Some insects have detachable penises, others produce sperm that is 20 times the size of their own body. Others have evolved with special equipment to help them tear rivals off potential mates. Insects can be creepy, promiscuous or murderous—but they are rarely dull.

The stag beetle male—Europe’s largest beetle has huge jaws known as antlers designed for prising mating pairs apart. This behavior is seen in numerous beetles, with horns of various shapes horns that have evolved to lever males off females. The Japanese rhinocerous beetle has a horn resembling a fork. Antlers are also used in battle to wrestle other males over access to females.

In many of these species, smaller males don’t stand a chance of winning a fight, so instead have evolved sneaky mating tactics. They wait for males to fight, then slink in and copulate with the female while the males are distracted. Small male dung beetles slip past large males that guard entrances to tunnels containing females, and dig secret passages to find the underground females while the larger males’ backs are turned.

Sperm competition

In addition to the physical contests between males, competition to fertilize an egg also happens between sperm. In the animal kingdom, females are rarely faithful to their mates, so there is probably sperm from a number of males inside a female reproductive tract. Males have evolved several ways to counter this, such as producing large sperm. Fruit fly sperm, is almost 6cm long when uncoiled, around 20 times the size of the fly.

But, perhaps the most extraordinary method to win the sperm competition is seen in the odonata (dragonflies and damselflies) who have evolved ornate penises. These come complete with hooks and whips, to dislodge the sperm of rival males and pack the male’s own sperm into the far corners of the female reproductive tract, away from other male penises.

And it’s not just the males that have elaborate penises. The female cave insects of Brazil compete for access to males. The insects have sex-reversed genitalia, where the males have an opening and the females have a spiky erectile organ. The female uses her “penis” to suck sperm out of the male, and she can even decide which of two chambers in her body to store the sperm in. It is thought that this behavior evolved as an adaptation to a limited food supply as the females gain energy from feasting on the seminal fluid acquired during copulation, which can last up to 70 hours.

Butterflies only live for a few weeks, so if males are going to father any offspring, they can’t hang around. Except, some do. Many butterflies are sexually mature as soon as they emerge from their chrysalis. So, in some species the males emerge a few days before the females, then sit and wait, copulating with the females as soon as possible.

More disturbing behavior is seen in the bed bug. Males simply pierce a female’s abdomen then inject sperm through the wound into her abdominal cavity. As insects have an open circulatory system without arteries and veins, the sperm can easily migrate from the abdominal cavity to the ovaries for fertilization.

Sexual cannibalism

Probably the most famous of the insect sexual behavior is that of the praying mantis, where the female bites the head off her partner during or after sex, gaining nutrients for herself and her offspring. This behavior increases the number of eggs that males fertilize. Recently, scientists found that males also attack females. They don’t eat the females although they sometimes seriously injure them. Males that won fights with females were more likely to go on to mate rather than just get eaten.

Chastity belts

Many male insects only get to mate once, even when they aren’t eaten by their partners. For example, male bees ejaculate with such explosive force that it is loud enough for humans to hear. This ensures the sperm is passed to the female, but it results in paralysis of the male, which kills him. So, males need to make the most of their exploits.

One way of preventing other males from mating with a female is to produce a copulatory plug—something that will prevent a different male from inserting his sperm inside a female to fertilize her eggs. The European dwarf spider produces a plug by secreting a liquid during copulation that hardens over time. Researchers have found that longer copulations result in larger plugs which are more difficult for other males to remove.

In order to ensure that nobody else mates with his female once he is dead, the male orb-web spider has evolved an extreme copulatory plug. He has a detachable penis that remains inside the female once copulation is over. Although it is common for the tip of a spider’s penis to break off inside a female, preventing other males from entering, the orb-web spider’s detachable penis has an additional function as it continues to transfer sperm on its own—for over 20 minutes—increasing mating success.

So you see, insects are, in fact, amazing.

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Vision loss and visual impairment have long been a significant concern for human well-being amid an increasingly aging population. In a collaborative effort by researchers from The Hong Kong Polytechnic University (PolyU) and The University of Waterloo, they have invented a groundbreaking device that utilizes Augmented Reality (AR) technology, revolutionizing navigation for visually impaired individuals on their world. This device offers them a newfound sense of independence and freedom.

The research project “Augmented Reality Obstacle Detection” (ObstAR), is led by Prof. Allen Cheong, Associate Head (National and International Engagement) and Professor of the School of Optometry of PolyU, and Deputy Director of Centre for Eye and Vision Research (CEVR), in collaboration with Prof. Ben Thompson, University Research Chair and Professor, School of Optometry and Vision Science, the University of Waterloo, and Chief Executive Officer and Scientific Director of CEVR. The research aims to develop an AR-based navigation device that allows visually impaired individuals to minimize their dependence on conventional assistive tools, like walking canes or assistance from others. CEVR is a partnership between PolyU and the University of Waterloo, operating under the Health@InnoHK cluster.

Prof. Cheong said, “Individuals with visual impairments may encounter various forms of vision loss, which can be attributed to neurological or ocular disorders or even the natural aging process. Tailored route navigation solutions are required to meet the needs of people.” Prof. Cheong specializes in geriatric and vision rehabilitation, leading the Vision Rehabilitation Clinic of PolyU Optometry Clinic.

Clinical research for practical applications

The research combines a clinical study that examines behavior of visually impaired patients and healthy participants when navigating familiar and unfamiliar obstacles, with the practical implementation of a navigational aid built using AR glasses and an artificial intelligence recognition algorithm.

To enhance the ability to recognize the environment and avoid obstacles, the device integrates a suite of advanced algorithms, including obstacle avoidance navigation, object recognition and segmentation, scene recognition, text recognition, and gesture recognition. This comprehensive approach aims to meet the diverse navigation needs of patients, ensuring safe navigation and heightened environmental awareness.

One key research focus is identifying specific areas of interest (AOIs), such as traffic lights, zebra crossings, sharp turns, and large banners. This personalized guidance can greatly benefit users who frequently traverse the same routes, as the system can offer customized support based on their familiarity with the environment.

Navigating a new frontier

The distinguishing design of ObstAR lies in the development of an innovative algorithm for image segmentation and information fusion, using RGB (Red, Green, Blue) and depth cameras to enable real-time obstacle avoidance navigation. This advancement allows the identification of more distant navigable paths within the camera’s capture area, while also enabling more accurate recognition of obstacles that are difficult to identify using traditional image segmentation techniques. Also, the team aims to incorporate real-time text-to-speech instructions to supplement areas not covered by the AR, ensuring comprehensive support for users.

Notably, ObstAR stands at the forefront of assistive technology, offering a transformative solution for visually impaired individuals. It was awarded the prestigious “Gold Medal with Congratulations of the Jury” at the 49th Geneva Inventions Expo.

Prof. Cheong said, “The advancements in AR and its growing acceptance provide an ideal platform to introduce this new form of assistive technology. This project fully demonstrates the immense potential of technology to enhance the quality of life for the visually impaired. It promises to open up new possibilities for the mobility freedom and social inclusion of the visually impaired.”

Prof. Cheong’s research interests focus on the psychophysical, behavioral, and clinical aspects of aging and low vision research. Her primary goal is to use different interventions to improve patients’ functional performance in daily activities, such as reading, mobility and navigation. The research also aims to establish cost effective vision rehabilitation models to enhance patients’ quality of life.

Prof. Cheong believes that ObstAR’s has a profound potential impact. Users could gain confidence in tackling daily challenges, thereby enhancing their functional performance and overall well-being. “We are on a mission to redefine independence for those living with vision loss. It is not just about creating an innovative product, but about bringing change and improvement to their lives,” she said.