miss?
If you are just finding out about this web site and the cool Brood XIV Periodical Cicadas, you can get caught up on previous updates by consulting the Cicada Missions or click to the beginning of the 2008 season which starts here. Be warned though! If you haven't noticed already, I like to write so be prepared to read!! There's lots of cool information.