Classification

Papilionoidea: Lycaenidae: Theclinae: Strymon

Common name

pineapple borer, hairstreak

Synonyms

Callipareus, Callicista, Uranotes, Eiseliana, Heoda

Larval diagnosis (Detailed)

Several ports, mostly in the eastern United States, have intercepted lycaenid larvaelarva:
the stages between the egg and pupa of those insects having complete metamorphosis
on pineapple from Latin America over the last several decades (Weisman 1986Weisman 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., Kane 2008Kane 2008:
Kane, E. 2008. Analysis of AQAS data associated with the commercial importation of pineapples (Ananas sp.), with special emphasis on shipments originating from Costa Rica. U. S. Department of Agriculture, Animal and Plant Health Inspection Service, Plant Protection and Quarantine unpublished memo. 12 pp.). These larvaelarva:
the stages between the egg and pupa of those insects having complete metamorphosis
have a short frontfront:
the frons or frontal area, sometimes including the clypeus
that does not reach the epicranial notchepicranial notch:
the V-shaped dorsomedial space delimited laterally by the cranial halves
, five teeth and two setaeseta:
a hairlike projection of the body wall that is articulated in a socket; compare to spine
on the mandible, a very short second and third segment of the labial palpuslabial palpus:
a pair of small, segmented sensory structures arising on the distolateral portions of the labium
, a small triangular prothoracic shieldprothoracic shield:
the dorsal shieldlike covering of the first thoracic segment
covered with setaeseta:
a hairlike projection of the body wall that is articulated in a socket; compare to spine
, a small honey (= Newcomer's) gland on the posteriorposterior:
caudal or rear
portion of A7, and the spiracle of A8 moved dorsaddorsad:
toward the top or back
of the other abdominal spiracles. The body setaeseta:
a hairlike projection of the body wall that is articulated in a socket; compare to spine
are pointed and unmodified except for those surrounding the gland. We did not find a detailed larval description of any New World pest species of Lycaenidae on pineapples; however, several lines of evidence support an identification of Strymon.

First, literature records associate Strymon with pineapple (see review in Robbins 2010Robbins 2010:
Robbins, R. K. 2010. The "upside down" systematics of hairstreak butterflies (Lycaenidae) that eat pineapple and other Bromeliaceae. Studies on Neotropical Fauna and Environment 45: 21-37.). With regard to Costa Rica and Central America, where most recent port interceptions originated, Strymon is known as the pineapple borer (Saunders et al. 1983Saunders et al. 1983:
Saunders, J. L., A. B. S. King and C. L. Vargas. 1983. Plagas de cultivos en America Central. Una lista de referencia. Centro Agronomico Tropical de Investigacion y Ensenanza. Boletin tecnico 9. 90 pp.) or just fruit borer (Vargas Carrillo 2011Vargas Carrillo 2011:
Vargas Carrillo, E. 2011. Guide for integrated pest identification and management in pineapple. PROAGRION. San Carlos, Costa Rica. 31 pp.). It is specifically mentioned as a pest of pineapple in Mexico (McGuire and Crandall 1967), Guatemala (Carter 1934Carter 1934:
Carter, W. 1934. Notes on two pests of pineapple not known in Hawaii. Proceedings Hawaiian Entomological Society 8: 395-397.), and Costa Rica (Coto and Saunders 2004Coto and Saunders 2004:
Coto, D. and J. L. Saunders. 2004. Insectos plagas de cultivos perennes con enfasis en frutales en America Central. Centro Agronomico Tropical de Investigacion y Ensenanza. Serie Tecnica. Manual tecnico 52. 400 pp.). The study by Harris (1927)Harris (1927):
Harris, W. V. 1927. On a lycaenid butterfly attacking pineapples in Trinidad, B.W.I. Bulletin of Entomological Research 18: 183-188. in Trinidad probably refers to this species as well.

At the species level, Robbins (2010)Robbins (2010):
Robbins, R. K. 2010. The "upside down" systematics of hairstreak butterflies (Lycaenidae) that eat pineapple and other Bromeliaceae. Studies on Neotropical Fauna and Environment 45: 21-37. listed four taxa associated with pineapple: Strymon ziba, S. megarus, S. lucena, and S. oreala. The first two names are considered "superspecies" complexes that potentially could be divided in the future. He noted most published records lump S. ziba and S. megarus and misidentify them under the names Thecla basilides, Thecla basalides, or Tmolus echion. As defined by Robbins and Aiello (1982)Robbins and Aiello (1982):
Robbins, R. K. and A. Aiello. 1982. Foodplant and oviposition records for Panamenian Lycaenidae and Riodinidae. Journal of the Lepidopterists' Society 36: 65-75., T. echion feeds only on dicots. A recent host list of Neotropical butterflies (Beccaloni et al. 2008Beccaloni et al. 2008:
Beccaloni G. W, A. L. Viloria, S. K. Hall and G. S. Robinson. 2008. Catalogue of the hostplants of the Neotropical butterflies. Sociedad Entomologica Aragonesa. Zaragoza, Spain. 536 pp.) listed four species of Lycaenidae on pineapple (Strymon legota, S. megarus, S. oreala, and a riodinid - Napaea eucharila) plus other doubtful or incomplete records (Pseudolycaena marsyas, either S. megarus or S. ziba in publications from Mexico to Uruguay, and an unidentified species from Colombia). If Riodinidae is considered a separate family, all Lycaenidae larvaelarva:
the stages between the egg and pupa of those insects having complete metamorphosis
that eat Bromeliaceae in Latin America belong to the Strymon ziba and S. serapio species groups (Robbins 2010Robbins 2010:
Robbins, R. K. 2010. The "upside down" systematics of hairstreak butterflies (Lycaenidae) that eat pineapple and other Bromeliaceae. Studies on Neotropical Fauna and Environment 45: 21-37.).

Second, the intercepted lycaenid is morphologically similar to North American Strymon larvae. The distribution of body setaeseta:
a hairlike projection of the body wall that is articulated in a socket; compare to spine
matches the figure of Strymon melinus in Peterson (1962: L23) and their morphology agrees with the magnified drawing in Schnitzler et al. (2012: fig. 205). Ballmer and Pratt (1988: tables 1, 2) noted that Lycaeninae lack a honey gland that is present in the Theclinae. The intercepted lycaenid larvalarva:
the stages between the egg and pupa of those insects having complete metamorphosis
from pineapple has this gland as is expected for Strymon and other Theclinae.

Finally, the only reared example we have from port interceptions is a larvalarva:
the stages between the egg and pupa of those insects having complete metamorphosis
from Costa Rica, on Heliconia, sent in by C. Olsen in 2005. The single adult was determined by R. Robbins as S. megarus (USNM lot 0508026). Although not from pineapple, it demonstrates that ports do intercept Strymon from Costa Rica. The bright red color of the reared larvalarva:
the stages between the egg and pupa of those insects having complete metamorphosis
on Heliconia matches the specimens from pineapple illustrated in color by Coto and Saunders (2004)Coto and Saunders (2004):
Coto, D. and J. L. Saunders. 2004. Insectos plagas de cultivos perennes con enfasis en frutales en America Central. Centro Agronomico Tropical de Investigacion y Ensenanza. Serie Tecnica. Manual tecnico 52. 400 pp.. The related Strymon ziba normally is reared from Heliconiaceae and Haemodoraceae, thus Robbins (2010)Robbins (2010):
Robbins, R. K. 2010. The "upside down" systematics of hairstreak butterflies (Lycaenidae) that eat pineapple and other Bromeliaceae. Studies on Neotropical Fauna and Environment 45: 21-37. considered the above host association for S. megarus as needing confirmation. There have been many lycaenids intercepted from Heliconia at United States ports from Mexico to South America, especially from Costa Rica. Current knowledge would suggest most of these should be S. ziba, but without rearing or molecular studies, this shows the complexity of trying to evaluate port interceptions. There is a need to rear more of these Heliconia feeding Lycaenidae.

Identification Authority (Detailed)

It seems relatively safe to use the name Strymon for lycaenid larvaelarva:
the stages between the egg and pupa of those insects having complete metamorphosis
on pineapple from Latin America that have relatively unmodified body setaeseta:
a hairlike projection of the body wall that is articulated in a socket; compare to spine
and a honey gland on A7. One example of many interceptions from Philadelphia has the dorsum of A7 darkly pigmented. It is unclear if this is variation or another species. Living larvaelarva:
the stages between the egg and pupa of those insects having complete metamorphosis
can be cream, green, or bright red or pink (Coto and Saunders 2004Coto and Saunders 2004:
Coto, D. and J. L. Saunders. 2004. Insectos plagas de cultivos perennes con enfasis en frutales en America Central. Centro Agronomico Tropical de Investigacion y Ensenanza. Serie Tecnica. Manual tecnico 52. 400 pp., Robbins 2010Robbins 2010:
Robbins, R. K. 2010. The "upside down" systematics of hairstreak butterflies (Lycaenidae) that eat pineapple and other Bromeliaceae. Studies on Neotropical Fauna and Environment 45: 21-37.).

The presence of a riodinid, Napaea eucharila, on pineapple is cause for concern. There are many species in this group with unknown larvaelarva:
the stages between the egg and pupa of those insects having complete metamorphosis
, some of which could eat or stray on pineapple. The larvalarva:
the stages between the egg and pupa of those insects having complete metamorphosis
of N. eucharila was illustrated by DeVries (1997: fig. 42). It is a leaf feeder with much longer hairs than Strymon.

If there are no determined Strymon larvae in the port collection, use our figures or those of S. melinus in Peterson (1962)Peterson (1962):
Peterson, A. 1962. Larvae of insects: an introduction to Nearctic species. Part I: Lepidoptera and plant infesting Hymenoptera. Columbus, Ohio. 315 pp. for comparison. Anything that does not match Strymon should be left at family. In most cases, caterpillars of Strymon eat flowers and fruits, but larvaelarva:
the stages between the egg and pupa of those insects having complete metamorphosis
of S. megarus and S. ziba may also bore into leaves when flowers and fruits are unavailable (Robbins 2010Robbins 2010:
Robbins, R. K. 2010. The "upside down" systematics of hairstreak butterflies (Lycaenidae) that eat pineapple and other Bromeliaceae. Studies on Neotropical Fauna and Environment 45: 21-37.). Strymon is a large genus and we normally cannot recognize the larvaelarva:
the stages between the egg and pupa of those insects having complete metamorphosis
outside of two exceptions. If the host is Bromeliaceae from Latin America, Strymon sp. may be justified on a case by case bases. The number of possible species quickly grows if the host is not pineapple. If the larvalarva:
the stages between the egg and pupa of those insects having complete metamorphosis
is on beans from the New World, S. melinus is a possibility.

Origin records

Strymon have been intercepted from the following locations:

Brazil, Colombia, Costa Rica, Ecuador, Guatemala, Honduras, Mexico, Panama

Host records

Strymon have been intercepted on the following hosts:

Ananas comosus, Ananas sp., Annona cherimola, Bromeliaceae, Chenopodium album, Chenopodium ambrosioides, Dendrobium sp., Heliconia sp., Heliconia spectabilis, Phaseolus vulgaris, Pithecellobium dulce, Punica granatum, Zea mays

Records for Annona cherimola, Chenopodium album, Chenopodium ambrosioides, Dendrobium, Heliconia, Phaseolus vulgaris, Pithecellobium dulce, Punica granatum, and Zea mays need confirmation.

See Detailed information tab for a discussion of Heliconia-feeding Strymon.