A yellow lichen has died

This one turned crumbly before falling off its tree:

Its orange neighbors (see my featured post) seem fine though.

EDIT: all members of its morphospecies have apparently vanished from areas where I have been watering the branches, but one thallus I kept dry as an experimental control appears fine.

Placatory feeding: an overview

Cotinis mutabilis being placated

Welcome to part 1 of the Advanced Entomological Techniques series! More may or may not be coming soon.



Introduction

Unlike many vertebrates, insects and other arthropods often fail to react strongly or at all when they perceive danger. This can result in surreal scenarios; aphids can often be seen right next to sleeping coccinellids, and may even attempt to climb onto their shells! Furthermore, even normally wary taxa may calm down instantly after encountering food, and then become quite oblivious. This is often useful during photography, as feeding specimens generally cease to move.



Chart legends

Placatability:

H = highly placatable; specimens lose nearly all fear when they are fed

OH = often highly placatable; specimens lose nearly all fear when successfully fed, but sometimes may refuse food

S = somewhat placatable; specimens will refuse food when extremely alarmed, and lose some/most fear after successful feeding

F = placatable when force-fed; alarmed specimens will ignore food if they can flee; if they cannot flee, they will feed and calm down. Note that some highly placatable taxa refuse food only when force-fed, and some highly non-placatable taxa always accept it when force-fed.

R = rarely placatable; specimens normally do not accept food when alarmed. However, slightly moribund specimens may sometimes feed (note that heavily moribund insects usually refuse all food, even if normally highly placatable)

N = not placatable


Primary tasting organs:

These elicit strong feeding responses when the insect contacts a food source with them, if it is not sufficiently frightened. Note that many insects are poor at locating food and will only notice it if their primary tasting organs accidentally collide with a food source.

A = antennae

P = palps

L = legs




Placation chart, arranged by taxon

Note that I am unfamiliar with the behaviors of certain taxa, and these may be excluded or contain less accurate ratings. I have based this on local species; your results may vary. Morphologically anomalous species are excluded for convenience. Assume only adults/adultlike young are being discussed, unless otherwise indicated.


ORDER Coleoptera
- Tenebrionidae (adults/larvae): S or OH, A, P
- Elateridae: H, A?, P?
- Carabidae: OH, P; nocturnal spp. may eat in daylight
- Coccinellidae (all): OH, sometimes F, either or both A, P
- Scarabaeidae, Melolonthinae: R, P
- Scarabaeidae, Cotinis mutabilis: OH, P
- Chrysomelidae (adults/larvae): R?
- Melyridae, Collops quadrimaculatus(?): H?, P, A?
- Staphylinidae: R?

ORDER Hymenoptera
OH, A, P, sometimes S, F

ORDER Lepidoptera
- Larvae: either OH or S; primary taste-organs unclear but around mouthparts
- Adult moths, if not mouthless: H, A?, L
- Adult butterflies: OH if F, A? L

ORDER Hemiptera
- Hoppers: N
- Aphids: OH?
- Heteropterans: R, L, A?; however sometimes herbivorous spp. attempt to probe skin

ORDER Zygentoma
- Synanthropic silverfishes: R, A? P?

ORDER Embiidina
S, A?, P? Adult males cease feeding after eating the final molt.

ORDER Blattodea
- Roaches: am unfamiliar, but based on reliable reports from others: OH (at least some), A, P
- Termites: apparently N

ORDER Orthoptera
Highly variable between species; possibilities include OH when F, N, A?, P

ORDER Diptera
- "Classic" (large-eye) flies: OH when F, L
- Gnat/mosquito/midge-shaped: H when F, L, P
- Crane flies: OH when F, P
- "Classic" maggots: OH? Apparently almost completely fearless.

ORDER Neuroptera
- Green lacewings: H when F, P, A?

ORDER Araneae
Salticidae: S? Some species appear completely fearless, H for these
Other free-living spiders: possibly S/R
Obligate web-hunting spiders: N, but Gasteracantha and several others known to OH even when webless

ORDER Isopoda
S/R, A

Diaperis season ends

The Diaperis rufipes fungus has increased the thickness of its unchewed dorsal areas quite rapidly over the past few days. Unfortunately, I saw what appears to be a small vertebrate dropping sitting on top of it! Why do vertebrates always insist on defecating on all the best places?

Diaperis success

A brief reintroduction

Diaperis rufipes is a relatively small and severely understudied fungus tenebrionid, roughly the size, shape, and color of a stereotypical coccinellid beetle. Because it is preferentially nocturnal and its hosts' fruiting bodies are often quite distant from each other, its populations appear highly localized, clustered, and cryptic (probably why it is both understudied and very common near good hosts). Those of you who have been reading the old Splendid Unknowns (before spambot issues put it on perma-lockdown) may be familiar with it from two summers ago; it swarmed in vast numbers on a squishy polypore, eventually fleeing en masse once the host sufficiently rotted (a few did stay behind longer, though). Unfortunately, at the time my phone camera was even worse than it is now and I could not effectively document any science on them. The current fruiting is from the same tree, and I am scrambling to maximize science absorption before it dies again.




So what actually happened tonight?

I found two Diaperis rufipes specimens! Just as well, because the fungal fruitbody probably has not much longer to live (we appear to be in the stage when most of the beetles have fled). In an effort to photograph them, I accidentally launched the first one some distance off its host! D. rufipes appears to clamp tightly onto objects as a major defense mechanism (unlike classic tenebrionids such as Zophobas/Eleodes, which often accidentally fall off tall objects). Ironically, its other two major defenses are deliberately falling off tall objects and producing repellent secretions which smell exactly like those of Zophobas! Fortunately the second beetle was successfully prodded off the fungus and posed well while I fumbled angrily with the lighting.

Bonus video: when flipped, it will spread its elytra and flight wings in an attempt to right itself ("tenebrionids are flightless" is not a completely true statement)

Fun minor observation

Recently even flies have not been visiting the fungus much, but I've noticed that its unchewed meat is pale each morning and slowly darkens during the day; compare this pic with the one in the previous post:

Diaperis rufipes returns

The puffy shelf fungus is back! I found a Diaperis rufipes specimen last night. It cooperated quite nicely for the photoshoot, but my phone camera insisted on all sorts of nonsense (in several instances its AI firmly insisted that kitchen paper was in fact red!) so I don't have any pics worth sharing. At least my small-insect photographs are no longer blurry! In the meantime enjoy some closeups of the fungi and a visiting fly; I plan to do a live or semi-live timelapse video soon.

(the droplets are jelly secretions, not water)

giant lauxaniid, apparently

I find some gray lichens

Update: these are not Phaeophyscia hirsuta.

Some time ago the local park had been specially redesigned for the recent California water conservation program; earlier this month I went there and saw a sign mentioning that the vegetation and sidewalks were carefully arranged to neutralize the "heat island" effect of cities. I saw several lichens during my walk; these were mainly yellow and orange dots on some areas of aboveground concrete/roots and tons of gray foliose thalli on tree trunks (especially the bases).  I was quite thrilled to see further evidence of the "lichen sparsity in urbanized southern CA is caused mainly by heatstroke" hypothesis.



I captured some of the ubiquitous gray thalli (all others were in positions which could easily have been contaminated with vertebrate secretions) and was informed that they were probably Phaeophyscia hirsuta in a mostly hairless phase. Researchgate and JSTOR informed me that P. hirsuta was:

- a facultative nitrophile (it voraciously eats nutrients from car exhaust)
- adapted to xerothermic environments
- apparently an obligate shade-loving species
- also capable of growing on mosses (this probably means that captive specimens can colonize glass/plastic)
- calcium-preferring (fortunately all my water is hard water)

Based on my field observations, it probably makes its xerothermic adaptations compatible with its sunburn intolerance by growing in shaded places with hot air (lawn sprinklers were often nearby, though; one website I visited did say that it was capable of facultatively colonizing mesic areas).



Perhaps even stranger than its fear of sunscorch, however, is its conservation status. Currently it is listed as "globally vulnerable" on iNaturalist. I was initially quite alarmed at this, having taken precautions to only collect hyperabundant weedy species. However, the iNat status seems to be erroneous; all recently published P. hirsuta literature I found agreed that it was common/widespread in CA (phew!) To complicate matters, it is apparently in severe Canadian danger though: https://www.pnwfungi.org/index.php/pnwfungi/article/view/1266



I am keeping my samples in a manner consistent with the above-listed ecological preferences, with a hydration schedule of 12 hrs every two days, and have propped them up on a boiled stick to increase ventilation. Unfortunately the thallus surface is quite hydrophobic and thus has been constantly causing scheduling errors. Hydrophobicity in a lichen implies that the species in question may be vulnerable to excessive water absorption, which interferes with the physics of carbon dioxide capture and thus photosynthesis; however, in captivity the water repellence makes it difficult to water the thalli without violently soaking them. I really need to get a non-moldy mist bottle so I can stop using the tap!

Here are some pics (click to zoom, as always); it took me large amounts of effort to make the photographed colors accurate, and I even ruined several (not shown) samples by accident in the process.

dry (beautiful ivory colors!)

freshly soaked (it greens instantly!)

Unfortunately, more testing is needed. The specimens shown have not visibly grown yet, and I have not fertilized them yet (normal liquid fertilizers are probably a suitable replacement for noxious car gases, though). I have also discovered several dark maculations on some of the thalli, which might be parasitic fungi; they may be scientifically interesting and/or dangerous to the culture. Stay tuned for further updates!













Postscript: bonus research papers

https://link.springer.com/article/10.1007/BF00333715 (Pure acetone can also be used for disinfecting dry lichens non-fatally, which is useful; however it may wash away antibiotics created by the lichen. Fortunately P. hirsuta has no known secondary metabolites)

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2710189/ (Hydrophobicity and pollution tolerance are linked)

Lichens are invertebrates too

Squamulea subsoluta

Introduction

Lichens are well known for their bright colors, fungus-autotroph symbiosis, and ecosystemic value.

Despite their importance, information on "natural" lichen cultivation appears quite sparse. In laboratory dishes, lichen fungi often behave abnormally by failing to capture algae and forming fluffy networks resembling bread mold instead; resynthesis of behaviorally normal specimens has proven difficult. On the other hand, many websites intended for a general audience give poor advice ("lichens cannot last long in harsh sunlight" is easily refuted by the xerophytic yellow Squamulea on my old diving board!), and I have never seen anyone blog about their lichen gardens.

Candelaria pacifica(?)

The "heat islands" hypothesis

Although many species are well known as microhabitat specialists which quickly vanish from even slightly polluted areas, synanthropic lichens do exist. These are naturally more well suited to being captive specimens, since synanthropes are usually adaptable and highly generalistic. I was quite pleased to accidentally encounter the following research paper while half-heartedly foraging in a bibliography:

A simple outdoor culturing system for the foliose macrolichens Xanthoria parietina (L.) Th. Fr. and Parmelia sulcata Taylor

This strongly suggested that most synanthropic lichens could be easily grown as long as they did not succumb to brick poisoning or overwatering-induced rot. Unfortunately, I soon realized that synanthropic lichens seemed not very abundant here in southern California despite many non-poisonous surfaces being available. I became even more confused after a recent trip to the European rainforest, since their cities were covered in thick yellow and minty green coats of assorted species sitting happily next to small cigarette heaps.

My suspicions about CA semidesert aridity  being responsible were somewhat confirmed by an old lichenological bulletin I found after further fruitless searches; most notably, it stated that several microhabitat specialists here grow like weeds in soggy New Zealand!

CALS Bulletin, Summer 2003 (see first article, "urban lichens" section)

Naturally, this suggests a hypothesis: can improving hydration to local synanthropic lichens increase their abundance and biodiversity? I have started watering the pathetic dot and flake colonies in my yard [Update: I am no longer watering them], being careful to:

water only when shade appears, because they lower their defenses during photosynthesis

keep watered specimens wet for extended periods of time, because rapidly going in and out of dormancy harms photosynthetic efficiency

not keep them permanently wet, because dry periods are still important for many species (it facilitates normal morphological development and presumably discourages rot)

So far things have not been going well for them, because I get too excited whenever a cloud covers the sun; often it passes by quickly and I end up inducing fungal sunburn. The captive and wild local vertebrates are also occasionally contaminating most of the clusters with fecal dusts, which may prove useful as fertilizer but are very hazardous (they should dissipate quickly enough for me to not stop visiting the clusters, but I do not dare to bring any specimens indoors).

On a more pleasant note, today I have found more support for my hypothesis.

Collema experiences a massive growth boost when under unnaturally frequent hydration, although it is still slow:

Rapid ex situ culture of N-fixing soil lichens and biocrusts is enhanced by complementarity

in Mediterranean climates (like southern CA), lack of hydration caused by city-induced temperature increase can indeed be a population growth limiter more important than pollution: 

Lichens as ecological indicators in urban areas: beyond the effects of pollutants

Minor entowalk update

I have been quite busy lately, but I finally went on another entowalk in the public garden; the foliage is weedy and quite lush now, but the milkweed had only several(?) dozen unclustered Oncopeltus adults and an adult monarch.

Syrphids (mostly ubiquitous taxa like Allograpta obliqua and Toxomerus marginatus) and coccinellids are still not uncommon though; however, it seems a few Hippodamia have now been accompanying Cycloneda sanguinea.

Slime update

Unfortunately, the spring rains have stopped; I suppose I will have to wait until next year for wild plasmodia and fresh precipitation to appear.

How to catch really large protists

Introduction

The "plasmodial slime molds" (Myxomycetes or Myxogastria) are a diverse group of protists; many species are macroscopic(!) during considerable portions of their life cycles. The large yellow slime Physarum polycephalum is used as a laboratory model organism and is consequently well-studied and widely cultured (it is even commercially available), but many other species appear to be quite understudied in certain areas.

I have recently taken an interest in cultivation of large non-polycephalum myxomycetes. Oddly, this seems to be rarely attempted by anyone (especially non-researchers), despite the fact that many large species are aesthetically attractive and apparently photographed quite regularly by macrophotography hobbyists.



Analysis and current progress

According to this:

Order Physarales has phaneroplasmodia, which are typically large, colorful and conspicuous

Order Stemonitales has aphanoplasmodia, which are macroscopic but also typically transparent and cryptic until shortly before fruiting

Order Trichiales has trichiaceous plasmodia, which share morphological features with both of the above-listed

Order Echinosteliales has protoplasmodia, which are microscopic

Order Liceales was not mentioned; however, in another research article it was stated that the order contained both protoplasmodial and phaneroplasmodial species.


iNaturalist (unlike Bugguide) suffers from severe misidentification plagues; however, it is nevertheless useful for rough estimates. Within California, the most commonly observed species on its website include:

Fuligo septica (Physarales), a massive, ubiquitous yellow synanthrope, often mulch-associated

Lycogala epidendrum (Liceales), which forms puffy reddish fruiting bodies that darken to brown. It is probably large enough to have phanero- and not protoplasmodia; however, it seems largely restricted to rotted forest wood (I am currently unable to access forests due to various reasons, including severe dung contamination)

Enteridium/Reticularia lycoperdon (Liceales): round, white, large; according to this British paper, it is also found on rotting wood but is at least somewhat synanthropic.


Current slime-collection efforts have focused largely on F. septica due to its highly synanthropic behavior and conspicuous plasmodia. Despite the presence of intermittent rains for several weeks (Fuligo requires copious moisture for its large plasmodia, and I live in a semidesert), I have failed to detect any plasmodia in various small mulched flowerbeds. Perhaps the local public garden may be a more suitable area for exploring, as several iNaturalist Fuligo observations were located there.