by john west | Jan 14, 2019 | environmental, Tales From a Tiny Garden
Monarch caterpillars are voracious eating machines. They eat swan plants exclusively and will completely trash a large plant in days. Big caterpillars survive while smaller ones starve to death as the availability of leaves dwindles. Fully grown caterpillars will stand up on their rear legs and headbutt each other over a juicy leaf when supply is short.
Despite completely trashing their environment, leaving nothing but green twigs for younger generations Monarch caterpillars still have a swan planet B.
Step 1. Pupate, and hide away in a chrysalis for about 10 days.
Step 2. Bash your head against the Chrysallis to knock a hole in it. Squeeze out carefully and pump your wings up before flying off to another swan planet.
Luckily we are a bit smarter than Monarch caterpillars and have a plan for saving Lake Rotorua. It’s the rest of the planet I sometimes worry about.
Lake Rotorua Nutrient Management – Plan Change 10.
by john west | Jun 7, 2018 | school posts, Year 09, K-10
Work through The Introduction to the Periodic Table Prezi then do the quiz to check your understanding.
By the end of this unit you should know:
what the atomic number and mass number of an element is.
how elements are arranged on the periodic table.
what Periods and Groups are.
the physical and chemical properties of the group 1 metals.
the physical properties of group 17 elements.
the physical properties of group 18 elements
that sodium and chlorine react violently together.
that elements in the same group have similar properties. WHY!
by john west | Jun 6, 2018 | Tales From a Tiny Garden
A lonely potato continues its cycle. Dug up and replanted twice to investigate what happens out of sight in the dark wet soil. Late in the season it’s leaves are attacked by a plague of leaf chomping potato moth caterpillars.
Growth is powered initially by the tuber near the bottom of the tub. When leaf development is sufficient, excess sugars from photosynthesis are passed down the stem and stored in growing stolons as starch. Have a look.
by john west | Apr 29, 2018 | Tales From a Tiny Garden
Chemical warfare in a tiny garden in Rotorua.
A sunny afternoon relaxing in suburban Rotorua, above the lake not far from the CBD. Bad things happen in tiny gardens.
Early summer and dark chemical processes are at work in the bright sunlight. Swan plants are producing and stockpiling deadly molecules in their sap and leaves. A chemical defence system designed to kill insects foraging for food. The main components of this molecular arsenal are cardenolide glycosides, steroids with an attached sugar structure. These toxins can induce cardiac arrest.
Monarch caterpillars and butterflies are immune to these poisons. Caterpillars voraciously devour swan plant leaves. In the process they hijack the plant’s chemical defence system for use against predators. Birds associate becoming sick with a diet of brightly coloured caterpillars or butterflies and drop them from their diet.
Attack of the killer wasps.
Asian paper wasps are very determined predators of monarch caterpillars and are unaffected by the cardenolides. Wasps need protein for nest construction and developing larvae in spring and early summer. Caterpillars are a good source of protein at this stage.
I watched wasps make their way through dense foliage in relentless pursuit of their prey. Monarch caterpillars appear to understand the danger and some seek refuge amongst the spines of the swan plant seed pods. The aerial bombardment is relentless and a plant can be completely stripped of the caterpillar population in a day. The big mature caterpillars are a favourite target and I have seen them stand up on a leaf in a forlorn attempt to beat off a merciless attacker.
The assault has a number of stages
- The wasp lands on the caterpillar and probably stings it
- The wasp starts to skin the caterpillar while it is still moving. It bites through the skin which rolls back to reveal the underlying body.
- It may move the whole carcass to a more stable location where it slices it up into manageable chunks to fly away with.
In late summer when the need for protein has diminished, wasps change their diet, feasting instead on the nectar produced by swan plant flowers.
Relationship beteeen steroids and cardenolide glycosides
oleandrin a cardenolide glycoside
Oleandrin is one of the cardenolide glycosicdes found in swan plants. The structure hanging on to the bottom left of the steroid skeleton is based on a sugar unit hence the glycoside in the name.
by john west | Apr 26, 2018 | Tales From a Tiny Garden
A sunny afternoon, the perfect picture, where’s my camera when I need it? A white butterfly flutters gently on a pot plant decorating the fence line beside the tree nursery. It is rushing to fill the the tank with carb rich nectar. It’s dangerous to park here for too long. Something is amiss? The delicate wings are beating with too much urgency. Maybe two insects are locked in an embrace, rolling on the soft red petals. I need a closer look or perhaps a visit to Specsavers.
My tiny garden is a beautiful savage microcosm.The terrified butterfly is held in the death grip of a Praying Mantis. Two raptor arms encircle wings and abdomen. Pointy restraining attachments on the legs gouge the insect’s abdomen as it struggles to escape. Sharp teeth slice effortlessly through brain and neck ending the brief resistance.
After five minutes of carnage all that remains of the butterfly is a single surgically amputated winglet that escaped butchery, floating away on the gentle breeze.
The video was taken using a Canon EOS 60D camera. Invidual clips were editied together using Gopro Studio.