+------------+---+------------------------------------------------------+
| ![](me     |   | **Field Release of Phorid Flies (*Pseudacteon*       |
| dia/image1 |   | species) for the Biological Control of Imported Fire |
| .wmf){widt |   | Ants**                                               |
| h="0.65in" |   |                                                      |
| h          |   | **Draft Environmental Assessment**                   |
| eight="0.4 |   |                                                      |
| 0347222222 |   | July 2007                                            |
| 222223in"} |   |                                                      |
|            |   | **Field Release of Phorid Flies (*Pseudacteon*       |
| **United   |   | species) for the Biololgical Control of Imported     |
| States     |   | Fire Ants**                                          |
| Department |   |                                                      |
| of         |   | **Draft Environmental Assessment**                   |
| Agr        |   |                                                      |
| iculture** |   | July 2007                                            |
|            |   |                                                      |
| *          |   | Agency Contact:                                      |
| *Marketing |   |                                                      |
| and**      |   | Charles L. Brown                                     |
|            |   |                                                      |
| **Re       |   | Animal and Plant Health Inspection Service           |
| gulatory** |   |                                                      |
|            |   | U.S. Department of Agriculture                       |
| **         |   |                                                      |
| Programs** |   | 4700 River Road                                      |
|            |   |                                                      |
| **Animal   |   | Riverdale, MD 20737                                  |
| and**      |   |                                                      |
|            |   | Telephone: (301) 734--4838                           |
| **Plant    |   |                                                      |
| Health**   |   | **The U.S. Department of Agriculture (USDA)          |
|            |   | prohibits discrimination in all**                    |
| **In       |   |                                                      |
| spection** |   | **its programs and activities on the basis of race,  |
|            |   | color, national origin, sex,**                       |
| *          |   |                                                      |
| *Service** |   | **religion, age, disability, political beliefs,      |
|            |   | sexual orientation, or marital or family**           |
| ![](media/ |   |                                                      |
| image2.png |   | **status. (Not all prohibited bases apply to all     |
| ){width="0 |   | programs.) Persons with**                            |
| .459722222 |   |                                                      |
| 2222222in" |   | **disabilities who require alternative means for     |
| height="0. |   | communication of program**                           |
| 5104166666 |   |                                                      |
| 666666in"} |   | **information (Braille, large print, audiotape,      |
|            |   | etc.) should contact the USDA's**                    |
|            |   |                                                      |
|            |   | **TARGET Center at 202--720--2600 (voice and TDD).** |
|            |   |                                                      |
|            |   | **To file a complaint of discrimination, write USDA, |
|            |   | Director of Civil Rights,**                          |
|            |   |                                                      |
|            |   | **Room 326--W, Whitten Building, 14^th^ and          |
|            |   | Independence Avenue, SW,**                           |
|            |   |                                                      |
|            |   | **Washington, DC 20250--9410 or call 202--720--5964  |
|            |   | (voice and TDD).**                                   |
|            |   |                                                      |
|            |   | **USDA is an equal employment opportunity            |
|            |   | employer.**                                          |
|            |   |                                                      |
|            |   | Mention of companies or commercial products in this  |
|            |   | report does not imply                                |
|            |   |                                                      |
|            |   | recommendation or endorsement by the U.S. Department |
|            |   | of Agriculture                                       |
|            |   |                                                      |
|            |   | over others not mentioned. USDA neither guarantees   |
|            |   | nor 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**                                |
|            |   |                                                      |
|            |   | **1. Purpose and Need for Proposed Action 4**        |
|            |   |                                                      |
|            |   | **2. Background 5**                                  |
|            |   |                                                      |
|            |   | **3. Alternatives Including the Proposed Action 8**  |
|            |   |                                                      |
|            |   | **4. Affected Environment 9**                        |
|            |   |                                                      |
|            |   | **5. Environmental Effects of the Proposed Action    |
|            |   | and the Alternative 9**                              |
|            |   |                                                      |
|            |   | **6. Listing of Agencies and Persons Consulted 13**  |
|            |   |                                                      |
|            |   | **7. Literature Cited 13**                           |
|            |   |                                                      |
|            |   | **1. Purpose and Need for Proposed Action**          |
|            |   |                                                      |
|            |   | The U.S. Department of Agriculture (USDA), Animal    |
|            |   | and Plant Health Inspection Service (APHIS) is       |
|            |   | tasked with protecting American agriculture from     |
|            |   | pests.  Imported fire ants (IFA) are red fire        |
|            |   | antsNumber range CHAPTER, *Solenopsis invicta*       |
|            |   | Buren, black fire ants, *S. richteri* Forel, and a   |
|            |   | hybrid of those two species. IFA are an important    |
|            |   | pest of agriculture in the United States and a       |
|            |   | health hazard to humans, domestic animals, and       |
|            |   | wildlife. Since being introduced in the southern     |
|            |   | United States from South America more than 70 years  |
|            |   | ago, IFA are now an established pest in all or parts |
|            |   | of 13 states (Callcott and Collins, 1996).           |
|            |   |                                                      |
|            |   | APHIS, in cooperation with state agriculture         |
|            |   | departments, has established a quarantine to prevent |
|            |   | the artificial spread of IFA. The regulations for    |
|            |   | this quarantine are in the Code of Federal           |
|            |   | Regulations (CFR) at 7 CFR 301.81. APHIS is          |
|            |   | responsible for establishing quarantine areas and    |
|            |   | regulating the movement of articles that might       |
|            |   | contain these ants.                                  |
|            |   |                                                      |
|            |   | The treatment of regulated articles to prevent the   |
|            |   | artificial spread of IFA often involve the use of    |
|            |   | pesticides. An Environmental Assessment that         |
|            |   | addresses the impacts of the IFA Quarantine's        |
|            |   | regulatory activities has been prepared (USDA APHIS, |
|            |   | 2005), and this document will incorporate by         |
|            |   | reference the information in that Environmental      |
|            |   | Assessment.                                          |
|            |   |                                                      |
|            |   | An additional component of the IFA Quarantine is the |
|            |   | rearing and field release of phorid flies which are  |
|            |   | biological control agents that parasitize IFA. The   |
|            |   | objective of this aspect of the IFA Quarantine is    |
|            |   | not to eradicate fire ants, but to reduce the        |
|            |   | overall IFA populations in infested areas and help   |
|            |   | tilt the ecological balance in favor of native ants  |
|            |   | that IFA have displaced. Should IFA populations      |
|            |   | decline, it is then less likely that articles        |
|            |   | leaving the IFA quarantine area would be infested    |
|            |   | and cause IFA infestations outside the quarantine    |
|            |   | area.                                                |
|            |   |                                                      |
|            |   | APHIS is proposing to expand the number of phorid    |
|            |   | fly releases from the current 3 species to a total   |
|            |   | of 8 phorid fly species to control IFA (*Solenopsis* |
|            |   | *invicta*, *S*. *richteri*, and their hybrid) in 13  |
|            |   | States and the Commonwealth of Puerto Rico. The USDA |
|            |   | Agricultural Research Service has researched and     |
|            |   | developed biological control (biocontrol) agents of  |
|            |   | the genus *Psuedacteon* (phorid flies) which have    |
|            |   | the potential to reduce the area and intensity of    |
|            |   | IFA infestations. Fire ant populations in their      |
|            |   | South American homelands are about 10-20% of those   |
|            |   | normally found in North America (Porter *et al*.,    |
|            |   | 1997). Escape from the numerous natural enemies left |
|            |   | behind in South America is a likely explanation      |
|            |   | because intercontinental differences in fire ant     |
|            |   | densities do not appear to be related to differences |
|            |   | in climate, habitat, or other factors investigated.  |
|            |   |                                                      |
|            |   | This environmental assessment has been prepared,     |
|            |   | consistent with the APHIS National Environmental     |
|            |   | Policy Act implementing procedures (7 CFR part 372), |
|            |   | for the purpose of evaluating the extent of the      |
|            |   | impact the proposed action described below, as well  |
|            |   | as any alternatives, if implemented, may have on the |
|            |   | quality of the human environment. This environmental |
|            |   | assessment will be used to help determine whether or |
|            |   | not to prepare an environmental impact statement,    |
|            |   | which is a more comprehensive study of the proposed  |
|            |   | action and alternatives considered in this document. |
|            |   | An environmental impact statement must be prepared   |
|            |   | if implementation of the proposed action may         |
|            |   | significantly affect the quality of the human        |
|            |   | environment.                                         |
|            |   |                                                      |
|            |   | **2. Background**                                    |
|            |   |                                                      |
|            |   | **2.1 Imported Fire Ants (IFA)**                     |
|            |   |                                                      |
|            |   | The black imported fire ant, *Solenopsis richteri*   |
|            |   | Forel, was inadvertently introduced into the United  |
|            |   | States at the port of Mobile, Alabama, around 1918   |
|            |   | (Loding, 1929). The red imported fire ant            |
|            |   | *Solenopsis invicta* Buren was introduced into the   |
|            |   | same port some time during the 1930s (Lennartz,      |
|            |   | 1973). The red fire ant was by far the more          |
|            |   | successful of the two invaders. After its            |
|            |   | introduction in Mobile, Alabama, the black imported  |
|            |   | fire ant was driven northward by competition from    |
|            |   | the red imported fire ant and currently is           |
|            |   | restricted to a small region around the tri-state    |
|            |   | border of Mississippi, Alabama and Tennessee.        |
|            |   | However, a broad band of                             |
|            |   |                                                      |
|            |   | hybridization between red and black fire ants        |
|            |   | extends from the Mississippi River to Atlanta,       |
|            |   | Georgia (Shoemaker *et al.*, 1996). Red and black    |
|            |   | fire ants, however, are still considered separate    |
|            |   | species because hybridization apparently does not    |
|            |   | occur in native Argentine populations (Ross and      |
|            |   | Trager, 1990).                                       |
|            |   |                                                      |
|            |   | Economic damage attributed to IFA in the United      |
|            |   | States is estimated at nearly \$6 billion per year   |
|            |   | (Lard *et al.*, 2001; Pereira *et al.*, 2002), not   |
|            |   | including environmental damage. Damage from IFA can  |
|            |   | be grouped into four major categories: agricultural, |
|            |   | electrical, medical, and environmental. IFA          |
|            |   | adversely affect several important agricultural      |
|            |   | crops, including soybeans, corn, potatoes, and       |
|            |   | citrus (Adams,1986; Adams *et al.*, 1988; Banks *et  |
|            |   | al.*, 1991; Drees *et al.*, 1992). IFA are also      |
|            |   | known to prey on may beneficial insects including    |
|            |   | some biological control agents (Eubanks, 2001). IFA  |
|            |   | are also a major source of electrical problems:      |
|            |   | transformers, air conditioners, traffic switch       |
|            |   | boxes, airport lights, and other electrical          |
|            |   | equipment located on the ground are all susceptible  |
|            |   | to problems caused by fire ants chewing off          |
|            |   | insulation, jamming switches, or building mounds in  |
|            |   | electrical boxes (MacKay and Vinson, 1990; Vinson    |
|            |   | and MacKay, 1990). Medical problems from stings are  |
|            |   | the third major category of problems associated with |
|            |   | fire ants. Young children are commonly stung dozens  |
|            |   | to hundreds of times when they stand on fire ant     |
|            |   | mounds; several people die each year from fire ant   |
|            |   | stings -- mostly bedridden patients in nursing homes |
|            |   | or people who are unconscious or otherwise unable to |
|            |   | respond to the fire ants. About 1-2% of the          |
|            |   | population are sensitive or allergic to fire ant     |
|            |   | stings (Vinson, 1997). Environmental damage is also  |
|            |   | associated with IFA. High densities of fire ants can |
|            |   | displace most native ants from open habitats (Porter |
|            |   | and Savignano, 1990), especially in areas disturbed  |
|            |   | by urbanization, agriculture, or grazing. Deer,      |
|            |   | mice, shore birds, quail, and lizards are among the  |
|            |   | vertebrates that can be harmed by high IFA           |
|            |   | populations (Allen *et al.*,1998; Williams *et al.*, |
|            |   | 2003).                                               |
|            |   |                                                      |
|            |   | **2.2 The phorid fly biological control agents       |
|            |   | *Pseudacteon* species**                              |
|            |   |                                                      |
|            |   | At least 20 species of *Pseudacteon* flies have been |
|            |   | found attacking fire ants in South America (Porter   |
|            |   | and Gilbert, 2004). Up to nine species of these      |
|            |   | flies have been found at a single site. Each species |
|            |   | has a distinctively shaped ovipositor (Porter,       |
|            |   | 1998a) that is presumably used in a lock-and-key     |
|            |   | fashion to lay eggs in a particular part of its      |
|            |   | host's body. These flies appear to be common and     |
|            |   | active throughout most of the year (Fowler *et al*., |
|            |   | 1995), but different species are sometimes more      |
|            |   | active at different times of the day (Pesquero *et   |
|            |   | al*., 1996). Most species are broadly distributed    |
|            |   | (Borgmeier, 1969; Borgmeier and Prado, 1975;         |
|            |   | Folgarait *et al*., 2005; Calcaterra *et al*. 2005)  |
|            |   | across a wide range of habitats and climates.        |
|            |   |                                                      |
|            |   | Female *Pseudacteon* flies usually contain a hundred |
|            |   | or more torpedo-shaped eggs (Zacaro and Porter,      |
|            |   | 1999). During oviposition, one egg is rapidly        |
|            |   | injected into the ant thorax with a short hypodermic |
|            |   | shaped ovipositor. Shortly after hatching, maggots   |
|            |   | of *Pseudacteon* flies move into the heads of their  |
|            |   | hosts where they develop slowly for 2-3 weeks        |
|            |   | (Porter *et al*., 1995b). Just prior to pupation,    |
|            |   | the third instar maggot (Porter, 1998a) appears to   |
|            |   | release an enzyme that dissolves the membranes that  |
|            |   | hold the exoskeleton together. The maggot then       |
|            |   | proceeds to consume the entire contents of the       |
|            |   | ant\'s head, a process that usually results in rapid |
|            |   | decapitation of its living host (Porter, 1998a). The |
|            |   | headless body is usually left with its legs still    |
|            |   | twitching. Worker ants apparently carry the larva    |
|            |   | infested head capsule outside their nest several     |
|            |   | hours after the host is killed. The maggot then uses |
|            |   | hydraulic extensions to push the ant's mouth parts   |
|            |   | aside after which it pupates within the empty head   |
|            |   | capsule positioned so that the anterior three        |
|            |   | segments harden to form a plate that precisely fills |
|            |   | the ant's oral cavity (Porter, 1998a). The remainder |
|            |   | of the puparium remains unsclerotized and is         |
|            |   | protected by the ant's head capsule which functions  |
|            |   | as a pupal case. Pupal development requires 2-3      |
|            |   | weeks depending on temperature. Adult flies are      |
|            |   | mature and ready to mate and oviposit about 3 h      |
|            |   | after emergence.                                     |
|            |   |                                                      |
|            |   | Adult *Pseudacteon* flies can live a week or two     |
|            |   | (Fadimiro *et al*., 2005); however, high rates of    |
|            |   | activity associated with oviposition will shorten    |
|            |   | their lives to 1-3 days. Adults will eat a little    |
|            |   | sugar water or honey water if they accidentally      |
|            |   | contact it while running across a surface. However,  |
|            |   | flies are not attracted to honey, sugary solutions,  |
|            |   | or various kinds of fruits, vegetables, raw meat,    |
|            |   | prepared foods, animal excrement, or carrion         |
|            |   | (Porter, 1998a; Porter, 2000).                       |
|            |   |                                                      |
|            |   | During attacks, fire ant workers are keenly aware of |
|            |   | the presence of phorid flies. A single female fly    |
|            |   | usually stops or greatly reduces the foraging        |
|            |   | efforts of hundreds of fire ant workers in only a    |
|            |   | minute or two (Porter *et al*., 1995c). As soon as a |
|            |   | fly appears, most workers rapidly retreat into exit  |
|            |   | holes or find cover. Other workers curl into a       |
|            |   | stereotypical c-shaped posture (Porter, 1998a) that  |
|            |   | has not been seen except when the ants are under     |
|            |   | attack by phorids. The flies inhibit fire ant        |
|            |   | foraging as long as they are present, often for      |
|            |   | periods of several hours. Reduced foraging activity  |
|            |   | appears to facilitate competition from ants that     |
|            |   | might otherwise be excluded from food sources in     |
|            |   | fire ant territories (Feener, 1981; Orr *et al*.,    |
|            |   | 1995). Several flies are also sufficient to stop     |
|            |   | nest construction or freeze the activity of entire   |
|            |   | colonies in laboratory nest trays (Porter *et al*.,  |
|            |   | 1995c). The overall impact of these flies on fire    |
|            |   | ant populations is unknown; however, it is clearly   |
|            |   | sufficient to have caused the evolution of a number  |
|            |   | of phorid-specific defense behaviors.                |
|            |   |                                                      |
|            |   | **3. Alternatives Including the**                    |
|            |   |                                                      |
|            |   | **Proposed Action**                                  |
|            |   |                                                      |
|            |   | This environmental assessment analyzes potential     |
|            |   | environmental consequences of a program to reduce    |
|            |   | IFA populations in the U.S. and Puerto Rico through  |
|            |   | the release of phorid flies (species of              |
|            |   | *Psuedacteon*), which are biological control agents. |
|            |   | The two alternatives considered are 1) no action     |
|            |   | (APHIS will continue to release only the three       |
|            |   | *Psuedacteon* species that have currently been       |
|            |   | approved for release) and 2) the release of an       |
|            |   | additional five *Psuedacteon* species.               |
|            |   |                                                      |
|            |   | **3.1 No Action**                                    |
|            |   |                                                      |
|            |   | The regulations of the Council on Environmental      |
|            |   | Quality (CEQ) for implementing the procedural        |
|            |   | provisions of the National Environmental Policy Act  |
|            |   | (40 CFR parts 1500-1508) require the inclusion of a  |
|            |   | "No Action" alternative. Consistent with CEQ's       |
|            |   | guidance (CEQ-NEPA 40 Q&As, number 3), APHIS defines |
|            |   | "No Action" as meaning "No Change," i.e., continuing |
|            |   | with the present course of action. Under this        |
|            |   | alternative, three phorid fly species, *Pseudacteon* |
|            |   | *curvatus*, *P.* *litoralis*, and *P.* *tricuspis*,  |
|            |   | would continue to be released, however, no other     |
|            |   | phorid fly species would be released.                |
|            |   |                                                      |
|            |   | **3.2 Implement Program to Release Five Additional   |
|            |   | Phorid Fly Species (Preferred alternative)**         |
|            |   |                                                      |
|            |   | Under this alternative, APHIS is proposing to        |
|            |   | release an additional five species of phorid flies:  |
|            |   | *Pseudacteon cultellatus, P. nocens, P. nudicornis,  |
|            |   | P. obtusus, P. sp.* near *obtusus*. These releases   |
|            |   | would not occur at the same time or place, but       |
|            |   | rather over the course of many years as the          |
|            |   | exploration and development of rearing and release   |
|            |   | methods develop for these species.                   |
|            |   |                                                      |
|            |   | **3.3 Alternative Not Considered**                   |
|            |   |                                                      |
|            |   | A number of approaches have been taken to reduce IFA |
|            |   | populations in the United States, with insecticides  |
|            |   | being the most commonly used approach. Because       |
|            |   | insecticide use and other approaches are not         |
|            |   | proposed by APHIS and are typically beyond the       |
|            |   | control of APHIS, they will not be analyzed in this  |
|            |   | document. In addition, the release of biological     |
|            |   | control agents other than phorid flies will not be   |
|            |   | analyzed.                                            |
|            |   |                                                      |
|            |   | **4. Affected Environment**                          |
|            |   |                                                      |
|            |   | The environment affected by this action would be the |
|            |   | environment in the 13 states where IFA are currently |
|            |   | established: Alabama, Arkansas, California, Florida, |
|            |   | Georgia, Louisiana, Mississippi, North Carolina, New |
|            |   | Mexico, Oklahoma, South Carolina, Tennessee, and     |
|            |   | Texas, as well as the Commonwealth of Puerto Rico. A |
|            |   | map of the IFA Quarantine area is at:                |
|            |   | <http://www.aphis.usda.gov/ppq/maps/fireant.pdf> .   |
|            |   | Future areas where IFA will spread naturally cannot  |
|            |   | be accurately determined, but as those areas are     |
|            |   | infested it is likely that phorid flies could also   |
|            |   | inhabit those areas.                                 |
|            |   |                                                      |
|            |   | **5. Environmental effects of the proposed action    |
|            |   | and the alternative**                                |
|            |   |                                                      |
|            |   | **5.1 No Action Alternative**                        |
|            |   |                                                      |
|            |   | The effect of the No Action alternative would be     |
|            |   | that IFA populations would be suppressed by three    |
|            |   | phorid flies (*Pseudacteon* *curvatus*, *P.*         |
|            |   | *litoralis*, and *P.* *tricuspis*) at levels far     |
|            |   | below the levels of suppression that could be        |
|            |   | obtained should eight phorid fly species be          |
|            |   | released. While two of the three phorid fly species  |
|            |   | that have been released have successfully become     |
|            |   | established and are actively parasitizing fire ant   |
|            |   | colonies, there has been much less reduction in      |
|            |   | overall colonies than could be realized if five      |
|            |   | other phorid fly species were to also be released.   |
|            |   |                                                      |
|            |   | The host specificity of *Pseudacteon* flies was      |
|            |   | tested in the field at three areas in South America  |
|            |   | with 23 species of ants from 13 genera (Porter et    |
|            |   | al., 1995a). *Pseudacteon* flies were attracted only |
|            |   | to *Solenopsis* fire ants. Porter and Alonso (1999)  |
|            |   | conducted forced tests with *P. litoralis* and *P.   |
|            |   | tricuspis* in quarantine facilities in Gainesville,  |
|            |   | Florida with native ants in six genera. Generally,   |
|            |   | ants in these genera were ignored by these flies.    |
|            |   | Several possible attacks were observed, but no       |
|            |   | larvae developed from them. Porter (2000) also       |
|            |   | conducted forced tests in quarantine with a third    |
|            |   | fly species, *P. curvatus*, using 19 species of ants |
|            |   | from 12 genera. As with the previous two species,    |
|            |   | *P. curvatus* did not develop in ants outside the    |
|            |   | genus *Solenopsis.*                                  |
|            |   |                                                      |
|            |   | Field tests in Brazil with *P. tricuspis* and *P.    |
|            |   | litoralis* demonstrate that both flies show a very   |
|            |   | strong preference for fire ants from Brazil (Porter, |
|            |   | 1998b) over the tropical fire ant, *Solenopsis       |
|            |   | geminata*, which is native to parts of the United    |
|            |   | States. Laboratory choice and no-choice tests at     |
|            |   | quarantine facilities in the United States also      |
|            |   | indicate that *P. tricuspis*, *P. litoralis,* and    |
|            |   | *P. curvatus* have a high degree of preference for   |
|            |   | the imported fire ant *S. invicta* over the native   |
|            |   | fire ants *S. geminata* and *S. xyloni* (Gilbert and |
|            |   | Morrison 1997, Porter and Alonso 1999, Porter 2000). |
|            |   | Post release host specificity tests for *P.          |
|            |   | tricuspis and P. curvatus* (Vazquez and Porter,      |
|            |   | 2005; Morrison and Porter, 2006) confirm that        |
|            |   | pre-release laboratory tests accurately predicted    |
|            |   | high levels of host specificity. The decapitating    |
|            |   | fly *P. litoralis* has not yet been established in   |
|            |   | the field so post-release tests are currently not    |
|            |   | available.                                           |
|            |   |                                                      |
|            |   | **5.2 Implement Program to Release Five Additional   |
|            |   | Phorid Fly Species (Preferred alternative)**         |
|            |   |                                                      |
|            |   | Under this alternative, APHIS is proposing to        |
|            |   | release an additional five species of phorid flies:  |
|            |   | *Pseudacteon cultellatus, P. nocens, P. nudicornis,  |
|            |   | P. obtusus, P. sp.* near *obtusus*.                  |
|            |   |                                                      |
|            |   | All known flies in the genus *Pseudacteon* are       |
|            |   | parasites of ants (Porter and Gilbert 2004). They    |
|            |   | have never been reported to attack any other kind of |
|            |   | organism, and virtually all phylogenetically related |
|            |   | phorid genera are also ant parasites (Brown 1993,    |
|            |   | Disney 1994). Their elaborate ovipositors and the    |
|            |   | adaptation for pupation in the head capsules of      |
|            |   | worker ants further supports the conclusion that     |
|            |   | they are very specialized parasites (Porter 1998a).  |
|            |   |                                                      |
|            |   | *Pseudacteon* species that attack fire ants appear   |
|            |   | to be specific to fire ants (Porter and Gilbert      |
|            |   | 2004). Several species of *Pseudacteon* flies are    |
|            |   | specific parasites of ants in other genera (e.g.:    |
|            |   | *Crematogaster*, *Dorymyrmex*, *Linepithema*), but   |
|            |   | none of these species are known to attack ants       |
|            |   | outside of the genus of their primary host (Porter   |
|            |   | and Gilbert, 2004; Disney, 1994). Most if not all    |
|            |   | *Pseudacteon* flies, which attack fire ants, are     |
|            |   | apparently specific to different species groups      |
|            |   | within the genus *Solenopsis*. For instance, at      |
|            |   | least five species are known to parasitize *S.       |
|            |   | geminata* in the United States, but they have never  |
|            |   | been collected attacking imported fire ants even     |
|            |   | though they clearly have had the opportunity         |
|            |   | (Feener, 1987; Morrison et al., 1997). Laboratory    |
|            |   | oviposition tests with *P. nudicornis* and the small |
|            |   | species near *P. obtusus* show no attraction to      |
|            |   | native fire ants (Porter and Gilbert, 2004).         |
|            |   | Laboratory choice and no-choice tests summarized by  |
|            |   | Porter and Gilbert (2004) show that *P. obtusus, P.  |
|            |   | nocens, and P. cultellatus* all have a high degree   |
|            |   | of preference for the imported fire ant *S. invicta* |
|            |   | over the native fire ants *S. geminata* and *S.      |
|            |   | xyloni* (Gilbert and Morrison,1997; Porter and       |
|            |   | Alonso, 1999; Porter, 2000). Thus, all five species  |
|            |   | show a high degree of specificity to imported fire   |
|            |   | ants.                                                |
|            |   |                                                      |
|            |   | A strong preference for imported fire ants means     |
|            |   | that these flies will pose little or no risk to      |
|            |   | native fire ants. In fact, releases of these flies   |
|            |   | are much more likely to benefit native fire ants     |
|            |   | because imported fire ants are their primary enemy   |
|            |   | and these flies will almost certainly have much      |
|            |   | greater impacts on imported fire ants than native    |
|            |   | fire ants (Porter, 2000). Finally, risks to native   |
|            |   | fire ants need to be balanced against potential      |
|            |   | benefits to native ants in other genera and numerous |
|            |   | other native organisms that are negatively affected  |
|            |   | by imported fire ants including quail, mice,         |
|            |   | lizards, deer, and numerous rare and endangered      |
|            |   | species.                                             |
|            |   |                                                      |
|            |   | Several additional considerations are also important |
|            |   | in regard to the potential field release of these    |
|            |   | *Pseudacteon* flies-- 1) Since native fire ants      |
|            |   | already have several species of native *Pseudacteon* |
|            |   | phorids that parasitize them (Disney 1994), new      |
|            |   | *Pseudacteon* parasitoids from South America would   |
|            |   | not be completely novel parasitoids for which these  |
|            |   | ants have no defense. Consequently, risks should be  |
|            |   | lower than otherwise. 2) new *Pseudacteon* species   |
|            |   | will, at best, stress imported fire ant populations  |
|            |   | thus reducing their ability to compete with native   |
|            |   | ants. Consequently, there is no chance that          |
|            |   | releasing new species of flies will eradicate *S.    |
|            |   | invicta* or any of the native fire ants either. 3)   |
|            |   | *S. geminata* and *S. xyloni* are still very common  |
|            |   | species. *S. geminata* is found from South Carolina  |
|            |   | through Florida and over into Texas. *S. xyloni* is  |
|            |   | distributed across the entire southern United        |
|            |   | States. Both native species are often considered     |
|            |   | pests in areas where they occur (Smith 1936; Smith   |
|            |   | 1965; Thompson 1990). 4) Native fire ants were never |
|            |   | as abundant as the imported species (Porter *et al.* |
|            |   | 1988; Porter 1992; Vinson 1994) so there is little   |
|            |   | or no likelihood that they would simply replace each |
|            |   | other as community-dominating pests.                 |
|            |   |                                                      |
|            |   | **5.3 Endangered Species Act**                       |
|            |   |                                                      |
|            |   | No endangered or threatened species listed by        |
|            |   | federal or state governments utilize imported fire   |
|            |   | ants as a primary food source. To the contrary,      |
|            |   | imported fire ants are known to cause negative       |
|            |   | impacts for many native species including some       |
|            |   | threatened and endangered species. Therefore,        |
|            |   | releases of this fly are expected to produce no      |
|            |   | negative impact on endangered or threatened species  |
|            |   | and may in fact provide major benefits to many of    |
|            |   | these species.                                       |
|            |   |                                                      |
|            |   | **5.3.1 Other Environmental Statutes**               |
|            |   |                                                      |
|            |   | Some executive orders, such as Executive Order No.   |
|            |   | 13045, Protection of Children From Environmental     |
|            |   | Health Risks and Safety Risks, as well as            |
|            |   | departmental or agency directives, call for special  |
|            |   | environmental reviews in certain circumstances. No   |
|            |   | circumstance that would trigger the need for special |
|            |   | environmental reviews is involved in implementing    |
|            |   | the proposed action considered in this document.     |
|            |   |                                                      |
|            |   | **5.4** **Cumulative impacts**                       |
|            |   |                                                      |
|            |   | Under NEPA, one must analyze whether the action is   |
|            |   | related to other actions with individually           |
|            |   | insignificant but cumulatively significant impacts   |
|            |   | (40 CFR 1508.27(b)(7)). The regulations require that |
|            |   | the analysis of the cumulative effects include "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" (40 CFR 1508.7). Each individual action may |
|            |   | not have a significant effect; however, "Cumulative  |
|            |   | impacts can result from individually minor but       |
|            |   | collectively significant actions taking place over a |
|            |   | period of time" (40 CFR 1508.7).                     |
|            |   |                                                      |
|            |   | Because it is not possible to predict how quickly or |
|            |   | how extensively these biological control agents will |
|            |   | spread, it is not possible to definitively quantify  |
|            |   | the cumulative impact that these releases may have   |
|            |   | on reducing IFA populations. However, it is          |
|            |   | anticipated that releasing these agents in           |
|            |   | combination will substantially decrease the existing |
|            |   | populations of IFA and allow native ants a chance to |
|            |   | re-populate areas previously infested with IFA.      |
|            |   |                                                      |
|            |   | **6. Listing of Agencies and Persons Consulted**     |
|            |   |                                                      |
|            |   | Environmental Services                               |
|            |   |                                                      |
|            |   | Policy and Program Development                       |
|            |   |                                                      |
|            |   | Animal and Plant Health Inspection Service           |
|            |   |                                                      |
|            |   | U.S. Department of Agriculture                       |
|            |   |                                                      |
|            |   | 4700 River Road, Unit 149                            |
|            |   |                                                      |
|            |   | Riverdale, MD 2073                                   |
|            |   |                                                      |
|            |   | Soil Inhabiting Pests Section                        |
|            |   |                                                      |
|            |   | Center for Plant Health Science and Technology       |
|            |   |                                                      |
|            |   | Plant Protection and Quarantine                      |
|            |   |                                                      |
|            |   | Animal and Plant Health Inspection Service           |
|            |   |                                                      |
|            |   | U.S. Department of Agriculture                       |
|            |   |                                                      |
|            |   | 3505 25^th^ Avenue                                   |
|            |   |                                                      |
|            |   | Gulfport, MS 39501                                   |
|            |   |                                                      |
|            |   | Imported Fire Ant and Household Insects Research     |
|            |   | Unit                                                 |
|            |   |                                                      |
|            |   | Center for Medical, Agricultural, and Veterinary     |
|            |   | Entomology                                           |
|            |   |                                                      |
|            |   | Agricultural Research Service                        |
|            |   |                                                      |
|            |   | 1600 S.W. 23^rd^ Drive                               |
|            |   |                                                      |
|            |   | Gainesville, FL 32608                                |
|            |   |                                                      |
|            |   | **7. Literature Cited**                              |
|            |   |                                                      |
|            |   | Adams, C. T. 1986. Agricultural and medical impact   |
|            |   | of the imported fire ants, pp. 48-57. *In* Lofgren,  |
|            |   | C. S. and R. K. Vander Meer (eds.). *Fire Ants and   |
|            |   | Leaf Cutting Ants: Biology and Management*. Westview |
|            |   | Press, Boulder, Colorado, USA.                       |
|            |   |                                                      |
|            |   | Adams, C. T., W. A. Banks, and C. S. Lofgren. 1988.  |
|            |   | Red imported fire ant (Hymenoptera: Formicidae):     |
|            |   | correlation of ant density with damage to two        |
|            |   | cultivars of potatoes (*Solanum tuberosum* L.).      |
|            |   | *Journal of Economic Entomology* 81: 905-909.        |
|            |   |                                                      |
|            |   | Allen, C. R., R. S. Lutz, and S. Demaris. 1998.      |
|            |   | Ecological effects of the invasive nonindigenous     |
|            |   | ant, *Solenopsis invicta*, on native vertebrates:    |
|            |   | The wheels on the bus. *Transactions of the North*   |
|            |   |                                                      |
|            |   | *American Wildlife and Natural Resources Conference* |
|            |   | 63: 56-65.                                           |
|            |   |                                                      |
|            |   | Banks, W. A., C. T. Adams, and C. S. Lofgren. 1991.  |
|            |   | Damage to young citrus trees by the red imported     |
|            |   | fire ant (Hymenoptera: Formicidae). *Journal of      |
|            |   | Economic Entomology* 84: 241-246.                    |
|            |   |                                                      |
|            |   | Borgmeier, T. 1969. New or little-known phorid       |
|            |   | flies, mainly of the neotropical region (Diptera:    |
|            |   | Phoridae). Stud. Entomol. 12: 33-132.                |
|            |   |                                                      |
|            |   | Borgmeier, T. and A. P. Prado. 1975. New or little   |
|            |   | known neotropical phorid flies, with description of  |
|            |   | eight new genera (Diptera: Phoridae). Stud. Entomol. |
|            |   | 18: 3-90.                                            |
|            |   |                                                      |
|            |   | Brown, B. V. 1993. Taxonomy and preliminary          |
|            |   | phylogeny of the parasitic genus *Apocephalus*,      |
|            |   | subgenus *Mesophora* (Diptera: Phoridae). Syst.      |
|            |   | Entomol. 18: 191-230.                                |
|            |   |                                                      |
|            |   | Calcaterra, L. A., S. D. Porter, and J. A. Briano.   |
|            |   | 2005. Distribution and abundance of fire ant         |
|            |   | decapitating flies (Diptera: Phoridae: Pseudacteon), |
|            |   | in three regions of southern South America. Ann.     |
|            |   | Entomol. Soc. Am. 98: 85-95.                         |
|            |   |                                                      |
|            |   | Callcott, A. A. and Collins, H. L. 1996. Invasion    |
|            |   | and range expansion of imported fire ants            |
|            |   | (Hymenoptera: Formicidae) in North America from      |
|            |   | 1918-1995. Florida Entomol. 79:240-251.              |
|            |   |                                                      |
|            |   | Disney, R. H. L. 1994. Scuttle flies: the Phoridae.  |
|            |   | Chapman & Hall, London. 467 p.                       |
|            |   |                                                      |
|            |   | Drees, B. M., R. Cavazos, L. A. Berger, and S. B.    |
|            |   | Vinson. 1992. Impact of seed-protecting insecticides |
|            |   | on sorghum and corn seed feeding by red imported     |
|            |   | fire ants (Hymenoptera: Formicidae). J. Econ.        |
|            |   | Entomol. 85: 993-997.                                |
|            |   |                                                      |
|            |   | Eubanks, M.D. 2001. Estimates of the direct and      |
|            |   | indirect effects of red imported fire ants on        |
|            |   | biological control in field crops. Biological        |
|            |   | Control: Theory and Applications in Pest Management. |
|            |   | 21: 35-43.                                           |
|            |   |                                                      |
|            |   | Fadamiro, H. Y., L. Chen, E. O. Onagbola, and L. F.  |
|            |   | Graham. 2005. Lifespan and patterns of accumulation  |
|            |   | and mobilization of nutrients in sugar fed phorid    |
|            |   | fly, *Pseudacteon tricuspis*. Physiol. Entomol. (in  |
|            |   | press).                                              |
|            |   |                                                      |
|            |   | Feener, D. H., Jr. 1981. Competition between ant     |
|            |   | species: outcome controlled by parasitic flies.      |
|            |   | Science 214: 815-817.                                |
|            |   |                                                      |
|            |   | Feener, D. H., Jr. 1987. Size-selective oviposition  |
|            |   | in *Pseudacteon crawfordi* (Diptera: Phoridae), a    |
|            |   | parasite of fire ants. Ann. Entomol. Soc. Am. 80:    |
|            |   | 148-151.                                             |
|            |   |                                                      |
|            |   | Folgarait, P. J., O. Bruzzone, S. D. Porter, M. A.   |
|            |   | Pesquero, and L. E. Gilbert. 2005. Biogeography and  |
|            |   | macroecology of phorid flies that attack fire ants   |
|            |   | in south-eastern Brazil and Argentina. J.            |
|            |   | Biogeography 32: 353-367.                            |
|            |   |                                                      |
|            |   | Fowler, H. G., M. A. Pesquero, S. Campiolo, and S.   |
|            |   | D. Porter. 1995. Seasonal activity of species of     |
|            |   | *Pseudacteon* (Diptera: Phoridae) parasitoids of     |
|            |   | fire ants (Solenopsis saevissima) (Hymenoptera:      |
|            |   | Formicidae) in Brazil. Cientifica 23: 367-371.       |
|            |   |                                                      |
|            |   | Gilbert, L. E. and L. W. Morrison. 1997. Patterns of |
|            |   | host specificity in *Pseudacteon* parasitoid flies   |
|            |   | (Diptera: Phoridae) that attack *Solenopsis* fire    |
|            |   | ants (Hymenoptera: Formicidae). Environ. Entomol.    |
|            |   | 26: 1149-1154.                                       |
|            |   |                                                      |
|            |   | Lard, C. F., C. Hall, and V. Salin. 2001. The        |
|            |   | economic impact of the red imported fire ant on the  |
|            |   | homescape, landscape, and the urbanscape of selected |
|            |   | metroplexes of Texas. Department of                  |
|            |   |                                                      |
|            |   | Agricultural Economics, Texas A & M University,      |
|            |   | College Station, TX. Faculty Paper Series. FP 01-3.  |
|            |   |                                                      |
|            |   | Lennartz, F. E. 1973. Modes of dispersal of          |
|            |   | *Solenopsis invicta* from Brazil into the            |
|            |   | continental United States -- a study in spatial      |
|            |   | diffusion. M.S. thesis, University of Florida, 242   |
|            |   | pp.                                                  |
|            |   |                                                      |
|            |   | Loding, H. P. 1929. An ant (*Solenopsis saevissima   |
|            |   | richteri* Forel). *United States Department of       |
|            |   | Agriculture, Insect Pest Survey Bulletin* 9: 241.    |
|            |   |                                                      |
|            |   | MacKay, W. P. and S. B. Vinson. 1990. Control of the |
|            |   | red imported fire ant *Solenopsis invicta* in        |
|            |   | electrical equipment, pp. 614-619. *In* Vander Meer, |
|            |   | R. K., K. Jaffe, and A. Cedeno (eds.). *Applied      |
|            |   | Myrmecology: a World Perspective*. Westview Press,   |
|            |   | Boulder, Colorado, USA.                              |
|            |   |                                                      |
|            |   | Morrison, L. W., C. G. Dall\'aglio-Holvorcem, and L. |
|            |   | E. Gilbert. 1997. Oviposition behavior and           |
|            |   | development of *Pseudacteon* flies (Diptera:         |
|            |   | Phoridae), parasitoids of *Solenopsis* fire ants     |
|            |   | (Hymenoptera: Formicidae). Environ. Entomol. 26:     |
|            |   | 716-724.                                             |
|            |   |                                                      |
|            |   | Morrison, L. W. and L. E. Gilbert. 1998.             |
|            |   | Parasitoid-host relationships when host size varies: |
|            |   | the case of *Pseudacteon* flies and *Solenopsis*     |
|            |   | fire ants. Ecol. Entomol. 23: 409-416.               |
|            |   |                                                      |
|            |   | Morrison, L.W. and S.D. Porter. 2006. Post-release   |
|            |   | host-specificity testing of *Pseudacteon tricuspis*, |
|            |   | a phorid parasitoid of *Solenopsis invicta* fire     |
|            |   | ants. BioControl 51: 195-205.                        |
|            |   |                                                      |
|            |   | Orr, M. R., S. H. Seike, W. W. Benson, and L. E.     |
|            |   | Gilbert. 1995. Flies suppress fire ants. Nature 373: |
|            |   | 292.                                                 |
|            |   |                                                      |
|            |   | Pereira, R. M., D. F. Williams, J. J. Becnel, and D. |
|            |   | H. Oi. 2002. Yellow-head disease caused by a newly   |
|            |   | discovered *Mattesia* sp. in populations of the red  |
|            |   | imported fire ant, *Solenopsis invicta*. *Journal of |
|            |   | Invertebrate Pathology* 81: 45-48.                   |
|            |   |                                                      |
|            |   | Pesquero, M. A., S. Campiolo, H. G. Fowler, and S.   |
|            |   | D. Porter. 1996. Diurnal patterns of ovipositional   |
|            |   | activity in two *Pseudacteon* fly parasitoids        |
|            |   | (Diptera: Phoridae) of *Solenopsis* fire ants        |
|            |   | (Hymenoptera: Formicidae). Florida Entomol. 79:      |
|            |   | 455-456.                                             |
|            |   |                                                      |
|            |   | Porter, S. D. 1992. Frequency and distribution of    |
|            |   | polygyne fire ants (Hymenoptera: Formicidae) in      |
|            |   | Florida. Florida Entomol. 75: 248-257.               |
|            |   |                                                      |
|            |   | Porter, S. D. 1998a. Biology and behavior of         |
|            |   | *Pseudacteon* decapitating flies (Diptera: Phoridae) |
|            |   | that parasitize *Solenopsis* fire ants (Hymenoptera: |
|            |   | Formicidae). Florida Entomol. 81: 292-309.           |
|            |   |                                                      |
|            |   | Porter, S. D. 1998b. Host-specific attraction of     |
|            |   | *Pseudacteon* flies (Diptera: Phoridae) to fire ant  |
|            |   | colonies in Brazil. Florida Entomol. 81: 423-429.    |
|            |   |                                                      |
|            |   | Porter, S. D. 2000. Host specificity and risk        |
|            |   | assessment of releasing the decapitating fly,        |
|            |   | *Pseudacteon curvatus*, as a classical biocontrol    |
|            |   | agent for imported fire ants. Biol. Control 19:      |
|            |   | 35-47.                                               |
|            |   |                                                      |
|            |   | Porter, S. D. and L. E. Alonso. 1999. Host           |
|            |   | specificity of fire ant decapitating flies (Diptera: |
|            |   | Phoridae) in laboratory oviposition tests. J. Econ.  |
|            |   | Entomol. 92: 110-114.                                |
|            |   |                                                      |
|            |   | Porter, S. D., H. G. Fowler, S. Campiolo, and M. A.  |
|            |   | Pesquero. 1995a. Host specificity of several         |
|            |   | *Pseudacteon* (Diptera: Phoridae)                    |
|            |   |                                                      |
|            |   | parasites of fire ants (Hymenoptera: Formicidae) in  |
|            |   | South America. Florida Entomol. 78: 70-75.           |
|            |   |                                                      |
|            |   | Porter, S. D., and L. E. Gilbert. 2004. Assessing    |
|            |   | host specificity and field release potential of fire |
|            |   | ant decapitating flies (Phoridae: *Pseudacteon*),    |
|            |   | pp. 152-176. *In* R. G. Van Driesche and R. Reardon  |
|            |   | \[eds.\], Assessing host ranges for parasitoids and  |
|            |   | predators used for classical biological control: a   |
|            |   | guide to best practice. FHTET-2004-03, USDA Forest   |
|            |   | Service, Morgantown, West Virginia.                  |
|            |   |                                                      |
|            |   | Porter, S. D., M. A. Pesquero, S. Campiolo, and H.   |
|            |   | G. Fowler. 1995b. Growth and development of          |
|            |   | *Pseudacteon* phorid fly maggots (Diptera: Phoridae) |
|            |   | in the heads of *Solenopsis* fire ant workers        |
|            |   | (Hymenoptera: Formicidae). Environ. Entomol. 24:     |
|            |   | 475-479.                                             |
|            |   |                                                      |
|            |   | Porter, S. D. and D. A. Savignano. 1990. Invasion of |
|            |   | polygyne fire ants decimates native ants and         |
|            |   | disrupts arthropod community. Ecology 71: 2095-2106. |
|            |   |                                                      |
|            |   | Porter, S. D., R. K. Vander Meer, M. A. Pesquero, S. |
|            |   | Campiolo, and H. G. Fowler. 1995c. *Solenopsis*      |
|            |   | (Hymenoptera: Formicidae) fire ant reactions to      |
|            |   | attacks of *Pseudacteon* flies (Diptera: Phoridae)   |
|            |   | in southeastern Brazil. Ann. Entomol. Soc. Amer. 88: |
|            |   | 570-575.                                             |
|            |   |                                                      |
|            |   | Porter, S. D., B. Van Eimeren, and L. E. Gilbert.    |
|            |   | 1988. Invasion of red imported fire ants             |
|            |   | (Hymenoptera: Formicidae): microgeography of         |
|            |   | competitive replacement. Ann. Entomol. Soc. Am. 81:  |
|            |   | 913-918.                                             |
|            |   |                                                      |
|            |   | Porter, S. D., D. F. Williams, R. S. Patterson, and  |
|            |   | H. G. Fowler. 1997. Intercontinental differences in  |
|            |   | the abundance of *Solenopsis* fire ants              |
|            |   | (Hymenoptera: Formicidae): escape from natural       |
|            |   | enemies? Environ. Entomol. 26: 373-384.              |
|            |   |                                                      |
|            |   | Ross, K. G. and J. C. Trager. 1990. Systematics and  |
|            |   | population genetics of fire ants (*Solenopsis        |
|            |   | saevissima* complex) from Argentina. *Evolution* 44: |
|            |   | 2113-2134.                                           |
|            |   |                                                      |
|            |   | Shoemaker, D. D., K. G. Ross, and M. L. Arnold.      |
|            |   | 1996. Genetic structure and evolution of a fire ant  |
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|            |   | (submitted).                                         |
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