Monarch population comeback

Back in winter 2012 I posted about a monarch butterfly deformed upon emerging from its pupa.  I went on about how maybe the winter timing of its emergence had something to do with its deformity or difficulty eclosing.

This was clearly incorrect as the butterflies, and all of the caterpillars mentioned in that post as well, was infected with the OE parasite (Ophryocystis elektroscirrha).  The caterpillars ingest the spores of the parasite as they feed, which have been deposited there by their infected mother as she laid the eggs.

In an earlier post I was observing massive population of caterpillars decimating the milkweed, which had also been less than vigorous for some time at that point.  There was also a weak emerged adult in that post, likely a less severely infested victim of OE.

Turns out that winter 2012 was the peak of our OE infestation.  The emerging adults were so heavily infested they were unable to mate and reproduce, resulting in population crash.  I also removed all of the milkweed in January 2013 in the interest of preventing the spread of the parasite. 2013 there were zero monarchs about the estate.  At the house across the street, a lush stand of milkweed started up mid year and this adult emerged apparently healthy.

Through 2014 the milkweed stand across the street has prospered along with the monarchs and milkweed bugs.

In spring I found a pupating monarch on a new seedling milkweed in my own parkway strip, which later successfully emerged.  So perhaps the OE has ebbed.  Does population density play a part in the intensity of the infestation?  I think removal of milkweed supporting infected populations may be a good idea but also being aware of the signs of infestation although in light infestions there may be no indication short of microscopic examination.

Bunny tails tale

Mr. Cardui grew some Lagurus ovatus this spring from a packet of seed I picked up at the local nursery.

Bunny tails! have erupted all over them just in time for me to pot some up along with cosmos in a little meadow-like salute to summer along the driveway.

But what could be cuter than bunny tails is this tiny Mediteranean katydid nymph, , slowly and meticulously navigating the long awns of the grass flowers.  It's using its long antennae to investigate each step before taken, and with all that surface area of the flower parts it was a lengthy process.

This katydid is the second or third type I found in my garden, and the balance is in the balance apparently because I see far fewer of the once common Scudderia furcata and more of the Mediteranean, along with an occasional Microcentrum californicum.  According to UC IPM (which considers these guys pests) P. nana lays its eggs inserted under grape vine bark.  I do have a Vitis californica growing on the fence . . . must investigate for egg-sign.

Along with the katydid I found some colonies of aphids tucked right up next to the flowers along the peduncle.  Pests, yes.  Let's see how long it takes the predators (ladybirds, syrphids, lacewings) to find them.

Bunny tails; they may be invasive like some other ornamental grasses.  Plant with care if your garden is near a natural environment; with relative urban abandon if not.

More on Pomegranates

Since winter the state of my pomegranate tree (Punica granatum 'Nana') has improved.  The majority of its leaves are healthy and uncurled by the pomegranate leafroll mites (aceria granati) that I assume have been the cause of deformed leaves and greatly reduced plant vigor for the past several years.  The tree is also full of flowers and buds, many more than last spring.  So clearly the tree is doing better and has energy to pump into flower production.

What happened?  Since I haven't treated the tree with insect- or miticides, I think the chief player in mite control has been the cold snaps we had over the past winter.  The tree lost most of its leaves and maybe the cold helped kill off remaining mites.  So as spring warmed up the tree got a fresh start with lots of healthy photosynthesizing leaves.

On the other hand, there are areas of curling leaves starting up on the tree now . . . so I am planning a strategy to help the plant and reduce the mite population.  Maybe I'll prune off infested leaves, might try chemical control; probably will fertilize the plant and wash off the leaves periodically.

There still isn't much information about an outbreak of these mites in Southern California that I have been able to find, but I see troubled pomegranate trees in my local travels.  Anyone else have any info on this pest?

Monarch Success

How well do winter-eclosing monarch butterflies (Danaus plexippus) fare in southern California?

Three days ago I was observing the abundance of caterpillars, which will inevitably become pupae, then eclosing butterflies.  By the way, winter maturation of monarch caterpillars is common here; I see lots of them each winter.

I found one recently emerged adult the day I posted on the caterpillars.  The weather that day was cool, breezy and partly sunny.  By late afternoon, this butterfly was lying in the garden path.  I blew some hot air on it and it began to move in my cupped hand.  So I brought it inside for the night to see if it would take flight the next day.  It didn't.  You can see the wings have hardened in a slightly crinkled state, probably not likely to sustain flight.  I had offered the butterfly sliced orange as a food source but couldn't confirm if it had taken any.

The next day turned out to be rainy; while the rumpled butterfly hung on a twig in its wine box on the back porch, I found another monarch very recently emerged hanging from the foliage in a misty rain.  So I brought that one indoors too.

The outcome for each of these butterflies was not good.  The first one never took flight and seemed terribly weak by the morning of 12/19.  The second one's wing was malformed and parts of the chrysalis were stuck to its body.  It flapped its wings vigorously but never took flight.

I set the two butterflies in sunny spots in the garden where maybe, if butterflies have feelings, they could feel the warmth of the sun one time before they died.

I think these two were unlucky as to the timing of their eclosure: we do see successful monarch emergences during the winter months.  After all, southern CA winters are mild, and we have warm dry stretches good for butterfly-ing.

However I'm sure conditions in winter-- Rain, cold, cold wind, lack of abundant flowers to feed on, short day length--take a toll on the adult monarch population that manages to successfully eclose.  On the other hand, many more caterpillars thrive during the winter because the population of wasps that prey on them is so much lower in the cold, and weather conditions don't seem to harm the larvae as they can the adults.  Perhaps a higher number of less fit (genetically) caterpillars live longer in winter because they aren't eaten by wasps but then get weeded out by the perilous process of pupation, made even more risky by unfavorable weather.  Or, because there are so many more pupations this time of year (because so many more caterpillars are maturing) does it just seem like there are an awful lot of failures, but percentage-wise is it the same as during spring/summer/fall?

Monarch Season

Hello there.  It's a nice chilly 57 degrees here with light rain off and on.  We've had a week or so of intermittent rain and overcast and so I'd say it's looking a lot like spring.  Yep, this time of year is when our hills green up, the mallow seeds sprout (photos later), the holiday lights go up (photos later) and of course the monarch butterflies go bonkers.

I was out back checking on things (wasting time I should be shopping?  NOT) when I couldn't help notice the milkweed dripping with fat soon-to-pupate monarch caterpillars.

There were some small half-pint caterpillars too.  On one branch the two stages met.  You can appreciate the difference a few extra weeks of eating makes in the relative sizes of the two caterpillars seen here.

The monarchs eat a lot and can completely or nearly defoliate the plant they're on.  Meanwhile the oleander aphids proliferate in huge numbers and help in the defoliation process.  Also, I suppose, the depodding.  You can see lots of alar (winged) aphids on the seed pod.

I found two small caterpillars on this nearly leafless plant; one I relocated to a more lush feeding ground.  The other one, seen here heading toward and then eating a tiny leaf bud or nub covered in aphis nerii, I left alone.  I'm sure it will be able to find enough to eat, even if it has to climb down to the ground and up another plant.

I also found a monarch chrysalis that has turned transparent so the orange of wings can be seen inside.  Soon to eclose for sure.  It's hanging in the bronze fennel, former home of the anise swallowtails.  Monarch (and other) caterpillars do often go travelling when it's time to molt and pupate, and I more often find pupae in plants other than milkweed.  That's a drop of water there among the gold spots, by the way.

I went back for another look this morning--still pupating--but found a different floppy-winged, recently-eclosed butterfly clinging to some grass along the path.  It looked weak.  Cold and drizzle seem like an unlikely recipe for butterfly success.

Heading back to the house I saw this caterpillar gone wandering among the agapanthas.  It is surely searching for a pupation spot, likely to be up on a woody stem of the phlomis, same plant where other monarchs have pupated in seasons past.

You can see its searching behavior in this photo, where the caterpillar clings with its prolegs and stretches and waves its body back and forth in an effort to make contact with suitable substrate (based on texture? firmness? orientation to the horizontal? what?) to pupate upon.




Near sunset I went out to check on the butterfly's progress.  It was lying in the path motionless.  I picked it up and in a few moments it started to move.  So I took it inside where Mr. Cardui was building a fire in the woodstove.  The butterfly was soon able to climb to the top of a twig I placed inside a wine box and seems to be resting, nestled in an upper corner, for the night.  We'll see if tomorrow brings sun and butterfly first flight.

Crazy monarch behavior: preferable to frenetic human holiday behavior?

Return of the Lynx?

Is it really true the last time I posted about these super cool and beautiful spiders was December 2010?  Yup, I just checked.  Haven't seen any since . . . until today!

The honeybee carcass hanging below her lair caught my eye; I found the spider hanging out beneath a tangle of web above the honeybee and on top of the rose geranium espalier out on the front fence.  This fuzzy photo kind of depicts my amazed and befuddled condition when I first saw her.

The coloring is a bit odd . . . brighter green than I remember and missing the chevron pattern on the dorsal abdomen.  Still . . . must be green lynx, peucetia viridans, back from wherever spiders and other critters go when the population dynamic shifts.  Yay!

Wanderings of the Large Milkweed Bugs

I noticed these two oncopeltus fasciatus passing the time on Juan's aeonium outside my back door on March 3.  Of course I've observed the large milkweed bugs fraternizing and aggregating on aeonium arboreum before, and wondered why since aeonium is not even in the same family as milkweed which seeds are supposedly the only food for O. fasciatus.

Today I noticed this pair getting dangerously close to passing the time on a weedy passion vine leaf.  Interestingly, one of this pair has the same wing deformity as the one in the previous pair.  Same individual?

The milkweed itself has had a tough winter, and was mostly defoliated until recently.  There have been no sightings of large milkweed bug on milkweed since before I photographed this one in November on St. Catherine's lace, Eriogonum giganteum.  Seen here recently molted into an adult.

Assassins

Like many predator species in the garden this summer, the assassin bugs (these are Zelus renardii) have not been plentiful.  I like to think this is due to the large hunting wasp populations which may have both preyed upon these other predators and snapped up the majority of available prey.  However I have no proof except my own heresay.

Now the paper wasps (polistes apachus) were cut down 5 weeks ago, and suddenly there is an explosion of assassin bugs of various stages of development.  Coincidence?

On a recent misty morning I found a freshly molted adult.  In this picture this individual with its unhardened celadon exoskeleton forms a triad with its cast-off shed and another younger assassin bug among the angular branches and leaves of the acacia iteaphylla.