Molting and moon phases

[Graceface]

Has anyone ever looked into how (or if) moon phases/cycles affect insects and molting cycles? 

Fish and animals are affected by moon phases, you can calculate whether it is a good or bad time to hunt or fish based on moon phases. Also, the farmers almanac says plants focus on different types of growth during different moon phases, giving you advice on when to sow seeds, or take cuttings based on this. 

 I've noticed my mantises seem to molt in groups, with multiples molting at similar times. I'm not just talking about siblings, which would kind of make sense, but unrelated specimens. Just this week, I've had my Ghost babies molting to L2, 4 older Ghost nymphs molt to L4  (I think, could be L5), and multiple Orchids molting. It seems to come in waves. The moon was a new moon a few days ago, so potentially the new moon is a good molt time? 

I could be grasping at straws here, trying to make a connection, but it seems logical that insects would be affected by moon cycles

 

[Synapze]

I've never read anything on molting and moon phases. Obviously molting wouldn't be connected to the light of the moon, especially since the new moon phase is dark, and I can't think of any reason gravitational forces would either. I think it's simply related to development and not lunar phases.

Very interesting idea. Let us know if you find a connection.

 

[ohaple]

There is some evidence to support the idea, but I think it is highly unlikely in captivity where the mantids often have no way to observe the lunar cycle.

Here is a good study:

" Coupling of biological rhythms with the lunar cycle via photic stimuli associated with the moonlight cycle have been suggested for a number of marine, freshwater and terrestrial species, yet experimental evidence is still restricted to a few cases (for reviews, see 26,38,39). In most cases studied, photic lunar cues do not seem to act directly but as zeitgebers (entraining agents) of an endogenous (semi-) lunar rhythm. Irregularities in weather conditions make moonlight a rather unreliable cue in many parts of the world. An endogenous nature would allow for the maintenance of the rhythm even when the moon is occasionally obscured by clouds. "

" What selective advantage(s) do crayfish derive by synchronizing their molts (exuviations) with the days around new moon? The act of exuviation is a crucial event. At and immediately after exuviations, crayfish probably are vulnerable targets to predators and exposed to an increased danger of cannibalistic attacks. Benefits may arise in two different contexts which are not mutually exclusive: (1) Molts are timed to a distinct phase of the lunar cycle, as the environmental conditions at this point of time are more appropriate to successful molts than they are at other times. (2) Molting at the same time may provide some advantage to all individuals involved. In this case, synchronization with the external cycle would be but a devious route by which animals of a population achieve some interindividual synchrony. "

Here are some of the most on-point sources it uses:

• 22. Hauenschild C (1960) Lunar periodicity. Cold Spring Harb Symp Quant Biol 25: 491-497. doi:10.1101/SQB.1960.025.01.051. PubMed: 13712278. [PubMed]
  
• 23. Saigusa M (1980) Entrainment of a semilunar rhythm by a simulated moonlight cycle in the terrestrial Crab, Sesarma haematocheir . Oecologia (Berlin) 46: 38-44. doi:10.1007/BF00346963. [PubMed]
  
• 24. Neumann D (1985) Photoperiodic influences of the moon on behavioral and developmental performances of organisms. Int J Biometeorol 29, Suppl. 2: 165-177. PubMed: 3830926. [PubMed]
  
• 25. Mercier A, Ycaza RH, Hamel JF (2007) Long-term study of gamete release in a broadcast-spawning holothurians: predictable lunar and diel periodicities. Mar Ecol Prog Ser 329: 179-189. doi:10.3354/meps329179.
  
• 26. Takemura A, Rahman MS, Park YJ (2010) External and internal controls of lunar-related reproductive rhythms in fishes. J Fish Biol 76: 7-26. doi:10.1111/j.1095-8649.2009.02481.x. PubMed: 20738698. [PubMed]
  

I wonder if they let off some pheromone that makes others think it is a safe time to molt. That could explain the group molting, but I have no evidence one way or the other. I did think it was odd that my L5 giant rainforest molted within 24 hours of three sibling L3 ghosts, but it is probably just coincidence.

 

[Graceface]

I wonder if they let off some pheromone that makes others think it is a safe time to molt. That could explain the group molting, but I have no evidence one way or the other. I did think it was odd that my L5 giant rainforest molted within 24 hours of three sibling L3 ghosts, but it is probably just coincidence.

I assume it is coincidence, as individual development seems the most likely reason any individual would molt. However, I got to thinking after seeing a few other members say they had multiple molts happen, all of which occurred as I had 3 unrelated specimens molting in my home. One of my Orchids needed a molt quite bad, and had been refusing food for 4 days. He molted, but on the same night I had 2 Older Ghosts molt and my L1 ghosts molting, too. Odd, yes. Related, I doubt it, but who knows, right?

If other people are experiencing mantis molts at the same time, if there is a common denominator it would have to be something that affects all insects involved. I somehow doubt they let off a pheromone, as most mantids are opportunistic hunters and would seize any chance for an easy meal. Seems like a bad idea to broadcast that you will be vulnerable.

Yes, it would be hard for a captive mantis to physically observe moon cycles. It is possible they sense the gravitational changes, or differences in the magnetic field of earth (like birds flying south, etc) but I agree it sounds a bit unlikely. 

 

[ohaple]

I assume it is coincidence, as individual development seems the most likely reason any individual would molt. However, I got to thinking after seeing a few other members say they had multiple molts happen, all of which occurred as I had 3 unrelated specimens molting in my home. One of my Orchids needed a molt quite bad, and had been refusing food for 4 days. He molted, but on the same night I had 2 Older Ghosts molt and my L1 ghosts molting, too. Odd, yes. Related, I doubt it, but who knows, right?

If other people are experiencing mantis molts at the same time, if there is a common denominator it would have to be something that affects all insects involved. I somehow doubt they let off a pheromone, as most mantids are opportunistic hunters and would seize any chance for an easy meal. Seems like a bad idea to broadcast that you will be vulnerable.

Yes, it would be hard for a captive mantis to physically observe moon cycles. It is possible they sense the gravitational changes, or differences in the magnetic field of earth (like birds flying south, etc) but I agree it sounds a bit unlikely. 

It is interesting. I think that it is most likely to be external factors like the article discusses. Lunar cycles seemed to be more important for aquatic species near the shore, where the moon has more influence on the ecosystem. In mantids, they may look for other factors like temperature or humidity or light. Even though the natural cycles don't exist as much in our homes, we still create cycles that they might use to determine good molting times. Home thermostat programming, how often we mist the enclosures, and our habits with turning lights on and off may cause a similar reaction. I really would like to read some scientific literature on the subject but haven't found any that isn't locked behind a $40 paywall per article. I might need to make a point to visit the library to get several articles to read at once.

 

[River Dane]

That’s something I never really thought about. I have had several occasions where my mantids molted in synchrony and other times individually. But I’ve never had a large enough control group to really chalk it up to anything other than coincidence. It’s a pretty interesting topic. I’d have to say, though, that I lean towards the idea of warmer or more suitable temperatures triggering multiple molts, since, from what I understand, orchids and ghosts thrive in similar temperatures? Although the lunar cycles definitely are also intriguing. 

 

[Graceface]

Mainly, it got me wondering if they could 'sense' moon phases and use that as a potential contributing factor when deciding on the best time to molt. Maybe it is an item on their 'time to molt' checklist. Like...Enough Humidity? Check! Right Temp? Check! Moon phase? New, so plenty of darkness, check! Feeling ready to bust out of my exoskeleton? Check! Let's molt, baby!!!

I haven't tried tracking moon phases in my mantis notebook, but I think I will, just to see. Animals are capable of some pretty amazing stuff that I wouldn't have believed unless I'd seen it, so you never know!