Our oldest third instar Oregon Swallowtail caterpillars (Papilio machaon oregonius) have ecdysed into fourth instar. Admittedly, there hasn't been too many interesting observations to make about our Oregon Swallowtail caterpillars so far since they are almost identical to Anise Swallowtail caterpillars which we have raised thousands of. However, during the third instar, the caterpillars seemed slightly larger and lighter in color than typical anise swallowtail caterpillars raised under the same conditions and we suspected from the start that a main phenotypic difference between the two species' larvae was in their color based on internet searches. Anyway, today, two of our Oregon Swallowtail caterpillars molted into fourth instar, and we were amazed to see that both were green morph fourths, one being very green and the other somewhat whitish green. This is a clear difference between the two closely related species, as Anise Swallowtail caterpillars are typically black in the fourth instar when raised indoors and are only green when subject to very high temperatures and low humidity. In fact, we have only ever had a single indoor raised green morph fourth instar Anise out of thousandss we have reared. Thus, the fact that two of two of the fourth instar Oregon Swallowtail caterpillars reared under the same conditions as Anise are green is clearly not a coincidence and must be typical of the species. Since the Oregon swallowtail caterpillars are already green in the fourth instar, we assume they will be very green fifth instars with extremely thin black bands since this is typical of fifth instars produced from green morph fourth instar Anises. When speculating from an evolutionary standpoint, it would make sense for the oregonius caterpillars to be more green in the final instar with very thin black bands since most non-umbel feeding Swallowtail larvae are green with no black bands. The machaon group Swallowtails diverged from Rutaceae feeding Swallowtails by jumping onto Apiaceae, or umbels (possible due to phytochemical stimulant similarities) and all have very characteristic black bands and yellow or orange spots in the final instar unique to other Swallowtail larva which make them quite cryptic on umbels. However, since switching over to umbels, some of the machaon group swallowtails such as oregonius now almost exclusively utilize Artemisia in the wild rather than umbels, again due to phytochemical stimulant similarities. Thus, since oregonius no longer feed on umbels any more, their once cryptic black bands are probably not very cryptic anymore and thus greener caterpillars with thinner black bands are more cryptic and have higher fitness. Don't quote us on any of this though, since these are pure speculations that came to mind when comparing oregonius to zelicaon. - Alan
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Timeline 2012–2017
Albany, California This timeline is a series of daily posts recording our observations on and experiences with various insects in Albany California and surrounding areas, from 2012-2017. Since we did not publish this site until 2016, posts before that were constructed retroactively. Starting in August 2017, we moved to Ithaca, New York; posts from there on can be viewed at Timeline 2017-present: Ithaca, New York. Archives (1,011)
August 2017 (49) July 2017 (121) June 2017 (79) May 2017 (77) April 2017 (91) March 2017 (35) February 2017 (12) January 2017 (10) December 2016 (12) November 2016 (26) October 2016 (49) September 2016 (84) August 2016 (94) July 2016 (99) June 2016 (53) May 2016 (21) April 2016 (4) January 2016 (1) August 2015 (3) July 2015 (3) June 2015 (2) June 2014 (3) May 2014 (1) April 2014 (3) March 2014 (3) December 2013 (2) November 2013 (2) October 2013 (5) September 2013 (11) August 2013 (15) July 2013 (9) June 2013 (5) May 2013 (4) April 2013 (3) March 2013 (2) February 2013 (3) January 2013 (2) December 2012 (2) November 2012 (1) October 2012 (2) September 2012 (2) August 2012 (5) July 2012 (1) June 2012 (1) Authors
![]() ![]() Full Species List (Alphabetical by scientific name) Note: - Not every species we encounter is necessarily presented on this site, rather a selection of those that were of particular interest to us and that we felt were worth documenting. - We can't guarantee that all species have been identified accurately, particularly taxa we are not as familiar with. Lepidoptera Actias luna Adelpha californica Agraulis vanillae Allancastria cerisyi Antheraea mylitta Antheraea polyphemus Anthocharis sara Argema mimosae Attacus atlas Battus philenor hirsuta Bombyx mori Caligo atreus Callosamia promethea Coenonympha tullia california Citheronia regalis Cricula trifenestrata Danaus plexippus Eacles imperialis Erynnis tristis Estigmene acrea Eumorpha achemon Eupackardia calleta Furcula cinereoides Heliconius erato Heliconius hecale Heliconius sapho Heliconius sara Hyalophora cecropia Hyalophora columbia Hyalophora euryalus Hylephila phyleus Hyles lineata Junonia coenia Langia zenzeroides formosana Lophocampa maculata Manduca sexta Morpho peleides Nymphalis antiopa Orgyia vetusta Orthosia hibisci quenquefasciata Pachysphinx modesta Papilio cresphontes Papilio eurymedon Papilio glaucus Papilio machaon oregonius Papilio multicaudata Papilio polyxenes asterius Papilio rumiko Papilio rutulus Papilio zelicaon Phyciodes mylitta Phyciodes pulchella Pieris rapae Plejebus acmon Poanes melane Polites sabuleti Polygonia satyrus Pyrgus communis Rothschildia jacobaeae Samia cynthia advena Samia ricini Smerinthus cerisyi Smerinthus ophthalmica Strymon melinus Trichoplusia ni Uresephita reversalis Vanessa annabella Vanessa atalanta Vanessa cardui Unidentified Lepidoptera Hybrids Papilio glaucus × Papilio rutulus Papilio polyxenes asterius × Papilio zelicaon Orthoptera Melanoplus devastator Phaneroptera nana Pristoceuthophilus pacificus Scudderia mexicana Trimerotropis pallidipennis Phasmatodea Carausius morosus Phyllium giganteum Mantodea Mantis religiosa Phyllocrania paradoxa Hymenoptera Apis mellifera Bombus vosnesenskii Brachymeria ovata Linepithema humile Pediobius sp. Polistes dominula Xylocopa varipuncta Unidentified Diptera Lucilia sericata Unidentified Hemiptera Brochymena sp. Leptoglossus sp. Nezara viridula Odonata Argia vivida Libellula croceipennis Coleoptera Coccinella septempunctata Cycloneda polita Diabrotica undecimpunctata Hippodamia convergens Araneae (Class: Arachnida) Araneus diadematus Phidippus johnsoni |