United States 

Department of 

Agriculture

Marketing and 

Regulatory 

Programs

Animal and 

Plant Health 

Inspection 

Service

Field Release of Lilioceris 

cheni Gressit & Kimoto 

(Coleoptera: 

Chrysomelidae) for 

Biological Control of Air 

Potato, Dioscorea 

bulbifera (Dioscoreaceae),

in the Continental United 

States

Environmental Assessment,

September, 2010
Field Release of Lilioceris cheni 

Gressit & Kimoto (Coleoptera: 

Chrysomelidae) for Biological 

Control of Air Potato, Dioscorea 

bulbifera (Dioscoreaceae), in the 

Continental United States

Environmental Assessment, 

September, 2010

Agency Contact:

Shirley Wager-Page, Branch Chief

Pest Permitting

Plant Protection and Quarantine

Animal and Plant Health Inspection Service

U.S. Department of Agriculture

4700 River Road, Unit 133

Riverdale, MD 20737–1236

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program information (Braille, large print, audiotape, etc.) should contact 

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Rights, Room 326–W, Whitten Building, 1400 Independence Avenue, SW, 

Washington, DC 20250–9410 or call (202) 720–5964 (voice and TDD). 

USDA is an equal opportunity provider and employer. 

Mention of companies or commercial products in this report does not imply 

recommendation or endorsement by the U.S. Department of Agriculture 

(USDA) over others not mentioned. USDA neither guarantees or warrants 

the standard of any product mentioned. Product names are mentioned 

solely to report factually on available data and to provide specific information.

This publication reports research involving pesticides. All uses of pesticides

must be registered by appropriate State and/or Federal agencies before they 

can be recommended.

CAUTION: Pesticides can be injurious to humans, domestic animals, 

desirable plants, and fish or other wildlife–if they are not handled or applied 

properly. Use all pesticides selectively and carefully. Follow recommended 

practices for the disposal of surplus pesticides and pesticide containers.
Table of Contents

Purpose and Need for the Proposed Action....................... 1

Alternatives ........................................................................... 2

Affected Environment........................................................... 5

Environmental Consequences............................................. 7

Other Issues ........................................................................ 14

 

Agencies, Organizations, and Individuals Consulted...... 15

 

References........................................................................... 17

Table 1. Seven Categories of Plants Considered for the Test 

Plant List........................................................................ 9

Appendix A

Appendix B

Appendix C

Appendix D

Appendix E

Appendix F
1

I. Purpose and Need for the Proposed 

Action

The U.S. Department of Agriculture (USDA), Animal and Plant Health 

Inspection Service (APHIS), Plant Protection and Quarantine (PPQ) Pest 

Permitting Branch (PPB) is proposing to issue permits for release of the 

insect Lilioceris cheni (Coleoptera: Chrysomelidae). The agent would be 

used by the applicant for biological control of air potato, Dioscorea 

bulbifera L. (Dioscoreaceae), in the continental United States. Before 

permits are issued for release of L. cheni, the APHIS–PPQ PPB needs to

analyze the potential impacts of the release of this agent into the 

continental United States.

This environmental assessment1(EA) has been prepared, consistent with 

USDA–APHIS' National Environmental Policy Act of 1969 (NEPA) 

implementing procedures (Title 7 of the Code of Federal Regulations 

(CFR), part 372). It examines the potential effects on the quality of the 

human environment that may be associated with the release of L. cheni to 

control infestations of air potato within the continental United States. This 

EA considers a ―no action‖ alternative and the potential effects of the 

proposed action.

The applicant‘s purpose for releasing L. cheni is to reduce the severity of 

infestations of air potato (Dioscorea bulbifera) in the continental United 

States. Air potato is a twining vine 65 feet long or greater, capable of 

climbing and out-competing native vegetation (e.g., Schmitz et al., 1997; 

Langeland and Craddock Burks, 1998; Gordon et al., 1999). Air potato

was introduced to Florida as an ornamental from tropical Asia or Africa in 

1905 (Morton, 1976), and it now constitutes one of the most aggressive 

weeds ever introduced to Florida (Hammer, 1998). By the 1980s, this 

vine was found growing in thickets, waste areas, and hedges or fencerows 

in south and central Florida (Bell and Taylor, 1982). By 1999, air potato

was listed in Florida as a noxious weed by the Florida Department of 

Agricultural and Consumer Services (FDACS) (FLEPPC, 2003). Air 

potato is considered the most serious type of environmental threat, 

described as a Category I weed by the Florida Exotic Pest Plant Council 

(FLEPPC) (FLEPPC, 2003), ―invasive exotics that are altering native 

plant communities by displacing native species, changing community 

structure or ecological functions, or hybridizing with natives.‖ Presently,

air potato is well established in Florida and probably throughout the Gulf 

states (Raz, 2002) where it has the potential to severely disrupt entire 

ecosystems (Hammer, 1998). 

 

1

Regulations implementing the National Environmental Policy Act of 1969 (42 

United States Code 4321 et seq.) provide that an environmental assessment “[shall include brief 

discussions of the need for the proposal, of alternatives as required by section 102(2)(E), of the 

environmental impacts of the proposed action and alternatives, and a listing of agencies and persons 

consulted” (40 CFR § 1508.9). 
2

Existing air potato management options (discussed below) are ineffective, 

expensive, temporary, or have non-target impacts. For these reasons, the

applicant has a need to identify an effective, host-specific biological 

control organism and release it into the environment for the control of air 

potato. 

II. Alternatives

This section will explain the two alternatives available to the APHIS–PPQ

PPB—no action (no issuance of permits) and issuance of permits for 

environmental release of L. cheni. Although APHIS‘ alternatives are 

limited to a decision of whether to issue permits for release of L. cheni, 

other methods available for control of air potato are also described. These 

control methods are not decisions to be made by APHIS, and are likely to 

continue whether or not permits are issued for environmental release of L. 

cheni. These are methods presently being used to control air potato by 

public and private concerns. 

A third alternative was considered, but will not be analyzed further. 

Under this third alternative, the APHIS–PPQ PPB would have issued 

permits for the field release of L. cheni, however, the permits would 

contain special provisions or requirements concerning release procedures 

or mitigating measures, such as limited release of L. cheni. No issues have 

been raised which would indicate that special provisions or requirements 

are necessary.

A. No Action 

Under the no action alternative, the APHIS–PPQ PPB would not issue 

permits for the field release of L. cheni for the control of air potato—the 

release of this biological control agent would not take place. The 

following methods are presently being used to control air potato; these 

methods will continue under the ―no action‖ alternative and are likely to 

continue even if permits are issued for release of L. cheni. Presently, 

control of air potato populations is limited to chemical and mechanical 

control or a combination of these two methods.

Chemical control of vines requires repeated basal (cut stem) or foliar 

applications of triclopyr ester, triclopyr amine, and glyphosate herbicides 

(e.g., RemedyTM, Garlon 3ATM, or RoundupTM) and these treatments need to 

be repeated over a two or three year period (Mullahey and Brown, 1999). 

Herbicidal control with RoundupTM and RodeoTM of heavily infested areas 

(e.g., Fern Forest, Broward County Florida) that included other invasive 

weeds cost $1,750/hectare/year. In this example, complete control was 

not achieved as re-sprouting continued despite three herbicide treatments 

during nearly two years. 

1. Chemical 

Control
3

Manual removal of aboveground plants and bulbils (aerial tubers; small 

bulb or bulb-shaped growth arising from the leaf axil or in the place of 

flowers) has become a common activity employed by diverse volunteer 

groups (Duxbury et al., 2003). Manual removal of plants and bulbils was 

found to be as effective at controlling air potato as a combination of 

herbicide (e.g. RoundupTM) and hand pulling (Gordon et al., 1999).

B. Issue Permits for Environmental Release of 

L. cheni.

Under this alternative, the APHIS–PPQ PPB would issue permits upon 

request and after evaluation of each application for the field release of L. 

cheni for the control of air potato wherever it occurs in the continental 

United States. These permits would contain no special provisions or 

requirements concerning release procedures or mitigating measures.

a. Biological control organism information

Insect Taxonomy

Order: Coleoptera

Family: Chrysomelidae 

Subfamily: Criocerinae

Genus: Lilioceris Reitter

Species: cheni

Common name none

Lilioceris spp. adult beetles are typically 1 cm long by 0.5 cm wide at the 

abdomen. The beetle is a shiny patent leather black color except for its 

tan/light orange or bright red wing covers. The shape of the beetle is 

elongate, with a rectangular shaped abdomen, a thorax narrow and about 

half as wide as the abdomen, and narrow heads with bulging eyes. The 

shape somewhat resembles a square violin with a short neck.

Specimens of L. cheni were identified by Dr. Alex Konstantinov at the 

USDA, Agricultural Research Service, Systematic Entomology 

Laboratory (A. Konstantinov, pers. comm., June 7, 2010).

Overwintered adult females begin egg laying (oviposition) at the end of 

May and continue through mid June. The oviposition period averages

around 49 days with 13 active (effective) days of oviposition per female. 

Beetles lay an average of approximately 1,223 per female, or about 90 

eggs per female per active oviposition date. Mean egg hatch is nearly 80

percent. The mean incubation period for eggs is approximately four days.

2. Mechanical 

Control

1. Description

3. Life History

2. Taxonomic 

Information
4

Lilioceris eggs are entirely pale white when first laid. As the larvae inside 

develop, the eggs become more yellow, and later, the anterior end of the 

eggs becomes clear. Two days before hatching, two distinct patches of 

light maroon spots are visible that become the eyes of the larva.

The larvae are brown, soft bodied, and somewhat slug-like, except for the 

six legs and head capsule. They are yellow in the first two instars (larval 

developmental stages), but become dark grey before pupation. Lilioceris

larvae feed together in a group (gregariously) and skeletonize the leaves 

while moving across the undersides of the leaves, exuding frass (insect 

feces) onto their backs, producing a fecal shield. This fecal shield can 

deter predators, but can also attract parasites, (Schaffner and Müller,

2001). The larvae prefer tender, newly-emerged air potato leaves, but can 

also eat older toughened leaves. Early instar larvae can consume air 

potato bulbils if there is an initial tear through its surface, but more mature 

larvae can eat intact bulbils without difficulty. The average larval 

development period is approximately eight days (Pemberton, 2009).

When Lilioceris larvae finish feeding in their fourth instar, they move 

from the vines and enter the soil. The larvae secrete a white substance 

from their mouths and form a cocoon in which they pupate. The substance 

hardens to a Styrofoam-like substance. Pupation in the soil is done 

gregariously, often in clumps of six to eight individuals joined by the 

white StyrofoamTM-like substance. The pupal stage lasts approximately 

16 days. 

Lilioceris cheni has been reported from China, India, Laos, and Nepal. 

Pemberton (2009) found L. cheni in the subtropical Katmandu Valley of 

Nepal at approximately 27 degrees North, and in the Chiang Mai area of 

northern Thailand and in subtropical Xishuanbanna in southern Yunnan 

Province of China at about 22 degrees North (Pemberton, 2009). 

Lilioceris cheni is known only from subtropical and tropical areas of Asia. 

During the cool dry winter season its host plant, air potato, loses its leaves 

and the adult beetles seek shelter beneath debris on the ground. In the 

Katmandu Valley (4000 feet and approximately 28 degrees N) the source 

of the studied beetles, there are periodic frosts. This sheltering behavior of 

the beetles allows them to survive these conditions to successfully over 

winter. This may also allow the beetles to survive in northern Florida and 

the Gulf Coast states where air potato currently grows. Because these 

beetles are host specific to air potato, they will be limited to the current 

and potential geographic range of this plant in North America, which is 

Florida, the Gulf Coast areas and the adjacent interior areas.

Both the adults and larvae of L. cheni consume the leaves and aerial 

4. Native Range

6. Impact on 

Air Potato

5. Potential 

North American 

Range
5

bulbils of air potato. The larvae feed gregariously and quickly skeletonize 

leaves. The amount of leaf consumption by this beetle is very large. 

During the development of a single larva, it consumes approximately 11

square feet of leaf tissue, and the adults, which can live three months or 

more, can eat another 20 square feet of leaf. Thus, a single individual 

beetle can consume approximately 30 square feet of leaf tissue

(Pemberton, 2009). In laboratory studies, potted plants defoliated by L. 

cheni re-grew slowly. The ability of the beetle larvae and adults to feed 

on the bulbils is also important because in the United States the weed 

rarely flowers or produces fruit, so the aerial tubers are the primary means 

of air potato persistence and spread. In laboratory studies, even minimal 

bulbil feeding on the shoot area by L. cheni greatly decreased the bulbil‘s 

ability to sprout, reducing the plant‘s reproductive capacity. 

III. Affected Environment

Air potato is an herbaceous, perennial, twining vine 65 feet long or 

greater, capable of climbing and out-competing native vegetation (e.g., 

Schmitz et al., 1997; Langeland and Craddock Burks, 1998; Gordon et al.,

1999). Air potato was introduced to Florida as an ornamental from 

tropical Asia or Africa in 1905 (Morton, 1976), and it now constitutes one 

of the most aggressive weeds ever introduced to Florida (Hammer, 1998). 

By the 1980s, this vine was found growing in thickets, waste areas, and 

hedges or fencerows in south and central Florida (Bell and Taylor, 1982). 

A. Areas Affected by Air Potato

Air potato is native to and widely distributed in tropical and subtropical 

Asia and Africa (Burkill, 1960; Coursey, 1967; Tindall, 1993). In the 

Western Hemisphere, it is widely naturalized in the tropics and subtropics 

of the West Indies, Central, and South America (McVaugh, 1989; Schultz,

1993). Air potato is naturalized in central and southern Mexico (Colima, 

Mexico, Puebla, Veracruz, San Luis Potosi, Oaxaca, and Chiapas states), 

and the West Indies (USDA, SCS, 1982; Nesom and Brown, 1998; 

USDA, NRCS, 2002). It is reported to be established in Central America 

and northern South America (Tellez and Schubert, 1994; Bennett and 

Prance, 2000).

Since its introduction to Florida, air potato has aggressively spread 

throughout the state. From the northwestern panhandle, Escambia County, 

to the southern tip of the state, collections from herbaria and reports from 

biologists have listed 29 of 67 Florida counties infested with air potato

(Schmitz, 1994; Gann et al., 2001; Wunderlin and Hansen, 2003). This 

species has also been reported to be naturalized in Mississippi, Louisiana, 

Texas, and Hawaii (Nesom and Brown, 1998; USDA, SCS, 1982).

2. Present 

Distribution in 

the United 

States

1. Native and 

Worldwide 

Distribution
6

Based on the known range of air potato in North America, the plant can 

survive in areas with an average annual minimum temperature range of 

-12.2 to -9.5 C (10 to 15°F). Climatic data (minimum January temperature 

and annual rainfall) from locations where air potato is known to occur in 

Florida have been extrapolated outside of Florida to estimate its potential 

distribution in the United States (Pemberton, 2009). These data suggest 

that air potato may be able to spread throughout much of the Gulf coast 

and along the Atlantic coast as far north as Charleston, South Carolina

(Pemberton, 2009).

In Florida, air potato is frequently found in tropical and subtropical 

hammocks. A hammock is a dense stand of trees that grows on natural 

rises that are only a few inches higher than surrounding marshland. Air 

potato may also invade disturbed uplands, scrub, sinkholes, alluvial flood 

plain forests, and urban lots (Schultz, 1993; Gann et al., 2001), pinelands 

(Langeland and Craddock-Burks, 1998), and hedges or fencerows (Bell 

and Taylor, 1982). Evidence also suggests that air potato aggressively 

exploits disturbed sites, such as forest canopies damaged by hurricanes, 

and it impedes the reestablishment of native species (Horvitz et al., 1998; 

Gordon et al., 1999).

B. Plants Related to Air Potato and Their Distribution

Information regarding plants taxonomically related to air potato 

(Dioscorea bulbifera) is included because native plant species which are 

closely related to air potato have the most potential to be attacked by L. 

cheni.

The Dioscoreaceae (the plant family to which air potato belongs) includes 

either four (Caddick et al., 2002) or seven genera (Al-Shehbaz and 

Schubert, 1989; Raz 2002). The largest genus in the family, Dioscorea, 

contains approximately 600 species (Raz, 2002) (850 species according to 

Al-Shehbaz and Schubert, 1989), most of which grow in the subtropics or 

tropics, with only a few species growing in the warmer temperate regions 

(Al-Shehbaz and Schubert, 1989; Raz, 2002). The Dioscorea genus is 

grouped into subgeneric sections. The two native North American (north 

of Mexico) species, D. floridana Barlett (Florida yam) and D. villosa L. 

(wild yam), are assigned to the section Macropoda (Knuth, 1924; Raz,

2002). Traditionally air potato (D. bulbifera) has been placed in section 

Opsophyton (Knuth, 1924; Huber, 1998). Rajania, an endemic genus in 

the West Indies (Raz, 2002), is the only other genus of the Dioscoreaceae 

in North America. Although this genus is being revised (L. Raz, unpubl. 

data), the center of origin appears to be Cuba with 19 species distributed 

throughout the West Indies (Knuth, 1924; Raz, 2002).

In the Western Hemisphere, approximately 130 Dioscorea species occur 

in Brazil and 120 in Central America and Mexico (Al-Shehbaz and 

1. Taxonomically 

Related Plants

3. Habitat
7

Schubert, 1989). The most comprehensive treatment of the Mexican 

Dioscorea included 63 species (Matuda, 1953). Six Dioscorea species 

occur in the southeastern United States (Al-Shehbaz and Schubert, 1989; 

Raz, 2002) and, of these, four are naturalized from Asia and two are native 

(D. floridana and D. villosa) (Raz, 2002). There are nine native 

Dioscorea spp. and 19 species of the genus Rajania from the West Indies 

(Knuth, 1924; Raz, 2002; L. Raz, unpubl. data) with their greatest 

diversity in Cuba (Leon and Alain, 1974; L. Raz, unpubl. data). 

The closest Dioscorea species that occur in the northern extent of this 

range are south of the Texas border in the states of Chihuahua, Coahuila, 

Nuevo Leon, and Tamaulipas, Mexico. Dioscorea species that occur in 

these states that are hosts of biological control agents could potentially 

provide a bridge between D. bulbifera populations in Texas to more 

southern Dioscorea species in the state of Veracruz, Mexico, and 

southward. The only Dioscorea species known from this northern 

 ̳bridging area‘ are D. convolvulacea (Barrera, 1990), D. militaris, and D. 

remotiflora (McVaugh, 1989) and these are only reported from the state of 

Tamaulipas, south of the Texas border. In Texas, D. bulbifera is not 

known to be widespread (B.L. Turner and T. Wendt, University of Texas; 

and M.D. Reed, TAMU herbarium, Texas A&M University, personal. 

comm.). However, a few scattered specimens have been collected from 

wild plant populations (USDA, NRCS, 2002) in the eastern part of the 

state (Nesom and Brown, 1998). 

IV. Environmental Consequences 

A. No Action

a. Effects of air potato on native plants and animals

Air potato often dominates habitats that it invades, displacing native plants 

and the animals that depend on them. Air potato vines blanket native 

vegetation so completely that they may be injured or killed by shading 

(Langeland and Craddock Burks, 1998). Sometimes, air potato 

completely covers other vegetation so it is not possible to see other plants 

beneath it. Air potato is one of the more common natural area weeds in 

central and southern Florida. In southern Florida, the weed occurs in 15.2

percent of 315 of the conservation areas and 25 percent of 48 of the 

habitats surveyed (Gann et al., 2001). Air potato has a long-term impact 

on the community structure by invading and dominating sites following 

hurricane disturbance (Gordon et al., 1999).

Air potato is a Category I Florida Exotic Pest Plant Council plant. 

Invasive plants are assigned the Category I rating when they are 

1. Impact of Air 

Potato on the 

Environment
8

understood to alter native plant communities by displacing native species, 

changing community structure or ecological functions.

b. Beneficial uses of air potato

Air potato was originally introduced into the United States as an 

ornamental and perhaps to a limited degree as a food plant by immigrants 

from the West Indies, where it is occasionally cultivated (Coursey, 1967).

Dioscorea alata is the more popular yam used as an ethnic West Indian 

food plant, but home cultivation of this species in Florida is uncommon. 

No purposeful known cultivation of air potato in Florida is known and no 

commercial cultivation of other Dioscorea species is known in Florida. 

The attractive leaves and rapid lush growth promoted the introduction of 

the plant and the early use of it in Florida as an ornamental. Purposeful 

cultivation of the plant as an ornamental occurred to some degree for 

approximately 40 years (Long and Lakela, 1971), and may still occur

occasionally, but ornamental cultivation is problematic because it could 

result in new infestations of the weed. 

The continued use of chemical herbicides and mechanical controls at 

current levels would result if the ―no action‖ alternative is chosen, and 

may continue even if permits are issued for environmental release of L. 

cheni.

a. Chemical Control

Chemical control of air potato is expensive ($1,750/hectare/year) and 

requires multiple years of treatment to be effective. The herbicidal control 

has additional costs as non-target species, such as natives, may be injured 

due to the non-selective nature of these products.

b. Mechanical Control

Mechanical control can be effective in controlling air potato in accessible 

locations, but is expensive, labor-intensive, and results are short term. 

Plants that are located in natural areas, such as hammocks, may be 

difficult or impossible to access.

These environmental consequences may occur even with the 

implementation of the biological control alternative, depending on the 

efficacy of L. cheni to reduce air potato infestations in the continental 

United States. 

2. Impact from 

the Use of 

Other Control

Methods
9

B. Issue Permits for Environmental Release of L. 

cheni

Host Specificity Testing

Host range determination of L. cheni was based on plant species in seven 

categories listed in table 1 (Pemberton, 2009). 

Table 1. Seven Categories of Plants Considered for the Test Plant List. 

These plants were used for host specificity tests using L. cheni and were 

conducted in quarantine facilities.

Category 1—Genetic Type of the Target Weed Species (Air Potato).

Genus and Species Common Name Status

Dioscorea bulbifera air potato Native Asia & Africa; 

Cultivated West 

Indies; Introd. MS, LA 

TX, HI, and FL

Category 2—Species in the Same Genus (Dioscorea) as Air Potato.

Genus and Species Common Name Status

Dioscorea floridana Florida yam Native FL, GA and SC

Dioscorea villosa Wild yam Native FL north to 

Ontario,Canada and 

MN, west to TX.

Dioscorea altissima dunguey PR; exotic-native to 

Brazil

Rajania cordata (Dioscorea) cordata himber Cuba; Jamaica; 

Puerto Rico

Dioscorea pilosiuscula bulbous yam Hispaniola; Puerto 

Rico; VI; Jamaica

Dioscorea polygonoides mata gallina Hispaniola; Puerto 

Rico; Cuba; Jamaica

Dioscorea trifida cush cush yam West Indies; S. 

American, cultivated

Dioscorea alata white yam Native Africa Eastern 

US, PR, VI, Invasive in 

FL

Dioscorea cayenensis chinese yam Introduced FL north to 

VT

Dioscorea polystachya yellow guinea yam Cultivated West 

Indies; African

Dioscorea polystachya cultivated Chinese 

yam

Eastern US weed; 

Cultivation limited; 

Indochina

Dioscorea rotundata guinea yam Cultivated West 

Indies; African

Dioscorea sansibarensis Zanzibar yam Native East Africa 

Eradicated from FL

Disocorea trifida cush cush yam West Indies; S. 

American, cultivated

1. Impact of 

L. cheni on 

Non-target 

Plants
10

Category 3—Species in Other Genera but in the Same Family.

(Dioscoreaceae) as Air Potato.

Genus and Species Common Name Status

Tacca integrifolia bat flower Native Indochina, 

Malaysia; 

Ornamental in FL

Category 4—Threatened and Endangered Species in the Same Family as 

Air Potato.

There are no federally listed threatened or endangered species in the plant 

family Dioscoreaceae.

Category 5—Species in the Same Order (Liliales) as Air Potato.

Family, Genus, and Species Common name Status

Liliaceaceae; Lilium sp . lily Ornamental nonnative, native 

species occur in FL

Liliaceaceae; Zephyranthes grandiflora . rosepink zephyr lily Rare; Native FL & 

Mexico

Nartheciaceae; Aletris farinosa white colicroot Native Central N 

America & E. 

Canada

Smilacaceae; Smilax laurifolia laurel greenbrier Native Central N. 

America, Bahamas 

& Cuba

Category 6—Plant Species in Orders Other than Air Potato.

Order F Genus Family Species Common Name Status

Acrecaceae Arecales cabbage 

palm

Native SE US, 

Bahamas & 

Cuba

Alismatales Alismataceae Sagittaria latifolia broadleaf 

arrowhead

Native N. 

America

Asparagales Amaryllidaceae Crinum americanum Seven 

sisters

Native SE US; 

Invasive PR

Asparagales Iridaceae Iris virginica Virginia iris Native E. N. 

America; widely 

cultivated

Commelinales Commelinaceae Tradescantia ohiensis Ohio 

spiderwort

Native NE USA

Commelinales Pontederiaceae Pontederia cordata pickerelweed Native NE USA

Fabales Fabaceae Cassia (Senna) ligustrina privet wild 

sensitive 

plant

Native Africa & 

Asia; Inroduced 

Neotorpics: VI

Pandanales Pandanaceae Pandanus spiralis screw pine Native Australia

Poales Cyperaceae Cladium jamaicense Jamaica 

swamp 

sawgrass

Native Australia; 

Southern N. 

America; HI & 

PR

Poales Juncaceae Juncus effusus soft rush Cosmopolitan in 

temperate 

wetlands 
11

Order F Genus Family Species Common Name Status

worldwide

Poales Poaceae Saccharum officinarum sugarcane Native Asia; 

Cultivated FL to 

TX 

Lamiales Verbenaceae Callicarpa americana American 

beauty berry

FL, SE US

Zingerbales Cannaceae Canna flaccida bandana of 

the 

Everglades

Native

Neotropics: 

Widely cultivated

Zingerbales Cannaceae Canna indica indian shot Native to tropics; 

exotic

Zingerbales Coastaceae Costus woodsonii red button 

ginger

Native Asia & 

PR; cultivated 

widely in tropics

Zingerbales Heliconiaceae Heliconia caribaea lobsterclaw Native 

Caribbean; 

cultivated exotic

Haloragales Marantaceae Thalia geniculata alligatorflag Native Africa, N 

and S Americas; 

Invasive FL

Zingerbales Zingerberaceae Hedychium coronarium butterfly ginger Native Asia; 

exotic FL, GA, 

LA, HI & PR

Zingerbales Musaceae Musa acuminata edible banana Native Asia & 

Africa; cultivated 

widely in tropics

Category 7—Any Species on which L. cheni or its Close Relatives are 

Found.

Plant Order, Family, Genus,

and Species

L. cheni or Relatives Status

Dioscoreales, Dioscoraceae, 

Dioscorea alata

L. cheni Native to Africa. 

Introduced into GA, 

LA, PR, Virgin 

Islands. Invasive in 

FL

Urticales; Moraceae, 

Ficus elastica

L. cheni Native to Asia; 

Introduced into FL 

& PR; widely 

cultivated

Fabales; Fabaceae, 

Cassia (Senna) ligustrina*

L. cheni Native to Africa & 

Asia; Introduced 

into Neotropics; 

Virgin Islands

Lamiales; Verbenaceae; Callicarpa 

americana*

L. cheni Native to the SE 

USA and 

Caribbean

Asparagales; Asparagaceae;

Asparagus officinalis

Crioceris sp. Native N Africa 

Europe & Asia; 

Widely cultivated

Asparagales; Asparagaceae;

Asparagus sprengeri

Criocerus sp. Native S. Africa; 

Introduced into 

Australia, New 

Zealand, West 

Indies, FL, CA, & 

HI

*Target agent found on Cassia sophera and Callicarpa macrophylla
12

(1) Feeding and Survival Testing 

In no-choice testing slight feeding occurred on three Dioscorea species 

besides air potato (appendix B). In all choice tests, adult feeding occurred 

only on air potato (appendix C and D). 

In tests where L. cheni eggs were transferred directly to Dioscorea species 

test plants (air potato, Dioscorea altissima, Dioscorea floridana, 

Dioscorea polystachya, and Dioscorea villosa), 100 percent of larvae 

successfully hatched from the transferred eggs. First instar larvae died on 

all test plants without feeding except for air potato. Larvae hatched from 

eggs transferred onto air potato leaves fed immediately and began to grow 

(appendix E). 

(2) Oviposition Testing 

Three Dioscorea species (air potato and two native species) were used in 

oviposition studies (Pemberton, 2009). The native Dioscorea plants were 

used because they are the most closely related to air potato in Florida and 

thus would be considered at highest risk for attack by L. cheni. In testing, 

egg masses were laid on the two test species, Dioscorea villosa, and 

Dioscorea floridana, and the control, air potato (D. bulbifera).

Oviposition was consistently lower on test plants than on air potato. In 

these studies, neither larval feeding nor adult feeding was documented on 

either test plant but occurred on air potato (appendix F).

(3) Discussion

In host specificity testing conducted in the laboratory, this 

tropical/subtropical beetle, L. cheni, was found to be host specific to the 

target weed Dioscorea bulbifera (Pemberton, 2009). Although L. cheni

laid eggs on other Dioscorea plant species tested, no larvae were able to 

develop to the adult stage except on air potato. Very small amounts of test 

feeding by adult L. cheni were observed on the two North American and 

Florida native yams (D. floridana and D. villosa), and a naturalized weed 

(D. polystachya), and a Brazilian species naturalized in Puerto Rico (D. 

altissima), but larvae were unable to feed on the leaves of any of these 

Dioscorea species. In addition, there was no feeding or development by 

L. cheni on any cultivated Dioscorea species or plant representatives of 

monocot orders tested. 

Once a biological control agent, such as L. cheni, is released into the 

environment and becomes established, there is a slight possibility that it

could move from the target plant (air potato) to attack non-target plants, 

such as the native plants D. villosa or D. floridana. Host shifts by 

2. Uncertainties 

Regarding the 

Environmental 

Release of L. 

cheni 

cheniM. scutell

aris 
13

introduced weed biological control agents to unrelated plants are rare 

(Pemberton, 2000). Native species closely related to the target species are 

the most likely to be attacked (Louda et al., 2003). If other plant species 

were to be attacked by L. cheni, the resulting effects could be 

environmental impacts that may not be easily reversed. Biological control 

organisms such as L. cheni generally spread without intervention by man. 

In principle, therefore, release of this biological control agent at even one 

site must be considered equivalent to release over the entire area in which 

potential hosts occur, and in which the climate is suitable for reproduction 

and survival.

In addition, these agents may not be successful in reducing air potato

populations in the continental United States. Worldwide, biological weed 

control programs have had an overall success rate of 33 percent; success 

rates have been considerably higher for programs in individual countries 

(Culliney, 2005). Actual impacts on air potato by L. cheni will not be 

known until after release occurs and post-release monitoring has been 

conducted.

―Cumulative impacts are defined as the impact on the environment which 

results from the incremental impact of the action when added to other past, 

present and reasonably foreseeable future actions regardless of what 

agencies or person undertakes such other actions‖ (40 CFR 1508.7).

A variety of Federal, State, County, City, and private organizations work 

to control air potato. 

Archbold Biological Station in Lake Placid, Florida uses a combination of 

methods to control air potato, including hand collecting of bulbils during 

the late fall, winter, and spring months, manually removing vines from 

April through June before fruits are produced, and application of an 

herbicide during the growing season. 

The Nature Conservancy coordinates with state agencies, invasive pest 

plant councils and local groups to halt the further spread of air potato by 

educating people about this plant's harmful effects, and works on their

own lands as well as coordinating with other private and public land 

managers to control air potato on wild lands.

Palm Beach County has an ordinance that requires all properties within the 

County to remove air potato. In February 2003, the County created the 

Invasive Vine Strike Force Program in order to assist property owners 

with the treatment and removal of these vines. This program provides free 

treatment of the two vines for properties with infestations of

approximately two-acres or less. If necessary, the County will perform one 

re-treatment within six months of the initial treatment after which the 

property owner is required by County ordinance to keep their property free 

3. Cumulative 

Impacts
14

and clear of air potato.

The City of Gainesville Nature Operations Division organizes the annual 

Great Air Potato Round Up to keep the air potato reasonably under control 

for another year. Volunteers head out to some of the city's most infested 

areas to collect bulbils and destroy them.

Release of L. cheni is not expected to have any negative cumulative 

impacts in the continental United States because of its host specificity to 

air potato. Effective biological control of air potato will have beneficial 

effects for weed management programs, and may result in a long-term, 

non-damaging method to assist in the control of air potato, and prevent its 

spread into other areas potentially at risk from invasion.

Section 7 of the Endangered Species Act (ESA) and ESA‘s implementing 

regulations require Federal agencies to ensure that their actions are not 

likely to jeopardize the continued existence of federally listed threatened 

and endangered species, or result in the destruction or adverse 

modification of critical habitat. 

APHIS has determined that, based on the host specificity of L. cheni, there 

will be no effect on any listed plant or designated critical habitat in the 

continental United States. In host specificity testing, the biological control 

organism survived only on air potato. No federally listed threatened or 

endangered plants belong to the family Dioscoreaceae (USFWS, TESS, 

2010). In addition, no federally listed threatened or endangered species 

are known to depend on or use air potato. 

V. Other Issues

Consistent with Executive Order (EO) 12898, ―Federal Actions to Address 

Environmental Justice in Minority Populations and Low-income 

Populations,‖ APHIS considered the potential for disproportionately high 

and adverse human health or environmental effects on any minority 

populations and low-income populations. There are no adverse 

environmental or human health effects from the field release of L. cheni

and their release will not have disproportionate adverse effects to any 

minority or low-income populations. 

Consistent with EO 13045, ―Protection of Children From Environmental 

Health Risks and Safety Risks,‖ APHIS considered the potential for 

disproportionately high and adverse environmental health and safety risks 

to children. No circumstances that would trigger the need for special 

environmental reviews are involved in implementing the preferred 

alternative. Therefore, it is expected that no disproportionate effects on 

children are anticipated as a consequence of the field release of L. cheni.

4. Endangered 

Species Act
15

EO 13175, ―Consultation and Coordination with Indian Tribal 

Governments,‖ was issued to ensure that there would be ―meaningful 

consultation and collaboration with tribal officials in the development of 

Federal policies that have tribal implications....‖ In July 2010, APHIS sent 

out letters to potentially affected tribal leaders and organizations to give 

notification of the proposed environmental release of L. cheni and to 

request input from tribes. APHIS will continue to consult and collaborate

with Indian tribal officials to ensure that they are well-informed and 

represented in policy and program decisions that may impact their 

agricultural interests, in accordance with EO 13175.

VI. Agencies, Organizations, and 

Individuals Consulted

The Technical Advisory Group for the Biological Control Agents of 

Weeds (TAG) recommended the release of L. cheni on August 21, 2009. 

TAG members that reviewed the release petition (Pemberton, 2009) 

included representatives from USDA-Cooperative State Research, 

Education, and Extension Service, USDA-Animal and Plant Health 

Inspection Service, USDA-Agricultural Research Service, Environmental 

Protection Agency, California Department of Food and Agriculture, 

Oregon Department of Agriculture, U.S. Fish and Wildlife Service, U.S. 

Army Corps of Engineers, U.S. Forest Service, and Agriculture and AgriFood Canada, Health Canada. 

This EA was prepared and reviewed by APHIS. The addresses of 

participating APHIS units, cooperators, and consultants (as applicable) 

follow.

U.S. Department of Agriculture

Animal and Plant Health Inspection Service

Policy and Program Development 

Environmental and Risk Analysis Services

4700 River Road, Unit 149

Riverdale, MD 20737

U.S. Department of Agriculture

Animal and Plant Health Inspection Service

Plant Protection and Quarantine 

Registrations, Identification, Permits, and Plant Safeguarding

4700 River Road, Unit 133

Riverdale, MD 20737

U.S. Department of Agriculture

Agricultural Research Service
16

Invasive Plants Research Lab

3205 College Avenue

Fort Lauderdale, FL 33314
17

VII. References

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southeastern United States. Journal of the Arnold Arboretum. 1: 57−95.

Barrera, G.M. 1990. Plantas vasculares raras, amenazadas y en peligro de 

extincion en Tamaulipas. Biotam. 2: [no pg. nos.].

Bell, C.R., and B.J. Taylor. 1982. Florida Wild Flowers and Roadside 

Plants. Laurel Hill Press, Chapel Hill, N.C.

Bennett, B.C., and G.T. Prance. 2000. Introduced plants in the indigenous 

pharmacopoeia of northern South America. Economic Botany. 54:

90−102.

Burkill, I.H. 1960. The organography and the evolution of Dioscoreaceae. 

The family of the yams. Journal of the Linnean Society of Botany. 56:

319−412.

Caddick, L.R., P. Wilkin, P.J. Rudall, T.A.J. Hedderson, and M.W. Chase. 

2002. Yams reclassified: a recircumscription of Dioscoreaceae and 

Dioscoreales. Taxon. 51: 103−114. 

Coursey, D.G. 1967. Botany and taxonomy. Pp. 28-67. In: D. Rhind, [ed.], 

Yams. Longmans, Green, and Co., London.

Culliney, T.W., 2005. Benefits of classical biological control for 

managing invasive plants. Critical Reviews in Plant Sci. 24: 131–150.

Duxbury, C., S. Glasscock, and I. Staniszewska. 2003. Control of 

regrowth from air potato (Dioscorea bulbifera L.) bulbils. Wildland 

Weeds. 6: 14−15.

FLEPPC―see Florida Exotic Plant Pest Council

Florida Exotic Plant Pest Council, Plant List Committee. 2003. Florida 

Exotic Pest Plant Council‘s 2003 list of invasive species. Wildland Weeds.

6:suppl.

Gann, G. D., K. Bradley, and S.W. Woodmansee. 2001. Floristic 

Inventory of South Florida Database. Available online 

www.regionalconservation.org last accessed June 8, 2010.

Gordon, D.R., G.D. Gann, E. Carter, and K. Thomas. 1999. Posthurricane vegetation response in South Florida Hammocks with and 

without Dioscorea bulbifera L. control. Pp. 309-326. In: D.T. Jones and 

B.W. Gamble, [eds.], Florida‘s Garden of Good and Evil. South Florida 
18

Water Management District, West Palm Beach.

Hammer, R.L. 1998. Diognosis: Dioscorea. Wildland Weeds. 2: 8−10.

Horvitz, C.C., J.B. Pascarella, S. McMann, A. Freedman, and R.L. 

Hofstetter. 1998. Functional roles of invasive non-indigenous plants in 

hurricane-affected subtropical hardwood forests. Ecological Applications.

8: 947−974.

Huber, H. 1998. Dioscoreaceae. Pp. 216−235. In: K. Kubitzki, [ed.], The 

Families and Genera of Vascular Plants, Vol. 3. Springer-Verlag, Berlin.

Knuth, R. 1924. Dioscoreaceae. Pp 1-387 in A. Engler, ed., Das 

Pflanzenreich IV. 43 [Heft 87]. Engelmann, Leipzig, Germany.

Langeland, K.A., and K. Craddock Burks. 1998. Identification and 

Biology of Non-native Plants in Florida‘s Native Areas. University of 

Florida, Gainesville.

Leon, H., and H. Alain. 1974. Flora de Cuba, Vol. 1. Otto Koeltz Science 

Publishers, Koenigstein.

Long, R.W., and O. Lakela. 1976. A Flora of Tropical Florida: a Manual 

of the Seed Plants and Ferns of Southern Peninsular Florida. University of 

Miami Press, Coral Gables, Fla.

Louda, S.M., R.W. Pemberton, M.T. Johnson, and P.A. Follett. 2003. 

Nontarget effects—the Achilles‘ heel of biological control. Retrospective 

analyses to reduce risk associated with biological control introductions. 

Annual Rev. Entomol. 48: 365–396.

Matuda, E. 1953. Las Dioscoreaceas de Mexico. Anales del Instituto 

Biologia Méxicana. 24: 279−389.

McVaugh, R. 1989. Flora Novo-Galiciana: a descriptive Account of the 

Vascular Plants of Western Mexico. Vol. 15, Bromeliaceae to 

Dioscoreaceae. University of Michigan Herbarium, Ann Arbor. 

Morton, J.F. 1976. Pestiferous spread of many ornamental and fruit 

species in south Florida. Proceedings Florida State Horticultural Society.

89: 348−353.

Mullahey, J.J., and S.H. Brown. 1999. Weakening the grip of air potato. 

Pp. 285−290. In: D.T. Jones and B.W. Gamble, [eds.], Florida‘s Garden 

of Good and Evil. South Florida Water Management District, West Palm 

Beach.
19

Nesom, G.L., and L.E. Brown. 1998. Annotated checklist of the vascular 

plants of Walker, Montgomery, and San Jacinto Counties, East Texas. 

Phytologia. 84: 107−153.

Pemberton, R.W., 2009. Proposed field release of Lilioceris sp. near 

impressa (Fabricius) (Coleoptera: Chrysomelidae), a leaf and bulbil feeder 

of air potato, Dioscorea bulbifera L. (Dioscoreaceae) in Florida. Petition 

submitted to the Technical Advisory Group for Biological Control Agents 

of Weeds. 48 pp.

Pemberton, R.W., 2000. Predictable risk to native plants in weed 

biological control. Oecologia. 125: 489–494.

Raz, L. 2002. Dioscoreaceae: R. Brown: Yam Family. Pp. 479-485. In:

Editorial Committee, [ed.], Flora of North America, Vol. 26. Oxford 

University Press, New York.

Schaffner, U. and Müller, C. 2001 Exploitation of the fecal shield of the 

lily leaf beetle. Lilioceris lilii, (Coleoptera: Chrysomelidae), by the 

specialist parasitoid Lemophagus pulcher (Hymenoptera: Ichneumonidae). 

Journal of Insect Behavior. 14: 739−757.

Schmitz, D.C. 1994. The ecological impact of non-indigenous plants in 

Florida. TSS-94-100, Florida Department of Environmental Protection. 

Pp. 10-28. In: D.C. Schmitz and T.C. Brown, project directors, An 

assessment of invasive non-indigenous species in Florida‘s public lands. 

Florida Department of Environmental Protection, Tallahassee.

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1997. The ecological impact of nonindigenous plants. Pp. 39-61. In: D. 

Simberloff, D.C. Schmitz, and T.C. Brown, [eds.], Strangers in Paradise: 

Impact and Management of Nonindigenous Species in Florida. Island 

Press, Washington, D.C.

Schultz, G.E. 1993. Element Stewardship abstract for Dioscorea bulbifera 

Air potato. The Nature Conservancy, Davis, Calif.

Tellez, O.V., and B.G. Schubert. 1994. Alismataceae a Cyperaceae. Pp. 

319-332. In: G. Davidse, M.S. Sousa, and A.O. Chater, [eds.], Flora 

Mesoamericana. Universidad Nacional Autonoma de Mexico. Instituto de 

Biologia, Mexico, D.F.

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USDA, NRCS─See U.S. Department of Agriculture, Natural Resource

Conservation Service.
20

U.S. Department of Agriculture, Natural Resource Conservation Service. 

2002. The PLANTS Database. 3.5. Available online http://plants.usda.gov

National Plant Data Center, Baton Rouge, LA. Last accessed June 8, 

2010.

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Service.

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National List of Scientific Plant Names. SCS-TP-159, U.S. Department of 

Agriculture, Soil Conservation Service, Washington, D.C.

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Endangered Species System.

U.S. Fish and Wildlife Service, Threatened and Endangered Species 

System. http://ecos.fws.gov/tess_public/ last accessed June 8, 2010.

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Agric. Sci., Gainesville, Florida.

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environmental impact statement for freshwater aquatic plant management. 

Pub. No. 00–10–040.

WSDE─See Washington State Department of Ecology

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Florida, 2nd ed. University Press of Florida, Gainesville.
A–1

Appendix A. Results of Adult Feeding Tests

In these tests, besides air potato, only some minor feeding occurred on some non-target. 

Dioscorea species. Additional tests were conducted only on plants with feeding in adult feeding 

tests with cut material; NA indicates plants without adult feeding and therefore received no 

further testing. Florida natives in bold.

Cut Material Whole plants

Order; Family; 

(Section) 

Genus species Adult Larval Development Adult Larval Development

Feed Feed Pupa Adult Feed Feed Pupa Adult

Alismatales; 

Alismataceae

Sagittaria 

latifolia no NA NA NA NA NA NA NA

Arecales; 

Acrecaceae

Sabal 

palmetto no NA NA NA NA NA NA NA

Asparagales; 

Amarillidaceae

Crinum 

americanum no NA NA NA NA NA NA NA

Asparagales; 

Iridaceae Iris virginica no NA NA NA NA NA NA NA

Commelinales; 

Commelinaceae

Tradescantia 

ohiensis no NA NA NA NA NA NA NA

Commelinales; 

Pondeteriaceae

Pontederia 

cordata no NA NA NA NA NA NA NA

Dioscoreales; 

Dioscoreaceae

Tacca 

integrifolia no NA NA NA NA NA NA NA

Dioscoreales; 

Dioscoreaceae -

(Chondrocarpa)

Dioscorea 

altissima min no no no NA NA NA NA

Dioscoreales; 

Dioscoreaceae -

(Dematostemon)

Dioscorea 

polygonoides no NA NA NA NA NA NA NA

Dioscoreales; 

Dioscoreaceae -

(Enantiphyllum)

Dioscorea 

alata no NA NA NA NA NA NA NA

Dioscoreales; 

Dioscoreaceae -

(Enantiphyllum)

Dioscorea 

cayenensis no NA NA NA NA NA NA NA

Dioscoreales; 

Dioscoreaceae -

(Enantiphyllum)

Dioscorea 

polystachya no NA NA NA NA NA NA NA

Dioscoreales; 

Dioscoreaceae -

(Enantiphyllum)

Dioscorea 

polystachya 

(batatas)

min no no no NA NA NA NA

Dioscoreales; 

Dioscoreaceae -

(Enantiphyllum)

Dioscorea 

rotundata no NA NA NA NA NA NA NA
A

–2

Dioscoreales; 

Dioscoreaceae -

(Lynchonostemon)

Dioscorea 

pilosiuscula no NA NA NA NA NA NA NA

Dioscoreales; 

Dioscoreaceae -

(Macrogynodium)

Disocorea 

trifida no NA NA NA NA NA NA NA

Dioscoreales; 

Dioscoreaceae -

(Macropoda)

Dioscorea 

floridana min no no no no no no no

Dioscoreales; 

Dioscoreaceae -

(Macropoda)

Dioscorea 

villosa min no no no no no no no

Dioscoreales; 

Dioscoreaceae -

(Opsophyton)

Dioscorea 

bulbifera yes yes yes yes yes yes yes yes

Dioscoreales; 

Dioscoreaceae -

(Opsophyton)

Dioscorea 

sansibarensis no NA NA NA NA NA NA NA

Dioscoreales; 

Dioscoreaceae -

(Rajania)

Rajania

(Dioscorea)

cordata

no NA NA NA NA NA NA NA

Fabales; 

Fabaceae

Cassia 

ligustrina no NA NA NA NA NA NA NA

Lamiales; 

Verbenaceae

Callicarpa 

americana no NA NA NA NA NA NA NA

Liliales; 

Liliaceae

Asparagus 

officinalis no NA NA NA NA NA NA NA

Liliales; 

Liliaceae

Asparagus 

sprengeri no NA NA NA NA NA NA NA

Liliales; 

Liliaceae

Lilium sp 

(ornamental) no NA NA NA NA NA NA NA

Liliales; 

Liliaceae

Zephyranthes 

grandiflora no NA NA NA NA NA NA NA

Liliales; 

Nartheciaceae

Aletris 

farinosa no NA NA NA NA NA NA NA

Liliales; 

Smilacaceae

Smilax 

laurifolia no NA NA NA NA NA NA NA

Pandanales; 

Pandanaceae

Pandanus 

spiralis no NA NA NA NA NA NA NA

Poales; 

Poaceae

Saccharum 

officinarum no NA NA NA NA NA NA NA

Poales; 

Cyperaceae

Cladium 

mariscus no NA NA NA NA NA NA NA

Poales; 

Juncaceae

Juncus 

effusus no NA NA NA NA NA NA NA

Urticales; 

Moraceae Ficus elastica no NA NA NA NA NA NA NA
A–3

Zingerbales; 

Cannaceae

Canna 

flaccida no NA NA NA NA NA NA NA

Zingerbales; 

Cannaceae Canna indica no NA NA NA NA NA NA NA

Zingerbales; 

Costaceae

Costus 

woodsonii no NA NA NA NA NA NA NA

Zingerbales; 

Heliconiaceae

Heliconia 

caribeae no NA NA NA NA NA NA NA

Zingerbales; 

Marantaceae

Thalia 

geniculata no NA NA NA NA NA NA NA

Zingerbales; 

Musaceae

Musa 

acuminata no NA NA NA NA NA NA NA

Zingerbales; 

Zingerberaceae

Hedychium 

coronarium no NA NA NA NA NA NA NA

Source: Pemberton, 2009
B–1

Appendix B. Results of No-choice Adult Feeding

Tests 

In no-choice testing slight feeding occurred on three Dioscorea species besides air potato. 

Florida natives in bold.

Leaf Area Eaten (cm2)

Test Plant Species Total Mean se

A&B** Dioscorea bulbifera; air potato (Opsophyton) 1621.49* 324.30 62.18

A Dioscorea villosa; wild yam (Macropoda) 0.67 0.07 0.05

B Dioscorea floridana; Florida yam (Macropoda) 0.46 0.05 0.07

C Dioscorea bulbifera; air potato (Opsophyton) 1226.52* 306.63 63.81

C Dioscorea alata; water yam (Enantiophyllum) 0.00 0.00 0.00

D Dioscorea bulbifera; air potato (Opsophyton) 1216.06* 243.21 13.98

D Smilax laurifolia; bamboo vine 0.00 0.00 0.00

E Dioscorea bulbifera; air potato (Opsophyton) 637.53 127.51 38.47

E Dioscorea altissima; dunguey (Chondrocarpa) 0.17 0.06 0.01

E Dioscorea cayenensis; yellow guinea yam (Enantiophyllum) 0.00 0.00 0.00

E Rajania (Dioscorea) cordata; himber (Rajania) 0.00 0.00 0.00

E Dioscorea pilosiuscula; bulbous yam (Lynchonostemon) 0.00 0.00 0.00

E Dioscorea polygonoides; mata gallina (Dematostemon) 0.00 0.00 0.00

F Dioscorea bulbifera; air potato (Opsophyton) 615.67 123.13 30.27

F Dioscorea alata; water yam (Enantiophyllum) 0.00 0.00 0.00

F Dioscorea polystachya; cultivated chinese yam 

(Enantiophyllum)

0.00 0.00 0.00

F Dioscorea polystachya batatas; chinese yam (Enantiophyllum) 0.05 0.05 0.00

F Dioscorea rotundata; guinea yam (Enantiophyllum) 0.00 0.00 0.00

G Dioscorea bulbifera; air potato (Opsophyton) 310.57 62.11 24.36

G Dioscorea sansibarensis; Zanzibar yam (Opsophyton) 0.00 0.00 0.00

G Disocorea trifida; indian yam (Macrogynodium) 0.00 0.00 0.00

* Tests conducted for two months longer than others

** Tests conducted concurrently
C–1

Appendix C. Results of adult multi-choice feeding

tests using plant species other than Dioscorea (except 

for air potato).

In all choice tests, adult feeding occurred only on air potato (indicated in bold).

Leaf Area Eaten (cm2)

Test Species Total Mean se

A Dioscorea bulbifera; air potato 1226.52* 306.63 63.81

A Callicarpa americana; beauty berry 0 0 0

A Cassia ligustrina; senna 0 0 0

A Tacca integrifolia; bat flower 0 0 0

B&C** Dioscorea bulbifera; air potato 1366.88* 273.38 102.58

B Crinum americanum; FL swamp lily 0 0 0

B Pontederia cordata; pickerel weed 0 0 0

B Sagittaria latifolia; broadleaf arrowhead 0 0 0

B Thalia geniculata; arrowroot 0 0 0

C Ficus elastica; Indian rubber tree 0 0 0

C Pandanus spiralis; screw palm 0 0 0

C Sabal palmetto; sabal palm 0 0 0

C Saccharum officinarum; sugarcane 0 0 0

D Dioscorea bulbifera; air potato ( 374.91 74.98 20.07

D Musa acuminata; banana 0 0 0

D Tradescantia ohiensis; Ohio spiderwort 0 0 0

E Dioscorea bulbifera; air 379.63 75.93 18.48

E Costus woodsonii; red button ginger 0 0 0

E Hedychium coronarium; butterfly ginger 0 0 0

E Juncus effusus; soft rush 0 0 0

F&G** Dioscorea bulbifera; air potato 606.23 121.25 56.98

F Cladium mariscus; sawgrass 0 0 0

F Iris virginica; blue flag iris 0 0 0

F Lilium sp (ornamental); lily 0 0 0

G Aletris farinosa; colicroot 0 0 0

G Canna indica; indian shot 0 0 0

G Heliconia caribeae; 0 0 0

H Dioscorea bulbifera; air potato 323.39 64.68 9.69

H Zephyranthes grandiflorum; rose pink zephyr lily 0 0 0

H Canna flaccida; bandana of the Everglades 0 0 0

I Dioscorea bulbifera; air potato 369.58 73.92 10.94

I Asparagus officinalis; garden asparagus 0 0 0

I Asparagus sprengeri; asparagus fern 0 0 0
D–1

Appendix D. Results of adult feeding tests, 

including Dioscorea plant species.

In all tests, feeding occurred only on air potato (indicated in bold). 

Leaf Area Eaten (cm2)

Test Plant Species Total Mean se

A&B** Dioscorea bulbifera; air potato (Opsophyton) 1621.49* 324.30 62.18

A Dioscorea villosa; wild yam (Macropoda) 0.67 0.07 0.05

B Dioscorea floridana; Florida yam (Macropoda) 0.46 0.05 0.07

C Dioscorea bulbifera; air potato (Opsophyton) 1226.52* 306.63 63.81

C Dioscorea alata; water yam (Enantiophyllum) 0.00 0.00 0.00

D Dioscorea bulbifera; air potato (Opsophyton) 1216.06* 243.21 13.98

D Smilax laurifolia; bamboo vine 0.00 0.00 0.00

E Dioscorea bulbifera; air potato (Opsophyton) 637.53 127.51 38.47

E Dioscorea altissima; dunguey (Chondrocarpa) 0.17 0.06 0.01

E Dioscorea cayenensis; yellow guinea yam (Enantiophyllum) 0.00 0.00 0.00

E Rajania (Dioscorea) cordata; himber (Rajania) 0.00 0.00 0.00

E Dioscorea pilosiuscula; bulbous yam (Lynchonostemon) 0.00 0.00 0.00

E Dioscorea polygonoides; mata gallina (Dematostemon) 0.00 0.00 0.00

F Dioscorea bulbifera; air potato (Opsophyton) 615.67 123.13 30.27

F Dioscorea alata; water yam (Enantiophyllum) 0.00 0.00 0.00

F Dioscorea polystachya; cultivated chinese yam 

(Enantiophyllum)

0.00 0.00 0.00

F Dioscorea polystachya batatas; chinese yam (Enantiophyllum) 0.05 0.05 0.00

F Dioscorea rotundata; guinea yam (Enantiophyllum) 0.00 0.00 0.00

G Dioscorea bulbifera; air potato (Opsophyton) 310.57 62.11 24.36

G Dioscorea sansibarensis; Zanzibar yam (Opsophyton) 0.00 0.00 0.00

G Disocorea trifida; indian yam (Macrogynodium) 0.00 0.00 0.00

* Tests conducted for two months longer than others

** Tests conducted concurrently

Source: Pemberton, 2009.
E–1

Appendix E. No choice larval development tests –

egg transferal onto whole plants

Larvae that hatched from eggs transferred onto air potato leaves fed immediately and 

began to grow. First instar larvae placed on test leaves other than air potato died without 

feeding. Feeding measurement reflects one week of larval feeding. 

Florida natives in bold.

Leaf Area Eaten (cm2)

Plant Species Total Mean se

Dioscorea bulbifera; air potato (Section Opsophyton) 79.04 15.81 6.55

Dioscorea altissima; dunguey (Section Chondrocarpa) 0.00 0.00 0.00

Dioscorea floridana; Florida yam (Section Macropoda) 0.00 0.00 0.00

Dioscorea polystachya batatas; chinese yam (Section Enantiophyllum) 0.00 0.00 0.00

Dioscorea villosa; wild yam (Section Macropoda) 0.00 0.00 0.00

Source: Pemberton, 2009
F–1

Appendix F. Results of oviposition and larval 

development tests

Although eggs were laid on native Dioscorea plant species, no larvae were able to survive 

beyond the first instar on plants other than air potato. Larvae developed to the adult stage 

only on air potato. This test was repeated 4 times (A-D). 

Leaf area eaten (cm2)

1

Oviposition & 

development2

Test Plant species Total Mean se Eggs Adults

% to 

Adult

A D. bulbifera; air potato (Opsophyton) 523.79 104.76 19.90 124 118 95.16%

A D. floridana; Florida yam (Macropoda) 0.00 0.00 0.00 31 0 0.00%

A D. villosa; wild yam (Macropoda) 0.00 0.00 0.00 25 0 0.00%

B D. bulbifera; air potato (Opsophyton) 574.81 114.96 7.31 143 129 90.21%

B D. floridana; Florida yam (Macropoda) 0.00 0.00 0.00 21 0 0.00%

B D. villosa; wild yam (Macropoda) 0.00 0.00 0.00 40 0 0.00%

C D. bulbifera; air potato (Opsophyton) 348.21 69.64 17.38 201 189 94.03%

C D. floridana; Florida yam (Macropoda) 0.00 0.00 0.00 11 0 0.00%

C D. villosa; wild yam (Macropoda) 0.00 0.00 0.00 35 0 0.00%

D D. bulbifera; air potato (Opsophyton) 483.00 96.60 34.80 182 167 91.76%

D D. floridana; Florida yam (Macropoda) 0.00 0.00 0.00 38 0 0.00%

D D. villosa; wild yam (Macropoda) 0.00 0.00 0.00 45 0 0.00%

1 Adult feeding

2 Eggs laid on test plants, number of adults produced on each plant, and the percent of larvae developing into 

adults.

Source: Pemberton, 2009.