Litinsects

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...