Monday: 6 July 2009
Here’s something obscure, for you. If you wanted to know what the first insects were like, this is probably it.
Jumping Bristletails! This individual ended up on the front porch a couple of days ago, clearly out of its element, which would be leaf litter. It’s just about a centimeter long, and has a fairly good jumping ability. Apparently it uses its abdomen to snap itself into a jump.
Along with springtails, silverfish, and a few others, bristletails belong to the subclass Apterygota - insects that have never evolved wings. They’re considered to be primitive insect forms, and that extends to their appendages and mandibles, as well as their development, which is simple. (The remaining orders of insects, the vast majority, belong to the Pterygota, or winged insects. There are many wingless Pterygota, but unlike bristletails and their kin, wingless Pterygota have lost their wings.)
Bugguide doesn’t proceed much further than family for this group, listing only one species, Trigoniophthalmus alternatus in the family Machilidae. The posterior sports three “tails,” one long and two shorter.
The large compound eyes meet at the top of the head, and are described as “medially contiguous.” It gives them a quaint appearance, don’t you think? Slightly worried. The three tiny ocelli aren’t visible in this photograph, at least not that I can see.
They eat detritus and fungal hyphae, and they have a very dull sex life. They don’t mate - the males leave spermatophores lying about for the females to pick up.
Jumping Bristletails! This individual ended up on the front porch a couple of days ago, clearly out of its element, which would be leaf litter. It’s just about a centimeter long, and has a fairly good jumping ability. Apparently it uses its abdomen to snap itself into a jump.
Along with springtails, silverfish, and a few others, bristletails belong to the subclass Apterygota - insects that have never evolved wings. They’re considered to be primitive insect forms, and that extends to their appendages and mandibles, as well as their development, which is simple. (The remaining orders of insects, the vast majority, belong to the Pterygota, or winged insects. There are many wingless Pterygota, but unlike bristletails and their kin, wingless Pterygota have lost their wings.)
Bugguide doesn’t proceed much further than family for this group, listing only one species, Trigoniophthalmus alternatus in the family Machilidae. The posterior sports three “tails,” one long and two shorter.
The large compound eyes meet at the top of the head, and are described as “medially contiguous.” It gives them a quaint appearance, don’t you think? Slightly worried. The three tiny ocelli aren’t visible in this photograph, at least not that I can see.
They eat detritus and fungal hyphae, and they have a very dull sex life. They don’t mate - the males leave spermatophores lying about for the females to pick up.
