> Home | Listserves & events | TNC listserve | Listserve posting
Previous digest Subsequent digest

Global Invasive Species Team listserve digest #107
Sat Aug 17 2002 - 16:55:40 PDT

1. Spread of Cactoblastis cactorum moth (Caribbean, North America)
2. Pulling Together Initiative grants available (Nationwide, USA)
3. Sea Grant Proposals Opening (Nationwide, USA)
4. Lovegrass and weed displays (California, USA)
5. Spread of Sudden Oak Death (California, USA)
6. Trish Klahr on the air (Idaho, USA)
7. Literature reviews (Global)
8. More literature reviews (Global)


1. Spread of Cactoblastis cactorum moth (Caribbean, North America)
From: Doria Gordon (dgordon(at)botany.ufl.edu)

The cactus moth, Cactoblastis cactorum, known best as a biological control
success in places like Australia and South Africa, is now established in
North America and the Caribbean where it poses a critical threat to the
vast biodiversity of native prickly pear cacti. If you have any Opuntia
species in your area, please look for egg sticks of the moth laid on the
ends of cactus spines (looking very much like spines). Also look for the
larvae, which are bright orange with orange spots or lines. The larvae
burrow into and then hollow out cactus pads. The adult moth is much less
easy to identify. See pictures at:
http://creatures.ifas.ufl.edu/bfly/cactus_moth.htm and

Please Help! If you know of or find infestations in your area,
particularly if the sites are inland or in front of the leading edge,
please contact:
Dr. Stephen Hight
Tel.: 850-412-7262;
Fax: 850-412-7263;

The moth is native to northern Argentina, Uruguay, Paraguay, and southern
Brazil. Its larvae feed on many species of Opuntia cactus, primarily from
the subgenus Platyopuntia. Opuntias are a diverse group in North America,
with many endemics. There are 31 likely host Opuntia species for the moth
across the U.S. (9 endemic), and 56 in Mexico (38 endemic). According to
Britton and Rose (1963), there are 22 native species of Platyopuntia in
the Caribbean and 17 in Central America.

Cactoblastis cactorum was first recorded in the Florida Keys in 1989,
where it has already significantly reduced the native prickly pears. Since
then it has moved northward up the coastline of Florida, and is moving
rapidly around the Gulf Coast. As of July 2002, the moth has been
documented to be as far north as Charleston, SC along the Atlantic coast
and as far northwest as Alligator Point, FL (south of Tallahassee, FL and
about 200 miles east of the Alabama state line) along the Gulf coast. We
do not know the range limits of the moth in more inland areas. USDA
researchers are working to develop a sterile male release program that
might be used to slow or contain its distribution. However, USDA needs to
understand its distribution so that they can act quickly when the
technique is fully developed. Until that time, we may need to manually
protect rare Opuntia species by removing the egg sticks and infested pads.


2. Pulling Together Initiative grants available (Nationwide, USA)
From: Barry Rice (bamrice(at)ucdavis.edu)

The 2003 National Fish & Wildlife Foundation's Pulling Together
Initiative (PTI) Request for Proposals has been released. PTI encourages
federal agencies to partner with state and local agencies, private
landowners, and other interested parties in developing long-term,
integrated pest management strategies for invasive species control. The
grants typically range from $25,000 to $30,000.

PTI grants are "matching funds" grants, so you must raise at least an
equivalent amount of "challenge funds" from non-federal sources. The more
you raise beyond this 1:1 ratio of matching funds to challenge funds, the
more competitive your grant proposal will be. The proposal deadline is 6
November. For more information, including the proposal forms, point your
web browser to:


3. Sea Grant Proposals Opening (Nationwide, USA)
From: Barry Rice (bamrice(at)ucdavis.edu)

The draft text of the upcoming request for proposals for the Sea Grant
Aquatic Nuisance Species (ANS) Research and Outreach Program is now
available online, although the grant competition is not yet open.
Depending on the date that this request for proposals is published,
proposals are expected to be due about September 15, 2002. The Aquatic
Nuisance Species Program seeks to fund research and outreach projects for
the prevention and control of introduction and spread of aquatic nuisance

For more information, point your web browser to:


4. Lovegrass and weed displays (California, USA)
From: Nelroy E. Jackson (nelroy.e.jackson(at)monsanto.com)

Regarding posting #106:

I think that Vandenburg Air Force Base tackled lovegrass (Eragrostis
lehmanniana) 15 years ago. Roundup at the right timing should control it
postemergence, before viable seeds are produced. I do think that I know
the broom, but Roundup at 2% V/V is always a good treatment to try.

Steve Schoenig (sschoenig(at)cdfa.ca.gov) at California Dept. of Food and
Agriculture can give you a lot of great examples of displays from Weed
Management Areas.


5. Spread of Sudden Oak Death (California, USA)
From: Ann Bartuska (abartuska(at)tnc.org)

New evidence indicates that the pathogen responsible for sudden
oak death has scientists worried that limiting the spread of the pathogen
may be more difficult than previously thought. Scientists have learned
the fungus present in soils, streams, and in many other plants and trees,
although it doesn't always kill them. Scientists have also learned the
pathogen moves easily from place to place. A recent test at a Santa Cruz
Mountains park found that nine out of 10 hikers leaving the park had the
microbe on their shoes.

For more information concerning sudden oak death, visit the SAF website at



6. Trish Klahr on the air (Idaho, USA)
From: John Randall (jarandall(at)ucdavis.edu)

You can hear (TNC-Idaho's) Trish Klahr talking weeds as part of the
story broadcast on NPR.

National Public Radio's Jyl Hoyt interviewed the Conservancy's Trish Klahr
(and others) for a piece about weed invasions in Hells canyon,
partnerships, remote sensing, etc. used to control the weeds. The feature
aired August 7 on Oregon Public Broadcasting. To listen, on your computer
(RealAudio or MP3 format) click here:


7. Literature reviews (Global)
From: Tunyalee Martin (tamorisawa(at)ucdavis.edu)

Reitz, S.R. and J.T. Trumble. 2002. Competitive displacement among insects
and arachnids. Annual Review of Entomology 47:435-465.

This paper reviews 48 cases of competitive displacement, discussing the
mechanisms involved. The authors first defined competitive displacement as
"the removal of a formerly established species from a habitat through
superior use, acquisition, or defense of resources by another species."
They then get into the meat of the review by summarizing 8 general
mechanisms of how displacement can occur:

1. differential resource acquisition: the ability to obtain resources
2. differential female fecundity: the ability to produce
3. differential searching ability: the ability to locate and exploit
4. resource preemption: a greater ability to use resources before a
5. resource degradation: competitor degrades resource before another can
   use it
6. agonistic interference competition: contests with the winner getting
   the resource
7. reproductive interference: less selectivity for mating versus a species
   with greater selectivity leads to less fecundity in the species with
   greater selectivity
8. intraguild predation: predation at the same trophic level

They also noted that several factors could mediate the
severity of the displacement.

The bulk of the review described cases where competitive displacement was
observed. Cases involved predators and parasitoids, phytophages (plant
sucking insects, beetles and flies), medically important species
(mosquitoes and flies), social hymenoptera (ants, yellow jackets and honey
bees), and arachnids (spiders and mites). Displacements were observed at
all trophic levels. Fifty five percent of the cases were exotic species
displacing another exotic. Native species were displaced by exotics in 33%
of the cases and by another native in 14% of the cases. Half of the cases
involved a displacement between species within the same genus. Others
involved different genera, families, or orders. Multiple species were also
displaced by one species. Many of the cases were observed in
agroecosystems or anthropogenically disturbed habitats and synanthropic

The impact of competitive displacement can vary, but typically lead to
losses of biodiversity, reduced species richness, disturbed insect-plant
mutualisms (pollination, seed dispersal), and reduced effectiveness of
biological control programs. Possible evolutionary consequences included
the evolution of superior competitive abilities, adaptations to new
environmental conditions, speciation, and hybridization.


8. More literature reviews (Global)
From: John Randall (jarandall(at)ucdavis.edu)

**Articles on Phragmites strains:

Saltonstall, K. 2002. Cryptic invasion by a non-native genotype of
Phragmites australis into North America. Proceedings of the National
Academy of Sciences, USA. 99(4): 2445-2449.

This paper provides evidence supporting the hypothesis that a non-native
genotype of Phragmites was introduced to North America and spread
aggressively across the continent in the past 100+ years. Although
Phragmites australis is known to be native to much of North America, in
recent decades it has been aggressively invading coastal and inland
wetlands, particularly in the northeast, southeast and upper midwest. This
has prompted speculation about whether this aggressiveness is the result
of changed environmental conditions or the result of the introduction of
an aggressive genotype from somewhere else in the world. Kristin
Saltonstall carried out the research described in this paper to determine
whether or not non-native strains of Phragmites can be found in North
America. She examined the sequencing of two chloroplast DNA markers from
samples of Phragmites collected from 238 modern samples collected in North
America, Europe, Asia, Africa, Australia and South America and from 62
North American herbarium samples colllected before 1910. She found found a
total of 27 haplotypes among the modern samples. A cluster of 11
haplotypes were present only in her North American samples and are
considered to be native to the continent. These 11 haplotypes all share 5
insertion-deletion mutations which none of the other 16 haplotypes have.
Another haplotype, which she designated M, was the most abundant in modern
North American samples and is also found in Europe and Africa. Haplotype M
was found in a few pre-1910 samples from southern New England but it was
the only haplotype found in this area and along much of the Atlantic
seaboard in the modern samples. Three native North American haplotypes
found in southern New England in the pre-1910 samples were not present in
modern samples taken from the same locations and one them, haplotype AA,
was not found in any of the modern samples. Yet another haplotype,
designated I, was found in pre 1910 and modern samples from along the US
Gulf Coast and in modern samples from South America.

Saltonstall was careful, however, to state that her data does not prove
haplotype M is non-native since it was present in a few samples taken from
herbarium sheets dating from before 1910. However, she notes that the
evidence strongly suggests haplotype M that it was introduced to North
America following European settlement for at least three reasons: 1.)
haplotype M has none of the 5 mutations that all 11 of the exclusively
North American share; 2.) haplotype M is most closely related to other
EurAsian types; 3.) population structuring and genetic diversity have
declined significantly between pre-1910 samples and modern North American
samples. These declines are due to the spread of haplotype M across the
continent and the loss of some native haplotypes from New England sites
now populated exclusively with haplotype M plants. Saltonstall suggests
that haplotype M was likely introduced to the eastern seaboard in the
early 1800s and that its rapid srepad across the continent in the 1900s
was facilitated by human activities which disturbed wetlands and provided
railway, canal and highway corridors for dispersal.

You can see a periodically updated summary of this ongoing work and
download an adobe version of this paper and related articles from Kristin
Saltonstall's website: http://pantheon.yale.edu/~salt/

The site also has a table with summary data on all the specimens used in
the research described above; by my count at least 10 TNC sites from 9
U.S. states were represented among the many samples used!

Morphological differences between Phragmites haplotypes detected

Bernd Blossey and colleagues at Cornell University in NY state have found
what appear to be a suite of fairly consistent morphological differences
between the 11 North American haplotypes on the one hand, and haplotype M
(the putative non-native) on the other that Kristin Saltonstall identified
in her study. For example Blossey's observation indicate haplotype M
characteristically has stems that are tan at the base and at nodes while
the native types characteristically have stems that are purple or chestnut
at the base and nodes. Haplotype M tends to have thicker, more robust
stems which are rough to the touch and visibly ridged once the leaves have
been pulled off while the native haplotypes have stems that are thin and
very smooth. The picture is complicated by the fact that there are some
differences between the native haplotypes and the researchers don't yet
have enough samples of haplotype I, which is found along the U.S. Gulf
Coast and South America, to determine whether it has distinctive
characteristics. You can see a summary of the differences they have
identified on their website:

Blossey's lab continues to gather specimens from around the continent and
encourages you to send in samples so that they can be genetically typed
and their morphological characteristics checked against their table of
characteristics to see if it holds true. They also interested in
determining whether any populations of native haplotype plants remain in
New England (so far only one has been found, on Block Island, RI) and will
grow some specimens from different parts of the continent in a common
garden to determine whether differences remain even when different
haplotypes are grown side by side. Stems collected in the dormant season
will also be used to assess differences in insect herbivores attacking
native and introduced genotypes. They have preliminary evidence from
stands in New York that the insect communities in introduced and native
genotypes differ significantly. You'll benefit, too, by learning whether
your sample is of  the putative non-native haplotype or not.
Instructions on how to collect, prepare and send samples will soon be
posted at:

If you have questions or need instructions on sending a sample earlier,
contact Bernd Blossey at bb22(at)cornell.edu.

Updated August 2002
©The Nature Conservancy, 2002