Observaciones de arbonius

[Note: Due to iNat's upper image-size limit of 2048 x 2048 pixels, I've reduced the longest side of some of the original photos to 2048 pixels, and then included crops following those images that render here at the highest resolution I had.]

I think this is a cerambycid larva...or perhaps some other sort of wood-boring beetle larva?

As best I recall, it was found underneath outer bark and it's seen wandering on the now-exposed surface of the inner bark (for context, see tree section diagram here). I'm thinking the little brown pellets scattered on the surface may be frass from previously chewed & digested wood by it and/or various other sub-bark denizens?)

Scrutinizing the photos will reveal that this larva has impressive black mandibles; tiny antennae and palps; and also three pairs of tiny thoracic legs...each with 3 segments, the terminal one bristle-like.

In the full-size cropped images showing the abdomen, it's remarkable how translucent the cuticle is in some areas...and how clear the internal fluid is. Within the cuticle, one can see lots of white, pill-shaped blobs (fatty deposits? miniature organs? egg primordia?), and an intriguing network of fine, white, divaricating strands reminiscent of arteries. But insects don't have a vascular system for "blood" (i.e. haemolymph)...and I think those "arteries" are actually the tracheal system of branching tubes that lead from the spiracles to the interior, and provide oxygen via diffusion for cellular respiration. Spiracles are visable here as small orange ovals at "mid-height" on each abdominal segment...with a much larger one visible mid-way up the mesothoracic segment above the middle (mini)leg.

From the heft here I'm thinking this is a late instar (maybe final); and from the translucence, recently molted.

We came across this mating pair hovering in a "sun-speck" along the creek-adjacent, woodland trail/road though Mitchell Canyon. To the naked eye it wasn't entirely clear what it was, though I thought I could make out a foamy "nuptial gift" (suggesting a balloon-bearing empidid).

However, I didn't realize it was a mating pair until zooming-in on a photo on the camera display. We observed the two in (roughly) "stationary hover" for over two minutes...don't know how long they were hovering before we noticed them.

After posting this, I noticed @kueda made a very similar observation very nearby about 9 years earlier (with nice accompanying info, and a wonderfully sharp image!)...as did @abmdjoe about 3 weeks earlier here. Seems there's a stable population in the area :-).

This little Ceratina was resting calmly (and cooperatively ;-) on a flower of Lithophragma affine. It looks like some sort of (true) bug was perched on the upper-outside edge of the same flower. In the first photo, at full-size, one can discern the green-metallic sheen of the integument.

The presence of a bright-green squamulose thallus and podetia with distinct, avocado-green "apotheica cups" seems to clearly indicate genus Cladonia, but I couldn't arrive at a good species hypothesis (my best try was C. pyxidata...but that doesn't seem to fit altogether well).

Nectaring (and picking up a lot of pollen!) on flowers of buttercup (Ranunculus californicus).

The last picture shows the tip of its proboscis tucked under a fold/flap of tissue at the base of the petal that seems to represent a nectary-structure of R. californicus that I wasn't previously aware of.

Resting on a leaf of bee plant, Scrophularia californica...in a cool, shady, north-facing canyon woodland.

More info on the BugGuide species page here. Alice's observation (from east of Sacramento) show better detail for the upcurved, orange palps.

Powell & Opler(2009) indicate it's a "European immigrant" first found in California in an El Cerrito backyard in 1966, and reared the following year by Powell from black caterpillars found under bark of Quercus agrifolia in the Berkely Hills, 5 km from El Cerrito. By their 2009 publication date, Powell & Opler indicated it had been detected in Marin, Sonoma, and Napa counties.

The current iNat records map inset suggests it now reaches much further...i.e. east to Sacramento & beyond in Nevada City; north as far as Arcata; and south to Los Osos. And BugGuide currently has 2 Oregon posts from Corvallis & Portland. (But I'm not certain whether my and all the aforementioned posts are correctly ID'd...perhaps some represent similar-looking members of other species? Here's an enlarged version of the reference photo appearing in Plate 4.32 of Powell & Opler...and the "Moth Photographer's Group" species page.)

Based on attempting to photo-match using Sharnoff(2014) and McCune & Geiser(2009)...my best shot at ID here is Xanthoria parietina. Earlier I was thinking it might be the similar-looking Xanthomendoza hasseana.

Growing on a twig (of Quercus agrifolia?) in mesic, north-facing slope, canyon habitat. Appeared next to other lichens seen in 2nd photo...among which, I think, are Ramalina subleptocarpha (iNat obs 202609608)and Teloschistes chrysophthalmus (iNat obs 202611142).

These were spotted by @oceanf on herbaceous stems in grassland along the road side on the ridge.

I think they're braconid cocoons of the subfamily Microgastrinae...see the remarks on this university extension web page...and BugGuide search results for immatures of Microgastrinae.

An interesting photo on the Microgastrinae Wikipedia page shows cleanly circumscissile exit holes...whereas the fascinating video here shows little wasps exiting at more random and irregular spots on the cocoons.

But the wasps in the video are not the microgastrines that formed the pupae...but rather chalcidoid (hyper)parasitoids of the braconid parasitioids. This conclusion is reinforced by noting that:

• microgastrines have longer antennae than the wasplets in the video,
• microgastrines are generally not metallic green, and...
• microgastrines have very different wing venation.

One has to scrutinize the wasplets in the video closely, but if you do you'll notice their wings have hardly any veins at all...and only a tiny vestigial "(ptero)stigma" (e.g. see diagram at bottom of page here). Microgastrines, on the other hand, have numerous "closed cells" in their wing venation pattern...and a large black spot (or "pterostigma"...cf. here about halfway out on the leading edge of the forewing). One can verify these points by perusing many images of adult microgastrines here.

===== Habitat & Habitus of Plant =====

A small group of these plants were clumped at the side of a dirt road in a somewhat disturbed area of Baccharis-dominated coastal scrub. The main plant in view had somehow been "knocked over" but still remained well-rooted and seemed vigorously alive. It was very robust, with repeated-branching just above its base...the branches being thick and very tough (though not truly woody). This individual seemed more like a biennial than an annual. For scale, the blue walking pole is 135 cm long.

===== ID Notes =====

I've recently become somewhat fascinated with the weedy and worldwide-distributed "former-Conyza" species that occur in California. These are: the native Erigeron canadensis; and the non-native (originally South American) E. bonariensis, E. sumatrensis, and E. floribundus (preceding links lead to Wikipedia pages, which give useful info). Although these are not particularly glamorous plants, I'm intrigued by the "disciform" morphology of their flower heads...i.e. having numerous (rather than a single) series of pistillate flowers on the periphery of each head...and, except for E. canadensis, with those pistillate flowers having corollas that are filiform tubular (rather than the "strap-shaped ligules" found in the common daisy-like, or "radiate", members of Asteraceae).

There are lots of informative references & keys in various floras, and on various web sites, addressing how to separate these species. Some that I've found especially helpful are: the Jepson eFlora couplets 9-13; the paper Leaney(2017); the FNA Conyza treatment; and Nesom(2018). Note that the Jepson treatment considers E. floribundus a synonym under E. sumatrensis (and the FNA vice-versa!)...while Neson(2018) asserts E. floribundus is distinct and occurs in a number of CA counties (including San Mateo).

At any rate, here are four characters that support the ID of E. sumatrensis here:

1) The pistillate flowers here (in multiple peripheral series) do not have conspicuously long and wide ligules (as they do in E. canadensis).

2) In a number of heads examined, almost all the disk flowers had 5 lobes. There was one with 6 lobes...but none with 4 lobes. (In E. canadensis most disk corollas have 4 lobes.)

3) The phyllaries here had fairly dense, fine hairs. (In E. canadensis & E. floribundus the phyllaries are typically less hairy, to almost glabrous.)

4) In the last photo of the series, note the red "ribs" on the 3 achenes which are lying horizontally atop the fruiting head. Those red ribs are diagnostic for E. sumatrensis according to the Jepson eFlora key and species description (i.e. see last item in lead 13' and the entry for "Fruit" here).

I think E. bonariensis can be ruled out here...its heads are usually: "chunkier" (e.g. as wide as tall); have a distinctively almost uniform-width band of red-to-purple phyllary tips; and have a distinctively wider peripheral "rim" of pistillate flowers (e.g 5+ series) which noticeably exceed the height of the central disk flowers (giving the gestalt of a peripheral "fat lip" with a "depressed central area" to the heads).

The Jepson eFlora treatment doesn't currently recognize E. floribundus (though, again Nesom(2018) does)...but that species is said to have nearly glabrous phyllaries (unlike here) and those phyllaries are wider and less numerous (when viewing a flower head in profile) than seen here.

This colony of exquisitely beautiful mushrooms was found on the north-facing side of a large, standing tree trunk...a bit above head height. The mushrooms were small (I'd estimate < 30 mm?).

Their form fits well with the description of "pleuritoid" mushrooms here. Based on that, and study of resources on the MykoWeb website, I settled on a putative ID of Crepidotus amygdalosporus (description; image...both from the MycoWeb presentation of Hesler & Smith(1965)). I especially liked Hesler & Smith's description stating that the pileus was: "white, pubescent or tomentose, base byssoid"...and how that matched the distinctive tufts of long, erect, silky "hairs" which I had noticed were visible at the base of the pileus in my photo. (I had to look up the meaning of "byssoid", which is derived from the word byssus...and seemed to match those "tufts" perfectly.)

Turns out that C. amygdalosporus has been synonymized under C. caspari (e.g. see here). That had been a prime candidate when studying my copy of "California Mushrooms" (treatment reproduced here)...though no mention was made there of the basal "byssoid" tufts (and the gills seemed more densely-packed in their accompanying photo), so C. amygdalosporus had seemed a better choice. On the other hand, Hesler & Smith(1965) gave mainly eastern U.S. records for C. amygdalosporus, while the MycoWeb page confirmed its presence (as C. caspari) in CA.

On a wonderful field trip w/ Steve Matson, a number of us enjoyed puzzling over these woolly stem galls found on shrubs of Tetradymia glabrata, in the family Asteraceae. (See Steve's photos here.)

Searching the literature for gall-inducer candidates known on Tetradymia, I found just one gall midge species (family Cecidomyiidae, Diptera) and three moth species (family Gelechiidae, Lepidoptera).

The cecidomyiid candidate was found by doing a host plant word search on "Tetradymia" within this PDF for Gagné & Jaschof's 2021 catalog of Cecidomyiidae. It yielded only one species, Dasineura tetradymia (= Phytophaga tetradymia = Rhopalomyia tetradymia). Unfortunately, I was unable to find online access to Felt's 1925 original description (on BHL, access to the journal it appeared in stops at 1923).…and very little info is available for it online. The best I could find was this "Gallformers" page...which indicates D. tetradymia forms a woolly, ovoid/globular, lateral bud gall recorded on T. comosa...and that it's polythalamous (= many larvae per gall).

The gall larva here was solitary. And note that cecidomyiid larvae are legless...and have a tiny, black, narrowly-conical head capsule, which is usually largely retracted and only visible as a tiny black "dot"...cf. these BugGuide posts: CL1, CL2, CL3.

In constrast, scrutinizing the larval photos here reveals the presence of 3 small, black, pencil-tip like, larval (true) legs...and a head capsule that's fairly-large and roughly hemispherical (& heart-shaped above). Those characters rule out a cecidomyiid here, but conform well with a moth larva (cf. the gelechiid larva images GL1, GL2).

Ron Russo's recent gall book lists just two gall species associated with Tetradymia, namely: 1) Scrobipalpopsis tetradymiella (MPG, BOLD, Essig, iNat) recorded on T. stenolepis; and 2) Eurysaccoides gallaespinosae (MPG, Essig) recorded on "Tetradymia sp.". Both species are characterized as making stem galls, and both are members of the tribe Gnorimoschemini, in family Gelechiidae. These two species names only appear in a table in Russo’s book, with no additional info given. The same two species are also the only ones associated with host plant Tetradymia in the paper Powell & Povolny(2001) [see “Appendix 2” here]. Like Russo, they associate S. tetradymiella with T. stenolepis, but also cite T. canescens as a host plant (the latter being the host plant given for the type specimen in the original description as Gnorimoschema tetradymeilla by Busck from 1903). And they list T. spinosa as a specific host for Eurysaccoides gallaespinosae. I don't know of any key separating these two gelechiids. The original description of E. gallaespinosae appears in the paper:

POVOLNY, D. (1998): Neopalpa Povolny, gen. n. and Eurysaccoides Povolny, gen. n., two new genera of the tribe Gnorimoschemini from California with the description of three new species (Lepidoptera: Gelechiidae).– SHILAP Revta. lepid., 26(103):139-146

So far I've been unable to access that paper (it’s in an open-access journal, but the online archive of past issues currently only goes back to 2019). The adult type specimen for E. gallaespinosae is at the California Academy of Sciences, and two adult images appears on this BOLD page…but those don’t help in trying to ID a gall or larva photo. I’m hoping Povolny(1998) will help clarify some useful distinctions between the galls (and maybe even larvae) of the two species.

Note that there are currently a number of Tetradymia stem gall observations on iNat placed under S. tetradymiella. I wasn’t able to find any remarks/comments under those observations addressing why and whether or not they might be E. gallaespinosae? The iNat observations have a wide range of variation to my eye…from narrowly spindle-shaped and very “furry” to spheroid or watermelon-shaped and less hairy to glabrous. Much of that variation might be attributed to phenology, presence of parasitoids or inquilines, or other eco- and/or environmental factors...which brings me to the next item here.

In 1984, H. Hartman published a three-part series of papers on gelechiid galls on Tetradymia...the most pertinent here being his first paper on “gall size and shape”. Hartman focused on the ecology and variation of both the stem galls of Gnorimoschema (=Scrobipalpopsis) tetradymiella...and also the leaf galls of an undescribed gelechiid moth species he referred to as ”Scrobipalpa sp. n.". Hartman indicated that:

"leaf galls were hollow sessile green spheres when new, becoming wrinkled and
brown after drying."

Both galls were observed occurring on Tetradymia stenolepis, T. axillaris, and T. glabrata (and, he seemed to suggest, other Tetradymia species as well). Hartman noted substantial variation in gall shape & size and made various measurements and statistical analyses in an attempt to correlate that variation with the different Tetradymia host species & various ecological/enviromental variables. The variation Hartman reported may help explain some of the significant variation apparent in the iNat stem gall observations currently placed under S. tetradymiella…but how Povolny’s E. gallaespinosae fits in here is still a mystery! In particular, some of the current iNat observations may correspond to E. gallaespinosae.

Also, given the current number of Tetradymia stem gall observations...it's somewhat surprising no observations of Tetradymia leaf galls have been made. Hartman seemed to suggest the leaf galls were perhaps as common as the stem galls (though presumably smaller & less conspicuous). Note that Hartman's interests focused on ecological questions rather than taxonomy...and the leaf gall inducer he referred to as "Scrobipalpa sp. n." may still lack a formal name/description.

One last note. Some members of the dipteran family Tephritidae form stem galls...and according to Foote, Blanc, and Norrbom(1993), there are two tephritid species, Trupanea jonesi and Trupanea nigricornis, that use Tetradymia (and a number of other genera in Asteraceae) as host plants. However, these two species are not among the gall-inducing Trupanea. Their larvae simply feed on immature ovules and achenes within flower heads. Like most "higher diptera", tephritid larvae are legless and have tiny, pointy, black head capsules (cf. TL1, TL2). Keep an eye out for these too when in the field enjoying the wonders of Tetradymia ;-)

The orange dendritic & anastomosing network that is spreading over the litter of maple leaves & twigs here is the streaming (pseudo?)plasmoidial phase of an amoeboid myxomycetes (AKA "slime mold"). I think this is a late stage of the process, that begins as a uniformly-filled, forward-moving area, then gradually retracts onto a more reticulate, arterial-like network as the sheet of protoplasm advances. I'm not sure whether this is a gigantic, multi-nuleate, single-celled organism...or a multicellular aggregation...apparently that depends on the what taxonomic group of Myxomycetes this is (which I don't know how to determine).

For more info, see the online botany textbook chapter here and the nicely illustrated newsletter article here. A more thorough resource is:

Stephenson, S.L., & Stempen, H. (1994). Myxomycetes: A Handbook of Slime Molds.

These (super?)organisms are totally fascinating!

Note the dark color of the dorsum extends below the lower eyelid, engulfing the entire eye...which suggests Taricha granulosa. See the CaliforniaHerps Taricha page for more ID details.

Various prey species recorded for T. granulosa are listed on pp.18-19 of Stebbins(1951). Note that they include both terrestial and aquatic organisms...indicating T. granulosa feed in both their terrestial & aquatic life history stages.

Interestingly, Packer(1961) indicates that the congener T. rivularis only feeds in its terrestial phase (it has a shorter aquatic phase while mating in more robustly flowing streams than T. granulosa and T. torosa. The latter two species mate and oviposit in ponds or calmer portion of stream habitats...and spend a longer period in their aquatic stages.

A number of these ambush bugs where present on flowers of Solidago californica. Working with the helpful paper Masonick & Weirauch (2020), I arrived at Phymata metcalfi.

Males appear to have darker (black) maculations, and females a more orange ground color.

This observation is from same time/place/population as iNat observations 186816069 and 180454275.

A number of these ambush bugs where present on flowers of Solidago californica. Working with the helpful paper Masonick & Weirauch (2020), I arrived at Phymata metcalfi.

Based on the reference images in the key and species descriptions in Masonick & Weirauch (2020), my impression is that the decidely dark-black maculations here indicate a male.

This observation is from same time/place/population as iNat observations 186816959 and 180454275.

@uropappus (iNat obs 180455233) spotted a large number of these rather small beetles feeding & mating on the gently-rounded flower platforms of "yampah" (genus Perideridia...and species parishii, I think, as the leaves were all strictly ternate).

Using the key in Art Evans' wonderful western beetles book...and based, among other things, on the: elytra long (covering nearly the entire abdomen); antennae narrowly moniliform/filiform; and hind legs with 4 tarsi...I got to Tenebrionidae (a family I would not have guessed here...as in my prior experience they've been larger, chunkier, flightless, ground-rovers not associated with flowers). Perusing the photos in Art's book, and cross-referencing with BugGuide, I'm fairly well-convinced this is in genus Isomira from the overall gestalt (e.g. shape of the pronotum, elytra, palps, legs, color, etc.).

From the 2018 Catalog of Tenebrionidae here (see pg. 252) there are 5 species of Isomira known from California: I. comstocki, I. damnata, I. luscitiosa, I. monticola, and I. variabilis.

I. damnata was described in the paper Marshall(1970c), which I was unable to access [bibliographic details under "Print References" here]. The other 4 described CA species (and some of their synonyms) appear in the key and discussions of Casey(1891) and Papp(1956). The BOLD web site has images placed under I. comstocki, I. damnata, I. luscitiosa, and I. variabilis. Species determination in this genus appears to be difficult (due to subtleties/nearness of described distinctions & variation?). As such, I don't see an especially compelling fit with any particular one of these 5 species....but that's OK by me since, with insects, I'm often happy to get to genus ;-).

Note that the antennae seem to be consistently bicolored here (pale tawny/rufous on the proximal few antennal segments & blackish on the distal ones). I haven't noticed such bicolored antennae in other Isomira posts.