Litinsects

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...

© Didier Descouens Litinsects #41: Centipedes Now for the centipedes! If you missed my last post on millipedes, go back and check it out... So how do they differ from millipedes? Unlike millipedes, which are mainly detritivores, centipedes are VENOMOUS and PREDATORY. Millipedes have a more cylindrical body whereas centipedes are usually flattened. Millipedes have (as the Latin name Diplopoda suggests) two leg pair per body segment but centipedes have only one pair per segment. As for the number of legs, centipedes can range from having 15 to about 170 pairs; this is generally fewer than millipedes have but it’s not always the case. Finally, millipedes tend to travel pretty slowly while centipedes are fast runners. Centipedes make up the group CHILOPODA. In Greek, “khelios” means lip and “poda” means foot. The name describes a pair of pincer-like appendages called FORCIPULES, located right behind the head, with which they inject venom to paralyze prey. So the “bite” of a centipe...

Litinsects #40: Millipedes   The level of disgust for an arthropod often increases proportionately with the number of legs it has. Well I’m here to tell you: you don’t really need to fear millipedes! What is a millipede? Millipedes and centipedes (more on them to come) both belong to a group of arthropods called the MYRIAPODA. Why? Because they have a myriad of feet! Myriapoda are one of the four arthropod groups, the others being arachnids, crustaceans, and hexapods (aka insects). Millipedes are known as DIPLOPODA from the Greek “diploos” meaning double and “pod” meaning foot. Have a look at the close-up photo and see if you can guess why... With the exception of the first four body segments behind the head, every other segment of a millipede is actually two fused segments, known as a DIPLOSEGMENT, so it appears as though each one has TWO legs attached rather than one, hence the name!   Millipedes are some of the very earliest animals to colonize land, around 450 mill...

© 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...