Cicada Sexual Development
News Category: Cicadas 101
Cicada Sexual Development
Once a 5th Instar nymph molts into a full adult Cicada, they are not yet ready to reproduce. It would seem that 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 or more for Cicadas to build up the white waxy substance that appears on all male and female Tibicen Cicadas. 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 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 hear them call! That's a full 10 days after I obtained the first specimen. So there may be something to this after all.
- Proximity to Female Cicadas - It may be that male cicadas do not need to have fully developed timbals attract a female. It may be that just being in close proximity to a female cicada will enable male cicadas to mate with females. Several years ago newly molted male and female cicadas were placed in a terrarium for study. After approximately 10 days female cicadas started to oviposit in dead twigs placed within the terrarium. Perhaps some males mated with the females without males timbalizing. Another possibility may be that females laden with eggs may simply go through the process of ovipositing and perhaps the eggs laid may not have been viable. More work needs to be done to figure out what is actually going on.
Cicada Waxy Buildup Over Several Days