I 
112TH CONGRESS 
1ST SESSION H. R. 1042 
To amend the Endangered Species Act of 1973 to require that certain 
species be treated as extinct for purposes of that Act if there is not 
a substantial increase in the population of a species during the 15- 
year period beginning on the date the species is determined to be an 
endangered species, and for other purposes. 
IN THE HOUSE OF REPRESENTATIVES 
MARCH 11, 2011 
Mr. BACA (for himself, Mr. CALVERT, Mr. CARDOZA, Mr. COSTA, Mr. 
CUELLAR, Mr. LEWIS of California, Mr. YOUNG of Alaska, Mr. MCCLIN-
TOCK, and Mr. GARY G. MILLER of California) introduced the following 
bill; which was referred to the Committee on Natural Resources 
A BILL 
To amend the Endangered Species Act of 1973 to require 
that certain species be treated as extinct for purposes 
of that Act if there is not a substantial increase in 
the population of a species during the 15-year period 
beginning on the date the species is determined to be 
an endangered species, and for other purposes. 
Be it enacted by the Senate and House of Representa-
tives of the United States of America in Congress assembled, 
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SECTION 1. SHORT TITLE. 
This Act may be cited as the ‘‘Discredit Eternal List-
ing Inequality of Species Takings Act’’ or the ‘‘DELIST 
Act’’. 
SEC. 2. FINDINGS. 
Congress finds the following: 
(1) 
The 
Delhi 
Sands 
Flower-loving 
Fly 
(Rhaphiomidas terminates abdominalis) was listed 
as an endangered species under the Endangered 
Species Act of 1973 (16 U.S.C. 1531 et seq.) on 
September 23, 1993 (58 Fed. Reg. 49881). 
(2) Nineteen years have passed since the Delhi 
Sands Flower-loving Fly was listed as an endan-
gered species. 
(3) The Delhi Sands Flower-loving Fly’s listing 
was based on a high degree of threat and a low po-
tential for recovery for a listed subspecies that may 
be in conflict with construction or other development 
projects or other forms of economic activity. 
(4) On September 14, 1997, a recovery plan 
was issued for the Delhi Sands Flower-loving Fly. 
The plan claimed that the resolution of current pop-
ulation data is too poor to effectively evaluate abun-
dance trends or population distributions due to the 
cryptic nature and rarity of the Delhi Sands flower- 
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loving Fly. Thus, the recovery plan by definition 
could not establish delisting criteria. 
(5) The United States Fish and Wildlife Serv-
ice’s report entitled ‘‘Delhi Sands Flower-loving Fly 
(Rhaphiomidas terminatus abdominalis) 5-Year Re-
view: Summary and Evaluation’’ (March 2008; re-
ferred to in this section as the ‘‘5-year review re-
port’’) establishes that down-listing criterion 2 can-
not be evaluated with current knowledge of the Delhi 
Sands Flower-loving Fly. 
(6) None of the Delhi Sands Flower-loving Fly 
conservation areas are currently managed to main-
tain perpetual sand supply. There is currently insuf-
ficient information to determine the extent or long- 
term importance of this impact to maintaining the 
dune ecosystem. 
(7) The cryptic nature and low density of Delhi 
Sands Flower-loving Fly complicate efforts to effec-
tively monitor population abundance. 
(8) To date, it has proven difficult to conduct 
surveys that reliably quantify relevant population 
variables (e.g., density and relative abundance), and 
no populations are regularly surveyed with sufficient 
effort to effectively monitor population trends. 
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(9) Public support for conservation of the sand 
dune system upon which the Delhi Sands Flower-lov-
ing Fly depends is limited. 
(10) The life history of the Delhi Sands Flower- 
loving Fly is largely unknown. 
(11) The 5-year review report asserts that the 
Delhi Sands Flower-loving Fly was not used to ex-
plain larval stages of such fly because the population 
was too low. Instead, a comparison of entomologists 
observed several larvae of Rhaphiomidas trochilus, 
and because R. trochilus is closely related to the 
Delhi Sands Flower-loving Fly, these observations 
were used to understand larval biology of the Delhi 
Sands Flower-loving Fly. 
(12) A commenter mentioned in the 5-year re-
view report suggested that the Delhi Sands Flower- 
loving Fly may be non-native to the Riverside/San 
Bernardino area and may have been accidentally in-
troduced by the early settlers. 
(13) There is no new information in the sci-
entific literature suggesting that the range of the 
Delhi Sands Flower-loving Fly is more extensive 
than initially identified. 
(14) Although the area of potentially suitable 
habitat has expanded, no newly discovered occupied 
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site supports a major population of the Delhi Sands 
Flower-loving Fly that was not known at the time of 
the listing. 
(15) Within the section of the 5-year review re-
port relating to abundance, it stated that no clear 
trends emerge from the demographic data that have 
been generated since the listing of the Delhi Sands 
Flower-loving Fly. Due to the cryptic nature and 
rarity of the Delhi Sands flower loving fly, it is dif-
ficult to accurately estimate abundance or density 
for this subspecies. 
(16) The 5-year review report claims range- 
wide surveys have not been attempted due to lack of 
funding and issues with access to privately owned 
properties. 
(17) The 5-year review report indicated that 
United States Fish and Wildlife Service biologists 
initiated a study in 2004 designed to improve Delhi 
Sands Flower-loving Fly survey protocol rec-
ommendations. This study required the effort of 3 
biologists working 6 days a week during the peak of 
the flight season, and the data were only marginally 
adequate to estimate abundance, density, and detec-
tion probability. This effort indicated that measure-
ment of population demographic trends will likely re-
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quire substantial effort unless new techniques prove 
effective. 
(18) Because most Delhi Sands Flower-loving 
Fly habitat is in private ownership and no regula-
tions are in place to address loss of unoccupied 
Delhi Sands Flower-loving Fly habitat, the perma-
nent loss of potential and restorable Delhi Sands 
Flower-loving Fly habitat important to recovery 
often proceeds. 
(19) Most of the existing Delhi Sands Flower- 
loving Fly conservation sites are likely too small and 
fragmented to sustain Delhi Sands Flower-loving 
Fly populations through time. 
(20) In addition, while protected from develop-
ment, most of the existing conservation areas remain 
susceptible to invasion by nonnative grasses, off-road 
vehicle use, and other disturbances. 
(21) Most conservation areas do not have moni-
toring programs to track Delhi Sands flower-loving 
fly occupancy or habitat quality. 
(22) With at least 90 percent loss of historical 
Delhi Soils, potential and suitable Delhi Sands 
Flower-loving Fly habitat available for conservation 
and restoration is extremely limited. 
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(23) At the time of listing in 1993, there were 
only five small, isolated, extant populations of Delhi 
Sands Flower-loving Fly. 
(24) The 5-year review report states that recent 
observations, and the continued habitat loss and 
fragmentation, all suggest that population sizes of 
the Delhi Sands Flower-loving Fly are likely to be 
very small. Here, it is clear that the United States 
Fish and Wildlife Service does not know the size of 
the population. It may be possible that there is no 
longer a population to protect. 
(25) It is commonly accepted in conservation bi-
ology that small populations have higher prob-
abilities of extinction than larger populations be-
cause their low numbers make them susceptible to 
inbreeding, loss of genetic variation, high variability 
in age and sex ratios, demographic stochasticity, and 
random naturally occurring events such as wildfires, 
floods, droughts, or disease epidemics. 
(26) Delhi Sands Flower-loving Fly populations 
were considered to be at risk at the time the sub-
species was listed because of their small size and 
habitat fragmentation. We have no information sug-
gesting that these threats have been ameliorated 
since the time of listing. 
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(27) Monitoring efforts since the time of listing, 
though limited, do not suggest population increases, 
and it is reasonable to believe that Delhi Sands 
Flower-loving Fly populations are likely to be very 
small. 
(28) Together, small population size, isolation, 
populations in fragmented habitat, and increased 
vulnerability to introduced predators and competi-
tors increase the risk of extirpation of the remaining 
Delhi Sands Flower-loving Fly populations. 
(29) Continued listing of the Delhi Sands Flow-
er-loving Fly as an endangered species is not based 
on the best scientific and commercial data available. 
The 5-year review report relied on research con-
ducted in 1993 or 2002. The research is 19 and 9 
years old, respectively. The 5-year review report has 
not shown that the Delhi Sands Flower-loving Fly 
exist nor has there been a substantial increase of 
population during the 19 years of protection by the 
Endangered Species Act of 1973 (16 U.S.C. 1531 et 
seq.). 
SEC. 3. TREATMENT OF CERTAIN SPECIES AS EXTINCT. 
Section 4(a) of the Endangered Species Act of 1973 
(16 U.S.C. 1531 et sq.) is amended by adding at the end 
the following new paragraph: 
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‘‘(4) TREATMENT
OF CERTAIN SPECIES
AS EX-
TINCT.—(A) A limited listed species shall be treated as 
extinct for purposes of this Act upon the expiration of the 
15-year period beginning on the date it is determined by 
the Secretary to be an endangered species, unless the Sec-
retary publishes a finding that— 
‘‘(i) there has been a substantial increase in the 
population of the species during that period; or 
‘‘(ii) the continued listing of the species does 
not impose any economic hardship on communities 
located in the range of the species. 
‘‘(B) In this paragraph the term ‘limited listed spe-
cies’ means any species that is listed under subsection (c) 
as an endangered species for which it is not reasonably 
possible to determine whether the species has been extir-
pated from the range of the species that existed on the 
date the species was listed because not all individuals of 
the species were identified at the time of such listing.’’. 
Æ 
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