Today our first Pipevine Swallowtail (Battus philenor) of the year eclosed! The Pipevine Swallowtail (Battus philenor) is a species of tropical origin and there is evidence that suggests that its arrival here in California is relatively recent. Most of its relatives in the Aristolochia Swallowtail tribe Triodini live in the tropics, a biome characterized by indistinct seasons and more or less constant temperatures throughout the year. Whether or not this is responsible for their irregular diapausing schedules is unclear, but it probably is one reason. After all, the pupae do not seem to be very responsive to photoperiod like other species. Some of the Pipevine Swallowtails that we caught as mature caterpillars in June that pupated have mostly stayed in diapause until now. One of the thirteen healthy chrysalises that pupated on 6/21, the only one that did not diapause, was going to emerge on 7/14 but the chrysalis was badly deformed and the misshapen butterfly died while attempting to break out of the cuticle. Another two chrysalises that became quite pharate around 8/1 never eclosed; after several days we broke them open and found very dead butterflies. Forgiving our misfortune, this data is probably consistent with their irregular diapausing schedules in which some eclose in the normal amount of time (two to three weeks) without undergoing any sort of diapause, some diapause but then eclose later in the season of the same year (allowing them to fly as late as October!), and the rest diapause and eclose in the following spring. Basically, it is mixed bag, even with individuals of the same clutch as these probably were. Whether or not the cues for diapause are affected at all by typical regulators as photoperiod and temperature is unclear; it seems more or less random for the most part. Probably another important factor to consider, though, is host plant. In California, the Pipevine Swallowtail utilizes only the native California pipevine (Aristolochia californica, another recent arrival of tropical origin) which stops proliferating by summertime unless forced to regenerate, which is unfortunate because the swallowtails lay exclusively on the new shoot tips. Perhaps there is an element of "bet-hedging" to the split flights in which the species depends on at least some individuals eclosing at a favorable time. Plus, it has been suggested that diapause may be somehow related to the water content of the plant that the caterpillar fed on. Anyways, it has been observed that the "estival" diapausers tend to break sometime in August (at least, this is when the numbers spike). This is probably true. Today, in the middle of August, one of our June chrysalises finally eclosed about two months after pupation. He was a beautiful prismatic blue male, which is a much more attractive look than the mostly drab gray female we caught in June. Like in the treasured birdwing butterflies (Ornithoptera) and many other Triodini relatives, it is always the male that is the very showy one and the female that is plain. The wing shape is also more typical of Triodini members than either of our two fluted swallowtails (Papilionini), the Anise Swallowtail (Papilio zelicaon) or Western Tiger Swallowtail (Papilio rutulus); the forewings are relatively long and angular. Not to mention the rather short tails, which would make sense as they are a highly aposematic species (birdwings don't even have tails!) and the tails normally serve as a form of defense (fake antennae to confuse an attacking bird into biting the wing instead of the body). The same lack of traditional defense is seen in the caterpillar too, which are also aposematic; they rarely employ their stink horns (osmetarium) which rely on both retraction speed to ward off motion-sensitive predators (or parisitoids) and chemical assault (butyric acid). They feed openly, often gregariously at least when they are young, and as a result they are routinely parasitized by chalcid wasps. Sadly, of course, no other chrysalis shows any sign at all of emerging at this time so we released it. Otherwise we could have attempted to hand-pair. - 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 |