Paul Cherubini paulcher at
Tue Jun 29 17:42:26 EDT 1999

gwang wrote:

> Futhermore, some of even pupating
> prematurely and I've found that most of these larvae can't properly
> latch on to their silk pads either.  Almost all of them fall to the
> bottom of the container unless I happen to be their to reattach them
> manually.  Does anyone have any idea as to what might be causing this
> and if this is naturaly at all?

Could be poor nutrition, poor hydration, excessive numbers of neogregarine protozoan 
parasites, excessive crowding with its associated poor sanitation or using rearing 
containers that don't allow fresh air circulation. As with almost any creature, when body 
wastes are consumed due to inadequate sanitation, sickness and weakness and sometimes 
death follow.

Suboptimal nutrition & inadequate hydration can result from feeding caterpillars cut 
milkweed that is not changed twice a day.

The best food for monarch caterpillars, in my opinion, is milkweed growing in the 
ground or in pots. Next best choice is cut milkweed with the stems immersed in water. 
Third choice is just cut milkweed. Outdoor screened cages help provide ventilation. 

As you can see, there are half a dozen key variables that need to be controlled. It's alot of 
work maintaining optimal rearing conditions! And I havn't even touched on all the 
parasites and predators that love to eat monarch eggs, caterpillars and chrysalids.

Most eggs should hatch, but maybe 2 out of 10 won't. Eggs are very susceptible to 
predators, including nocturnal ones (e.g spiders, ants, earwigs, etc)

Paul Cherubini

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