Monday, August 31, 2009
I met two intrepid caterpillar hunters at my local Armstrong Garden Center one hot afternoon. I was shopping plants, they were gathering monarch caterpillars from the asclepias curassavica plants on display on one of the endcaps. Apparently they grow lots of butterfly larval food plants, or go and gather them, and raise lots of butterflies to be released into their neighborhoods. It's hard work because the caterpillars are always eating, and because predators like wasps and spiders are always hunting for a juicy caterpillar unless you protect them with netting. I asked why do nice young men such as yourselves go to the effort to raise butterflies. They said: because we like them, they are beautiful, the neighbors love them. I was humbled by their efforts and have made plans to incorporate even more larval food plants into my own garden this fall.
Sunday, August 30, 2009
I found this dead Xylocopa varipuncta on the driveway. The larvae of this female carpenter bee could have become the prey of the larvae of the Xenox habrosus bee fly in yesterday's post. The name xylocopa is from the Latin for wood cutting, which is what the female bee does to form her nest in old logs mostly but sometimes lumber in your house.
Saturday, August 29, 2009
So I was standing in the driveway next to the cactus collection about an hour before sunset on a day last month when I heard an unusual buzz go by. I'm not saying I can id any bug by its buzz, but when you've been observing insects awhile you get tuned into the particular sounds each species makes as it flies. So I recognized that this one was different: a loud-ish, dry/clattery sound of a lower than average pitch. The maker of the sound became apparent as it landed on a pod of the nearby feathery cassia (Senna artemisioides): a large (body length about 3/4", wingspan a bit more) fly with highly decorated wings and unusual (kinda scary-looking) eyes.
This is a bee fly (family bombyliidae) in genus Xenox. I'm semi-educated-guessing the species as X. habrosus based on comparison of the wing markings and appearance of the thorax in photos here. (Thanks guys at NatHist of OC). The generic name xenox comes from the Greek for stranger or alien, and those weird bug-eyes must have inspired the name. This fly has been a stranger to my property, this being the first time I've seen (or heard) it. This particular individual hung out on the cassia pod until after dark . . . maybe spent the night there, but was gone by the next day.
These bee flies parasitize solitary bees, such as the valley carpenter bees (xylocopa varipuncta) which are so plentiful around here. The female fly places her egg inside the entrance to the bee's nest where the fly larva feeds on the provender placed there for the bee larvae for part of its life cycle. Then the fly larva switches to feeding on the bee larva itself.
There has not been another sighting of this alien since July 24, but I've got my ears on for them.
Monday, August 24, 2009
Ruben is justifiably proud of his pepper plant that grows in a pot in my backyard. He started it from seed last year, it grew and overwintered then started growing again as summer 2009 progressed. It now has a large crop of jalapeno-style fruits ready for picking.
As solanaceae will, the pepper plant has inevitably attracted a Carolina sphinx moth to lay some eggs. Manduca sexta is an attractive large (up to 4 inches or more wingspan) with six pairs of yellow spots on the abdomen. It is also known as the tobacco hornworm in its larval stages, and this one had been hiding out on the pepper plant for some time. These caterpillars grow to be large (over 3" long) but can be surprisingly hard to see on the plant, often giving away their presence if not their exact location by the damage they cause and their droppings.
To distinguish them from the very similar tomato hornworm, Manduca quinquemaculata, know that the caterpillars of M. sexta have 7 white backslashes on each side (as opposed to Vs), and a reddish horn which is usually hooked (as opposed to a blackish horn usually straight). I think both species are happy to eat whatever tomato, potato, pepper, datura, and other members of the nightshade family you have been pampering in your garden.
Understandably Ruben was not keen on allowing this hornworm (or its sibling) to stay on as a guest among his beautiful peppers. He squished one of them, but agreed to let me get a few pictures before the 2nd pest met its demise.
Saturday, August 15, 2009
I have a bit of buddleia growing among the dodonaea, and it seems butterflies aren't the only thing the sweet smelling blossoms attract. Two predators have made their home among the seductive flowers, hoping to and succeeding in preying upon whatever stops there to feed on the nectar.
There is at least one mantis (Stagmomantis californica) growing among the butterfly bush. Here he/she is hanging out under a blossom that is tucked among the dodonaea foliage which offers a quick hideout if needed when a larger predator threatens. The photo at the top of this post shows possibly the same individual (more mature, notice the wing buds) checking out the prospects at a nice new flower.
The green lynx spider, Peucetia viridans, characteristically chooses a flower toward the top of the bush out in the sun and camps out there, spinning a bit of web. Once that flower fades (as in the first photo) she begins to get a clue that it's not a very good lure anymore and is seen in the last photo to have moved on to a fresh bloom. After mating she will produce an egg sac and attach it on or near a flower so she can continue to catch prey while tending her eggs.
Fennel? you say. Not often cited as a fancy eye-catching bloom, the tiny yellow flowers could be described as ethereal, even non-descript. Nevertheless, taken as a group the flat-topped umbrella shaped inflorescences make interesting patterns as they tower overhead on top of the six- to eight-foot tall stalks of this bronze fennel (Foeniculum vulgare 'Purpureum').
Fennel is a member of the plant family I know as Umbelliferae, those of the umbels, the hollow stems, and the aromatic leaves and seeds; such noteworthies as dill, celery, caraway, cilantro, carrot, parsley, angelica, anise, and of course Queen Anne's lace, all of which attract lots of insects in a small unassuming way. Syrphid flies, assassin bugs, aphids, pirate bugs, katydids, smaller butterflies such as skippers and brush footed species, as well as the unnamed plant bugs all find these flowers attractive whether as a direct food source or a great hunting ground for those attracted by the flowers. This unidentified spider has been making an easy living off of the bloom of low-hanging aphids ripe for picking.
Katydids seem to like eating fennel flowers. This female Scudderia furcata nymph can and may eat her way through this entire inflorescence. Or she might get spooked and hop off to a different one nearby.
A much younger S. furcata investigates a fallen tecomaria blossom, both temporarily captured inside a dried fennel umbel, displaying the architectural beauty of these seemingly insignificant flowers.
And the fennel umbels make beautiful shadows on whatever is below, in this case a leaf of salvia madrensis, a species tall enough to cohabit the same airspace as the fennel.
On a recent foray into the retail garden center universe awash in mid-summer blahs I found an end-cap full of some surprising one gallon blooming plants completely new to me: sneezeweed. Hmm, plants with "weed" in the common name can be wonderful or they might be trouble. I bought some since the price was right, the way the petals fall back away from the maturing seed heads was appealing, and the tie-dye colors were irresistible; but I never plant anything new without doing a bit of research.
Turns out these particular plants, variety Mardi Gras, are a hybrid of unknown (to me) parents from the fairly well populated genus Helenium of native North American daisy- or coneflower-like plants. I was surprised and tantalized to learn how many Heleniums there are. But for now, I have planted this one in a large clay pot close to a hose spigot. Another common name for this plant, swamp sunflower, proclaims sneezeweed's preference for damp, rich soil. Even in an arid land with water police patrolling the neighborhoods, I can still safely provide that kind of environment in a pot, ergo, the pot. After they finish blooming and go dormant I'll see about planting these out or maybe giving them to someone with a wetter garden. Today there is a profusion of flowers to enjoy and that's nothing to sneeze at.
Sneezeweed was apparently once used as some sort of herbal remedy that was snuffed up the nose, causing the snuffer to sneeze profusely. Hence the name. The genus name Helenium of course comes from the Greek helios which is the sun. Full sun is recommended for growing the happiest sneezeweeds, again along with plenty of water.
Compositae, especially coneflowers and sunflowers, are magnets for female eupithecia moths. Sure enough, the helenium flowers are loaded with pugs, the pseudo-affectionate name for the caterpillars of these ubiquitous if generally unnoticed small drab moths. The larvae feed on the disk flower parts, and can be seen here in their many positions, including the stretch, the squiggle, the loop and the arch. Pugs (like other caterpillars in the Geometrid family) have only two pairs of prolegs at the end of their body (unlike other caterpillars which have up to five) and so move in the characteristic inchworm fashion.
The caterpillars take on various colorations, probably as a result of their food source. The variety seen here is typical. Colorful pugs, colorful blooms.
Thursday, August 13, 2009
Tuesday, August 11, 2009
In a messy garden such as mine own, and even in more tidy ones like yours you'll find sheets of spider webs draped across the shrubs. Sometimes these horizontal sheets cover several square feet, and on a dewy morning or after you run your low flow spinner-spitter sprinklers the webs will glisten with the captured droplets of water in them. It's amazing how much water these webs will hold, and amazing just how many webs there are in the garden and how extensive they can become. Here are some of my rudbeckia hirta flowers without the web shown in the top photo.
The spiders responsible for the sheets of webs are Agelenidae, the funnel web spiders. If you examine a web you'll find off to the side or in a low spot a funnel of silk retreating into a quiet recess within the shrubs, or a folded niche inside a flower and sometimes a crevice in some wood or other stuff you've got laying around the yard. This is where the spider hides waiting for prey to become entangled in the large web she's woven. The female spider stays in the web eating and gaining weight, waiting for a wandering male to find and mate with her. She then produces a flat disc-shaped egg sac and will probably die as winter progresses.
These spiders eat whatever insects (and sometimes other spiders) that wander into their grasp and so help to maintain the ecological balance of the garden. The remains of their predations can easily be found in the webs, as well as other random garden detritus that falls onto the horizontal silk surfaces. Here is a fiery skipper that meant to nectar at the rudbeckia flower but ended up giving its life for the cause of more funnel web spiders. A big web traverses several stalks of my bronze fennel, Foeniculum vulgare 'Purpureum' and holds a shed exoskeleton of the fork-tailed bush katydid Scudderia furcata along with fallen flower parts of the fennel itself. The shed exoskeleton of the spider herself is seen suspended as if dancing.
There are 85 known North American species in the funnel-web family Agelenidae so it's hard to say which species my sheet-weavers are. However, I would wager a guess these are in the genus Hololena based on their appearance and that genus is the most commonly found in southern California. Here are some female funnel-web spiders: the one responsible for the massive web entangling the rudbeckia; an attractive one that lives on a dusty miller leaf; and the one living and weaving on the fennel which appears to gravid: swollen with eggs.
Yes, the webs can be messy. Occasionally even I hose off webs which have become especially encrusted with dust, fallen plant parts, etc. I'm not entirely sure this measured cleaning effort is detrimental to these spiders' endeavors. The old webs covered with debris possibly aren't that effective at catching prey and may even have been abandoned by the spiders, except as a familiar hangout, in favor of fresher webs. That said, of course if you're out there fanatically cleaning away webs every day or so the spiders are not going to prosper and will move on to a quieter more natural garden. Giving the spiders a bit of space to dwell in gives me their services of predation as well as another interesting microcosm to study and enjoy.
Monday, August 03, 2009
Here are two typical bugs, and by that I mean certain buggies of the order hemiptera grouped together in the suborder heteroptera and also called true bugs (as opposed to lying stinking backstabbing bugs) or typical bugs. As such these bugs possess certain typical features: mouthparts elongated into a beak for piercing tissue (usually plant but sometimes animal), partially hardened forewings that do not cover the membranous portion or the hind wings, an "X" across the back of the bug formed by the triangular scuttelum and the leading edge of the folded wings. Their metamorphosis is incomplete, meaning they grow through several stages that resemble the adult and do not pupate. They typically use the same food source throughout their life stages, and often are agricultural or garden pests.
The first photo is an adult harlequin bug, Murgantia histrionica. It is resting on a sprig of sweet alyssum (lobularia maritima) that shows typical stippling damage from the feeding of these bugs. Their preferred food is most any plant in the cabbage family, but they will feed on other stuff in the absence of crucifers. What usually happens in my garden is the alyssum sprouts from seed, and grows nicely for a month or two until the harlequin population builds up and the plants look like that shown here. I get sick of looking at them and pull them out; the bugs just seem to go away. The weather turns cool, the alyssum seeds sprout, and we start all over again.
The second photo is of a bug quite common on flowers in my garden, and formerly identified here only as a "mirid bug". Thanks to Peter Bryant and the experts at Bugguide I can now make your acquaintance to Creontiades rubrinervis, which is quite a mouthful and there is unfortunately no common name yet available as far as I know. Here is a nice photo of the nymph stage, very attractive little buggies often seen in my garden and on this blog. This post has some interesting photos of an adult C. rubrinervis that had been parasitised. These mirid bugs are plant feeders and I guess if their numbers built up they could be damaging; apparently the parasites and predators are keeping them in check in my garden.
Saturday, August 01, 2009
This is a funereal duskywing aka the 7th duskywing, Erynnis funeralis, feeding on a dusty miller flower. These small dark butterflies actually are cute if not pretty; this is simply an unflattering photograph of one for your enjoyment. E. funeralis is common around here and has been flying in my garden for about a month, since the June gloom burned off the the weather turned warm and sunnier. Its larval food includes various leguminous plants which I don't grow, so the caterpillars are likely in someone else's yard or a nearby untended lot.