Classification

Tortricoidea: Tortricidae: Olethreutinae: Grapholitini: Cydia splendana (Hübner)

Common name

chestnut fruit tortrix, acorn moth

Synonyms

Tinea bicolorana, Tinea bicolorata, Tortrix glandella, Tortrix pencleriana, Tortrix penkleriana, Carpocapsa reaumurana

Cydia splendana is sometimes referred to as "C. triangulella" in the literature (e.g., Razowski 2003Razowski 2003:
Razowski, J. 2003. Tortricidae of Europe, Vol. 2, Olethreutinae. Frantisek Slamka, Slovakia. 301 pp.). An explanation for the use of this alternate name is provided by Brown (2005: Note 16).

Larval diagnosis (Detailed)

Cydia on chestnut (Castanea sativa) are the most commonly intercepted tortricids at U.S. ports of entry. Tortricids found in chestnuts from the Old World were historically identified as C. splendana or Pammene fasciana (or Cydia sp.) until Komai and Ishikawa (1987)Komai and Ishikawa (1987):
Komai, F. and K. Ishikawa. 1987. Infestation of chestnut fruits in China with two species of the genus Cydia (Lepidoptera: Tortricidae). Japanese journal of Applied Entomology and Zoology 31: 55-62. demonstrated that other Cydia species were responsible for infesting chestnuts in Asia. Brown and Komai (2008)Brown and Komai (2008):
Brown, J. W. and F. Komai. 2008. Key to larvae of Castanea-feeding Olethreutinae frequently intercepted at U.S. ports-of-entry (Lepidoptera : Tortricidae). Tropical Lepidoptera Research 18: 2-4. provided a key to Castanea-feeding tortricids and included both Asian and European species. The majority of information provided here is from this key, modified slightly by Brown (2011)Brown (2011):
Brown, J. W. 2011. Tools for identifying the larvae of leafrollers (Lepidoptera: Tortricidae) frequently intercepted at U.S. ports of entry. Systematic Entomology Laboratory, PSI, Agricultural Research Service, U.S. Department of Agriculture c/o National Museum of Natural History, Washington, D.C. 19 pp..

Brown (2011)Brown (2011):
Brown, J. W. 2011. Tools for identifying the larvae of leafrollers (Lepidoptera: Tortricidae) frequently intercepted at U.S. ports of entry. Systematic Entomology Laboratory, PSI, Agricultural Research Service, U.S. Department of Agriculture c/o National Museum of Natural History, Washington, D.C. 19 pp. divided intercepted tortricid larvaelarva:
the stages between the egg and pupa of those insects having complete metamorphosis
into four "types." Larvaelarva:
the stages between the egg and pupa of those insects having complete metamorphosis
of C. splendana are grouped under the "Cydia type" with D1 and SD1 on the same pinaculumpinaculum:
a small, flat, or slightly elevated chitinized area bearing a seta or setae
on A9, the L group on T1 not extending beneath the spiracle, and an anal combanal comb:
the mesal sclerotized prong ventrad of the anal plate and adjacent to the anus; used to eject frass
absent. He used the following characters to identify larvaelarva:
the stages between the egg and pupa of those insects having complete metamorphosis
of C. splendana: body pinkish or whitish, pinaculapinaculum:
a small, flat, or slightly elevated chitinized area bearing a seta or setae
mostly concolorous with body; distance between V setaeseta:
a hairlike projection of the body wall that is articulated in a socket; compare to spine
on A9 slightly to conspicuously greater than that between V setaeseta:
a hairlike projection of the body wall that is articulated in a socket; compare to spine
on A8; number of crochetscrochets:
sclerotized, hooklike structures, usually arranged in rows or circles on the prolegs of Lepidoptera larvae
on most prolegsprolegs:
fleshy, unjointed abdominal legs with or without crochets; false legs
19 or fewer (variable from proleg to proleg); D2 setaeseta:
a hairlike projection of the body wall that is articulated in a socket; compare to spine
on A9 on separate or same pinaculapinaculum:
a small, flat, or slightly elevated chitinized area bearing a seta or setae
; SV group variable on abdominal segments; prothoracic shieldprothoracic shield:
the dorsal shieldlike covering of the first thoracic segment
without typical C. pomonella mottling (or very faint); on Castanea.

The larvalarva:
the stages between the egg and pupa of those insects having complete metamorphosis
of C. splendana was partially described by Swatschek (1958)Swatschek (1958):
Swatschek, B. 1958. Die larvalsystematik der Wickler (Tortricidae und Carposinidae). Abhandlungen Zur Larvalsystematik der Insekten nr. 3. Akademie-Verlag, Berlin, Germany. 269 pp. including an illustration of the head. According to Erickson (1960), the head is light brown, the prothoracic and anal shields are yellowish, and the body is white. The cuticle is weakly granulate and the L setaeseta:
a hairlike projection of the body wall that is articulated in a socket; compare to spine
are arranged vertically on A1. There are 14-21 crochetscrochets:
sclerotized, hooklike structures, usually arranged in rows or circles on the prolegs of Lepidoptera larvae
on A3-6 and 7-9 crochetscrochets:
sclerotized, hooklike structures, usually arranged in rows or circles on the prolegs of Lepidoptera larvae
on A10. The SV counts for A1,2,7,8,9 are 3,3,2,1,1. However both the crochet number and SV counts can vary. The spacing of the V setaeseta:
a hairlike projection of the body wall that is articulated in a socket; compare to spine
on A9 is greater than A8. Brown and Komai (2008)Brown and Komai (2008):
Brown, J. W. and F. Komai. 2008. Key to larvae of Castanea-feeding Olethreutinae frequently intercepted at U.S. ports-of-entry (Lepidoptera : Tortricidae). Tropical Lepidoptera Research 18: 2-4. added that the crochetscrochets:
sclerotized, hooklike structures, usually arranged in rows or circles on the prolegs of Lepidoptera larvae
are uniordinaluniordinal:
crochets arranged so they are of a single length or slightly shorter toward the ends of the row
, the D2 setaeseta:
a hairlike projection of the body wall that is articulated in a socket; compare to spine
of A9 are often on separate pinaculapinaculum:
a small, flat, or slightly elevated chitinized area bearing a seta or setae
and an anal combanal comb:
the mesal sclerotized prong ventrad of the anal plate and adjacent to the anus; used to eject frass
is absent.

The keys in Brown and Komai (2008)Brown and Komai (2008):
Brown, J. W. and F. Komai. 2008. Key to larvae of Castanea-feeding Olethreutinae frequently intercepted at U.S. ports-of-entry (Lepidoptera : Tortricidae). Tropical Lepidoptera Research 18: 2-4. and Brown (2011)Brown (2011):
Brown, J. W. 2011. Tools for identifying the larvae of leafrollers (Lepidoptera: Tortricidae) frequently intercepted at U.S. ports of entry. Systematic Entomology Laboratory, PSI, Agricultural Research Service, U.S. Department of Agriculture c/o National Museum of Natural History, Washington, D.C. 19 pp. use body color in some couplets to separate the various species of Castanea-feeding Cydia. It should be noted that body color fades rapidly in preserved specimens, and the usefulness of any color character will depend on the quality of the specimens and their state of preservation. Poorly preserved specimens often turn black or brown. The color photo of C. splendana is Villagran et al. (2000: fig. 2) is an example of this problem. In cases where color is present in a specimen (reddish abdomen or pinaculapinaculum:
a small, flat, or slightly elevated chitinized area bearing a seta or setae
), these characters will be useful; in cases where reddish color is not present, it should not be assumed that the specimen is one of the whitish (non-colored) species without other supporting evidence. It may just be that the red color has faded. Weisman (1986)Weisman (1986):
Weisman, D. M. 1986. Keys for the identification of some frequently intercepted lepidopterous larvae. U.S. Department of Agriculture, Animal and Plant Health Inspection Service, Plant Protection and Quarantine series 81-47. 64 pp. said the head is clear yellow and the body is always white for C. splendana. We very tentatively accept this. As a conflicting example, this is not the case for the codling moth that can be white or red causing Swatschek (1958)Swatschek (1958):
Swatschek, B. 1958. Die larvalsystematik der Wickler (Tortricidae und Carposinidae). Abhandlungen Zur Larvalsystematik der Insekten nr. 3. Akademie-Verlag, Berlin, Germany. 269 pp. to describe this species as "white with a reddish tinge" (Erickson 1960). Clearly color variation in larval Cydia larvae needs more study and different species may well have different color variations. Compounding the problem, many caterpillars turn pink before pupation. Thus, it may not be possible to key out prepupae.

Other tortricid Castanea pests include: P. fasciana (western Europe east to the Ukraine), C. fagiglandana (Europe south to northern Iran and east to the Trans-Caucasus and the mountains of Turkestan), C. glandicolana (China, Korea, and Japan), C. kurokoi (China, Korea, and Japan), and Fibuloides (= Eucoenogenes) aestuosa (northern India, China, Korea, and Japan). For morphological characters to separate the Asian species (C. glandicolana, C. kurokoi, and F. aestuosa), consult Brown and Komai (2008)Brown and Komai (2008):
Brown, J. W. and F. Komai. 2008. Key to larvae of Castanea-feeding Olethreutinae frequently intercepted at U.S. ports-of-entry (Lepidoptera : Tortricidae). Tropical Lepidoptera Research 18: 2-4. or Brown (2011)Brown (2011):
Brown, J. W. 2011. Tools for identifying the larvae of leafrollers (Lepidoptera: Tortricidae) frequently intercepted at U.S. ports of entry. Systematic Entomology Laboratory, PSI, Agricultural Research Service, U.S. Department of Agriculture c/o National Museum of Natural History, Washington, D.C. 19 pp.. The European species that may be confused with C. splendana are discussed in detail here.

Larvaelarva:
the stages between the egg and pupa of those insects having complete metamorphosis
of Pammene fasciana are easily distinguished from Cydia by their large dark brown pinaculapinaculum:
a small, flat, or slightly elevated chitinized area bearing a seta or setae
and anal combanal comb:
the mesal sclerotized prong ventrad of the anal plate and adjacent to the anus; used to eject frass
(Villagran et al. 2000: fig. 3). In C. splendana the pinaculapinaculum:
a small, flat, or slightly elevated chitinized area bearing a seta or setae
are moderately small, concolorous with the body, and an anal combanal comb:
the mesal sclerotized prong ventrad of the anal plate and adjacent to the anus; used to eject frass
is absent.

Larvaelarva:
the stages between the egg and pupa of those insects having complete metamorphosis
of C. fagiglandana are more difficult to separate from those of C. splendana. Both species exhibit the same suite of "typical" Cydia characters: D1 and SD1 on the same pinaculumpinaculum:
a small, flat, or slightly elevated chitinized area bearing a seta or setae
on A9; D2 setaeseta:
a hairlike projection of the body wall that is articulated in a socket; compare to spine
on A9 on separate or same pinaculapinaculum:
a small, flat, or slightly elevated chitinized area bearing a seta or setae
; SV group counts variable; anal combanal comb:
the mesal sclerotized prong ventrad of the anal plate and adjacent to the anus; used to eject frass
absent. Brown (2011)Brown (2011):
Brown, J. W. 2011. Tools for identifying the larvae of leafrollers (Lepidoptera: Tortricidae) frequently intercepted at U.S. ports of entry. Systematic Entomology Laboratory, PSI, Agricultural Research Service, U.S. Department of Agriculture c/o National Museum of Natural History, Washington, D.C. 19 pp. separated the two species using the following description for C. fagiglandana: body reddish white, pinaculapinaculum:
a small, flat, or slightly elevated chitinized area bearing a seta or setae
red (see Villagran et al. 2000: fig. 1); distance between Vs on A9 usually about the same as that between Vs on A8; number of crochetscrochets:
sclerotized, hooklike structures, usually arranged in rows or circles on the prolegs of Lepidoptera larvae
on most prolegsprolegs:
fleshy, unjointed abdominal legs with or without crochets; false legs
18-24. In the C. fagiglandana specimens we examined, the reddish color was present in the body and pinaculapinaculum:
a small, flat, or slightly elevated chitinized area bearing a seta or setae
, but it had faded considerably from live specimens. Thus, the distance between V setaeseta:
a hairlike projection of the body wall that is articulated in a socket; compare to spine
on A9 (slightly to conspicuously greater than that between Vs on A8 in C. splendana) and crochet counts (19 or less in C. splendana) are probably more reliable characters to separate preserved specimens of these two species.

Villagran et al. (2000) attempted to separate larvaelarva:
the stages between the egg and pupa of those insects having complete metamorphosis
of C. splendana (as C. penkleriana), C. fagiglandana, and P. fasciana using head setaeseta:
a hairlike projection of the body wall that is articulated in a socket; compare to spine
and pores in the vicinity of the stemmatastemma:
a simple eye of holometabolous larvae
. They characterized P. fasciana with Oa and SOa present, C. fagiglandana with Oa or SOa absent, and C. splendana with SO3 absent (terminology from Hinton 1946Hinton 1946:
Hinton, H. E. 1946. On the homology and nomenclature of the setae of lepidopterous larvae, with some notes on the phylogeny of the Lepidoptera. Transactions of the Royal Entomological Society of London 97: 1-37.). We were unable to confirm these characters, and their practical use is questionable, especially given that the other characters listed here work to separate these species most of the time.

Other species of Cydia originating in Europe, especially C. pomonella, are similar to C. splendana. These two species are usually separable by host: Rosaceae for C. pomonella and Castanea for C. splendana. However, Weisman (1987: 263) did record C. pomonella from chestnuts. The two species can be separated by their color pattern; C. splendana usually lacks the characteristic mottling found on the prothoracic and anal shields of C. pomonella. In addition, crochet counts are different (19 or less in C. splendana versus 25-35 in C. pomonella).

Identification Authority (Detailed)

Host and origin information is important for positive identifications of C. splendana. Larvaelarva:
the stages between the egg and pupa of those insects having complete metamorphosis
should originate from Europe on Castanea and possess the combination of characters listed above, including the distance between V setaeseta:
a hairlike projection of the body wall that is articulated in a socket; compare to spine
on A9 slightly to conspicuously greater than that between Vs on A8 and with 19 or less crochetscrochets:
sclerotized, hooklike structures, usually arranged in rows or circles on the prolegs of Lepidoptera larvae
on the abdominal prolegsabdominal prolegs:
all prolegs on any abdominal segment except the last, which are Anal prolegs
. Similar larvaelarva:
the stages between the egg and pupa of those insects having complete metamorphosis
from Castanea with the distance between V setaeseta:
a hairlike projection of the body wall that is articulated in a socket; compare to spine
on A9 usually about the same as that between Vs on A8 and 18-24 crochetscrochets:
sclerotized, hooklike structures, usually arranged in rows or circles on the prolegs of Lepidoptera larvae
on most abdominal prolegsabdominal prolegs:
all prolegs on any abdominal segment except the last, which are Anal prolegs
can be identified as C. fagiglandana. The other common European Castanea-feeding tortricid is P. fasciana, which is easily distinguished with its large dark brown pinaculapinaculum:
a small, flat, or slightly elevated chitinized area bearing a seta or setae
and anal combanal comb:
the mesal sclerotized prong ventrad of the anal plate and adjacent to the anus; used to eject frass
.

Tortricid larvaelarva:
the stages between the egg and pupa of those insects having complete metamorphosis
originating from Asia on Castanea are likely C. glandicolana, C. kurokoi, or F. aestuosa. Consult Brown and Komai (2008)Brown and Komai (2008):
Brown, J. W. and F. Komai. 2008. Key to larvae of Castanea-feeding Olethreutinae frequently intercepted at U.S. ports-of-entry (Lepidoptera : Tortricidae). Tropical Lepidoptera Research 18: 2-4. or Brown (2011)Brown (2011):
Brown, J. W. 2011. Tools for identifying the larvae of leafrollers (Lepidoptera: Tortricidae) frequently intercepted at U.S. ports of entry. Systematic Entomology Laboratory, PSI, Agricultural Research Service, U.S. Department of Agriculture c/o National Museum of Natural History, Washington, D.C. 19 pp. for characters to diagnose these species. Weisman (1987)Weisman (1987):
Weisman, D. M. 1987 (1991). Larval moths (Lepidoptera). In: J. R. Gorham (ed.). Insect and mite pests in food. An illustrated key. Volume 1. U. S. Department of Agriculture Handbook 655. 767 pp. recorded Cydia latiferreana in chestnuts from Mexico. We did not study early instars of any chestnut feeding species, these may differ in appearance from the late instars.

Key to larval Tortricidae intercepted, or potentially encountered, at U.S. ports of entry

Origin records

Genus species has been intercepted from the following locations:

Albania, Armenia, Austria, Azerbaijan, Azores, Belarus, Belgium, Bosnia and Herzegovina, Bulgaria, Croatia, France, Georgia, Germany, Greece, Hungary, Israel, Italy, Jordan, Kazakhstan, Lebanon, Macedonia, Montenegro, Morocco (?), Netherlands, Poland, Portugal, Romania, Russia, Serbia, Serbia and Montenegro, Slovakia, Spain, Switzerland, Turkey, Ukraine (?), United Kingdom of Great Britain and N. Ireland, Yugoslavia

Origins from outside of Europe likely represent misidentifications and are not listed here.

Host records

Genus species has been intercepted on the following hosts:

Castanea crenata, Castanea dentata, Castanea mollissima, Castanea sativa, Castanea sp., Fabaceae, Fagaceae, Malus domestica, Prunus persica, Prunus sp., Quercus coccifera, Quercus rubra, Quercus sp.

Hosts listed here outside of the Fagaceae need confirmation; those in the Rosaceae likely represent interceptions of C. pomonella