caterpillars / butterflies in Santa Barbara...
Does it make any sense???
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gallery of milkweed and Monarch caterpillars & butterflies
eat butternut squash
flies are killing my monarch caterpillars!
caterpillars failed to complete pupating into chrysalis... why?
We've been trying to "raise" Monarch caterpillars and butterflies for almost
two years. Raising probably isn't the right word, but I couldn't think of a
better one. What we've really been doing is attempting to grow milkweed as a
food source for the Monarch caterpillars (and the Monarch butterflies can
feed on the flowers as well). I discuss how we got started on this backyard
project in an
earlier post here. Needless to say, growing milkweed here in Santa
Barbara (coastal Southern California) and attempting to "raise" Monarch
caterpillars has been a challenge. I realize it's not that much of an effort
to plant some seeds and water the plants, but once one commits and become
emotionally invested, one would like to succeed and an actually see some
caterpillars turn into chrysalises and subsequently into Monarch
butterflies. We have had some success, but more often than not, we have
faced three very real problems: (1) young milkweed plants wiped out, (2)
overpopulation/famine, and (3)
the dreaded Tachinid fly! These issues have
caused me to wonder... is migration critical to Monarch butterfly survival?
And does it make sense to grow milkweed in Santa Barbara?
(1) young milkweed plants constantly
(3) the dreaded Tachinid fly!
(4) is migration critical to
Monarch butterfly survival?
(1) Young Milkweed Plants Constantly
Get Wiped Out:
I have planted a LOT of milkweed seeds. I've used both tropical milkweed (Asclepias
curassavica) seed I got at our local hippy nursery/feed store that
seemed to be mainly yellow-flowered tropical milkweed, as well as some
red-flowered (blood flower) tropical milkweed seed I got from our local "butterfly lady" that
I think she
"harvested" from her backyard milkweed plants. I've had better luck
with the yellow-flowered tropical milkweed, but even so, I've only got ONE
large milkweed plant (about 3 feet tall and round). All our other milkweed
plants around the backyard and front yard are small and stunted. The problem
is that in Santa Barbara, we have Monarch butterflies around all year long
(or so it seems), and they are egg-laying machines! The Monarch butterflies
come here in late fall to spend the winter in our nearby coastal Eucalyptus
groves, and then in the spring almost all of them leave and migrate
back up into the Sierra mountains and beyond for the spring, summer, and
fall, and then return the following winter. But some of the Monarchs must
stay here. I'm pretty sure several people here are growing backyard
milkweed, and that at least a few Monarchs lay eggs here in the spring, and
the resulting Monarch butterfly offspring stay in this area and keep
reproducing throughout the year. In an event, we see Monarch butterflies
around throughout the year. The problem is that my small milkweed seedlings
never get much of a chance to grow before they get eggs laid on them, and
the eggs of course
turn into hungry little caterpillars that eat the little plants. The small
plants can recover once or twice, but always seem stunted ever after.
Somehow I've managed to grow one nice, fairly-large established milkweed
plant in the backyard (which has already been completely defoliated twice
this year by caterpillars, but has also recovered, at least until the next
wave of caterpillars). But all my other scattered milkweed plants are small
and stunted (and the butterflies still seem to keep finding them and laying
eggs)! I'm not giving up though... my large milkweed plant produced some
seed this summer which I was able to collect, and I'm making one more go at
starting a half dozen big pots of milkweed.
I've read that a single Monarch butterfly can lay 100 to 300 eggs, and we
have multiple Monarchs fluttering around the backyard. I'm guessing that
lots of eggs get laid on our single big milkweed plant. In any
event, we have repeatedly found dozens of caterpillars at a time on our
milkweed. The problem is the caterpillars eat up all the leaves before they
are completely grown, and then have no more food. The butterflies are laying
too many eggs for the available milkweed! It's heartbreaking to have a bunch
of hungry caterpillars and no milkweed. Last year
we fed one hungry
monarch caterpillar some butternut squash, but that doesn't seem like a
very realistic long-term solution. This problem makes me seriously question
growing backyard milkweed if the butterflies lay too many eggs and none of
the resulting caterpillars have enough food to grow to full size. I'm not
sure if growing more milkweed is a solution if it just attracts more
butterflies (with each butterfly carrying a 300 egg payload!).
(3) The Dreaded Tachinid Fly!
This spring, our lone large milkweed plant got completely defoliated (again)
along with every other small milkweed plant nearby, but we managed to grow at
least twenty big Monarch caterpillars before the milkweed was wiped out. We
leave the caterpillars alone and they wander off to different spots in the
yard and elsewhere to turn into Chrysalises. Sadly, when we excitedly went
looking for chrysalises (like going on an Easter egg hunt), all we found
were two chrysalises, and at least a dozen dead hanging Monarch caterpillars
that had been killed by Tachinid flies. We'd experienced Tachinid fly
problems before, but to a lesser degree, and I was hoping it might be
seasonal. But now it's looking like it is a year round problem and the vast
majority of the caterpillars are getting killed by
Tachinid flies. Again,
when you get your hopes up to see the beauty of that pale green chrysalis
and then the magic of that regal black and orange Monarch butterfly
emerging, it's really disappointing and heartbreaking to see a shriveled
dead hanging caterpillar. From my research at this point, I have no idea
what to do about my new nemesis (the Tachinid fly).
The above problems of the butterflies being able to overwhelm the available
local food supply and the problem of the Tachinid fly make me wonder if
growing milkweed for the Monarch butterfly IN SANTA BARBARA makes any sense,
and it leads me to this question...
(4) Is Migration Critical to
Monarch Butterfly Survival?
Maybe growing milkweed here in coastal California where so many butterflies congregate for the winter
is fools errand? Maybe the Monarchs migrate as a way to survive, and they
aren't intended to stay and live year round in coastal California (Santa
Barbara). They come here in the winter to keep from freezing to death. But
maybe they then migrate in the spring to disperse and look for a food supply
(new milkweed). They then keep moving north and spreading out even more so
they are always finding new milkweed plants and are also thinning their
numbers so they don't overwhelm the local food supply. Equally important,
they spend the summer up in the Sierras (and in Reno where I remember seeing
them as a kid) where many of their natural enemies don't exist because it
FREEZES every winter. They can fly away to sunny Southern California or
Mexico for the winter, but their fellow insect predators (like the Tachinid
fly) get frozen each winter and don't exist. So maybe to insure adequate
food and safety from predatory insects, Monarchs need to migrate every year
Although I'm beginning to question if growing milkweed in Santa Barbara
makes much sense, I'm not giving up. We will still keep planting and growing milkweed. I
recently collected several seed pods full of yellow flower tropical
milkweed, and planted a half dozen new pots of milkweed. Much of the
milkweed has sprouted, and now all of the pots have many milkweed seedlings
in each of them. The challenge will be to keep the butterflies and aphids
off of the young plants so they can grow and and get big enough to be
transplanted around the yard. If you have any thoughts or personal
experience on this please feel free to share them below.
Comments / Questions / Feedback:
Comment by Adriana Stuven on Saturday, October 10, 2015
Thank for the information, very good I learn a lot. On Sep 29 2015 I bought
a asclepiad in the Las Positas nursery to attract butterfly to my home, I did
believe they using to put there eggs on the leaf, now 10/10/15 I found 4
caterpillar in the plant wish is small plant, I read in youtube they need a lot
of leaf to grow, I went back to nursery I bought another plant. Now reading you
article my question is they will survive the coming cool weather over here? I
live in Goleta City 93117. Please help me :Do I making a mistake to grow this
carterpilla or I live in the back yard were they are now or to live to their
luck or I protected and get more plant to feed the caterpillar inside the home.
How big they get, How much they eat I never saw caterpilla before. Thank very
much Adriana Stuven
Reply by Steve (Cranial Borborygmus)
Hi Adriana, Thanks for your comment and question. I've never counted, but I
think Monarch caterpillars can end up eating between 20 and 30 full size
tropical milkweed leaves during their life before they are big enough to turn
into a chrysalis. They eat less when they are small, and then eat more and more
as they get bigger. Regarding the weather here, I think Monarch caterpillars can
grow year round here in Goleta and Santa Barbara, so if there is enough milkweed
available, your caterpillars should do fine. But if you get more milkweed,
you'll probably find Monarch butterflies have laid more eggs, and you'll end up
with even more little hungry caterpillars. Hopefully you've got enough milkweed
to get these four caterpillars to full size and they'll be able to turn into
chrysalises. Although your milkweed plant(s) will be missing all their leaves,
if you keep watering them, they will grow new leaves. It can be tough, but it's
amazing to see the caterpillars turn into chrysalises, and then see the Monarch
butterflies emerge. Good luck!
Comment by Jon Frye on Saturday, November 18, 2017
Steve, awesome website! I'm new to providing habitat for monarchs, in my
second "cycle" of the egg to cat to chrysalis, and observing things that are
both wonderful and troubling. Randomly found your page not knowing that you also
are in Santa Barbara! You have covered everything that I had questions about.
You even touch on the emotions that somehow come along with watching these
little creatures!! I've bookmarked your page and intend to digest it all! Jon
Reply by Steve (Cranial Borborygmus)
Hi John, Thanks for your comment. I think you nicely summed up "raising" Monarch
caterpillars... it can be both wonderful and troubling. I hope my
experience and information can help a bit, though there are lots of other
sources of good information out there on the internet.
This year we personally haven't seen that many caterpillars and now have lots of
milkweed. But in just the past week or two we've had several butterflies laying
eggs, so maybe now we'll get some caterpillars. The toughest thing so far over
the past couple of years has been the tachinid fly. It is a curse! Anyway, good
luck and welcome to the wonderful world of the Monarch!
Comment by Anastasia Alexander on Monday, May 18, 2020
Hello, I have 2 questions:
1. I often find smaller (aka not ready to chrysalize) caterpillars wandering
around the yard or climbing up other plants. Is this normal and, if they wander
off, are they able to find milkweed again?
2. I have one large milkweed plant that none of the caterpillars seems to care
for. It is large and healthy yet when I move a caterpillar from a desecrated
plant with barely any leaves to this one, the caterpillars all seem to move back
to the original one. Very puzzled.
Thank you! Anastasia
Reply by Steve (Cranial Borborygmus)
Hi Anastasia, To answer you first question, I too have seen smaller caterpillars
wandering around away from the plants. They need to molt and shed their skin
several times before they are big enough to turn into a chrysalis. I think they
like to leave the plant sometimes before they molt. I assume they then make it
back to a milkweed plant. I'm not sure on your second question... I don't know
why they would leave a healthy milkweed plant if you put them on it. Is the
plant in any way different from the other plants? Did you get it from a nursery
that may have sprayed it with something? I'm not sure what else it might be... I
agree that it is puzzling.
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