Queens typically have pronounced paired yellow elliptical spots dorsally. On Bill's caterpillar, these marks are maroon. Also, the series of white bands on Queens are typically intact, whereas the terminal band in each series on the abdomen of the above caterpillar are consistently broken.
However, Bill's caterpillar was feeding on Antelope Horn Milkweed (A. asperula), a hostplant not recorded for the Solder. This would also be an early central Texas record for D. eresimus as the first adult Solders haven't been recorded that far north prior to the first week in September, per Chris Durden's Austin data.
Given the above conflicts and the fact that no one I contacted was able to definitively determine the identity of this caterpillar, Bill went back to here he first photographed the caterpillar and collected it for rearing purposes.
Working though numerous contacts, I was finally directed to John Calhoun of Florida who replied on June 11 that, " It does look like a dark form of D. gilippus. I figured a similar larva in my paper on D. eresimus in Florida (Holarctic Lepid, 3: 7-18, 1996)." (Partial list of Calhoun's publications.)
John sent me a PDF file of Fig. 8-12 from this paper and granted permission to post it here. Figure10 is of a dark form mature Queen larva reared in 1994 (Manatee Co., FL). Figures 8 and 9 are of normal mature Soldier and Queen larvae respectively.
After some searching, I did find a photo of a similar dark form Queen larva in Emmel & Kenney (1997) but the accompanying text makes no mention of this larva being unusual. No other Florida, Caribbean, U.S., Mexico, etc. reference that I have mentions or shows a dark form Queen.
Amazingly, no books that I have (other than Ackery & Vane-Wright) show a Soldier larva either. The only web image of an immature Soldier that I found was shot in French Guiana. This web image is a good match for the larval description from DeVries (1987) which he attributes to the unpublished drawings of Margaret Fountaine in the British Museum.
I asked John if the photo in Ackery and Vane-Wright might be misidentified or possibly of a dark form Solder. Here is John's reply:
In my paper, I address this photo as follows:
"Ackery and Vane-Wright (1984) figured what they believed to represent a mature larva of D. eresimus montezuma Talbot from El Salvador. However, this larva does not resemble the drawing of larval D. e. eresimus in Fontaine (1980) or any of the larvae of D. eresimus tethys I reared in 1994. Rather, it appears to be identical to a dark form of larval D. gilippus berenice Cramer that I also reared in 1994. This could represent an extreme example of the sex-linked (female) form of D. gilippus larva discussed by Hopf (1954) in which several dorsal spots are obscured. P. R. Ackery (pers comm) did not personally photograph the larva used for his figure and could not confirm its identity. He admitted that the original photographic slide could have been mislabeled. The larvae of D. eresimus I reared in 1994 were virtually identical to the larva figured in Fountaine (1980), suggesting that the species exhibits the same distinctive pattern throughout its range. Thus, the larva identified as D. eresimus montezuma by Ackery and Vane-Wright (1984) is probably referable to D. gilippus thersippus Bates from El Salvador."
On June 20, 2003, the Queen emerged
As this is a male, this contradicts Calhoun's theory that this larval trait might be female sex linked.
John Calhoun sent a PDF file of his Florida Soldier paper (which I posted via a link below). This is a thorough review of the literature on Soldiers (Danaus eresimus) and I highly recommend it to all with an interest in Monarchs, Queens and Soldiers.
Oct. 2002, Austin, Travis Co., TX
Since Bill Lindemann's record came to light, Coby Dinges of south Austin sent me this photo of a 5th instar dark form Queen larva. It had just left a Green Milkweed (Asclepias viridis) in his backyard.
These photos appear to be the first U.S. records of dark
form Queen larvae outside of Florida.
Mike Quinn, Invertebrate Biologist, Wildlife Diversity Branch, Texas Parks & Wildlife, 3000 I-35 South, Suite 100, Austin, Texas 78704, firstname.lastname@example.org
Ackery, P.R. & R.I. Vane-Wright. 1984. Milkweed butterflies: their cladistics and biology. Cornell, Ithaca. 425 pp.
Calhoun, J.V. 1996. Conquering soldiers: the successful invasion of Florida by Danaus eresimus (Lepidoptera: Nymphalidae). Holarctic Lepidoptera 3:7-18. [Figs 4-7] [Figs 8-12] (All PDF files)
DeVries, P.J. 1987. The butterflies of Costa Rica and their natural history: Volume I: Papilionidae, Pieridae, Nymphalidae. Princeton University Press, Princeton, NJ. 456 pp.
Emmel, T.C., & B. Kenney. 1997. Florida's fabulous butterflies. World Publications, Tampa. 96 pp.
Fountaine, M.E. 1980. Love among the butterflies: The travels and adventures of a Victorian lady. Collins, London. 223 pp., 32 pls.
Fountaine, M.E. [ ]. Unpublished watercolours of larvae and pupae. 4 vols. [British Museum (Natural History) collection].
Hopf, A.L. 1954. Sex differences observed in larvae of Danaus
berenice. Lepidopterists' News 8:123-124.