                  FOR PUBLICATION
  UNITED STATES COURT OF APPEALS
       FOR THE NINTH CIRCUIT

CACTUS CORNER, LLC, a California        
Limited Liability Corporation;
VENIDA PACKING COMPANY, a
California Corporation; CALIFORNIA
CITRUS MUTUAL; CALIFORNIA
GRAPE AND TREE FRUIT LEAGUE,
               Plaintiffs-Appellants,
                 v.
U.S. DEPARTMENT OF AGRICULTURE;             No. 04-16003
ANN M. VENEMAN, Secretary of
Agriculture; BOBBY R. ACORD,                  D.C. No.
Administrator, Animal and Plant            CV-02-06270-
Health Inspection Service,                   OWW/SMS
             Defendants-Appellees,            OPINION
INTERCITRUS, a Spanish Trade
Association; IBERTRADE
COMMERCIAL CORPORATION, a New
York Corporation; LGS SPECIALTY
SALES, LTD., a New York “S”
Corporation; LUKE G. SEARS,
President of LGS Specialty Sales,
Ltd.,
 Defendants-Intervenors-Appellees.
                                        
        Appeal from the United States District Court
            for the Eastern District of California
        Oliver W. Wanger, District Judge, Presiding

                 Argued and Submitted
        March 15, 2006—San Francisco, California

                      Filed June 8, 2006

                             6371
6372            CACTUS CORNER v. USDA
   Before: Pamela Ann Rymer, William A. Fletcher, and
            Richard R. Clifton, Circuit Judges.

                Opinion by Judge Clifton
6374              CACTUS CORNER v. USDA


                       COUNSEL

Roger M. Witten, Neil J. King (argued), Wilmer Cutler Pick-
ering Hale and Dorr LLP, Washington, D.C., for the
plaintiffs-appellants.
                   CACTUS CORNER v. USDA                   6375
Jan L. Kahn, Kahn, Soares & Conway, Hanford, California,
for the plaintiffs-appellants.

Peter D. Keisler, McGregor W. Scott, Michael S. Raab, Teal
Luthy Miller (argued), U.S. Department of Justice, Washing-
ton, D.C., for the defendants-appellees.

David A. Holzworth, Hiromi Maruyama, Lepon Holzworth &
Kato, PLLC, Washington, D.C., for the intervenors-appellees.


                          OPINION

CLIFTON, Circuit Judge:

   The Mediterranean fruit fly, widely known as the medfly,
may be tiny — slightly smaller than a common housefly —
but it carries enormous weight. It is widely regarded as one
of the world’s most destructive fruit pests. The medfly dam-
ages citrus and other fruits by planting eggs that hatch inside
the fruit, and it reproduces rapidly: a female medfly can lay
as many as 800 eggs during a lifetime of less than a month.
The species originated in sub-Saharan Africa and is not estab-
lished in the United States, except in Hawaii, which has been
infested for nearly a century. The first U.S. mainland infesta-
tion was reported in Florida in 1929. Several infestations have
been reported since then, especially in recent years, but inten-
sive detection and eradication programs, notably in Califor-
nia, are believed to have prevented the pest from becoming
permanently established.

   The medfly is viewed as a serious threat to California’s
agricultural sector and general economy. California, the
world’s fifth largest agricultural economy, produces more
than $13 billion worth of fruits and vegetables annually. Med-
fly infestation threatens that production, and an infestation
would particularly hinder exports because other countries
6376               CACTUS CORNER v. USDA
often restrict imports from medfly-infested areas. Because
many believe that California’s recent medfly outbreaks have
been caused by the importation of infested fruit, it is unsur-
prising that California growers are wary of fruit brought from
other parts of the world. At the same time, there are those who
believe that the growers’ position is motivated as much or
more by their desire to protect themselves against foreign
competition in the multi-billion dollar domestic produce mar-
ket.

   It is within that context that this case arises. In 2001, med-
fly larvae were discovered in fruit imported from Spain, spe-
cifically in clementines, a variety of mandarin orange. The
U.S. Department of Agriculture promptly halted further
imports of clementines from Spain. Several months later, the
USDA issued a rule that permitted the importation of Spanish
clementines to resume, subject to certain conditions intended
to prevent the introduction of medflies into this country.
Domestic fruit growers challenged that rule by bringing this
action. Spanish fruit growers intervened in support of the rule,
and both sides filed motions for summary judgment. The dis-
trict court granted summary judgment to the USDA, thus sus-
taining the rule against the domestic growers’ challenge. See
Cactus Corner, LLC v. USDA, 346 F. Supp. 2d 1075 (E.D.
Cal. 2004).

   This appeal requires us to consider which requirements
administrative agencies must satisfy in decisionmaking. The
domestic fruit grower plaintiffs urge us to require agencies to
articulate explicit standards, quantitative or otherwise, that
would then be used to guide the agency’s decisionmaking
process. Specifically, plaintiffs argue that the USDA must
identify the level of risk it will accept in performing its duty
“to prevent the introduction into the United States . . . of a
plant pest,” 7 U.S.C. § 7712(a), and that the department’s fail-
ure to do so violated the Administrative Procedure Act
(“APA”). We are not persuaded. Although a governmental
agency must “articulate a satisfactory explanation for its
                    CACTUS CORNER v. USDA                      6377
action including a rational connection between the facts found
and the choice made,” it need not define an explicit standard
to guide its decisionmaking. Motor Vehicle Mfrs. Ass’n of
U.S., Inc. v. State Farm Mut. Auto. Ins. Co., 463 U.S. 29, 43
(1983) (quotation marks and citation omitted). Because the
government has “cogently explain[ed] why it has exercised its
discretion in a given manner,” id. at 48, we cannot conclude
that the USDA’s action in adopting the new rule was arbitrary
and capricious. We also reject plaintiffs’ argument that the
USDA’s factual determinations are not supported by the
administrative record.

I.   BACKGROUND

   The facts of this case are fully set forth in the district
court’s opinion, 346 F. Supp. 2d at 1081-92, and we summa-
rize them briefly here. Until 2001, clementines were imported
from Spain under a permit authorized by 7 C.F.R. § 319.56-
2(e). The permit required that Spanish clementines be sub-
jected to a cold treatment — storage at a specified cold tem-
perature for a specified minimum period of time. The cold
treatment was designed to kill any medfly larvae before they
reached the United States. Importation continued without inci-
dent until November 2001, when consumers and agricultural
officials discovered live medfly larvae in Spanish clementines
at scattered locations around the country. Id. at 1081-82.

   On December 5, 2001, the USDA’s Animal and Plant
Health Inspection Service (“APHIS”) temporarily suspended
the importation of Spanish clementines. The agency did so
under the authority of the Plant Protection Act, which permits
the Secretary of Agriculture to “prohibit or restrict the impor-
tation . . . of any plant . . . if the Secretary determines that the
prohibition or restriction is necessary to prevent the introduc-
tion into the United States . . . of a plant pest.” 7 U.S.C.
§ 7712(a). APHIS quickly assembled a team that visited Spain
in mid-December. After identifying several possible causes
for the appearance of medfly larvae, the team recommended
6378                     CACTUS CORNER v. USDA
that a “systems approach” be adopted. 346 F. Supp. 2d at
1085. Under this approach, medflies would be subjected to
multiple pest control measures, “at least two of which have an
independent effect in mitigating” the risk of infestation. 7
U.S.C. § 7702(18) (defining “systems approach”); see also id.
§ 7712(e) (requiring the Secretary of Agriculture to conduct
a study of “systems approaches designed to guard against the
introduction of plant pathogens”).

   Because of concerns about the effectiveness of the cold
treatment protocol, APHIS also convened a panel of experts
to review the existing literature on the subject. The panel
issued its findings on May 2, 2002. The panel concluded that
the existing cold treatment protocol “does not provide 100%
mortality, and even falls short of probit 9 security.”1 The
panel therefore recommended revising the protocol by
increasing “the required treatment time at each temperature by
two days.” For example, while the existing protocol only
required 12 days of treatment at 34°F, the revised protocol
called for 14 days at that temperature. In addition to recom-
mending this immediate revision, the panel stressed the need
for “long-term research plans . . . to verify the efficacy of the
proposed new cold treatment parameters.”

   APHIS further analyzed the cold treatment protocols in a
study prepared by its Office of Risk Assessment and Cost-
Benefit Analysis (“ORACBA”). The ORACBA study pro-
vided a quantitative analysis of the effectiveness of cold treat-
ment. The report agreed with the May 2002 study that the
existing cold treatment protocol was inadequate, but con-
cluded that the revised treatment protocol “should achieve the
probit 9 level of security.”
  1
     Probit 9 “refers to a level or percentage of mortality of target pests (i.e.,
99.9968 percent mortality or 32 survivors out of a million) caused by a
control measure. APHIS has historically used the term ‘probit 9’ in associ-
ation with the mortality rate caused by commodity treatments (including
. . . cold treatments) for fruit flies.” 67 Fed. Reg. 64702, 64704 (Oct. 21,
2002).
                    CACTUS CORNER v. USDA                    6379
   In addition to the cold treatment studies, APHIS prepared
a risk management analysis, which provided a more compre-
hensive evaluation of medfly control measures. The agency
released the final version on October 4, 2002. This analysis
assisted the agency’s decisionmaking process by estimating
the likelihood that a mated pair of medflies could enter a
region of the United States with a climate suitable for medfly
populations. The agency focused on mated pairs because a
single medfly cannot cause much damage. Unless a mated
pair comes together in a suitable climate, there is little risk of
infestation.

   The risk management analysis evaluated the efficacy of the
“systems approach,” under which two independent pest con-
trol measures would be implemented. One was “the applica-
tion of quarantine cold treatments such that probit 9 mortality
is approximated,” as described above. The other was a man-
agement program designed to limit medfly populations within
Spanish orchards, prior to any cold treatment or shipment of
clementines to the United States.

   To determine the risk of medfly introduction, the risk man-
agement analysis used a five-variable model. These variables
estimated (1) the number of clementines shipped from Spain;
(2) the proportion of fruit infested with larvae; (3) the number
of larvae per fruit that will develop into adults; (4) the mortal-
ity rate resulting from the revised cold treatment protocol; and
(5) the proportion of fruit discarded in areas of the United
States with medfly-suitable climates. After examining these
variables, APHIS concluded that the proposed control mea-
sures would reduce the likelihood of medfly introduction to
less than 0.0001, or “less than one in more than ten thousand
years.” Even at the 95% confidence level, the likelihood was
only 0.0004, or “less than one in two thousand years.”

   Meanwhile, in July APHIS published a rule proposing that
the importation of clementines be resumed. See 67 Fed. Reg.
45922 (July 11, 2002). APHIS solicited comments on the pro-
6380               CACTUS CORNER v. USDA
posal and held two public hearings. After evaluating these
comments, and making revisions to the risk management
analysis and the proposed treatment methods, APHIS issued
the Final Rule. 67 Fed. Reg. 64702 (Oct. 21, 2002); see also
7 C.F.R. § 319.56-2jj. In promulgating the Final Rule, the
agency expressly relied on the risk management analysis, the
May 2002 panel review, the ORACBA study, and “the deter-
minations of USDA technical experts.” 67 Fed. Reg. at
64703.

   The Final Rule follows the recommendations of the risk
management analysis by implementing two major changes to
the Spanish clementine program. First, the Final Rule man-
dates the use of the revised cold treatment protocol. 7 C.F.R.
§ 319.56-2jj(g). Second, the Final Rule requires that the Span-
ish government take aggressive steps, including an APHIS-
approved management program, to reduce the medfly popula-
tion in that country’s orchards. Id. § 319.56-2jj(b)-(d). The
Final Rule tests the efficacy of those efforts by requiring that
200 fruit from each shipment be sampled before the shipment
undergoes cold treatment. Id. § 319.56-2jj(f). If, during this
pre-treatment sampling, “inspectors find a single live Mediter-
ranean fruit fly in any stage of development . . ., the entire
shipment of clementines will be rejected.” Id. In addition, if
a single live medfly “is found in any two lots of fruit from the
same orchard during the same shipping season, that orchard
will be removed from the export program for the remainder
of the shipping season.” Id. The Rule also provides for the
inspection of clementines at U.S. ports of entry. If any live
medfly or medfly larvae are found during such an inspection,
“the shipment will be held until an investigation is completed
and appropriate remedial actions have been implemented.” Id.
§ 319.56-2jj(h).

  Plaintiffs filed suit in the Eastern District of California,
arguing that the Final Rule violates the APA and other laws.
After a group of Spanish clementine exporters intervened in
support of APHIS and the Final Rule, both sides moved for
                    CACTUS CORNER v. USDA                 6381
summary judgment. On March 11, 2004, the district court
granted the agency’s motion for summary judgment, 346 F.
Supp. 2d at 1123, and plaintiffs timely appealed.

II.    DISCUSSION

   Plaintiffs challenge the Final Rule on two grounds. First,
they contend that APHIS improperly issued the Final Rule
without defining what level of risk it would accept in “pre-
vent[ing] the introduction” of medflies under the Plant Protec-
tion Act. Second, they argue that the agency’s factual
determinations are not supported by the record.

   We review the district court’s grant of summary judgment
de novo. Baccarat Fremont Developers, LLC v. U.S. Army
Corps of Engineers, 425 F.3d 1150, 1153 (9th Cir. 2005). We
may set aside the agency’s decision if it is “arbitrary, capri-
cious, an abuse of discretion, or otherwise not in accordance
with the law.” 5 U.S.C. § 706(2)(A). In our review under the
APA, “we ask whether the decision was based on a consider-
ation of the relevant factors and whether there has been a
clear error of judgment.” Baccarat Fremont, 425 F.3d at 1153
(citing Marsh v. Oregon Natural Res. Council, 490 U.S. 360,
378 (1989)).

  A.    Articulation of an Acceptable Level of Risk

   Plaintiffs argue that the Final Rule violates the APA
because the agency “simply declar[ed] that the measures it
has adopted will ‘prevent the introduction’ of Medfly without
explaining what criterion it applied to make that determina-
tion or why.” According to plaintiffs, APHIS was obligated to
identify the level of risk it considers to be unacceptable, and
the agency’s failure to do so requires that the Final Rule be
set aside. In support of their argument, plaintiffs cite Harlan
Land Company v. USDA, 186 F. Supp. 2d 1076 (E.D. Cal.
2001), as well as decisions relied on in Harlan Land, includ-
ing Ober v. Whitman, 243 F.3d 1190, 1195 (9th Cir. 2001).
6382                      CACTUS CORNER v. USDA
The court in Harlan Land overturned a similar rule because
APHIS “did not establish a level above which the risk [of pest
introduction] would no longer be negligible.” Id. at 1080.
Harlan Land thus suggests that APHIS was required to “pro-
vide a negligible risk threshold” before issuing the Final Rule.
Id. at 1087.

   [1] Plaintiffs’ argument is foreclosed by our recent decision
in Ranchers Cattlemen Action Legal Fund v. USDA, 415 F.3d
1078 (9th Cir. 2005). In Ranchers Cattlemen, we considered
this issue in the context of the Animal Health Protection Act,
which is substantively identical to the Plant Protection Act.2
The district court in that case had relied on Harlan Land to
enjoin a USDA rule permitting the importation of Canadian
beef and cattle. The district court specifically held “that
USDA failed adequately to quantify the risk of Canadian cat-
tle to humans.” Id. at 1091. The agency appealed, and we
reversed.

   [2] On appeal, we squarely rejected the premise of plain-
tiffs’ argument, holding that the Animal Health Protection Act
“does not require the Secretary to quantify a permissible level
of risk or to conduct a risk assessment.” Id. at 1097. We also
emphasized the USDA’s “wide discretion in dealing with the
importation of plant and animal products,” and we noted that
  2
  The relevant language in the two statutes is nearly identical. Under the
Animal Health Protection Act, the Secretary of Agriculture
      may prohibit or restrict . . . the importation . . . of any animal . . .
      if the Secretary determines that the prohibition or restriction is
      necessary to prevent the introduction into . . . the United States
      of any pest.
7 U.S.C. § 8303(a)(1). Under the Plant Protection Act, the Secretary
      may prohibit or restrict the importation . . . of any plant . . . if the
      Secretary determines that the prohibition or restriction is neces-
      sary to prevent the introduction into the United States . . . of a
      plant pest.
7 U.S.C. § 7712(a).
                    CACTUS CORNER v. USDA                     6383
“the statute’s use of the word ‘may’ suggests that [USDA] is
given discretion over such decisions as whether to close the
borders.” Id. at 1094. In this case, where APHIS has issued
a rule under a substantively identical statute, we follow our
holding in Ranchers Cattleman and reject this point of appeal.

  B.   APHIS’s Factual Determinations

  Plaintiffs further argue that the administrative record does
not support the factual determinations underlying the Final
Rule. They have identified four problems with the agency’s
analysis which, plaintiffs contend, demonstrate that the Final
Rule is arbitrary and capricious. We conclude that these
objections are without merit.

   [3] Plaintiffs first point out that the risk management analy-
sis improperly presented four different estimates, varying by
a large margin, for the probability that a mated pair of med-
flies will be introduced in a medfly-suitable region. These
inconsistencies are not fatal to the Final Rule. The underlying
data are consistent with the figures cited in the analysis’s
executive summary and with the agency’s ultimate conclu-
sions about the likelihood of medfly introduction. Because
these discrepancies within the risk management analysis do
not appear to have affected APHIS’s final decision, we
decline to overturn the regulation on this basis. See Alaska
Dep’t of Environmental Conservation v. EPA, 540 U.S. 461,
497 (2004) (“Even when an agency explains its decision with
less than ideal clarity, a reviewing court will not upset the
decision on that account if the agency’s path may reasonably
be discerned.”) (quotation marks and citation omitted).

   [4] Plaintiffs’ second objection concerns the risk manage-
ment analysis’s estimate of eight as the maximum number of
larvae per fruit that will lead to viable adults. Plaintiffs assert
that this estimate is baseless because the agency’s direct sam-
pling in 2001 indicated that the average larvae per fruit varied
between four and twelve. We are unpersuaded by this argu-
6384                  CACTUS CORNER v. USDA
ment for two reasons. First, the estimate used in the risk man-
agement analysis is not equivalent to the figure cited by
plaintiffs. The risk management analysis estimated the num-
ber of viable larvae (i.e., those that will reach adulthood),
while the 2001 sampling data merely represents the number
of larvae observed, without adjusting for larvae mortality.
Although APHIS discovered clementines that contained as
many as twelve larvae, only about 10% of those larvae would
be expected to reach adulthood. Plaintiffs argue that this 90%
mortality rate is offset by the fact that only 10% of larvae are
detected, but the detection rate cited by plaintiffs is based on
grapefruit data. Although the agency discussed this grapefruit
data in the risk management analysis, APHIS never assumed
that the detection rate for grapefruit is identical to the clemen-
tine’s, a decision supported by the agency’s observation that
the characteristics of these fruits differ.3 Indeed, elsewhere
APHIS assumed that medflies are more easily detected in
clementines than in grapefruit. Compare A.R. 1401 (citing a
study in which only 35% of infested grapefruit were detected)
with 67 Fed. Reg. at 64736 (assuming that 75% of infested
clementines will be detected). In short, the 2001 sampling
data does not support plaintiffs’ claim that the maximum
number of viable larvae is greater than eight.

   [5] The second reason we reject plaintiffs’ argument is that,
even if the 2001 sampling data would support a different esti-
mate than the one chosen, APHIS was within its discretion in
using an alternative method to calculate this value. The
agency relied on a 1999 study of clementines which suggested
that the maximum survival rate for medfly larvae is less than
8%. Conservatively assuming that an infested clementine
could contain up to 100 eggs, the risk management analysis
estimated that the maximum number of viable larvae was
eight. See A.R. 1402-03 ((100 eggs per fruit) x (maximum
  3
   “We note . . . that clementines are smaller fruit than grapefruit and
have therefore a much larger surface area to inspect. Clementines are also
easier to dissect than grapefruit.” A.R. 1401.
                      CACTUS CORNER v. USDA                          6385
survival rate of .0765) = 8 viable larvae per fruit). Because we
“defer to the evaluations of agencies when the evidence pre-
sents conflicting views,” Pacific Coast Federation of Fisher-
men’s Associations v. Bureau of Reclamation, 426 F.3d 1082,
1090 (9th Cir. 2005), we reject this challenge to the Final
Rule.

   Third, plaintiffs maintain that the Final Rule’s control mea-
sures cannot logically fix the medfly problem, because the
infestation rate observed in 2001 was 0.16% while the Final
Rule only protects against infestation rates greater than 1.5%.4
Plaintiffs thus question how “[l]imiting the maximum infesta-
tion rate under the Rule to a value almost ten times higher
than the infestation rate in 2001 would [ ] be expected to
make a difference.” But APHIS addressed this issue in the
Final Rule, explaining that it was “unconvinced that the level
of infestation observed in samples taken later in the shipping
season are representative of” the infestation rates that existed
earlier in the season. 67 Fed. Reg. at 64713. APHIS believed
that the medfly infestation rates in Spain varied over the
course of the 2001-2002 shipping season. The agency con-
cluded that these rates were greater than 0.16% early in the
season, when the first shipments reached American shores. It
was within these early-season clementines, which were on the
market by November 2001, that live medfly larvae were
found. According to APHIS, by the time it began collecting
data later that season, the infestation rates had fallen. Because
“the infestations associated with early season shipments”
were greater than 0.16%, APHIS chose not to rely on its sam-
pling data in the risk management analysis. Id. at 64714.
  4
   APHIS can detect infestation levels as low as 1.5% because the Final
Rule requires that “APHIS inspectors [ ] cut and inspect 200 fruit that are
randomly selected” from each shipment of clementines. 7 C.F.R.
§ 319.56-2jj(f). By sampling 200 fruit, there is a 95% probability that the
agency will detect medfly larvae in shipments in which only 1.5% of the
clementines are infested. 67 Fed. Reg. at 64712.
6386                 CACTUS CORNER v. USDA
   [6] The agency’s assumption, that the early-season infesta-
tion rates exceeded 0.16%, is supported by empirical evi-
dence, including the “higher than average trap captures” and
“higher than average temperatures” that existed early in the
season. Id. Because APHIS addressed plaintiffs’ specific con-
cern, and its selection of the target rate is otherwise defensi-
ble, we will not disturb the agency’s judgment. See Pacific
Coast, 426 F.3d at 1090 (“an agency must have discretion to
rely on the reasonable opinions of its own qualified experts”)
(citation omitted).

   [7] Fourth, Plaintiffs challenge the revised cold treatment
protocol, arguing that APHIS was wrong to implement this
protocol because the agency’s experts could not validate the
protocol’s effectiveness. Although a panel of experts recom-
mended further research in May 2002, APHIS subsequently
conducted the ORACBA study, whose results demonstrated
“a high degree of confidence” that the revised treatment pro-
tocol “should achieve the probit 9 level of security.” Given
the ORACBA results, APHIS’s decision to implement the
revised protocol did not “run[ ] counter to the evidence before
the agency.” Id. (citation omitted).

   In their reply brief, plaintiffs argue for the first time that the
ORACBA report does not support the risk management analy-
sis’s assumption that the revised protocol will result in probit
9 mortality. They contend that the ORACBA report only sup-
ports the use of an 18-day treatment, and that the report’s con-
clusions regarding the 14-day treatment (which is permitted
under the Final Rule) are inapplicable because ORACBA
relied on a study of lemons, not clementines. This argument
is without merit. Even assuming that plaintiffs could properly
raise this issue in the reply brief, we decline plaintiffs’ invita-
tion to second-guess the agency. In promulgating the Final
Rule, APHIS considered and addressed numerous comments
pertaining to the revised cold treatment protocol, including
concerns about the efficacy of treatments shorter than 18
days. See, e.g., 67 Fed. Reg. at 64730-64733. The agency’s
                    CACTUS CORNER v. USDA                6387
reliance on a study of lemons in devising the 14-day protocol
was a discretionary judgment call to which we defer. See
Pacific Coast, 426 F.3d at 1090.

III.   CONCLUSION

   [8] Because APHIS was not required to define a negligible
risk standard under the Plant Protection Act, and because the
agency has “articulated a rational connection between the
facts found and the choices made,” Ranchers Cattlemen, 415
F.3d at 1093 (citation omitted), we conclude that the Final
Rule is neither arbitrary nor capricious. The district court’s
grant of summary judgment in favor of the government was
appropriate.

  AFFIRMED.
