Behaviors: Cicada Emergence Distribution and Sexual Development

"Adult Cicada Behaviors and Development - Stick With What Works."

During my hunt for Cicadas, I traveled to many different areas in Massachusetts. Unfortunately, while I did find exuvia evidence in different areas, I generally focused my efforts on Saint Patrick Cemetery in Lowell, Massachusetts. After all, you stick to where you have been successful in finding specimens. All the Cicada specimens that I refer to will be from this cemetery.

"When and How Much? - Tibicen Cicada Emergence and Distribution."

I heard the first call of a Tibicen canicularis Cicada in my area of the world on July 9th, which is when I truly started my hunt for Cicadas. After two long arduous weeks of never-ending searches I was finally successful in finding some specimens. The trees that I was successful in finding Cicadas on during the first part of the season seemed to be ash, maple and oak. However, later on in the season most Cicadas (which ended up being Tibicen canicularis) were on pine trees.

For the most part, I have been successful in finding Cicada nymphs and/or tenerals at all times of the day. The following table is a breakdown of the Cicadas I have found and the time of day in which I found them.

Specimen

T. lyricen (f)

T. lyricen (m)

T. lyricen (f)

T. lyricen (m)

T. lyricen (f)

T. canicularis (m)

T. canicularis x2

T. lyricen (m) x2

T. lyricen (f)

T. canicularis x3

T. canicularis (f) x2

T. lyricen

T. canicularis

T. lyricen

T. canicularis x2

T. canicularis (m) x2

T. canicularis (f) x3

T. canicularis (m) x4

T. canicularis (f) x2

T. canicularis x5

T. canicularis (f) x2

T. canicularis x2

T. canicularis

T. canicularis (f)

T. canicularis (f) x4

T. canicularis (m)

T. canicularis (f) x2

T. canicularis x8

T. canicularis (f)

Date

7/26/04

7/29/04

7/31/04

8/1/04

8/2/04

8/6/04

8/7/04

8/8/04

8/12/04

8/14/04

8/19/04

8/20/04

8/23/04

8/24/04

8/26/04

9/1/04

9/3/04

Time

10:15am

9:30am

10:309m

10:30PM

9:00pm

9:30pm

11:00am

10:30pm

11:50am

11:00am

9:15pm

8:15am

1:00pm

9:30pm

11:00am

1:00pm

9:00pm

11:30am

It seems that at the beginning of the Cicada season, I was obtaining mostly T. lyricen specimens, then towards the middle of the season, I had a mixture of both T. canicularis and T. lyricen, then towards the end of the season, I was obtaining all T. canicularis. This is indicative of Saint Patrick Cemetery only, as this is where I spent most of my time, it may not be indicative of the emergence of Cicadas elsewhere in Massachusetts. The emergence patterns may be vastly different elsewhere.

While I was unable to obtain any more T. lyricen specimens after August 8, 2004 I could still hear the call of the male T. lyricen up till about mid September 2004. After that it was mostly T. canicularis.

What would be good is to find another source for Cicadas next year in addition to returning to Saint Patrick Cemetery to see if the emergence pattern repeats itself.

The distribution of female vs. male Cicada emergence times during the year at best seems to be 50%. i.e.; you can find each gender at all times of their season for both species. However, the data above is only accurate in so far as that on some occasions I have neglected to note down the gender of the specimens that I have collected. For the 2005 season I will take accurate data to see if this percentage changes.

"Cicada Sexual Development - When are They Good To Go?"

Once a 5th Instar Nymph molts into a full adult Cicada, they are not yet ready to reproduce. Several criteria, which I have noted have to take place first.

Post-Teneral Stage - Cicadas have to develop into a fully hardened adult from the teneral stage which is the point directly after the molt process. This process takes several hours (see the section on Cicada Molt Process for more information).
Waxy Buildup (Pruinosity development) - Once they are fully hardened, while Cicadas can fly and feed they as of yet are not ready for sexual reproduction. It takes up to 4 days in order for Cicadas to build up the white waxy substance that appears on all male and female Tibicen Cicadas ventrally. The thumbnails below show a male Tibicen canicularis the day after molting and the development of it's pruinosity over three days. As you can see on the third day, the white waxy buildup is still minimal.
Timbal Development - It can take 7 days or more for the male Cicada's timbals to develop completely in order for the male to make their distinctive mating call. So not much happens for a male Cicada at this time. While the timbals themselves are actually a form of striated muscle which are expanded rapidly inwards and outwards, maybe it's the male's timbal covers (the opercula) that need to harden sufficently in order for males to make their call. Very few of the newly molted males that I observed in captivity for as long as 7 days or more actually developed the ability to make their tell-tale alarm call. Because of this characteristic alone, one would assume that male Cicadas would emerge first during a season to give their timbals time to sufficiently develop but apparently this isn't the case.
Special Update 07/05: This year I decided to test this theory on sexual development. I started looking for T. lyricen way before they started calling. The first specimen I found eclosing was on July 4th. For 10 days I still heard no T. lyricens calling. Then on the 14th of July I started to here them call! That's a full 10 days after I found my first specimen. So there may be something to this after all.