The last two fifth instar anise swallowtail (Papilio zelicaon) caterpillars from an October brood still have yet to pupate after two and a half months! On 10/8 we caught a wild female anise swallowtail (Papilio zelicaon) adult who laid three dozen or so eggs that we collected and raised. On 11/24 we harvested the chrysalises formed from this brood of caterpillars. At the time of this chrysalis harvest, there were still two young fifth instar caterpillars that had been lagging behind. Today, they are still somehow with us. They have made gradual progress over the weeks, having clearly eaten and grown over time, and they appear to be completely healthy. Needless to say, we are quite baffled. As herb feeders, anise swallowtails normally have an extremely fast growth rate. At room temperature, say 60=70 degreed Farenheit, these caterpillars have absolutely no problem completing development from the time they hatch to pupation in three, possibly four weeks (assuming other rearing conditions are not decent enough). When our October brood of caterpillars were fourth instar, they were only about at day or two apart in development but by the time they reached fifth instar, only about have of them seemed to develop at a normal rate and completed larval development in the expected three weeks. The other half pupated over the course of November in what seemed to be a complete random order. By the time we collected the chrysalises on 11/24, a few had only just finished pupating. The ones that lagged behind were cleary growing at a raye that is completely out of the scope of what should have been normal even given that the temperatures have gradually dipped a few degrees over the course of the month. But nothing can compare to the two individuals that are still eating and growing as this post is being written, almost two months since the first few individuals of this group pupated. These are caterpillars that hatched from eggs laid on the exact same day! Why did this happen? These are not sickly individuals. They are not like some sick caterpillars that fight a prolonged battle with a virus or a parasite that they inevitably succumb to. We have seen plenty of those in our time rearing lepidopterans. No, these two fifth instars appear and act completely healthy and are not undersized (see the left and middle images). And as seen in the picture at the right, they have produced quite a bit of frass in one day, no less than what we would expect of them. The temperatures are currently 50-60 degrees Farenheit, no where near intolerable (bear in mind that the temperature wasn't always so low back in October and November, when the lived most of the lives thus far). So how are we supposed to explain this one? The only logical assumption that we can make is that this is caused by having experienced too many stressors, including the temperature (as of late). And, of course, the lagging behind only results in a downward spiral where caterpillars that are already slightly behind are more susceptible to getting even more behind; the two individuals right now have experienced a nightmare of rain and cool temperatures that the faster grower never experienced and this is making them lag behind even more than they would have. Its plausible that when stress reaches a tipping point, things start not working right as they do in so many other animals including ourselves, including stunted growth. - Brian
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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 |