There is some uncertainty regarding whether or not Chytonix sensilis is actually the same species as the very similar Chytonix ruperti.
It is not clear how rare this is in New York, in part due to the possibility Chytonix ruperti is the same species as Chytonix sensilis. At present, definite populations of Chytonix sensilis are recognized in New York in the Albany Pine Bush and on Long Island. If Chytonix sensilis and Chytonix ruperti are actually separate species, it is possible that records from Clinton County, which are treated as Chytonix sensilis, might prove to be Chytonix ruperti. The number of known occurrences of Chytonix sensilis has increased with increased inventory work in appropriate habitats and it is very likely that a few more populations occur on Long Island. However even if all of these occurrences are considered the same species, there are fewer than ten recently known in New York
This species should have increased both on Long Island, after the massive wildfires in the 1990s, and at the Albany Pine Bush due to prescribed burning. More data on the short-term trends is needed, however.
The long-term trend indicates that there has been a moderate decline in the population from historical numbers, as a large amount of habitat has been developed around Albany and on Long Island.
The biology of this species is poorly known, making the threats difficult to assess. The larva is a fungus feeder that forages in the leaf litter, apparently feeding mostly off of dead wood. At some locations, lack of fire could reduce populations, but complete burning of the occupied habitat also could be a threat since most or all of the year is spent above ground.
In sandy pine barrens, this species seems to be somewhat fire dependent. However, it is unclear if this is the case on flatrock barrens habitats. Populations in Ontario of the possibly conspecific Chytonix ruperti can be dense with or without recent fires (Dale Schweitzer).
This species is typically confined to xeric (dry) sites. It is known from pitch pine-scrub oak barrens at Albany and Long Island and sandstone pavement barrens in Clinton County. The habitats are similar elsewhere in the range and are usually on sand, but they occasionally occur on acid rocks like granite. Many apparently suitable habitats lack this species. Populations may increase a few years after fires, but they can persist at low density for decades without fire. Populations of Chytonix ruperti, which may be the same species, are more predictably present in suitable habitats with sandy oak openings, oak woodland, oak savanna, or dunes near the Great Lakes.
At a minimum, this species occurs in the Albany area and on Long Island. There are also records from Clinton County, but these could be Chytonix ruperti which may or may not be conspecific (belonging to the same species).
If the taxon Chytonix ruperti is not included, then the approximate historical range is southern New Hampshire to southern Michigan and formerly southern Ohio, eastward extending south, mostly in the coastal plain, from New Jersey to central Florida. Chytonix ruperti occurs in the Great Lakes region from western New York to Minnesota, especially in Ontario.
Chytonix sensilis is very similar to other species in the genus. Even experts will have difficulty separating Chytonix sensilis from Chytonix ruperti, which could be the same species. The illustrations in Rings et al. (1992) and Rockburn and Lafontaine (1976) appear to be Chytonix ruperti. In general, Chytonix sensilis (and ruperti) adults are much grayer than the common Chytonix palliatricula and have a shorter flight season. Any specimens found before mid-July and in September, except possibly on Long Island, can be assumed to be Chytonix palliatricula. The typical southern Chytonix sensilis is illustrated by Kimball (1965).
The flight season is a strong clue that will aid in the identification of this species, as it will be found in July or August. It is much grayer than Chytonix palliatricula and differs in genitalia (see Forbes 1954). The possibly conspecific Chytonix ruperti differs slightly in genitalia, as shown by Forbes (1954) and tends to be brighter gray with less brown, more crisply marked and with a clear, sharply defined white spot on the forewing. The subterminal line of the forewing is preceded by a vague dark shade on Chytonix sensilis and usually by a series of dark spots on the lower half in Chytonix ruperti. Any identification of this species must be verified by an expert and may require genitalia dissection if the specimen is worn or to distinguish Chytonix ruperti from Chytonix sensilis. Field photographs under artificial lights should not be used for the basis of identification.
The adults come readily to blacklights and sometimes also come to bait.
The larvae apparently graze fungi in the leaf litter, mostly off of dead wood.
This species, including Chytonix ruperti, is strictly single brooded flying in about late July to mid-August in the Albany area. It likely occurs a bit later on Long Island (in August) and earlier in Clinton County (by mid-July). Specimens of this genus collected later or earlier than these dates are the common Chytonix palliatricula, which likely flies from May into September, as it does in New Jersey.
The time of year you would expect to find Sensitive Chytonix reproducing, larvae present and active, and pupae or prepupae present in New York.
Chytonix sensilis Grote, 1881
There is disagreement among experts as to whether Chytonix ruperti is a synonym (or subspecies) of Chytonix sensilis or a separate species, as was originally proposed. Much of this confusion stems from the failure to recognize that Ontario, Wisconsin, most of Michigan, and northern Ohio populations are referable to Chytonix ruperti, as is suggested by the ranges given by Forbes (1954). The differences in wing characters are quite minor (see Forbes 1954), but do seem consistent at least in Ontario and Wisconsin. The genitalia difference is also quite minor and it is unknown whether this is consistent or not. If these in fact are separate species, it is possible some recent New York records would refer to Chytonix ruperti, but those from the Albany area and all recent specimens from Long Island are normal Chytonix sensilis.
Allen, T.J., J.P. Brock, and J. Glassberg. 2005. Caterpillars in the field and garden. Oxford University Press, New York. 232 pp.
Brock, J. P., and K. Kaufman. 2003. Butterflies of North America. Kaufman Focus Field Guides, Houghton Mifflin Company, New York, NY 284 pp.
Ferge, L. A., and G. J. Balogh. 2000. Checklist of Wisconsin Moths (Superfamilies Drepanoidea, Geometroidea, Mimmallonoidea, Bombycoidea, Sphingoidea, and Noctuiodea). Contributions in Biology and Geology of the Milwaukee Public Museum No. 93. Milwaukee, Wisconsin. 55 pp. and one color plate.
Forbes, William T. M. 1954. Lepidoptera of New York and neighboring states part III. Cornell University Experiment Station Memoir 329.
Handfield, Louis, 1999. Le Guide des Papillons du Quebec, Scientific Version. Broquet Inc, Boucherville, Quebec, Canada, 155pp + plates.
Kimball, C. P. 1965. The Lepidoptera of Florida. Arthropods of Florida and Neighboring Land Areas, Vol. 1. Florida Department of Agriculture and Consumer Services. Gainesville, Florida. 363 pp. and 26 plates.
New York Natural Heritage Program. 2019. New York Natural Heritage Program Databases. Albany, NY.
Rings, R. W., E. H. Metzler, F. J. Arnold, and D. H. Harris. 1992. The Owlet Moths of Ohio (Order Lepidoptera, family Noctuidae). Ohio Biol. Surv. Bull. New Series, Vol. 9, no. 2, vi. + 219 pp., 16 color plates.
Rockburne, E. W., and J. D. LaFontaine. 1976. The cutworm moths of Ontario and Quebec. Research Branch, Canada Department of Agriculture. Publication 1593. 164 pp.
Information for this guide was last updated on: January 7, 2008
Please cite this page as:
New York Natural Heritage Program. 2019. Online Conservation Guide for Chytonix sensilis. Available from: https://guides.nynhp.org/sensitive-chytonix/. Accessed August 25, 2019.