Spraying tachnid flies with a salt solution did not kill them.
Tachnid flies are attracted by the SIGHT of caterpillars. To demonstrate this fact, put a large caterpillar in a clear container: a tachnid will soon present itself for swatting.
You fill find caterpillars resting on vertical surfaces. They’re molting. Leave them alone. Caterpillars need to shed their skin multiple times during their development, and they need a firm, vertical surface as they do that.
Keep milkweed well-watered. Basically, water the milkweed whenever the soil appears slightly dry.
The refuge cages should be set upright, so the door is easily accessible.
The refuge cages should be weighted down with paving stones, otherwise, the refuge cages will be blown over by the wind.
Be careful: if you try to drag the refuge cage somewhere, the paying stone will tear a hole in the bottom of the cage. Take the paving stone out of the refuge cage before you try to move it somewhere.
These cages will not need to be accessed very often. So, these cages can be set flat, which will maximize available space.
Set these cages flat, with the door facing downward to the ground.
Roll up the door flap with a 4-foot iron pipe, about 1-inch in diameter. This keeps the cage from blowing away.
NEWLY-PURCHASED MILKWEED PLANTS
Leave the milkweeds in the pots you bought them in. There is no need to put them in the ground.
Transplanting newly-purchased milkweeds will send them into transplant shock.
Place newly-purchased milkweed and their pots in a separate quarantine cage.
This is because tachnids may be in the soil, ready to emerge and kill your caterpillars.
Best to wait at least a week before moving the milkweed plants to any other part of your sanctuary.
Test any newly-purchased milkweed for insecticides. Inexpensive kits to test for insecticides can be purchased online. People use these kits to test for insecticides on the fruits and vegetables that they purchase at the store.
Another reason to quarantine newly-purchased milkweed: aphids. Even if you inspect the milkweed carefully at the nursery, you may fail to see yellow aphids. After the milkweed has been in quarantine for a week, any aphids will have multiplied to the extent that they are plainly visible.
Milkweed will regrow, even after caterpillars have eaten most of the leaves. To recycle the milkweed plants, you must first remove all the remaining leaves. That way, you can be sure there are no lurking aphids. Then, leave the milkweeds out in the open for one week. That way, you can be sure that there are absolutely no aphids on the plants. Then, put the milkweeds in the regrow cage.
Caterpillars tend to rest under leaves, out of view of aerial predators. They will position along the spine of the milkweed leaf.
When a caterpillar decides to become a chrysalis, it will seek an overhead surface to attach to. A caterpillar that decides to become a chrysalis under a leaf will always attach to the spine of the leaf, which is the most stable part of the leaf if the leaf should dry up and shrivel.
Water the milkweeds directly thru the netting of the cages. Open the cages as infrequently as possible: a tachnid takes only a second to fly in and kill a caterpillar.
Don’t use fertilizer on the milkweeds – fertilizer will attract ants, which stress the caterpillars.
AT THE MILKWEED NURSERY
Are there monarchs flying around the milkweed? If not, don’t buy your milkweed there.
Check the milkweed leaves for small yellow aphids. Even a few is too many … they multiply rapidly.
NEW MONARCHS THAT JUST EMERGED FROM THE CHRYSALIS
A monarch that has just emerged from its chrysalis must hang upside down as soon as possible.
Hanging upside down allows the new monarch’s wings to expand.
If a newly-emerged monarchs does not immediately get into an upside down position, its wings will never expand.
If a newly-emerged monarch falls off the chrysalis, try to place it back on the chrysalis. Failing that, place the monarch onto a milkweed leaf so it can maneuver into an upside down position.
A newly-emerged monarch does not need food. It needs to get immediately into an upside down position so its wings can expand.
Aphids will suck water out of the milkweed plants and devitalize them.
Aphids seem to irritate the monarch caterpillars.
Obviously, you can’t use insecticide on the aphids, or you will be killing the monarch caterpillars.
There is no way to get rid of aphids once they are on your milkweeds.
You can’t rinse them off. You can’t pick them off.
HOW TO REHANG A CHRYSALIS
If a chrysalis falls from its attachments the butterfly will not emerge, UNLESS, the chrysalis is rehung.
Use dental floss to rehang the chrysalis.
Thread is too thin and will damage the chrysalis.
Fishing line is too thin and will damage the chrysalis.
Make two loose knots in the dental floss as illustrated.
Tighten the upper knot.
Carefully tighten the lower knot around the stem of the chrysalis.
The stem is only a fraction of an inch long, so tighten the knot SLOWLY.
An assistant can gently hold the chrysalis in position while you tighten the knot.
Use the upper two strings to tie a knot around a branch or stem.
We call our rehung chrysalis area the Hanging Garden of Second Chances.