Skip to main content

#30: Aphids


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, or ALATE, offspring that have the ability to disperse to other plants
  • Aphids feed on plant sap, which brings me to the honeydew I mentioned... Plant sap has incredibly high concentrations of sugar so aphids have to actually get rid of some of it. These excess sugars accumulate in the aphid‘s digestive tract (along with waste products) and are secreted as droplets out of the anus. These sugary secretions are important food sources for other animals and some ants even „farm“ aphids for their honeydew! (And yes, you read that right, it comes out their rear ends)
  • Because their diet lacks certain essential amino acids, aphids have BACTERIAL ENDOSYMBIONTS living inside them that help produce amino acids (and also help in other ways)
  • Some aphid species can produce CAROTENOIDS (the red/orange pigments responsible for the color of carrots, flamingos, tomatoes, lobster, etc.). This is possible due to an extremely rare GENE TRANSFER from fungi! Only two other animal species (a mite and a hornet) have acquired this ability, all other animals must extract carotenoids from their food
  • Aphids can reproduce asexually through PARTHENOGENESIS, in which a female essentially produces clones of herself. Aphids usually alternate between sexual and asexual generations but there are some external factors that also contribute to this. There is no known species of aphid that reproduces through sexual reproduction alone
  • Parthenogenic aphids are VIVIPAROUS, meaning they give birth to live young instead of laying eggs! Pretty crazy...
  • But that’s not all! The daughters born by parthenogenesis already have parthenogenically developing embryos inside them so they are technically BORN PREGNANT! This is known as TELESCOPING OF GENERATIONS
  • Mothers that parthenogenically produce sexual offspring (usually around autumn) produce males that are genetically identical to their mothers except for lacking one sex chromosome, which is responsible for sex determination. (They can also control offspring sex ratio). The sexual generation, usually winged, flies to a different plant, mates, and lays eggs that overwinter and hatch in the spring

So even though you might continue to hate them because of the destruction they cause your plants, I hope you can at least begrudgingly agree that they’re seriously fascinating in a lot of ways! Ok, nerd rant over for the time being 🤓

Comments

Popular posts from this blog

#8: Butterfly Wings

Litinsects #8: Butterfly Wings Have you ever heard that you shouldn’t touch a butterfly’s wings or it will die? Well why is that...? Who remembers what I explained yesterday about Latin names? Butterflies and moths belong to the group LEPIDOPTERA, from the Greek words lepis for scale and pteron for wing. You probably guessed it already: butterfly wings are covered in SCALES! (Anyone starting to see a pattern with the names here? 😉 ) Butterfly scales are actually modified, flattened SETAE (aka hairs) that either partially or entirely cover the wings of most species. Some look like roof tiles, like on this here monarch, while some look more thread-like Scales protect and insulate the insect, but underneath the wing is actually transparent! Some species, like the GLASSWING BUTTERFLY, lack scales and have totally amazing see-through wings! Scales are responsible for the coloration of butterfly wings in one of two ways. First of all, scales contain...

#58: Tardigrades

Litinsects #58: Tardigrades Anyone recognize these weird-looking little guys? They are actually not insects, as a matter of fact they are not even arthropods but they are cool enough to deserve a post. These are TARDIGRADES, also known as water bears or moss piglets. They are best known for their bizarre abilities to survive some of the most extreme conditions imaginable... © Science Faction Images -As always, the name’s etymology describes them a bit. It comes from the Latin “tardus” meaning “slow” and “gradior” for “step/walk”. Their common name comes from the fact that their walk looks a bit like a bear’s -Tardigrades are a PHYLUM of animals consisting of around 1,300 species. (Side note: the TAXONOMIC LEVEL of a group has nothing to do with how many species it contains. For example phylum Arthropoda, a taxonomically equivalent category consists of around 1 million described species and possibly millions more not yet described!). -These animals are all microscopic, ranging in ...

#60: Cockroaches

Litinsects #60: Cockroaches Cockroaches belong to the order BLATTODEA, which is derived from the Greek word “blatta” meaning cockroach. Did you know that the Blattodea contains cockroaches AND termites? That’s right; termites are actually considered 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 than previously thought. -Roaches are characterized by their broad, flat bodies. They have long antennae and generalized chewing mouthparts. In contrast to many other insects, which have 3, cockroaches have only 2 ocelli (or simple eyes) -Most people consider roaches to be disgusting, disease-spreading pests. But of 4,500 species, only 30 live in human habitats and are considered pests -The common name is derived from the Spanish word for the insect, “cucaracha” -Cockroaches can be found in a wide variety of habitats around the world. Many live in the tropics but...