Wasps!

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Dead wasps are the best wasps.

Wasps, hornets and yellow jackets that get established within landscapes or buildings are a serious problem. They are not so easily avoided like those out in the wild are. They are aggressive to people and pets who get too close to their nests, and attack with painful stings. Such behavior is unacceptable within the publicly accessible landscapes at work.

There are a few species of wasp, hornet or yellow jacket here. We do not get sufficiently acquainted with any of them to actually identify them. Our priority is eliminating as many of them as possible from the landscapes. Some get trapped. Others get evicted from the few nests that we locate. It is unpleasant work, but it is better than others getting stung.

Wasps, hornets, yellow jackets, or whatever they are, become more of a problem later in summer. They are just getting started for now. We were surprised to find two subterranean nests in a landscape that is in the process of being cleared for renovation. More surprisingly, they were only eight feet apart. Whomever they were, they should have been more territorial than that.

Since they are just getting started, there were not very many to get aggressive when we got too close to them. There were scarcely enough to follow as they entered and emerged from their nests. They were surprisingly easy to kill. The first nest was quite small. The second nest was a bit more concerning. We dug both out as the last few visible insects were dying.

The picture above shows a few waffle-like layers of the larger nest. Empty cells were likely left by the adult insects that were flying about and trying to defend the nest. Other cells are full of larvae that would have matured to many more of the same!

Horridculture – Pesticide

P90828Pesticides are a topic that I do not talk much about. There really is not much to say about them. Only a few are used at the farm, and only while certain destructive insects or perhaps mites are active. Even less pesticides are used in the landscape. It is not that I have serious issue with them. They are just not as useful for controlling pests as proper horticultural techniques are.

Plants that we would expect to require pesticides simply are not welcome in our landscapes. We know that snapdragons and hollyhocks are very likely to be detrimentally infested with rust. Therefore, we grow neither.

Roses live in some of the landscapes only because we do what we must to help them avoid infestation by the various pathogens that they are susceptible to. They get pruned aggressively in winter so that their new growth grows faster than aphid and mildew that try to infest them in spring. Their fallen foliar debris that fungal pathogens overwinter in gets raked away cleanly.

On rare occasion, we find weeds that we would like to kill with herbicide; but we can’t because they are too close to riparian environments. With two creeks and two streams flowing through here, many of the landscapes are too close to water. We must instead pull the weeds that we can, and hope that more aggressive cover crops overwhelm what remains before they recover.

One of the few insect problems that we sometimes notice is the thrip on the rhododendrons. They are sort of always there, but had been tolerable. Aggressive pruning to stimulate vigorous new growth, and also improve air circulation, should have inhibited the thrip. Instead, the damage has been worse than it has been in a very long time. It was necessary to spray insecticide.P90828+The pictures above and below show the worst of the damage caused by thrip. The picture below compares damaged foliage on the left to undamaged foliage on the right. Thrip rasp the foliar surfaces so that they can lap up the juices within. The process causes silvery discoloration, and ruins the foliage. Young damaged foliage is likely to get crispy around the edges, or get shed.P90828++For this sort of damage, I do not mind using insecticide. However, I have doubts about this particular insecticide, or whatever it is. It is supposed to be three in one; insecticide, fungicide and miticide. How is that even possible? Insects, mites and fungi are physiologically completely different. Anything that kills all three must be very nasty stuff! Yet, it is somehow safe for bees?!

There are several active ingredients, but I do not recognize many of them. I suppose that some could be insecticidal, some could be fungicidal, and some could be miticidal. The label does not explain the functions of the various components. None are hazardous enough to warrant a use permit like we need for agricultural pesticides. This product is available at the hardware store.

I do not doubt that this nonselective ‘pesticide’ is safe for bees, even though it is supposedly formulated to kill just about anything that might bother the rhododendrons. However, since it will not kill bees, and bees are insects, I do sort of doubt that this product will kill many other insects, including thrip.

 

Incidentally, I am sorry for the delay of posting my weekly ‘Horridculture’ rant, which should have posted yesterday. It normally posts on Wednesdays. The article that posted yesterday really should have posted today instead.

A Bee See

P90609They were impossible to miss. They came at a weird time too.
As guests were arriving for a big event, a fire alarm was activated, and compelled everyone to leave the building that they were gathering in. The swarming bees met the guests as they came outside. The bees just happened to show up in the same place and at the same time as the guests were forced outside. Fortunately, no one seemed to mind, and some found the swarming bees to be compelling enough to stop and take pictures.
Initially, all the bees were flying in a big swarm. Those closest to the middle of the swarm were flying fast, sort of like angry wasps. No one saw the queen that the swarm was centered around, but she apparently landed on this redwood limb about forty feet up. The swarming bees slowly collected in this mass around the queen. By the time I took this picture, almost all were attached to the mass, with only a few still flying about.
At least three swarms started to establish new hives in buildings near here last year, and needed to be removed by beekeepers. One hive started to develop where another had just been removed. Another swarm was removed before establishing a new hive.
Bees seem to be attracted here. Perhaps they appreciate all the flowers in the landscapes. It is unfortunate that they can not stay where they typically try to move in. Most of us really like them.
This swarm was still here when I left, so I do not know what happened to it afterward. Hopefully, it either left the area, or at least moved into a place where it will not be problem, such as in a rotten tree trunk out in the forest where bees belong.

 

Plant Problems Are Sometimes Exaggerated

04It is not easy for wild trees to adapt to a refined landscape. After a lifetime of adapting to their native environment and dispersing their roots to where the moisture is through the dry summers, they must adapt to all sorts of modifications such as excavation, irrigation and soil amendment. Newly installed plants grow into a new landscape while some mature trees succumb to disease and rot.

Oak root rot is such a common disease in California that there are only a few places where it is not found in the soil. It is not often a problem to new plants, but often becomes a problem to mature trees that suddenly get more water than they are naturally adapted to, particularly if roots have been violated, and the soil has been amended to retain more moisture. Change is not always good.

However, many of the same trees that are so susceptible to oak root rot if the environment around them changes can be remarkable adaptable as young trees. California sycamore happens to be a riparian tree that naturally grows near water. Although old trees may not adapt well to change, young trees planted in new landscapes will adapt to the water that is available as they mature.

California sycamore trees that are adapted to landscape or lawn irrigation are not likely to be bothered by oak root rot until they get old. Realistically though, any old sycamore is susceptible to oak root rot. The only difference is that those that get more water mature faster, so get old sooner. A California sycamore tree planted into a home garden may live only one century instead of two.

Verticillium wilt is another disease that can be found in most places throughout California. It is notorious for severely disfiguring and killing ash trees and many other plants. However, it needs moist soil in which to proliferate. Because lawns are irrigated so frequently and often excessively, ash trees in lawns are innately susceptible to verticillium wilt. In situations that are not irrigated so frequently, newly planted ash trees can mature into healthy shade trees.

Just When You Thought It Was Safe To Go Back To The Park –

P80722You would think that those who maintain the County Parks would be prepared for anything. They nearly are. They know how to deal with gophers, moles, voles, weeds, flooding, all sorts of unpleasant weather, and of course, spontaneous limb failure of massive trees. They apparently did not plan for this one.
This improvisation with a bit of dirty old plywood and a felt marker certainly does not imply that they could not handle the situation. They merely lacked a sign to warn those in the Park to avoid the area where the now exterminated yellow jackets had started to build their subterranean hive. Some brave person already attacked the hive with a can of insecticide that can be sprayed from a distance, waited for returning yellow jackets to die, and finally dug the hive up. The sign is only there because of the possibility that some yellow jackets might return much later, and that those who could return may not die now that the excavation of the hive mixed soil with the insecticide.
This was NO simple task. Yellow jackets and wasps are NASTY! I found it necessary to exterminate a hive of wasps just last summer. Wasps do not pursue their assailants so aggressively, and the particular wasps that I exterminated were not so numerous. I am certain that it was considerably more risky for whomever sprayed and dug the hive that was below where this warning sign is now.
When yellow jackets and wasps are flying about and annoying people, but their hive can not be located, it is sometimes necessary to put out traps. These traps are particularly useful in trees that are infested with scale or aphid that excrete honeydew that attracts wasps and such. The instructions that come with the traps are rather amusing. They include a rather extensive list of the various species and varieties of wasps and yellow jackets, with pictures of their distinctive coloration and patterns, so that they can be identified. I do not want to get acquainted with them. I just want them DEAD!P80722+

Dead Box Elder Update

P71223P71223+What is killing the box elders? (https://tonytomeo.wordpress.com/2017/10/04/what-is-killing-the-box-elders/) I still do not know. I know that does not sound like much of an update. All I can share is some pictures of secondary symptoms observed now that the affected trees are deteriorating.

The two pictures above, although not relevant to any symptoms, are important to our Community because the historic Felton Covered Bridge just got a new roof! (https://tonytomeo.wordpress.com/2017/12/02/felton-covered-bridge/) Dead box elders that are already starting to destabilize and collapse are now leaning onto the edge of the new shingles! They really need to be removed before winter storms move them around, and they dislodge any shingles.

The first of the two pictures below show basidiocarps associated with fungal decay of the trunks and roots. This decay destabilized and compromised the structural integrity of the necrotic trees with remarkably efficiency. The trees died only last spring, and are already collapsing! The second of the two pictures below simply shows decaying bark peeling from a necrotic trunk.P71223++P71223+++

This all happened so suddenly. Like SODS (Sudden Oak Death Syndrome) it is likely to be misdiagnosed a few times before the primary pathogen is actually identified. Also like SODS, it may be ignored as an isolated situation affecting a few trees that are not very popular anyway. When SODS first started killing a few of the unpopular tanoaks, it did not seem like much of a problem. It did not get much attention until it started taking out majestic coast live oaks that had been healthy for centuries.

The two pictures below show a cross section of a necrotic trunk that needed to be cleared from a bridle trail. Galleries have been excavated by the larvae of unidentified boring insects. The second picture is merely a closeup of the first.P71223++++P71223+++++

Butterfly

P71022Before you send me a comment about it, I am already aware that this is a very bad picture. It was taken with my primitive telephone because it was convenient at the time. This tired looking butterfly might not have waited for me to get the camera. It passed away, seemingly peacefully, right there on the hood of the old Chevrolet. It did not seem to be injured in any way. It probably simply expired like butterflies do after breeding. It is a natural process that the butterfly did not seem to be too distressed about. It gets no obituary because I am not qualified to write one. We are not sufficiently acquainted. I do not even know the specie of this butterfly.

Now that he or she is deceased, I ponder the beauty of these insects. They are so graceful and very colorful. They flutter about like animated flowers. Everyone likes them. Some of us grow flowers that attract them to the garden, and plants to sustain their baby caterpillars.

All flowers are designed to appeal to their pollinators of choice. Those that are pollinated by wind lack color, fragrance and other bling, but are very abundant. Those that are pollinated by flies smell like what flies like. Those that want to attract nocturnal pollinators are fragrant, luminescent (with ultraviolet patterns that are invisible to us), and open at night. Bee pollinated flowers use infrared patterns, and lots of other colors that bees like, and reward them with nectar and superfluous pollen. Well, you get the point. Floral structure, size, patterns, color, fragrance and schedule are all designed around pollinators.

It is difficult to say what butterflies like. They visit such a variety of flowers. Some have abundant pollen. Others have a bit nectar. Some are tiny flowers in dense groups. Others are larger composite (daisy-like) flowers. Butterflies can see both infrared and ultraviolet color, so it is hard to know what they see in flowers.

Some of the clustered small flowers that butterflies like are alyssum, fennel, goldenrod, phlox, Queen Anne’s lace, verbena, yarrow and of course, butterfly bush. They also like flower of the mint family, such as bee balm, lavender, oregano, rosemary and the various sages. Their favorite composite flowers include aster, calendula, cosmos, marigold, coneflower, zinnia and all the daisies and sunflowers.

What Is Killing The Box Elders?

P71004Remember our concern about the mistletoe? (https://wordpress.com/view/tonytomeo.wordpress.com) You might think that everyone would be pleased to see it gone. Yet, there is the concern that whatever killed the mistletoe might kill something else. That is what happened when the SODS killed so many coast live oaks after being ignored for a long time in the tan oaks. We were aware that the tan oaks were dying, but because the trees were so unpopular, we were not too concerned about it.

Now the box elders are dying around Felton. It is hard to say how widespread the problem is because it has not been investigated yet. Like tan oaks and mistletoe, the native box elders are not exactly popular trees. They do not even make good firewood. We only use them as firewood to get rid of them. However, when so many are die, it leaves big holes in the forest canopy. This is not really a problem, since the forest will have no problem filling the holes in, but it certainly gets our attention. Will the disease or insect pathogen that killed the box elders kill something else next?

The trees seemed healthy as they defoliated last autumn. They were bare through winter when the San Lorenzo River came up higher than it had since 1982. A few box elders got taken away by the River, along with all sorts of other riparian trees from the flood zone, but that is to be expected. Then, after the River receded, many box elders that were in the flood zone did not foliate in the spring. A few foliated, only to have their new foliage shrivel and die shortly afterward. Some of the dead trees became infested with boring beetles. All of the dead trees deteriorated rapidly through summer, and some have dropped big limbs or fallen over.

What is happening with the box elders could be completely normal, and caused by an endemic pathogen; but it makes one wonder. There are so many new insects and diseases being brought in with plants arriving from all over the world, without any regulations to limit the spread of such insects and diseases.P71004+