We received eastern tiger swallowtail (Papilio glaucus) and black swallowtail (Papilio polyxenes asterius) eggs from Iowa. The state of the eggs and potential differences between Iowa and local populations of the two species is speculated upon and discussed. We received approximately 80 F0 ("wild") eggs each of Papilio glaucus and P. polyxenes asterius from a supplier in Iowa. The glaucus eggs are shown below: Most of these glaucus eggs have already reached the late stages of the yellow mottling phase. A few are partially black and may hatch tomorrow while a few also are green and therefore likely infertile. In addition, we noticed that some of the partially developed eggs had collapsed; this was not the case with the P. polyxenes asterius eggs, which were received in the same package. This is interesting because we have struggled with hatching glaucus-group eggs in particular in the past, namely, with P. rutulus but rarely with those of machaon-group species. It may be that glaucus-group eggs are inherently more susceptible to damage than machaon-group eggs, perhaps owing to their differing ecology (glaucus-group eggs are laid on trees whereas machaon-group eggs are laid on forbs), though this is purely speculation. The polyxenes eggs, shown below, are in excellent shape, for the most part. They seem to be much more varied in age than the glaucus though. Some of the eggs have already almost completed development and will likely hatch tomorrow. It will be interesting to see how these differ from the local, Ithaca populations of these species seeing as Iowa has a strong population of the mimicry model, Battus philenor, which is absent in Upstate New York. In Iowa, female glaucus are reportedly 95% the black form, whereas the local glaucus are predominantly yellow (personally, we have yet to see a black female at all). We shall see whether this is the case for ourselves when we rear the glaucus eggs. As for polyxenes, we have recently noted how the wild female that we captured yesterday had a substantial amount of yellow scales, which should be undesirable in mimetic selection, so we are interested to know how the Iowa adults turn out. There will likely be other differences in life history traits between the populations of both species depending on what host plants are preferred in the respective localities and the climate. While the glaucus here are probably almost always obligately univoltine, the Iowa glaucus are said to be bivoltine, which is another way of saying they can be reared indefinitely without diapause under the right conditions. This will be advantageous for rearing a larger second generation of these eggs since pupae tend to die or have unreliable eclosion after a period of overwintering. While we have yet to take note of the voltinism of the local polyxenes, it is almost certain that these Iowa types are strongly multivoltine. ![]() Brian Liang Brian Liang is a student at Cornell University in Ithaca, New York pursuing an undergraduate degree in entomology. He is co-owner and a main contributor of the Liang Insects blog, insects articles, and site design.
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Timeline 2017–present
Ithaca, New York This timeline is a series of daily posts recording our observations and experiences with various insects (primarily Lepidoptera) around the Cornell University campus in Ithaca, New York, starting from the time we moved here in 2017. As this is a personal blog, we try to keep collections/rearings for university research and course work to a minimum, and mainly focus on just the species we catch and raise for our own fun and interest. Posts prior to this time can be viewed at Timeline 2012-2017: Albany, California, though there is occasionally some crossover when we have returned home during breaks or reared stock derived from home (see Albany, California Updates). Archives (232)
July 2020 (1) August 2019 (2) July 2019 (35) June 2019 (46) May 2019 (20) March 2019 (1) January 2019 (1) November 2018* October 2018* September 2018 (1)* August 2018 (9)* July 2018 (11)* June 2018 (22*) May 2018 (18)* April 2018 (2)* January 2018 (6) December 2017 (5) November 2017 (1) October 2017 (5) September 2017 (26) August 2017 (19) *Currently, a significant portion of 2018 posts are missing. The notes/photos for this time period are saved on our personal files but the posts were never built due to a busy schedule that year. We are still actively building these posts when we have the time. 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 Agraulis vanillae Allancastria cerisyi Amphion floridensis Ancyloxypha numintor Antheraea polyphemus Battus philenor hirsuta Callosamia promethea Colias eurytheme Citheronia regalis Cupido comyntas Danaus plexippus Darapsa myron Diadema inscriptum Epargyreus clarus Erynnis baptisiae Estigmene acrea Euchaetes egle Eumorpha pandorus Hemaris diffinis Hyalophora cecropia Limenitis archippus Liminitis arthemis arthemis Limenitis arthemis astyanax Manduca sexta Orgyia leucostigma Pachysphinx modesta Paonias myops Papilio cresphontes Papilio eurymedon Papilio glaucus Papilio polyxenes asterius Papilio rutulus Papilio troilus Papilio zelicaon Pyrgus communis Samia ricini Smerinthus ophthalmica Speyeria cybele Sphecodina abbottii Vanessa atalanta Vanessa cardui Vanessa virginiensis Lepidoptera Hybrids Papilio polyxenes asterius × Papilio zelicaon Orthoptera Conocephalus sp. Dissosteira carolina Melanoplus femurrubrum Neoconocephalus ensiger Neoxabea bipunctata Phasmatodea Carausius morosus Diapheromera femorata Mantodea Mantis religiosa Albany, California Updates |