Odontomantis planiceps, commonly known as the Asian ant mantis, is a small mantis that has been sighted in a number of locations in Singapore. Despite being so widespread, there are no publications on this particular species, and reliable information on their morphology, behaviour and phylogeny is unclear.
These mantids seem to be able to thrive in highly disturbed environments and conserved areas. They can be considered as one of the more urban species, which are more mobile and can be found in areas with very little vegetation.
Screenshot of the map of Singapore, taken from iNaturalist (Permission granted). Red markers indicate the location of O. planiceps sightings reported by iNaturalist users, purple markers indicate locations that O. planiceps were personally observed.
The genus name is a combination of the prefix Odonto- (from Greek word odous, meaning “tooth”) and Mantis, while the species planiceps is derived from a combination of Latin words - planus (meaning “flat”) and ceps (meaning “head”).
However, looking at the organism we have here… it’s a true mystery how it actually got its’ name.
Similar to cockroaches, praying mantids lay their individual eggs in egg cases termed as ootheca. Each ootheca is a huge investment by a single female because she invests in multiple offspring in one sitting. The ootheca functions as a shield from environmental stressors such as temp and water CITE. Many mantids tend to lay on solid surfaces such as branches and stems. But due to the built up environment Singapore has, a lot of urban-adapted species lay their ooths on surfaces like railings, walls, and windows (personal observation).
Ootheca have been known to have the potential to delimit species, if not higher level taxa, due to the variation between different species1 2 . However, ootheca morphology has been severely understudied throughout literature. Each ootheca can house up to hundreds of individual eggs, but in O. planiceps, the hatchlings usually vary between 5 and 30 individuals (personal observation). Below are some examples of other ootheca laid/formed by a few common local mantids.
In O. planiceps, external dorsal walls of ootheca were white and foamy upon formation, but gradually developed into a hue of mustard yellow, with a coarse, scaly surface. They are formed from proximal to distal ends. The emergence area is where the nymphs will hatch from the ootheca
Labelled images of an O. planiceps ootheca.
How this species managed to get the common name is because of the uncanning ant mimicry that juveniles adopt3 . Using this form of mimicry, the young and almost defenceless nymphs are able to camouflage as ants as a defence mechanism4 . However, ant mimicry only persists up to 3rd instar. From the 4th instar onwards, it becomes quite evident that they’re not ants. Moreover, many mantids look like ants during early nymphal stages, especially hymenopodids, so it is unclear why only this particular species has been termed as an ant mantis.
Although juvenile morphology is extremely important, it has been neglected in a lot of studies. As juveniles are also carnivorous and cannibalistic, as they prey on other arthropods and even their own kind. Hence, they do have the same ecological significance as adults and deserve just as much attention in research that adults do.
Find photos pls
With prey (Diet of a mantis)
Mantids are strictly predators, as they are only known to eat live prey. Some aggressive individuals have been known to take down insects as large as them, which includes their mates, lizards, fishes, and small birds5 . Many predatory insects can even be beneficial in agricultural pest suppression. For example, Tenodera sinensis was introduced into North America as a form of biological pest control6 . Afterall, mantids are extremely voracious feeders and are able to eat a wide variety of prey items, and has even shown that some mantises are able to gut the toxic innards of caterpillars7 . However, O. planiceps is a small mantis that don’t usually exceed 2cm in length. So in general, they are only able to consume smaller prey items like flies. Mantids are also generally stalking or ambush predators.
Praying mantids catch prey using a quick striking motion with their forearms, and accuracy is usually high. However, there are times where the prey are quick to flee or the mantid has generally poor aiming skills.
With predators (Mantids as food)
Mantises have a single ear located at the ventral metathorax8 . Although it only provides non-directional hearing, it is known to be extra sensitive to ultrasonic sounds. When it senses ultrasonic frequencies commonly used by bats that navigate and forage using echolocation, the mantis is able to fly downwards in a spiral, which helps them to escape predation9 .
Crop photo from alethea
Mantids are also a common prey item for other carnivores such as birds. Recently, Fluffy, an albino kingfisher has been in the spotlight among birders due to its’ unusual colouration and concern for its’ ability to hunt independently.
place photo soon. still awaiting permission
With parasites (Mantids as victims)
Horsehair worms are one of the most common parasites that people often associate with mantids, most likely due to the gruesomeness of its emergence. However, they are not known to be common in Singapore (personal observation). The worms are parasitic nematomorphs that have a free living stage, intermediate host stage, and the intermediate hosts are consumed by mantids which end up being the final host that gets killed upon emergence of the parasite10 . The parasite spends the free-living stage in water bodies, hence the intermediate stages only affect insects that spend a portion of their lives in water (ie. aquatic nymphal development).
Obtained from YouTube under Fair Use guidelines
Tachinid flies have been recorded to lay their eggs on juvenile mantises and the larvae then boring into the hosts’ body (Young, 2009). Symptoms of this form of parasitism include delayed moults and swelling of the mantis’s abdomens. Upon emergence, the individual mantids all died within 48 hours. These larvae burrow in soil and pupate. This type of parasitism has been observed within Singapore (unpublished personal observations), but remains understudied.
With humans (Mantids in the pet trade)