Invasive Weevil Species in the Southeastern USA

1
Invasive Weevil Species in the Southeastern USA

• Professor Charles W. O Brien
• Dept. of Entomology
• University of Arizona Tucson AZ
• Visiting Scholar, Retired
• cobrien6_at_cox.net

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Myllocerus undatus Marshall

• Distribution Rapidly spreading in south and
  central FL. Taken in mall in Phoenix AZ..
• Origin Sri Lanka (Ceylon), first collected in
  south Florida in 1995, but not identified until
  collected again in 2000.
• Potential Spread This species could easily
  spread through much of the US, especially in the
  warmer areas. May be spread as larvae in soil or
  on roots of nursery stock.
• Known Host Associations This species has the
  potential to become a major pest of crops and of
  ornamentals. It feeds on more than 100 species of
  plants, including citrus and many common
  ornamentals. Its sister species, Myllocerus
  undecimpustulatus Faust, from India is a major
  pest of cotton and of more than 50 crop species
  there.
• General or Specific Biology The adults and
  larvae are typical Entiminae, feeding on leaves
  and roots, respectively. The species is bisexual
  and winged.

3
Myllocerus undatus Marshall

• Diagnosis A medium-sized species, 4.5-8.0 mm. in
  length, elongate oval, snout short and broad, as
  broad as thorax, elytra much broader with
  angulate protruding shoulders, clothed with dense
  white to grey scales, often covered with a white
  wax like coating prothorax with one to three
  black vittae clothed with sparser narrow seta
  like scales, elytra with similar dark to black
  markings, rostrum with yellowish coating.
• The hind femur tridentate.

4
Listroderes difficilis Germain (Vegetable
Weevil)

• Origin Argentina
• Distribution AR, FL, GA, MS, NC, SC, AZ, BJ, CA,
  TX South America Old World.
• Potential Spread Is likely to spread to any area
  that lacks long term hard freezes.
• Known Host Associations Initially a pest of
  turnip, carrot, tomato, potato, and cabbage
  subsequently attacking all principle vegetable
  crops and numerous flower crops. It also feeds on
  numerous weeds and non-crop plants
• General or Specific Biology The adults are
  general feeders on foliage, often cutting stems
  of young plants, much like cutworms, and
  occasionally they feed on roots as well. They are
  mainly nocturnal in their feeding. The larvae
  feed in the roots of their many hosts causing
  damage equal to that of the adults. Currently in
  the subfamily Cyclominae, tribe Rhytirrhinini.

5
Listroderes difficilis Germain (Vegetable
Weevil)

• Diagnosis A medium-sized to large species,
  6.1-9.2 mm. in length, elongate with sides
  subparallel snout moderately long and moderately
  broad prothorax broadly trapezoidal, slightly
  narrower than elytra elytra with strong rounded
  shoulders clothed densely with shingled scales,
  forming various patterns of tan, brown, black,
  and whitish markings, some with erect fascicles
  of black scale like setae, and all with well
  separated erect seta like bristles.
• Snout tricarinate metasternum (underside of
  metathorax) laterally clothed with sparse,
  bristle like setae and dense, round, recumbent,
  metallic scales.

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Sitona lineatus (Linnaeus) ( Pea Leaf Weevil)

• Origin Northern Europe
• Distribution Discovered in 1936 on Vancouver
  Island, spreading in the 1940s to WA and Central
  BC. Now in WA, OR, ID, northern CA and San
  Francisco. Found in VA in 1985 and spread
  southwards to SC, GA, and FL.
• Potential Spread Could spread readily throughout
  the USA.
• Known Host Associations A serious pest of
  cultivated peas, Pisum sativum, and on beans,
  sweet peas, alfalfa, various clovers, trefoil,
  wild and cultivated vetch, and chickpea (Bright,
  1994)
• General or Specific Biology Adults feed
  extensively on foliage of host plants and the
  larvae feed on the roots, causing great damage
  and death of many plants.

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Sitona lineatus (Linnaeus) ( Pea Leaf Weevil)

• Diagnosis A small species, 3.2-4.5 mm. in
  length, elongate scarcely oval snout short and
  broad, as wide as frons between eyes prothorax
  with strongly rounded sides, trivittate with pale
  scales, narrower than elytra elytra with strong
  round shoulders, clothed densely with contiguous
  oval recumbent scales, usually metallic, and rows
  of scarcely evident subrecumbent scale like
  setae.
• With lines of pale scales on elytra (lineate),
  often interrupted. Front coxal cavities touch
  groove on apical margin of prosternum.

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Pseudocneorhinus bifasciatus Roelofs
(Twobanded Japanese Weevil)

• Origin Japan, and first recorded from CT in
  1920.
• Distribution New England, West to the Lake
  States, south to the Carolinas and recently
  collected in south GA and north FL.
• Potential Spread The species is spreading
  southward rapidly and is now in southern GA and
  in FL. It has the potential to spread throughout
  the South and may be able to survive in the
  riparian areas of the Central states as well,
  since it can survive long term hard freezes. They
  may easily be spread by shipments of nursery
  plants, since although they are not very small,
  they are very cryptic as adults and in soil on
  roots as larvae.
• Known Host Associations It appears to do well on
  numerous ornamental plants grown in the North and
  South. Among its primary wild and cultivated
  hosts are mountain laurel, great rhododendron,
  European privet, flowering dogwood, and roses.
• General or Specific Biology The adults and
  larvae are typical Entiminae, feeding on leaves
  and roots, respectively. The species is
  parthenogenetic, apterous, and univoltine.

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Pseudocneorhinus bifasciatus Roelofs
(Twobanded Japanese Weevil)

• Diagnosis A small to medium-sized species,
  3.8-5.1 mm. in length fat, convex, round snout
  short and broad prothorax short and broad with
  strongly rounded sides elytra basally strongly
  angled, lacking shoulders, strongly rounded to
  apex, clothed with dense dull brown and paler
  shining metallic pale shingled scales, frequently
  covered by adhering soil at least declivity with
  moderately dense erect acute bristles.
• Dark elytral scales forming two distinct
  transverse bands snout with very deep,
  triangular, apical, median emargination.

10
Trachyphloeosoma advena Zimmerman (No Common
Name)

• Origin Japan
• Distribution Originally described as an
  invasive species in Honolulu HI, where Zimmerman
  assumed it was probably from Japan. In 1984, I
  reported it from Tallahassee FL and AL. It was
  discovered soon after that the species had been
  described from Japan, as a junior synonym of
  Zimmermans species.
• Potential Spread The species is spreading
  northward rapidly and is now in northern GA and
  in SC. It has the potential to spread throughout
  the South and may be able to survive in the North
  and Central states as well, since it can survive
  long term hard freezes. They may easily be spread
  by shipments of nursery plants since they are
  very small and very cryptic as adults and in soil
  on roots as larvae.
• Known Host Associations The species has been
  found feeding on Twin Star and Vacciniaceae. It
  appears to do well on numerous ornamental plants
  grown in the South.
• General or Specific Biology The adults and
  larvae are typical Entiminae, feeding on leaves
  and roots, respectively.

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Trachyphloeosoma advena Zimmerman (No Common
Name)

• Diagnosis A very small species, 1.8-2.4 mm. in
  length, round-oval snout short, broad, ca. half
  as wide as prothorax, latter nearly round elytra
  basally angled, lacking shoulders, sides nearly
  parallel to rounded apex, clothed densely with
  scales, usually concealed by secreted earthen
  like coating, and with dense erect spatulate
  scale like setae.
• The very small size of this broadnosed weevil
  and its erect spatulate setae distinguish it
  readily.

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Diaprepes abbreviatus (Linnaeus) (Diaprepes
Root Weevil)

• Origin Puerto Rico, first collected in Apopka,
  Florida in 1964.
• Distribution In central and southern FL, the
  Brownsville area of the Rio Grande, TX and in
  2005 and 2006 in 3 areas in southern CA and
  widespread in the Greater and Lesser Antilles.
• Potential Spread This species could easily
  spread through citrus growing areas of the US.
  May be, and has been, spread as larvae in soil or
  on roots of nursery stock.
• Known Host Associations This species is a major
  pest of Citrus, but has at least 270 plant
  species on which it is known to feed.
• General or Specific Biology The adults and
  larvae are typical Entiminae, feeding on leaves
  and roots, respectively. This large species is
  bisexual and winged. The larvae produce severe
  damage to the roots and reduce the harvest on
  larger trees and kill the younger plants.

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Diaprepes abbreviatus (Linnaeus) (Diaprepes
Root Weevil)

• Diagnosis A large species, 9.5-19.0 mm. in
  length, elongate oval snout short and broad,
  apex as wide as head, tricarinate prothorax
  broadest at base, sides subparallel to
  constricted apical fourth, some nearly evenly
  narrowed from base to apex elytra with strong
  rounded shoulders, sides subparallel to slightly
  swollen, clothed with dense scales and with
  stripes of bare black cuticle of various lengths,
  scales white and metallic green, often concealed
  by wax like yellow or red coating.
• Very large with striking color, black with
  metallic green scales in large puncture on
  prothorax, striped elytra, and large white spots
  of scales on sides of the meso-, meta-, and
  abdominal sterna.

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Naupactus cervinus (Boheman) (Fullers Rose
Beetle)

• Origin Argentina, It has been known from the US
  from NJ to MT since 1876, when Horn described
  it as a new species, Aramigus fulleri Horn, a
  junior synonym of N. cervinus.
• Distribution Found in southern Canada, New
  England to the Pacific Coast, throughout the
  Southeast, west to AZ. In South America it is
  found widespread in Argentina, Brazil, Chile, and
  Paraguay. It is common in the West Indies and
  Central America, and it is a pest species in
  Africa, Morocco and South Africa and in Europe
  and Australia. It is found in Hawaii and
  Polynesia as well.
• Potential Spread This species could spread
  anywhere in the US where it is not currently
  present.
• Known Host Associations A major pest of a great
  many crops, shrubs, trees and ornamentals.
• General or Specific Biology The adults and
  larvae are typical Entiminae, feeding on leaves
  and roots, respectively. The species is
  parthenogenetic, with a one year life cycle.

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Naupactus cervinus (Boheman) (Fullers Rose
Beetle)

• Diagnosis A medium-sized species, 6.5-8.0 mm. in
  length, elongate broad-oval snout short and
  broad, ca. 2/3 as wide as head, bicarinate
  prothorax with base slightly wider than apex,
  sides weakly rounded, clothed with dense mix of
  scales and setae elytra lacking shoulders, with
  sides strongly rounded behind to strongly
  narrowed subtruncate apex clothed with
  moderately dense not contiguous scales and some
  short recumbent scale like setae.
• This nondescript brown weevil has a distinctive
  white angled band on the sides of the elytra
  which extend to the outer margins can be seen in
  dorsal view. It lacks the erect fine hairlike
  setae of its close relatives. The noncontiguous
  scales also are diagnostic.

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Naupactus leucoloma (Boheman) (White Fringed
Beetle)

• Origin Argentina. First found in FL in 1936.
• Distribution Found throughout the Southeast.
  Reported from CA, and perhaps established there.
  In South America it is found in Argentina,
  Bolivia, Brazil, Paraguay and Uruguay. It has
  been introduced into Chile, Peru, Australia, New
  Zealand and South Africa.
• Potential Spread Could easily spread further
  west to TX, and north through the Smoky
  Mountains.
• Known Host Associations A serious pest of many
  crops, e. g. alfalfa, beans, cotton, lettuce,
  peppers, strawberry, tobacco, and nursery plants.
• General or Specific Biology The adults and
  larvae are typical Entiminae, feeding on leaves
  and roots, respectively. The species is
  parthenogenetic (with bisexual populations known
  in Argentina too) with a one year life cycle.
  This is a large apterous species, which is not
  particularly cryptic, but can be expected to be
  spread in part by larvae on roots in soil on
  nursery plants.

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Naupactus leucoloma (Boheman) (White Fringed
Beetle)

• Diagnosis A medium-sized to large species,
  8.0-12.0 mm. in length, broad-oval snout short
  and broad, ca. 2/3 width of head, bicarinate
  prothorax broad-oval with sides moderately
  rounded, trivittate with shingled white scales
  elytra with scarcely evident small rounded
  shoulders, evenly rounded behind to rounded apex
  clothed with stripes of contiguous white scales
  and subcontiguous grey scales, and with erect
  fine hair like setae.
• Long, fine, erect, hair like setae and fringe
  of white scales along sides of thorax and elytra
  easily seen.

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Naupactus peregrinus (Buchanan) (White Fringed
Beetle)

• Origin Argentina, but described first from the
  USA in Gulfport MS in 1939.
• Distribution Found throughout the Southeast,
  west to TX. In South America it is found
  widespread in Argentina and Paraguay.
• Potential Spread Although this species could
  spread further in the US, it is likely to do so
  slowly or not at all.
• Known Host Associations A minor pest of many
  ornamentals. Its potential importance is based on
  the frequent misidentification with its larger
  relative, the serious pest, N. leucoloma
  (Boheman).
• General or Specific Biology The adults and
  larvae are typical Entiminae, feeding on leaves
  and roots, respectively. The species is
  parthenogenetic (with bisexual populations known
  in Argentina too (Lanteri, 1984)) with a one year
  life cycle.

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Naupactus peregrinus (Buchanan) (White Fringed
Beetle)

• Diagnosis A medium-sized to large species,
  7.0-10.5 mm. in length snout short and broad,
  slightly more than ½ as wide as head prothorax
  with base and apex equally wide, sides evenly
  rounded, most scales shingled, bristle like setae
  mainly suberect elytra lacking evident
  shoulders, clothed with dense, contiguous and
  shingled scales, and mix of short to moderately
  long bristle like setae, scales in medial half
  brown, with stripe of black next to broad white
  lateral stripe.
• Similar to N. leucoloma but usually smaller and
  lacking fine, erect, hairlike setae, and elytra
  laterally with both an inner black and outer
  white stripe.

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Cyrtepistomus castaneus (Roelofs) (Asiatic Oak
Weevil)

• Origin Japan. First found in Montclair NJ in
  1933.
• Distribution Widespread through the Northeast,
  Southeast, and in KS, MO, and CA.
• Potential Spread It is probable that this
  species will expand its range, wherever oaks grow
  in the non-desert regions of the USA.
• Known Host Associations Attacks a number of
  species of oaks and other hardwoods, including
  hickory, beech, red maple, and dogwoods as well
  as raspberry.
• General or Specific Biology The adults and
  larvae are typical Entiminae, feeding on leaves
  and roots, respectively. It is parthenogenetic
  with a one year life cycle. Not apterous, the
  species is known to travel long distances in vast
  numbers from heavy infestations. At such times,
  it has been known to be a nuisance, invading
  homes in huge numbers. He larvae are associated
  especially with oak seedlings where they do a
  great deal of damage. The adults are diurnal,
  feeding on the leaves, leaving only the veins or
  ragged leaves. They are known to defoliate entire
  forests of oaks especially.

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Cyrtepistomus castaneus (Roelofs) (Asiatic Oak
Weevil)

• Diagnosis A small to medium-sized species,
  5.1-6.8 mm. in length snout short and broad,
  narrower towards base, and strongly expanded at
  apex, apex 4/5 as wide as head, tricarinate
  prothorax with base and apex equally wide, sides
  nearly parallel, disk clothed with dense setae,
  and with scales lateral only elytra with strong
  slightly protruding rounded shoulders, reddish to
  black, with medial area with moderately dense
  brownish recumbent setae, lateral areas with oval
  to round noncontiguous metallic gold to green
  scales, freshly emerged specimens often appear
  grey due to wax like secretion.
• Shining reddish to black body, with green to
  gold metallic scales on head and lateral areas of
  pronotum and elytra and very long slender
  antennae extending to middle of prothorax in
  repose.

22
Calomycterus setarius Roelofs (Imported
Longhorned Weevil)

• Origin Japan. First found in NY in 1929.
• Distribution New England, west to WI, south to
  SC, and in the Plains States.
• Potential Spread The wide range of this species
  indicates a potential for no restrictions on its
  distribution in the contiguous 48 states.
• Known Host Associations Known as a pest of
  clovers, alfalfa, roses and numerous ornamentals,
  see Johnson, J. P. for a lengthy list of more
  than 75 host plants (1944).
• General or Specific Biology The adults and
  larvae are typical Entiminae, feeding on leaves
  and roots, respectively. It is parthenogenetic
  with a one year life cycle. Although apterous,
  the species is known to travel long distances in
  vast numbers from heavy infestations. At such
  times, it has been known to be a nuisance,
  invading homes in huge numbers.

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Calomycterus setarius Roelofs (Imported
Longhorned Weevil)

• Diagnosis A small species, 3.5-4.7 mm. in
  length snout short and broad, expanded at apex,
  as wide at base, 2/3 as wide as head, not
  carinate prothorax slightly wider at apex than
  base, sides weakly rounded, disk with dense
  metallic scales and large punctures, each
  puncture with short suberect bristle like seta
  elytra lacking shoulders, strongly rounded behind
  to rounded apex, disk with dense brown to grey
  metallic scales forming uneven mottled pattern,
  strial punctures evident and black, intervals
  each with row of suberect bristle like setae.
• Small and round with no shoulders, nonimbricate
  scales, suberect bristle like setae and long
  antennae extending past the edge of the prothorax
  in repose together distinguish the species.

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Cylas formicarius (Fabricius) (Sweet Potato
Weevil)

• Origin India. Known first in the US from LA in
  1875.
• Distribution In the Southeast, SC to FL west to
  NM in Central America the West Indies South
  America HI Southeast Asia, New Guinea and
  Madagascar.
• Potential Spread It is probable that this
  species will not expand its range in the USA.
  However it is a significant pest where it is
  found.
• Known Host Associations A primary pest of sweet
  potatoes, Ipomoea batata, and breeds also in
  stems of seaside morning glory, Ipomoea
  pes-capreae Linnaeus.
• General or Specific Biology This is an atypical
  member of the family Brentidae. The adults and
  larvae feed by preference on and in sweet potato
  tubers and stems. It is bisexual and fully
  winged, although frequently reported erroneously
  to be apterous. It has 5 to 8 generations per
  year in the South. All stages overwinter and do
  not diapause. Feeding by larvae and adults
  produces chemicals in the tubers that affect
  their smell and make the tuber unpalatable as
  well. It is as serious a pest in storage as in
  the field.

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Cylas formicarius (Fabricius) (Sweet Potato
Weevil)

• Diagnosis A medium-sized species, 5.5-8.0 mm in
  length snout long and moderately slender, nearly
  straight in dorsal and lateral view antennae
  straight, single segmented club elongate, in male
  longer than remainder of antenna prothorax
  distinctly shaped, broadest behind apex, then
  strongly constricted and moderately swollen
  behind constriction to slightly narrowed base
  elytra with weak angulate shoulders, weakly
  expanded behind to truncate-emarginate apex.
• Distinct species with black head and rostrum,
  orange thorax and legs and blue elytra and
  abdomen glabrous (no setae, no scales), eyes
  covered with crystalline lens.

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Oedophrys hilleri (Faust) (No Common Name)

• Origin Japan
• Distribution Found in New England south to SC
  and west to KY.
• Potential Spread This species could easily
  spread south and west in the areas of woodlands.
• Known Host Associations To date, this is a minor
  pest of ornamentals, especially roses. It feeds
  on shrubs and has potential to become a nursery
  pest.
• General or Specific Biology The adults and
  larvae are typical Entiminae, feeding on leaves
  and roots, respectively. The species is
  parthenogenetic.

27
Oedophrys hilleri (Faust) (No Common Name)

• Diagnosis A small species, 3.1-4.9 mm. in
  length snout short and broad, nearly as wide at
  apex as width of head prothorax scarcely wider
  at apex than at base, sides scarcely rounded,
  disk with surface undulate, clothed with dense
  shingled scales, with small punctures each with
  short subrecumbent truncate scale like seta
  elytra with strong protruding shoulders, sides
  gradually expanding to widely rounded apical
  third then narrowed to rounded apex, clothed
  densely with shingled brown, black, and whitish
  scales, each interval with single row of suberect
  brown and white bristle like setae.
• Nondescript species with long antennae reaching
  past anterior margin of prothorax unevenly
  mottled pattern of scales, often with two black
  marks on the elytral posterior third sides of
  elytra not evenly rounded and only moderately
  long, bristle like, suberect setae.

28
Polytus mellerborgii (Boheman) (Lesser Banana
Weevil)

• Origin Indo-Malaya. First found in Miami FL in
  2007.
• Distribution Widespread through the tropical
  banana growing world. Recently found in Ecuador,
  the first record for South America.
• Potential Spread It is probable that this
  species will not expand its range in the US. In
  general, it is considered a secondary, minor
  pest.
• Known Host Associations Musa, banana.
• General or Specific Biology The adults and
  larvae bore in the decaying corms and stalks of
  banana. They can develop in the wettest parts of
  the plants and have been distributed by commerce.
  Now placed in the family Dryophthoridae.

29
Polytus mellerborgii (Boheman) (Lesser Banana
Weevil)

• Diagnosis A small species, 3.6-4.7 mm. in
  length, elongate oval snout long and narrow,
  swollen somewhat at base, apex subcylindrical and
  ca. ½ width of head prothorax elongate, apically
  narrow and strongly constricted, sides evenly
  expanding to broad base, disk shining black with
  dense punctures, bottom of each with grey
  coating, elytra with scarcely evident shoulders,
  behind evenly strongly narrowed to rounded apex,
  intervals narrower than striae, all punctures
  with grey coating, otherwise shining black and
  glabrous.
• A distinctive species with 6 segmented antennal
  funicle, club basally glabrous with less than
  apical ½ pubescent glabrous black body, with
  specialized tomentose grey matte coating,
  especially on underside and appendages.

30

• BRENTIDAE
• Apionidae
• Cyladidae
• Cyladinae
• Cylas Latreille 1802
• Cylanus Rafinesque 1815
• Protocylas Pierce 1941
• formicarius (Fabricius) 1798 (Brentus)
• formicarius elegantulus (Summers) 1875
  (Otidocephalus)
• CURCULIONIDAE Latreille 1802
• Cyclominae Schoenherr 1826
• Hipporhinides Lacordaire 1863
• Listroderes Schoenherr 1826
• difficilis Germain 1895
• hypocritus Hustache 1926
• nociva (Lea) 1909 (Desiantha
• novica (French) 1908 (Desiantha)
• obliquus Klug 1829

31

• Entiminae Schoenherr 1823 (continued)
• Diaprepes Schoenherr 1923
• abbreviatus (Linnaeus) 1757 (Curculio)
• festivus (Fabricius) 1792-476 (Curculio)
• irregularis (Panzer) 1798-67 (Curculio)
• also incorrectly attributed to Voet
• japonensis (Voet) 1806-52 (Curculeones)
• v. brevis (Olivier) 1790-549 (Curculio)
• quadrilineatus (Olivier) 1807-310(Curculio)
• v. distinguendus Gyllenhal 1834-10
• festivus (Olivier) 1807-312 (Curculio)
• not Fabricius 1792
• vicinus Dejean 1834-252 1837-275 nomen
  nudum
• v. guadeloupensis Gyllenhal 1834-11
• guadelupensis Hustache 1929-184
• not guadeloupensis Gyllenhal 1834
• Myosides Roelofs 1873
• sereihispidus Roelofs 1873
• Myllocerus Schoenherr 1823

32

• Naupactus Dejean 1821 (continued)
• leucoloma Boheman 1840
• dubius (Buchanan) 1942-109 (Pantomorus)
• pilosus (Buchanan) 1942-107 (Pantomorus)
• striatus (Buchanan) 1942-108 (Pantomorus)
• peregrinus Buchanan 1939 (Pantomorus)
• Oedophrys Marshall 1941
• hilleri (Faust) 1889 (Myllocerus)
• Pseudocneorhinus Roelofs 1873
• bifasciatus Roelofs 1880
• Sitona Germar 1817
• Sitones Schoenherr 1840 lineatus (Linnaeus)
  1758 (Curculio)
• Trachyphloeosoma Wollaston 1869
• advena Zimmerman 1956
• DRYOPHTHORIDAE Schoenherr 1823
• Rhynchophorinae Schoenherr 1833