January 27, 2001
The new year has begun very cold. Freezing temperatures have reached down to about twenty miles above our location on several nights and the immediate forecast is basically for more of the same although we are yet not expecting a freeze here for the immediate future at least. For those who may read this and are in northern climates (which is to say everyone twenty miles north of here at this writing), St. Petersburg is situated mid way down the peninsula of Florida and the freeze line, the lowest point in North America temperatures reach 32 degrees f. , dips below us on average of every three years or so, but is generally just above us. Usually, the freeze doesn't kill the plants totally here when it occurs because the ground doesn't freeze deeply enough to kill the root system, but it does nevertheless kill many plants, especially annuals, and those that are damaged need time to recover. Milkweed is in the latter group. This creates a zone of transitional plant life. Below us, further south, it is more tropical, above us, more temperate.
As you may imagine, this also effects the butterflies we see. There are tropical species south of us that rarely come up the state this far and more temperate species that do not make it this far south. Then, there are also exceptions. White peacocks, for example, retreat southward for the winter and return in the summer as do a number of other species. Painted lady butterflies are known to migrate into the state in the fall and produce over wintering populations in the southern part of the state. They migrate out of the state in the spring and, at least here, are rarely seen in the summer months. Here, they are very heavily predated by birds and predatory insects which are much more active in the summer. Their larval hosts are thistles and mallows of which many are annuals here. By the occurrence of summer's heat, they have almost all gone to seed and died down. They grow better in the cool months of winter and springtime which is good for the over wintering painted lady butterflies. I won't say there are absolutely no larval host plants for them year 'round, but as common as they are, reputedly the most cosmopolitan and common of all butterfly species, they are a very rare site in my butterfly garden. Of course, we are very urbanized here and our place is in reality just an small oasis in a desert of often pesticide poisoned dead landscapes.
I just took a walk outside to check on the situation. It is about 11:00 a.m., sunny and cloudless, and the temperature is about 55 degrees. One male monarch did fly over to the pentas to feed. He is the only butterfly flying at the moment. I think I'll name him, as the resident territorial male of record today, Millennium Mike.
I observed half a dozen or so 5th instar monarch larva sunning themselves. There are probably more. The plants appear to be thus far undamaged by the cold. There are a few pockets of aphids here and there on the milkweed and I also did spot a lady bug, so I don't expect they'll get far. The population explosion of aphids this late fall in turn produced a population explosion of lady bugs. Aside from butterflies, the garden puts a lot of lady bugs into the neighborhood.
It has been not only cold, but also dry, and the milkweed plants now have spider mites on them which annually seem to show up during our winter dry season. I'll have to do something about those critters. They can spread and destroy the milkweed plants. My method for dealing with them is to cut the plant back to bare stem to get rid of the foliage with the spider mites on them and spray the stem with plant oil solution to smother any eggs or adults that may remain. It isn't a 100% cure, but it keeps their numbers in check to the point they don't do a great deal of damage. If you spray the plants with a pesticide, you may defeat the purpose of having the plant for the butterflies. Spider mites here are a dry weather problem. In the warmer, humid, and wetter summer months, I don't see them. I have observed monarch caterpillars happily consuming leaves crawling with spider mites. They don't seem to be effected by them. Actually, as they consume the leaves, you could say they are a natural predator of spider mites, even though only in an accidental manner. However, they do achieve the same result. Spider mites, I have been told, lay their eggs not on the leaves where they are feeding, but on the stem of the plant (remember the plant oil), which, now that I think of it, makes a good deal of sense. In the scale of things, a 5th instar monarch caterpillar to them is about the size of ... umm ... Godzilla.
So long Tokyo.
January 5, 2001
For the record, the forecasters have stated we have just weathered the longest cold spell for this time of the year (below average temps of 15-20 degrees - highs only reached into the 50's for over a week - our norm is in the 70's) since the mid 1950's. Today has finally warmed to over 60, but I have not seen a single monarch adult flying. I did see a red admiral, a rare site in my neck of the woods. I have quite a number of false nettle plants (a larval host). They must have attracted it in. We, fortunately, have avoided a freeze, but to the north from here to the Arctic, east across the state, and inland south for about fifty miles, freezes occurred. Frostproof, a town apparently named for it's immunity to the cold, appeared to be living up to its name remaining just outside the forecast freeze area for over a week, but even Frostproof froze last night. We missed freezing here by only two bare degrees f. However, the monarch larva on the milkweed seem to be fine. They were merrily munching on milkweed spiced with spider mites this afternoon. I've been placing the larva I find in the effected areas so they can help me control them. I don't place them on plants with leaves that are obviously too far gone due to the mites, but where the leaves are still in decent shape although the spider mites have spread to them. There they are yet in relatively low numbers. Essentially, I'm using the caterpillars to help me build a "fire break" and conserve the unaffected milkweed at the same time.
February 26, 2001
The cold has passed. The freeze was severe in Florida this winter. Reports placed damage all the way south as far as Miami. The dry weather, a drought, combined with the dead plant material left the landscape ripe for wild fires which were occurring until this past weekend when a front bearing rain finally arrived. The fires are out and the plant life is recovering.
March 12, 2001
Two weeks ago, a giant swallowtail appeared from nowhere on the porch. Apparently, all winter several giant swallowtail pupa had escaped my attention until one morning, there was a beautiful giant on the screening. Six have emerged to this point in all. Last week, the first of my overwintering polydamas swallowtail pupa emerged. Today, two more emerged with several others yet in chrysalis. I also observed one flying in the yard. I've also seen a red admiral and a white peacock. There are orange barred giant sulphur larva on the cassias and I found four giant swallowtail larva on one of the hercules clubs which sprung back to life a few weeks ago and are now nice and green with new growth and in flower. The paw paw and the hackberry I have are just budding out and sprouting their first leaves.
As far as the monarchs, they have been flying at squadron strength the past few weeks and are a mix of new butterflies and several very tattered older ones. The larva, undoubtabley due to the cold, have not exploded in number and devastated the milkweed as has been the norm, but have been steady in number and surviving without heavy predation from the wasps, but the warmth has brought the wasps out again. I did receive an email during the cold spell from a reader reporting monarch chrysalis in her yard she was unable to bring inside to protect survived several nights of high twenties temperatures without being killed. I had always been under the impression that monarchs could not tolerate below freezing temperatures, but these did and survived, emerging as normal adults. During the cold spell in January, I measured the emergence of a few of the chrysalis I had at 20 days.
Although these observations are on the monarchs in Florida, more specifically, my back yard, there is breaking news as I write concerning the monarchs in Mexico. This is a very serious situation as I write and I am posting some of the posts from the articles for your reading.
The following bulletins are posts from the dplex list at Monarch Watch.
Mexico loggers said to decimate butterflies
By Elizabeth Fullerton
MEXICO CITY (Reuters) - To regain protected forest land, loggers may have
deliberately wiped out some 22 million Monarch butterflies which migrate
annually from Canada to Mexico for the winter, a top environmentalist said
Homero Aridjis, head of the environmental lobby Group of 100, told Reuters
loggers were believed to have sprayed pesticide on the orange and black
butterflies in order to regain some 216 square miles of forest declared
protected by the government.
"There has been a massive slaughter of the butterflies in two sanctuaries,"
Aridjis said. "This will affect the reproduction process completely. Now we
don't know how many butterflies will come this autumn."
Millions of monarch butterflies migrate some 3,000 miles annually to flee
the icy winter in Canada and the United States for the warmer fir forests in
Mexico's central Michoacan state, some 70 miles west of Mexico City.
For five months of the year, Michoacan's trees are turned into a flaming
orange and the forest is carpeted with the delicate winged creatures.
The migration has taken place for the past 10,000 years, Aridjis said. The
butterflies normally arrive in early November and return north to lay eggs
at the end of March.
In November last year, the government of former President Ernesto Zedillo
extended the land devoted to five sanctuaries.
The move was in response to a study showing that farming and illegal logging
had destroyed 44 percent of the original forest since 1971. Without drastic
action, the study predicted the original forest would disappear in under 50
"The new decree could have prompted this," Aridjis said. "If there are no
butterflies they can claim the trees without problem."
But government environmental watchdog Profepa said it had not heard of the
butterfly slaughter, according to inspector Joel Rodriguez.
"We haven't ever registered people using pesticides. But it's one of the
zones where they have the most illegal logging," he said. "It (the butterfly
deaths) could also be a result of the freezing this winter which happens
every four or five years."
The U.S.-based nonprofit group Packard Foundation donated more than $5
million to the Worldwide Fund for Nature to help the Mexican government rent
or buy logging rights from local residents to compensate for lost income
while developing alternative job sources.
Aridjis said the loggers had targeted two sanctuaries -- Cerro San Andres
and Las Palomas -- in the past two weeks.
"The wings of the butterflies found inert on the ground had a strange luster
and there was a smell of pesticide and petrol in the sanctuaries," he said.
Date: Wed, 7 Mar 2001 14:50:45 -0500
From: Monarch Watch <firstname.lastname@example.org>
The following is a rough (unedited) translation of the recent posting
by Mike Quinn that is related to the pesticide kill story Mike posted
earlier in the day. Sorry I don't have time to clean this up but you
can get the gist of the story. Note the similarities and differences
between the two accounts.
There was a report to this effect on CNN today. I didn't see it but
the report I just posted from David Marriott could mean that the
report attributing the monarch kill to pesticides is in error. On the
other hand the locations do not match well so there could be two
stories here. Stay tuned I'm doing my best to track this down. Chip
MEXICO.- thousand of butterfly Monarch that hibernaban in the Hill of
Saint Andr*s, in the reserve natural locate in Michoac¦n, have appear
die apparently by the action of plaguicidas sprinkle by talamontes
clandestine, although not discard that have be by a frost.
" It is a barbarism, it is the first time that we detected an
aggression against the butterflies ", Homero Aridjis denounced,
president of the Group of the One hundred According to this group, in
the sanctuaries referred located between the municipalities of
Maravat'o, Hidalgo City and Zinap*cuaro, the assumptions talamontes
sprinkled with pesticidas the trunks and branches of oyameles and to
the butterflies monarchs.
Aridjis reported that supporting of his grouping they found thousands
of inert butterflies in the ground, with " a rare " brightness and
smelling of pesticidas and petroleum
In Michoac¦n, presumed ecocidio was confirmed yesterday by the
Federal Office of the judge advocate general of Protection to the
In a report given to mass media, the federal dependency attributes
the massive death of butterflies to the low temperatures,
nevertheless, inhabitants of the forest blame to the bands of
talamontes of to have caused the extinction to depredate the trees of
" the death of the butterflies happened by freezing ", considered the
Profepa. But inhabitants of the community of the Doves have another
version. Eduardo Barrier affirmed in interview that the death of
Monarch could be caused by the bands of talamontes that they operate
in the region.
The Faustus Perez added that the disappearance of butterflies in that
colony was absolute. There are no survivors. All is dead between
demolished trees and the accesses that take to their sanctuary.
It commented that in previous years the colony got to resist
temperatures of up to 10 degrees below cero
Dplex-L: send message "info Dplex-L" to Listproc@ku.edu
p: 1 (888) TAGGING (toll-free!) -or- 1 (785) 864 4441
f: 1 (785) 864 4441 -or- 1 (785) 864 5321
usps: University of Kansas, Entomology Program, 1200 Sunnyside
Avenue, Lawrence, KS 66045-7534
Date: Wed, 07 Mar 2001 16:36:50 -0500
Subject: Poisoning monarchs in Mexico
Take a look at this from GRIST magazine. I feel sick.
Loggers in Mexico may have poisoned 22 million monarch butterflies in
an attempt to gain access to protected forestland, says Homero
Aridjis, head of the Mexican environmental organization Group of 100.
Aridjis said the butterflies, which migrate each winter from Canada
to fir forests in the Michoacan state of central Mexico, were found
dead on the ground in the last two weeks, with a smell of pesticides
in the air. Mexico last fall expanded the size of the sanctuaries
set aside for the butterflies, concerned that illegal logging was
devastating monarch habitat. Aridjis said the new decree could have
provoked the loggers to poison the butterflies. In other butterfly
news, the Center for Biological Diversity is suing the U.S.
government to protect the rare Sacramento Mountains checkerspot
butterfly as an endangered species.
straight to the source: CNN.com, Reuters, 07 Mar 2001
March 30, 2001
The following updated report is for those who are students of Journalism. Not always are initial stories and reports accurate.
Monday March 12 9:47 PM ET
Mexico Says Monarch Butterflies Killed by the Cold
MEXICO CITY (Reuters) - The Mexican government's environmental
watchdog said on Monday millions of Monarch butterflies, which
migrate south eachwinter from Canada, had died from the cold weather
rather than deliberate poisoning by loggers, as some environmentalists
Last week, Homero Aridjis, head of the environmental lobby Group of
100, told Reuters that loggers were believed to have sprayed pesticides
on the orange and black butterflies, killing 22 million of them, to try
and regain some 216 square miles of forest protected by the
Aridjis said the butterflies had been found with a strange luster on
their wings and that there was a smell of pesticide and gasoline in
two sanctuaries in the protected reserve.
But the Mexican environmental watchdog Profepa said in a statement
that a scientific analysis of 300 butterfly corpses from the Cerro
San Andres sanctuary in central Michoacan state showed no trace of
toxic substances from pesticides.
It concluded that the butterflies had died from the cold.
Well, it seems the poor monarch butterflies in Mexico probably succumbed to natural causes. OK. Back to our backyard in Florida.
March 30, 2001
To date, there are yet surviving monarch larva and I find emerging adults in the garden fairly often. There are adults flying in fair number regularly. Peggy, my wife, mentioned that she has recently seen several wasps carrying small monarch larva. They must have young now. It is warmer. With the last brood of larva I raised in the protected environment of the porch, I have begun to see a disease problem once again begin to develop in the larva. This would be mid March. I am still at a loss for a proper diagnosis of the problem. I've only discovered over the years that it is cyclical and follows an annual pattern here. This is the beginning of the end of the boom time for the monarch larva.
May 1, 2001
The adult monarchs have been flying at squadron strength in my backyard all spring. I did find three surviving fifth instar monarch larva on the milkweed which I brought in and are now pupa. I have not discovered any since. There are eggs on the plants, but I do not find any surviving larva. I did bring in a number of leaves with eggs on them, but most actually died with few hatching. It may be some problem associated with the eggs themselves. Either they are not fertile or some parasite or fungus may be doing them in. I know from keeping eggs on leaves in a container too long fungus can attack them very easily.
This year, the monarch larva numbers have been relatively steady, but in smaller quantity than in previous years, and there was no winter "population explosion." There was, to be sure, a relative increase in numbers of larva during the winter months, just not overwhelming. In past years, the winter larva have devastated the milkweed, but not this year. The plants were not chewed to bits. It has been a colder than normal winter for us and I suspect the cold took its toll on the younger and hatchling larva.
I have seen a few red admirals and white peacocks fly in occasionally and there are some skippers about. There are a pair of giant swallowtails regularly visiting each day currently and I have seen a couple of black swallowtails, but did not get close enough to identify the species. I did observe one a polydamas swallowtail, but it may have been a male because no eggs were laid on the pipevine I could locate and there have been no larva to date this spring. There are quite a few gulf fritillaries and their larva have been on the passion vines regularly for some time. The seem to prefer the P. incarnata and P. incense. over the others planted.
July 2, 2001
Well, there has been something interesting going on. For those who have followed this haphazard chronicle, you are aware the survival of the monarch larva in the summer has been observably practically zero or next to zero over the years either due to predators, mainly wasps and ants (hatchlings), or the "Florida Plague," a malady of monarch larva that I have observed that seems to follow an annual cycle, absent in the cooler, drier winter, present in the hotter and humid summer. After so many years of trying to figure this malady out (I now hesitate to qualify it as a disease), I have begun to wonder if the problem really isn't a microbe, but something to do with the plant itself which, in Florida, is generally Asclepias curassavica, commonly known as Mexican milkweed, butterfly weed, scarlet (also yellow) milkweed, or tropical milkweed. This species is the most common sold at nurseries in Florida and most commonly grown by breeders of monarchs in the south. In fact, when groups try to reestablish habitat, this is also the species commonly planted for monarchs. It is common knowledge among breeders here in Florida that monarchs are extremely difficult to keep healthy in the summer months. Most simply cease attempting to raise them. It is noteworthy that everyone uses A. curassavica as their plant of choice as host. It is also noteworthy that most breeders I've contacted do relatively well the first year, but run into this problem the second year. The age of the plants may also have some correlation to this malady. As they have been shocked by being chomped down to stems a few times as well as cut back, the plant probably puts more energy in this state into its root system and it may be capable of, as it ages, becoming increasingly more toxic as it matures over the years. The toxins it produces, after all, are the plant's primary defense.
I know from my own experience over the years the plant is much more toxic in the summer than in the winter. I don't need any extensive chemical analysis to determine there is a chemical change from the winter to the summer. If I get the smallest amount of sap, and I am referring to a trace, in my eye in the summer by wiping the sweat from my brow with hands that have been picking milkweed, my eyes have an extremely adverse reaction, but in the winter, I can handle the plant cuttings with impunity.
So this year I began to locate and bring in other species of milkweeds to test. Initially, I ran some larva through on A. perennis, white milkweed, a Florida native, with mixed results, but the sample was small and I did discover that the plants had become contaminated with powdery mildew or another similar fungus which may have caused the problems. I will run this test through again later.
However, I did also manage to get in about thirty A. incarnata plants, swamp milkweed, which is also considered native to Florida, but not common any longer due to the massive swamp draining that has been going on here for the past century. Who knows how common this species was in 1900? I assume much more common than it is today as well as all our other native flora. As I mentioned, commonly A. curassavica has been grown and used in habitat replacement projects. This species is grown by Pinellas County and is used in the parks. The North American Butterfly Association (NABA) local chapter planted several thousand of these plants a year or two ago to help the monarch. Members of the scientific community I have run questions by in the past have tended to dismiss the monarch butterfly population in and have called have called Florida a "sink," attributing the winter population of monarch butterflies an aberration caused by planting of A. curassavica throughout the state in projects and butterfly gardens. In other words, the monarch butterfly population in Florida is a man made phenomenon.
Well, last week I went out to get a few A. incarnata plants to collect some eggs on and begin my experiment when I discovered the plants were already hosting a fair number of 5th instar monarch larva. The butterflies had started the experiment on their own. There is also two small seedling beds of A. curassavica next to the A. incarnata that also had growing larva. I have never, in all the years of maintaining this chronicle, found this many surviving larva in one spot at this time of the year in my backyard. There are well over a thousand mature A. curassavica plants in the shade and in the sun that are totally absent of larva. This is a puzzlement.
I did capture the larva and raised each in isolation in containers with screened tops and most have pupated as I write. Most appear normal, but four incarnata grown chrysalis died, being girdled by the caterpillar skin as it shed, another one died and appeared malformed, and two died due to tachinid fly larva. Approximately 2 dozen appear to be in good shape. I'll know more when they emerge as adults. The larva on the A. curassavica seedlings have also pupated for the most part, but one of the 5th instar larva did die.
Why did the wasps not attack these larva? Why are there larva no elsewhere in the forest of mature A. curassavica. This is raising a lot of questions concerning A. curassavica in my mind. If this goes the way I think it is, the entire state of Florida may be being planted with a species of milkweed that is beneficial to the monarch in the winter, but actually detrimental in the summer. Well, at this writing this is only conjecture, but these caterpillars have certainly raised my eyebrow. Hmmmm...
October 1, 2001
Since my last entry, which has been too long ago, I'll recap as well as able. Of the chrysalis formed from the early July group, from the A. Incarnata batch, 6 chrysalis either died outright or the emerging adults were weak or otherwise unable to survive in my judgment and destroyed, 7 succumbed to tachinid fly larva, and 17 emerged in good shape, a survival rate of 56%. Of the pupa from the seedling A. curassavica, 4 did not survive and 14 were good, a survival rate of over 75%, but apparently the tachinid flies did not discover these larva as no deaths of pupa were attributed to their presence. During this period, no larva were found on any of the mature A. curassavica. Since these surviving larva were found in late June, only a few 5th instar larva from time to time have been found, all on the recovering foliated seedling A. curassavica and, as well, an occasional solitary caterpillar on the A. incarnata.
The temperatures here have now fallen to lows in the sixties and highs in the low eighties, and, as well, the humidity has lessened. I have been raising monarch larva in containers again with growing success. A number yet succumb to the "malady," but the number of sickly larva has been diminishing. As I recall from the spring, the "malady" began to appear and spread as the temperatures climbed over the eighty degree mark and the lows were higher as well. We are currently as I write in the midst of climatically changing from our "wet season" to our "dry season." For the first time since last spring, when I walk into our air conditioned house, the morning air feels warmer rather than cooler. Whatever the "malady" turns out to actually be, disease or toxic poisoning or "all of the above," it does appear to be temperature and humidity related. However, I have tried raising the larva in air conditioning in the summer where the humidity is lower and the temperature is under 74 degrees with little success as well, so temperature and humidity is probably not the whole picture. I do wish it was that simple. The only spin or two on the "malady" I managed to nail down is that it is cyclical over the climatic year and it is not a sudden process, but a gradual one. The larva begin to "get well" in some smaller number at first in the fall and their health improves as winter approaches with the winter broods virtually absent of the "malady" (Jan./Feb.), and as well, in the spring, a few begin to die initially, and with each generation, the number of fatalities keeps increasing until it eventually becomes universal.
I have been maintaining a breeding colony of question mark butterflies here in captivity for over a year now. While I have had problems from time to time in the heat of summer, they still have been surviving in decent numbers as well as the captive breeding colony of zebra longwings. I currently have also a half dozen eastern black swallowtail chrysalis which I raised from a parsley plant I noticed had eggs on it. Earlier in the summer, I had raised eastern blacks, but lost the colony mid summer to "wilt." They do not do well here either in the heat and humidity of our summer, although they certainly do survive in sufficient numbers to maintain the species. The spring and fall generations seem to do well compared to the mid summer larva.
I also have been raising polydamas swallowtails on pipevine and giant swallowtails on hercules club, hop tree, and wild lime all summer with decent results. What ever it is with the monarchs, it doesn't appear to transfer to these other species with the same effect if it is transferring at all. There have been larval casualties, but always, with the exception of the mid summer loss of the eastern blacks, a good number reached maturity and were good adults. With the monarchs, the loss has been most often entire through the rainy season.
However, the monarch adults have been present all summer and in decent number. They have been daily flying out in the yard. I've been finding eggs regularly, but the wasps keep the caterpillars down I'm sure. The wasps should be at about the end of their season, but they're still out there as I write. The milkweed is also being attacked by a goodly number of aphids, but the lady bugs are also present. I wonder if there is a correlation between the aphids and the plant toxicity? They've been curiously absent for some time.
Aphidline: First fall infestation of aphids begins late September.
Well, Columbus Day is approaching, my unofficial day for the arrival of the northern migration of monarchs to my back yard. With the increased tagging from Monarch Watch this year, maybe I'll recover one. I'll certainly be looking.
October 19, 2001
If you have stumbled across these pages in the past, you know that Columbus Day, October 12th, is my unofficial day for the arrival of the fall migrating monarchs in my backyard. However, since my first observations manually recording this date, there has been some science done at the University of Kansas (MonarchWatch) concerning the migration and the relationship to the sun's angle on the horizon.
"Dr. Chip Taylor has been able to establish that the fall migration of monarchs is triggered by the altitude angle of the sun at its zenith (noon). Migration genes are turned on when the altitude angle is 56 degrees, peaks at 52 degrees and most have left a particular latitude when the altitude angle has reached 47 degrees. The window of migration is about 3.5 weeks. If you do not know your latitude, go to www.indo.com/distance/ and type in your nearest city. Then visit http://susdesign.com/sunangle/ and follow the instructions."
Using these sites, the fall migration at 'Butterflies on the Potomac' begins on Sept. 11, reaches its peak on Sept. 21 and is essentially finished on Oct. 4."
'Butterflies on the Potomac' is located in Maryland and owned by a friend and avid butterfly enthusiast and I thank him for the posting.
I ran the numbers for St. Petersburg, FL, and we are 82 W-27N. The altitude angle is 53.59 at 12 noon on October 12.
Hey, what da ya know, Columbus Day is official. Science has confirmed my observation is actually fairly accurate. The butterflies are indeed probably fall migrants, not residents, especially in the years the monarchs absented themselves for the late summer/early fall period. I did not find any tags yet though. I'm still looking.
I have only seen one single wild 5th instar monarch larva of late, but I am seeing improvement (less mortality) now in the caterpillars I have been raising. There are wild eggs on the milkweed. The temperatures have cooled. We've been below 85 degrees for a couple of weeks now and the humidity is lower as well.
Aphidline: The aphids are still present in sizable numbers. The lady bug larva and hover fly are both present as well. This generation of aphids is forming pupa of which there are many covering the underside of the milkweed leaves as I write. I expect the lady bug larva to begin gaining on the remaining aphids fairly soon. There are a good number of them present now.
November 28, 2001
The monarch larva in my backyard have been steadily increasing in numbers. Over the weekend, the first wild collected monarch larva of the fall emerged from their pupa as adults. The adults were full size and appeared healthy with fat and clearly marked abdomens. Over the past weeks, I have collected about two dozen more 5th instar larva. They appear healthy for the most part, but a few do still exhibit problems, a couple were scarred and a couple produced the tell tale red stained frass before pupating. However, the healthy number as a percentage is much, much higher now. For the most part, their appetites are very good (too good - I almost forgot how much they can consume) and they feed completely to term. As I have mentioned before, the process of the larva surviving this malady that plagues them in the summer is gradual. A few still exhibit symptoms, but most now do not. The tropic queen larva I have been raising which also demonstrated the same problem this summer have now also become healthy again.
Interestingly, I recall the problem seemed to develop in the spring when the temperatures began breaking into the eighties and now the temperatures are dropping back to the low eighties and high seventies with the lows in the sixties at night. I think it may be time to visit some weather data.
December 29, 2001
Well, it is time again to wrap up the year. The monarchs are flying in good numbers. This year, the adults have been present all year. I took a rough census of the flying adults. There were 16 total in my small backyard. Ten were male with three of the males showing quite a bit of wing damage, the others being in better shape an probably younger. Six females were netted with only one showing signs of advanced age. Of the larva I raised recently, 8 died as larva, 15 formed chrysalis, but were not by my judgment healthy, and 75 chrysalis formed appeared large and healthy. The chrysalis are emerging as I write and some are not doing well, but a small number. The butterflies insofar as the "Florida malady" is concerned seem to be following the usual trend: gradual improvement during December. We experienced an abnormally high warm and humid period a couple of weeks ago with the highs in the eighties. The larva that followed the batch noted above suffered a noticeable downturn and much higher mortality.
It appears as the temperatures (highs) cross the 80 degree mark with lows in the 60s or 70s, the "malady" presents itself. Lower, that is with high temps in the 70s and lows in the 50s, the mortality decreases. There is the varying factor of humidity and I am sure other variables including the possible seasonal variance in toxicity/chemistry of the host plant, for the most part, A. curassavica, employed throughout Florida.
On to 2002.
We will post further observations as warranted.
Thanks for visiting.
Dale & Peggy McClung