The wonderful things about studying raising phasmatids in your home is
that almost has been plublished about them. Just about anything you
care to measure or observe will be novel and unpublished. Really!
Observations of Eggs
They just sit there, right? Nothing to observe?
Try this quick quiz:
How big are they? There are specific ways of measuring eggs,
I'll add a diagram of what to measure, eventually.
You'll need a micrometer.
How much do they weigh? Preferably fresh. Weigh heaps of them
(say, 50 or 100) at a time, and take the average. A single egg is
unlikely to even register on equipment affordable to the amateur.
I will prepare a set of prelimiary egg characters. Score the eggs
for yes/no on each character. This is important for developing an
identification key.
When were they laid? How many were laid? Most species have seasonal
characters, laying will build up, level off and then taper out.
When did they hatch? How many hatched? This is important
information, it tells you when to go out and beat bushes looking
for nymphs.
Diapause: if you have the courage and a microscope (and a sufficient
abundance of eggs) you could try dissecting eggs, looking at fetal
development. When does the embyo start to develop? An initial delay
is one sort of diapause. When does the embryo finish developing?
A mature delay is a second sort or diapause. Some species have both!
What proportion of eggs use each sort, or none?
Egg dissections can also reveal information about parasitization,
and the proportion of non-viable embryos.
Husbandry: what effect do light, temperature and humidity have on
fetal development? On yield?
What proportion of eggs hatch male? Hatch female?
Take photographs of the eggs.
There are standard orientations to photograph,
see Clark (1976).
Observations of Nymphs
Nymphs are one of the most appealing aspects of raising stick insects.
Some thing different to observe every few weeks.
The exact number of instars in most species is unknown. Close
observation is required to establish just how many instars occur.
While females almost have at least one more instar than males, it can
be more. While the number of instars are usually constant for each
species, this isn't always the case. If you find a species with a
variable number of instars, what are proportions? Does foof type,
temperature or humidly have any effect?
How big are they? There are specific anatomical structures to
measure. I'll add a diagram of what to measure, eventually.
Measure males and females independently.
How much do they weigh? Preferably immediately after moulting.
(Some smaller species have nyphms which weigh significanty less
than a gram, making this very difficult to measure.)
Measure males and females independently.
I will prepare a set of prelimiary
characters. Score the nymphs for yes/no on each character.
Score males and females separately. This is important for developing
an identification key.
What is the mortality during an instar, and during the moult.
What factors (e.g. temperatory or humidity) affect mortality?
Take photographs of each sex in each instar.
There are standard orientations to photograph.
Note that most observations and measurements are identical to the
following things for adults. While this is handy for reducing the amount
of documentation I need to write, the ultimate goal is to procuce an
identification key which includes both adults and nymphs.
Observations of Adults
How big are they? There are specific anatomical structures
to measure. I'll add a diagram of what to measure, eventually.
Measure males and females independently.
How much do they weigh? Preferably immediately after moulting,
and also at "midlife" if this can be determined. Measure males
and females independently.
I will prepare a set of prelimiary
characters. Score the adults for yes/no on each character.
This is important for developing an identification key.
Measure males and females independently.
Take photographs of each sex when adult.
There are standard orientations to photograph.
How long from the final moult until females mate?
How long from the final moult until males mate?
How long from the final moult until females start to lays eggs?
Do females lay eggs without mating?
If they must mate, how long before eggs are layed?
I have no idea now you design an experiment for this:
how do you tell how long a female can store sperm?
The literature suggests some species can only do this for a week,
while others can store it for many months.
Parthenogenesis: do females lay fertile aggs without mating?
(What proportion of females have this faculty?)
Are parthenogenic eggs always female or mixed male and female?
(Examples of both exist in the Australian phasmatodea.)
If mixed, at what proportions?
