How to determine if a Jumper is an adult?

[MrZorak]

Hi everyone, newbie here. I have recently taken in some species and I was wondering how I can best determine if they are adult. For purposes if this discussion I will be talking about Bronze Jumpers (Eris militaris) in particular as well as Bold Jumpers (Phidippus audax).

Are there any key things to look out for with these species? For example, I have two female Bronze jumpers. One is a bit smaller and less fat. The other is far more rotund and that makes me suspect they will be able to lay eggs soon.

For Bold Jumpers, is it that they are only true adults when they get their green/blue palps? Any information you can provide would be appreciated!

 

[Lucky123]

Hi everyone, newbie here. I have recently taken in some species and I was wondering how I can best determine if they are adult. For purposes if this discussion I will be talking about Bronze Jumpers (Eris militaris) in particular as well as Bold Jumpers (Phidippus audax).

Are there any key things to look out for with these species? For example, I have two female Bronze jumpers. One is a bit smaller and less fat. The other is far more rotund and that makes me suspect they will be able to lay eggs soon.

For Bold Jumpers, is it that they are only true adults when they get their green/blue palps? Any information you can provide would be appreciated!

Don’t really know about E. militaris, but for P. audax I think you are talking about the chelicerae (the palps are what they use to hold stuff) for mature male P. audax they have big fuzzy arms with white stripes. With both sexes of P. audax generally the juvenile’s have orange markings on their backs, while when mature it changes to white. Although in some regions such as Florida their are exceptions and they stay orange for their entire lives. Hope you found this information helpful!
Here is a picture of my juevinile P. audax most likely 4th instar, the green parts above the fangs are chelicerae

 

[MrZorak]

Don’t really know about E. militaris, but for P. audax I think you are talking about the chelicerae (the palps are what they use to hold stuff) for mature male P. audax they have big fuzzy arms with white stripes. With both sexes of P. audax generally the juvenile’s have orange markings on their backs, while when mature it changes to white. Although in some regions such as Florida their are exceptions and they stay orange for their entire lives. Hope you found this information helpful!
Here is a picture of my juevinile P. audax most likely 4th instar, the green parts above the fangs are chelicerae
View attachment 345020

Don’t really know about E. militaris, but for P. audax I think you are talking about the chelicerae (the palps are what they use to hold stuff) for mature male P. audax they have big fuzzy arms with white stripes. With both sexes of P. audax generally the juvenile’s have orange markings on their backs, while when mature it changes to white. Although in some regions such as Florida their are exceptions and they stay orange for their entire lives. Hope you found this information helpful!
Here is a picture of my juevinile P. audax most likely 4th instar, the green parts above the fangs are chelicerae
View attachment 345020

Yes I meant chelicerae. Still very much learning here!

My P. audax male didn't have visible green chelicerae when at the phase where his back had orange. Do you know if there are any other indicators for adulthood? It would confuse me a lot of I ended up having one with orange that PERSISTED with that coloration, especially for the females who would then look similar between subadult and adult. I am used to the cut and dry aspect of sexing and determining age for mantids!

 

[Lucky123]

Yes I meant chelicerae. Still very much learning here!

My P. audax male didn't have visible green chelicerae when at the phase where his back had orange. Do you know if there are any other indicators for adulthood? It would confuse me a lot of I ended up having one with orange that PERSISTED with that coloration, especially for the females who would then look similar between subadult and adult. I am used to the cut and dry aspect of sexing and determining age for mantids!

With the chelicerae on juveniles it can be hard to see. Do you no what instar it is (how many molts is has had)? They generally live to molt about 5-6 times, in a span of 6 months to a year. For captive breed spiders it is easy to keep track but for wild caught ones I use the process of elimination. 5th instar is usually considered mature, on their last molt they lose the ability to stick to plastic/glass, so if it can still climb glass it is not senior, if it is still orange then that eliminates 5th instar, so it could be 1st 2nd 3rd or 4th. 1st would be really tiny (around 3mm), and 2nd would be about the size of a Salticus scenicus, 3rd would larger and closer to the size of an adult female Habronatus pyrithrix. 4th is close to adult size about the size of your pinky finger. I apologize if you don’t understand, I was just using some of the wild species of jumping spider that I see a lot. So hopefully this will help you rule out the maturity, front legs that are fuzzy and longer than the rest means a mature male, females will also get quite a bit fuzzier and generally the spots turn white, for most of their life they have iridescent chelicerae, but it is hard to notice until the fangs get big.

 

[MrZorak]

Oh no you are making sense, don't worry. I keep mantids, so I know instars, just very new to jumpers. I also have a Salticus scenicus so that comparison works for me! I didn't know they lose capacity to climb smoother surfaces as adults.

I do not know which instar, since all are wild caught. Thanks for the feedback, this helps!

 

[Lucky123]

Oh no you are making sense, don't worry. I keep mantids, so I know instars, just very new to jumpers. I also have a Salticus scenicus so that comparison works for me! I didn't know they lose capacity to climb smoother surfaces as adults.

I do not know which instar, since all are wild caught. Thanks for the feedback, this helps!

It is not necessarily the adults, because 5th instar is considered mature but when they lose the ability to stick to glass it means they will not molt again before their life is over.

 

[InvertebrateGuild]

With the chelicerae on juveniles it can be hard to see. Do you no what instar it is (how many molts is has had)? They generally live to molt about 5-6 times, in a span of 6 months to a year. For captive breed spiders it is easy to keep track but for wild caught ones I use the process of elimination. 5th instar is usually considered mature, on their last molt they lose the ability to stick to plastic/glass, so if it can still climb glass it is not senior, if it is still orange then that eliminates 5th instar, so it could be 1st 2nd 3rd or 4th. 1st would be really tiny (around 3mm), and 2nd would be about the size of a Salticus scenicus, 3rd would larger and closer to the size of an adult female Habronatus pyrithrix. 4th is close to adult size about the size of your pinky finger. I apologize if you don’t understand, I was just using some of the wild species of jumping spider that I see a lot. So hopefully this will help you rule out the maturity, front legs that are fuzzy and longer than the rest means a mature male, females will also get quite a bit fuzzier and generally the spots turn white, for most of their life they have iridescent chelicerae, but it is hard to notice until the fangs get big.

This is extremely helpful, thanks for sharing @Lucky123!

 

[Nomad177six]

It is not necessarily the adults, because 5th instar is considered mature but when they lose the ability to stick to glass it means they will not molt again before their life is over.

I know your messages on here are about 3 years old but I'm hoping you may still be around and see this anyways. I have a male Phidippus Audax that is wild caught and i have had him about 5 weeks now and he has not molted during that time and he still has orange spots but he also can't climb the plastic of his enclosure. I know that some of the P Audax in Florida keep their orange colors even into adulthood but i am on the opposite side of the country in Idaho.

So i am a little confused about whether my little friend is mature or not. He is pretty big, he is easily bigger than a nickel with his legs spread out but he can't climb plastic and still has orange. So could it be possible that adult males can keep their orange spots into adulthood no matter what part of the country they are in? Everything about my spider points to fully mature other than his spots and everywhere i read i see that orange means he is a juvenile.

The only other thing i can think of is when i washed his enclosure before putting him in, i used dawn dish soap but i rinsed it well and wiped it dry. Could the dish soap be the reason he can't climb the plastic? Just curious if you might have any answers. You seem to really know what you're talking about from what i have read here so far.