Litinsects

© Gail Sumway  Litinsects #39: Leaf cutter ants You’ve likely seen them in nature documentaries; countless individuals on a trail with abstract leaf cut-outs on their backs... these are LEAF CUTTER ANTS. They can carry impressively heavy loads on their backs, up to 20 times their body weight. But have you ever wondered what they do with all these leaves that they carry back to their nests? You might assume that they eat them but they don’t! What they actually do is way cooler than that. Leaf cutter ants participate in a MUTUALISTIC SYMBIOSIS with fungi, a close relationship that benefits all parties. Ants cultivate underground fungus gardens in their nests and it’s actually the fungi that eat the leaves as they decompose. The fungus in turn serves as food for the ant colony! Because the fungus needs the ants to stay alive, it is a mutually beneficial relationship. Ants actively groom the gardens by removing parasites and even secrete anti-microbial substances to prevent growth ...

Harvestman (aka daddy longlegs) Mite Spider   Litinsects #38: Arachnids Today we are taking a little excursion outside the world of insects into a neighboring class of arthropods, the ARACHNIDS. Most people think spiders when they hear arachnids but the group includes so much more than that! In addition to spiders , the arachnids consist of mites and ticks, scorpions , pseudoscorpions, tailless whip scorpions, and harvestmen (aka daddy longlegs which are NOT actually spiders!). The closest relatives of arachnids are horseshoe crabs Like insects (and all other arthropods), arachnids have jointed appendages and a hard exoskeleton and grow by molting Arachnids have neither wings nor antennae. They possess only simple and no compound eyes Unlike insects, which have 3 body segments (head, thorax, and abdomen) arachnids generally have two body sections, the PROSOMA, aka head, and the OPISTHOSOMA, aka abdomen (but the two may be fused into one in some groups) Arachnids are easily recogniz...

© 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...

Dragonfly wings Dipteran (fly) wing Monarch butterfly wing Lacewing wings Litinsects #34: Insect Wings Let’s talk wings. The ability to fly has existed in only 4 groups of animals: birds , bats , pterosaurs , and of course insects . The first three groups, all vertebrates, each evolved flight independently (in other words, they have no winged ancestor in common) and the wings replace a pair of limbs. Insect wings on the other hand, which first showed up around 400 million years ago, are not derived from legs but are completely separate structures. The big debate about the evolution of insect wings is whether they developed from pre-existing structures (like gills or extensions of the thorax) or were entirely new structures. There is very little fossil evidence documenting this evolutionary transition so no one has yet definitively answered this question... Insect wings attach to the second and third thoracic segments. At rest they may be held vertically over the back, horizontally ou...

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...