Image credit: Christoph von Beeren and Alexey K. Tishechkin
Nymphister kronaueri is a tiny beetle that lives among ants. They live exclusively among one species of army ant, Eciton mexicanum in Costa Rica. These army ants are nomadic, spending a few weeks in one place before migrating for about three weeks to new territory.
Shown in green circle is the beetle, attached to the abdomen of ant. Image credit: D. Kronauer
The beetle can move about and feed while the host colony is stationary, but when the ants move, so must the beetles. There come the mimicry. The beetle with only 1.5 millimeters length, is shaped, sized and colored just like the abdomen of a worker ant.
The beetle uses its tiny mandibles to clamp down on its host’s abdomen as the ants move. This makes it look like the ant has two abdomens. Like other myrmecophiles, or ant-lovers, these beetles likely use similar chemical signals as the host ants to avoid detection. The exact mechanism is not yet known.
Suggested Reading
1. von Beeren C, Tishechkin AK. Nymphister kronaueri von Beeren & Tishechkin sp. nov., an army ant-associated beetle species (Coleoptera: Histeridae: Haeteriinae) with an exceptional mechanism of phoresy. B. 2017;2(1). doi:10.1186/s40850-016-0010-x
A new species of trap jaw ant and has been described by a group of scientists from USA. This new species of ant described is already extinct and estimated to have lived almost 100 million years ago. The specimen was found preserved in amber dated 98 million years from Myanmar.
What is a trap jaw mechanism?
Ants with trap jaw mechanism can keep their mandible in open position. Then they can close it rapidly by striking it with clypeus above. (Clypeus is a broad plate at the front of an insect’s head.) Clypeus is usually reinforced in these ants. Most of the trap jaw ants have a trigger hairs associated with mandibles or clypeus. These trigger hairs initiate mandible closure when triggered.
Trap-jaw behaviour has evolved at least four times in three families of ants: Formicinae, Myrmicinae and Ponerinae.
Taxonomic position of new species
Newly described species Linguamyrmex vladi is placed under the Order Hymenoptera, Family Formicidae and Subfamily Haidomyrmecini. Haidomyrmecines are unique and are known as ‘Hell ants’ due to the presence of unique mandibles. Their mandibles are scythe like and can be moved in vertical plane.
Hell ants are extinct, but is not the ancestors of modern day ants. They appear to be a stem group which went extinct before the common ancestor of modern day ants appeared.
The newly described hell ant reveals stunning morphological features in detailed examination. Modem day ants have plain centre facing mandibles. But L. vladi had giant scythe like mandibles that pointed upwards. This type of mandibles are not found in any ant groups living today.
The ant had a clypeus, that is reinforced with deposited metals. The metals were incorporated into the underside of clypeal paddle along the centre. The specimen was preserved with mandibles positioned near this spot. This suggests that the reinforcement is intended to accommodate the mandibular impact.
They also possess elongate, paired setae on the clypeus. These setae are interpreted as trigger hairs that close the mandibles at horrifying speeds.
The researchers also discovered a channel, much like a tube in between the mandibles. According to them, the ant probably sucked haemolymph out of the body of its prey. Clarifying this statement, they also found a fossilised soft bodied larva along with L vladi.
These predatory ants must have fed on soft bodied animals. When they encounter their prey, their clypeal hairs touch its body. This triggers the sudden closure of mandibles in upward direction. Pointed mandibles now pierce the prey’s body. Using the channels in mandibles, these ants can suck haemolymph (blood) out of the body of prey.
Upward moving mandibles are stopped by the expanded clypeus extending beyond the head. Heavily reinforced under side of the clypeus helps to withstand the impact pressure of upward directed mandibles.
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Bibliography
1.
Barden P., Herhold H.W. & Grimaldi D.A. (2017). – A new genus of hell ants from the Cretaceous (Hymenoptera: Formicidae: Haidomyrmecini) with a novel head structure. Systematic Entomology, 42 (4), 837–846. doi: 10.1111/syen.12253
A beautiful orchid, isn’t it? But it is an insect, commonly called as Orchid mantis. It is known by various common names including walking flower mantis and orchid mantis. It is one of several species known as flower mantises from their resemblance and behaviour. This one, Hymenopus coronatus, can be found in the rain forests of Southeast Asia.
Even though it seems like an ant, it is not! This is one of 3,000 species of wasps in the family Mutillidae of Order Hymenoptera. Commonly known as Velvet ants, but black and white specimens are sometimes known as panda ants due to their hair coloration resembling that of the giant panda. Their bright colors serve as aposematic signals. They are known for their extremely painful stings, hence the common name cow killer or cow ant. However, mutillids are not aggressive and sting only in defense. Unlike true ants, they are solitary, and lack complex social systems.
