Spring has sprung

Well, it has if your are in the northern hemisphere; those of you in the south, happy autumn!  There is something about spring: the colors, the smell, the temperatures fluctuating around like a drunk on a teeter-totter.  Best of all is the insects starting to get active again.  So in honor of the beginning of spring, I give you the mighty springtail.

arizona collembola
A species collected from Arizona

These tiny insects are considered primitive.  There’s been some question on whether

stamp collembola
1982 stamp from the Falklands

they are in the class Insecta, many taxonomists now put them in the class Entognatha.  I just call them entomologically awesome.  There are around 6,000 currently described species but it is estimated that there are more than 50,000 undescribed.  They occur throughout the world, including Antartica.

 

No matter where you place them taxonomically, there is a huge amount of diversity in the group.  They are all tiny, usually less than a quarter of an inch (6mm) and all have this tube-like structure called a collophore on the bottom of the first abdominal segment.  It

line collembolla
Shows the furcula (springtail) and the collophore

 

was originally thought that it acted like a little suction cup that helped to stabilize the insect when it jumped, but now is thought to help in regulating water uptake.  Check out the video at the bottom that shows how they expand it to reach up over their head to help “waterproof” themselves.  Many species also have a furcula.  This is how they get the common name of springtail.  This device is like a little tail that they keep tucked up on the underside of the abdomen.  When released it springs out, launching the insect into the air like a firework shooting off.  And this all happens in about 18 MILLIseconds!

Gabor-Keresztes-Croatia
Some species can be very colorful like this Neanurinae species from Croatia.

Springtails are omnivorous and feed primarily on fungal spores but also plant material, pollen, carrion, and bacteria.  As such, they are found in leaf litter, soil, and other decaying material.  When Haldane said that “God had an inordinate fondness for beetles”, he must have forgotten about springtails because these miniature insects are more prevalent than online photos of the Kardashians.  It is estimated that there are more than 100,000 individuals per square meter of soil!  I remember back in college collecting for these and digging up soil and putting it in the Berlese funnel with the light on top to slowly dry out the soil, forcing the insects down until the fall out into the cup of alcohol at the bottom.  Kinda like an excited little kid staring at the chimney waiting for Santa to drop down.

Pseudobourletiella spinata
This Virginia species (Pseudobourletiella spinata) is one of the globe shaped species.

One of the coolest things (I think) with these little critters is that they can “reverse molt”.  So all insects need to molt, shed the exoskeleton, in order to get bigger.  These tiny insects can molt to get smaller.  Huh?  Why would they do something silly like that?  Well, if conditions aren’t good a smaller size means more water retention, less food needed, and maybe even a slightly lower metabolic rate.  Which means greater chance of survival in poor conditions.  Now that is entomologically awesome!

 

So spring on up and share this entomological awesomeness with someone who needs to add a little spring to their step on this spring morning!

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