# Hierodula patellifera

Hierodula patellifera, commonly known as giant Asian mantis, Asian mantis, Indochina mantis and Harabiro Mantis, is a species of praying mantis in the family Mantidae. They are found in Malaysia, Hawaii, India, Nepal, Italy (San Paolo Solbrito), Indonesia (Java, West Sumba,), Korean Peninsula, Philippines, New Guinea, southern China, Taiwan, Vietnam, and Japan (Honshu, Shikoku, Kyushu, Okinawa). H. patellifera lives in trees and in grasslands at the edges of forests.

## Description

H. patellifera, a species part of the subfamily Hierodlinae. Its distinct appearance make this species recognizable due to elongated prothorax and slender body, in which contributes into its overall stick structure. This species can be seen around the South East Asia region, it inhabits grasslands and forest in where it appearance can be effective due to its ability to camouflage. Males are about 5.19 cm long while females ranges from 6.06 cm long, with individual varying into two different colours, green or brown. Significant morphological diversity has been observed within this species across populations. Research has observed different variation of body size, shape of spine in forelegs and genitalia size. This degree of variations could suggest a high intraspecific variability, which indicate genetic cohesion, and be classified as a single unit

## Reproductive Behavior

In the unique world of insect communication, H. patellifera, portray a unique type of behavior that benefits sexual reproduction in their species. According to a study by Perez (2005), virgin female mantis has a unique adaptation that help them attract mate. This type of behaviour is portraying body posture, signalling mates that they are available for mating. This type of behaviour is combined with the arching of the abdomen, exposing its dorsal surface and pumping movement in which releases chemical signals such as pheromones which primarily attracts males. Perez's observation that this posture is linked with the female mantis's nutritional state and reproductive readiness. Males that are attracted to the released pheromones can detect between virgin and mated mantises, as only virgin mantises practice this kind of behaviour. Additionally, intricate predatory movement can also have effects in mate selection. Displaying the ability to stalk and ability to successfully capture prey can be used a signal to display over male Fitness.

## Climate Change Bioindicator

H. patellifera is a type of thermophilic mantid native in the South-East Asia region. A company in Korea has used this species as a Biological Indicator Species, due to the mantis’ sensitivity toward climatic changes. Studies have shown that this species of mantises have developed phenology and geographical changes. H. patellifera has been observed to start foraging earlier, expand their geographical habitat into cooler regions. This adjustment has resulted in shortened dormancy and delayed senescence. This study started from 1988 to 2022 from the help of citizen sciences, highlighting the role of the public understanding of biodiversity changes. The behaviour observed have helped researchers understand survival strategies that H. patellifera; moreover understand if similar thermophilic species has the same ability to detect and to see how climate change impacts the overall species. The responsive predatory behaviour observed in mantises such as the stalking behaviour is based on temperature, showing direct relationship with to changing climate conditions

## Crypsis

In the world of prey-predator relationship, the praying mantis, H. patellifera, exhibits a unique behavioral adaptations due to environmental pressures. The behaviors that the mantis exhibits, is how they modify their behavior to lower risk of predation in different wind conditions. The observed behavior is that increased wind velocity, resulted in body-swaying and cryptic walking behaviors, this increased their chance of being camouflage within their environment. Furthermore, the color polymorphism observed in H. patellifera, from vivid green to muted brown provides a significant advantage for mantises to blend seamlessly with their environment.

## Predatory Behavior

One of the unique adaptation of H. patellifera is its ability to stalk and approach its prey, showcasing advanced predatory behaviors. In a field experiment, mantid was observed exhibiting a "peering" movements swaying back and forth while advancing toward its prey (moth). this is similar to their movement to be camouflaged within their surrounding by mimicking nearby leaves and producing this behavior in wind conditions. The peering movement not only help blend with its surrounding but also to gauge distance and increase perception of the insect. Despite the mantis probing the moth with its raptorial forelegs, the mantis refrained from attacking due to many reason such as moths size is too big or lack of feeding motivation.
In a field study conducted in the Quetta and Pishin districts in Pakistan, over 380 specimens on H. patellifera were collected; this marks the first record of this species in the Pakistani region. H. patellifera has been observed feeding mainly on Homopterans.
A study by Sugiura (2021) highlights the interaction of H. patellifera and bombardier beetles. The interaction between the two species showed how bombardier beetle defend themselves against predators such as the mantis. When the mantis attacked the beetle, the beetle released hot chemicals, this causes the mantis loosen its grip allowing the beetle to escape. The mantis was observed cleaning itself, which could suggest that the chemical irritates the mantis significantly

## Circadian Rhythms

H. patellifera, has been observed that they exhibits a circadian rhythms that regulate visual physiology, behavior and locomotion. Studies use eletroretinograms (ERGs) to see the reaction of photoreceptors, they found that during night time the sensitivity of the photoreceptors increases while decreases during day time. Pigment within the compound system aligns with light-dark cycles, it has been observed that it darkened during night and lightens in the morning. the behaviour of the H. patellifera is closely related to environmental light cycles. More activity has been observed more during day time compared to night time.

## Range Expansion

The introduction of H. patellifera to countries far away from the peninsula are mostly due to human-linked activities such as cargo transport from Asian countries or its popularity on the exotic trade market. This particular species is native to the South East Asia region, but due to the growing global trade the species has also been found in the Mediterranean countries. Due to the species ability to adapt accordingly to its new environment, it enable itself to strive locating itself in the south region of France. The increasing global trade and the expansion of the exotic trade market has allowed H. patellifera beyond its native ecosystem spreading concerns over the possibility to compete with the native species and destabilize the overall ecological system.

## Additional images

* Underside of adult female Hierodula patellifera Osaka-ful, Japan
* Ootheca of Hierodula patellifera
* Hierodula patellifera laying ootheca
* Hierodula patellifera preying on cicada
* Hierodula patellifera filmed in Tokyo, Japan
* Hierodula patellifera found in Seoul, South Korea.