Litinsects

Litinsects #59: Gynandromorphs Ok people, pretty sure I’m gonna blow your minds with this one. No, these pictures are not some freakish cut-and-paste Frankenstein experiments. These animals are absolutely real and extremely rare GYNANDROMORPHS. Common blue gynandromorph (left male, right female) © Burkhard Hinnersmann This word comes from the Greek “gyne” for female, “andro” for male, and “morph” for form... meaning that these individuals contain BOTH MALE AND FEMALE tissues! Firstly, this is not the same thing as a hermaphrodite, which is an organism that contains both types of gonads or can create both sperm and eggs. Gynandromorphs literally have some body parts that are genetically female and others that are genetically male. So I’m sure you’re asking... how?! Malaysian stick insect (left male, right female) https://commons.wikimedia.org/wiki/File:Heteropteryx_dilatata_0034b_L.D.jpg Many different genetic systems exist in the animal kingdom. In humans XX codes for female and ...

Litinsects #57: Fireflies ©  Radim Schreiber You may know them as fireflies, lightning bugs, or glowworms depending on where you grew up…  these glowing bugs are actually neither flies, nor bugs, nor worms but beetles. They are a special group known for their BIOLUMINESCENCE. So how does that work? Bioluminescence is light produced by an organism through a chemical reaction. In some animals light is produced by bacterial symbionts, in others the light is produced by the organisms themselves, as is the case with fireflies. (Side note: this is different than biofluorescence, which is the absorption and re-emission of certain wavelengths but it doesn’t involve a chemical reaction.) Fireflies have a LIGHT ORGAN in their lower abdomen in which a special reaction takes place; it produces light but no heat (thus often called “cold light”). A compound called LUCIFERIN, coming from the Latin word for „light-bearing“ (also the same etymology for the name Lucifer) is contained in t...

Litinsects #51: Mayflies Mayflies are aquatic freshwater insects and belong to one of the most primitive winged insect lineages! First off, what’s in a name? Mayflies’ common name comes from the fact that some species start “hatching” from the water in May. But their scientific name is much more interesting and accurate; this order is named EPHEMEROPTERA from the Greek “ephemera” for “lasting one day / temporary” and “pteron” for “wing”. A more fitting name would be dayfly, considering their adult lifespan... Most live less than 24 hours after emerging, the shortest adult lifespan of any insect! -Mayflies have triangular-shaped wings that are held upright over their bodies when at rest (sort of like a butterfly) and have three long tail-like filaments. These characteristics, both of which make them easily recognizable, are probably traits that were present in the most primitive flying insects -They are HEMIMETABOLOUS insects, meaning they go through incomplete metamorphosis, with multi...

Litinsects #43: Butterflies & Moths - What's the Difference? What’s the difference between butterflies and moths? They both belong to the same order 🦋 LEPIDOPTERA, meaning „scale-wings“ (I talked about these scales back in my day 8 post). Taxonomically speaking, butterflies are a MONOPHYLETIC group within Lepidoptera and moths are PARAPHYLETIC and I am fully aware that if you haven’t studied biology you will have absolutely no idea what that just meant… basically, all butterflies share common ancestry and can be considered a specialized group within the larger group of moths. General differences include:   Resting wing position: Moths tend to hold their wings FLAT out to the sides or tent-like over their backs and butterflies rest with their wings closed VERTICALLY over their backs. Butterflies do sometimes open their wings flat to bask in the sun though Behavior: Moths tend to to be NOCTURNAL (active at night) whereas butterflies are DIURNAL (active during the day...

Litinsects #42: Weevils We are back on insects! Who has heard of weevils before? Weevils are a type of beetle known for their long “nose” or ROSTRUM. They are also called snout beetles and, believe it or not, some of those snouts are pretty cute. “Weevil” can mean either PRIMITIVE WEEVILS, which have straight antennae, or TRUE WEEVILS, which have elbowed antennae. Primitive weevils describe a number of different families whereas true weevils comprise a single family (which is a level of classification above genus). True weevils are considered one of the most SPECIOSE (aka species-rich) families of animals on earth. Disclaimer: of course we can only say this based on our current knowledge and not with absolute certainty because there are countless insect species yet to be discovered... but there are currently around 45,000 described species of true weevils! Let me give you some perspective on that number: if you added up all the living species of birds, mammals, reptiles, and amp...

© Scott Bauer   Litinsects #37: Termites   TERMITES might get a bit of a bad rap for causing damage but they are super interesting insects! Did you know that... Termites are actually considered to be a specialized group of cockroaches! They used to be classified in an entirely different order of insects but recent genetic studies found a closer relation to cockroaches Termites form EUSOCIAL COLONIES (just like ants and bees). Termite colonies have not only a queen but also a fertile king along with sterile workers and soldiers. All castes are anatomically different with specializations to their tasks They are found on all continents except Antarctica, though more species are found in AFRICA than anywhere else Termites go through INCOMPLETE METAMORPHOSIS, with nymphal stages that resemble adults Termite colonies live in huge and complex structures called mounds. COMPASS TERMITES build their mounds oriented north-south, which helps with THERMOREGULATION. With the l...

  Litinsects #36: Honey  Honey is the only insect-made product consumed by humans! But how exactly is it made?   It all starts with a forager bee collecting nectar from flowers. The nectar is stored in a special sac called a CROP or honey stomach and transported back to the hive, where it is regurgitated and ingested by a processor bee. Inside the bee’s honey stomach special glands secrete proteins and ENZYMES, which begin to break down large sugar molecules into smaller ones and change the chemical composition of the nectar. The regurgitation and ingestion process happens multiple times until finally the pre-honey is put into a hexagonal cell made of beeswax inside the hive. Bees fan the nectar with their wings which evaporates a lot of water and raises the sugar content, preventing microbes from being able to grow. Finally, the cell is capped with wax and the honey can be stored for the bees to eat later. Because honey sustains a hive over the winter, beekeepers can’t t...

Litinsects #35: Lice Today you’ll be learning about a rather hated group of insects: lice   Lice are wingless OBLIGATE ECTOPARASITES meaning that they need a host to complete their lifecycle and they live on the OUTSIDE of their host’s body (as opposed to ENDOparasites which live inside a host). Lice belong to the order PHTHIRAPTERA (the PH is silent), which comes from the Greek “phtheir” meaning louse and “aptera” meaning wingless. Taxonomically, lice are actually grouped within the winged insects but lost their wings SECONDARILY due to their parasitic lifestyle There are two subgroups of lice: CHEWING lice and SUCKING lice. Chewing lice are found mainly on birds and occasionally on mammals. Their mouthparts are built for biting and they feed on skin debris, feathers, hair, and skin secretions. Sucking lice have mouthparts adapted for piercing and sucking, which they use to suck blood from their hosts. They mainly live on mammals, including humans Lice undergo incomplete metamorph...

A row of hamuli on the wing of a bee The top two hamuli shown here are hooked onto the back edge of the forewing. Litinsects #33: Hamuli Today’s post is another on anatomy and is about a structure found in a group of insects that probably everyone around the world is familiar with... The order HYMENOPTERA is comprised of bees, wasps, sawflies, and ants. (Yes, ants are actually related to bees and wasps.) At around 150,000 described species it is among the top 4 largest group of insects (along with beetles, flies, and butterflies). One defining characteristic of hymenopterans are HAMULI (see photos). Hamuli (singular hamulus) are microscopic hook-like structures on the front surface of the rear wing that hook into the back edge of the front wing. This system interlocks the two wing pairs during flight, allowing them to beat in unison and act as one functional pair of wings. Basically hymenopterans have developed an anatomical wing coupling feature to enhance flight efficiency. (In the t...

Litinsects #32: Circulatory System Sadly today’s picture has nothing to do with the post’s content but what I’m explaining today is kind of hard to photograph... the insect circulatory system Ever wondered why insects don’t bleed red? Insect “blood” is actually called HEMOLYMPH. It does not contain iron-based hemoglobin or red blood cells like we rely on for oxygen transport so it’s usually yellow/green/gray i n color Their circulatory system plays no role in gas exchange. As I explained in a previous post, insects breathe via their tracheal system, which is a network of small tubes with openings along the side of the body Insects have an OPEN CIRCULATORY SYSTEM, meaning their hemolymph is not contained within blood vessels. Instead, their tissues are bathed in hemolymph. One DORSAL VESSEL, a tube along the insect’s back, is responsible for the movement of hemolymph throughout the body through the contraction of muscles Like with our own circulatory system, res...

Litinsects #31: Lacewings Lacewings belong to the insect order NEUROPTERA, or net-winged insects, which I’d guess might be among the orders that you’ve never heard of... Neuropterans are characterized by membranous wings with many branching veins. Species in this order undergo complete metamorphosis. This here is a green lacewing and here are a few facts about these fellas. These insects are active predators but are omnivorous. They prey on scale insects, aphids, mites, and other small soft-bodied arthropods but may also feed on pollen, nectar, and aphid honeydew. The larvae are also predacious and are sometimes referred to as aphid lions Lacewings are often used as biological pest control They have tympanal organs at the base of their wings... remember these? They are the insect equivalents of eardrums. They can sense bat echolocation so when they hear a predator while flying, they drop to the ground to avoid being caught Individuals produce courtship songs through body vi...

Litinsects #30: Aphids This one’s a bit longer but I promise it’s really interesting! Ok, I know for gardeners and plant-lovers the general consensus on aphids is probably that you hate them. They are hugely destructive pests... Unfortunately they don’t only cause damage by sucking fluids from plants but they are vectors for various plant diseases and their honeydew (more info on that below) is often a sticky mess on plants that then attracts mold. All in all there probably aren’t many aphid fans out there. But there are honestly such cool things going on with aphid biology that make them unique and truly fascinating! Most aphids are easily recognized by their CORNICLES, two tube-like protrusions from their abdomen. When threatened, they excrete a defensive substance called cornicle wax out of these tubes Aphids are often wingless... but when food is in short supply, when a plant becomes overcrowded, or even in the presence of predators, aphids can produce winged, o...

Litinsects #29: Water striders It’s rare in nature but a few animals boast the ability to walk on water...among them, the water strider! These insects belong to the group HEMIPTERA, meaning they undergo incomplete metamorphosis and have mouthparts used for piercing and sucking. Here are some fun facts about these insects and their unusual ability: Water striders are not actually aquatic but PLEUSTON, meaning they live on the water’s surface The insects use their 6 legs to distribute their weight and use surface tension to stay on the surface of the water. Their legs and bodies are covered in tiny HYDROPHOBIC hairs, over 1,000 per square millimeter, which are waxy and water repellent and also help increase the body’s surface area These hairs not only repel water while on the surface but, if a water strider is accidentally submerged, the hairs TRAP AIR and give buoyancy while at the same time providing the insect air to breathe underwater! The short fron...

Photo: Todd Ryan Litinsects #26: Eusociality I’m sure everyone has heard of worker bees, queen bees and drones. Bees 🐝 have a complex and interesting social structure and they are not the only ones! There are many different kinds of social systems within the animal kingdom. Even within specific taxonomic groups, individual species can display vastly different social structures and behaviors. Today I’m talking about the highest level of social organization: EUSOCIALITY Eusociality (with the Greek prefix “eu-“ meaning “true”) is defined by 3 GENERAL CHARACTERISTIC: 1) OVERLAPPING GENERATIONS living within the same colony 2) COOPERATIVE BROOD CARE, meaning that individuals collectively care for offspring other than their own 3) REPRODUCTIVE DIVISION OF LABOR into specialized groups Continuing with the bee example, we know these 3 points pertain... different CASTES have specialized jobs pertaining to reproduction (queens produce offspring, drones are there ...

© Richard E. Lee Jr. Litinsects #25: Antarctic Midge Are you ready for a truly crazy-sounding fun fact? The Antarctic midge, a fly that measures 2-6 mm, is the largest fully terrestrial animal found on the entire continent of Antarctica!  It might sound crazy but it’s true! Animals that you immediately associate with the continent, such as penguins and seals, are not purely terrestrial because they spend a large portion of their lives in the water. The islands surrounding Antarctica are home to a few other invertebrates including mites, springtails, earthworms, and nematodes but the midge is special because it is ENDEMIC to Antarctica, meaning it is found nowhere else on earth. These tiny guys are FLIGHTLESS. It is thought that they have evolved to have reduced wings to prevent being blown away by wind They feed on terrestrial algae, moss, detritus, and microorganisms Of all insect genomes sequenced so far, the Antarctic midge has the smallest, a...