Gypsy moth news

20 Pages·1993·2.8 MB·English

Historic, Archive Document
Do not assume content reflects current
scientific knowledge, policies, or practices.
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July 1993
Counties with USDA
Gypsy Moth Suppression and Eradication Projects
in the United States, 1993
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Pe Eradication
Suppression
Source: USDA Forest Service and APHIS
United States
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Department of
Agriculture NORTHEASTERN AREA
State and Private Forestry
From the Editor
Contents
The map on this issue's cover and
our accompanying tables on pages
Letters to the Editor 10 and 11 illustrate both the
quantity and extent of suppression
Effects of the Fungal Pathogen Entomophaga
and eradication efforts in just one
Maimaiga on Non-Target Lepidoptera
year. Suppression is a term used
TECHNOLOGY UPDATE to reflect an attempt to reduce
numbers of gypsy moth to nondamaging levels. It takes
Gypsy Moth Rearing Problem Linked to Iron
place in the East where gypsy moth is permanently
(Fe) in Diet
established. Eradication is exactly that. An attempt to
Update on the National Gypsy Moth EIS eliminate all life stages of the insect from an area. The
objective is to eliminate the insect in hopes of slowing the
Understanding the Ecological Effects of
spread. Gypsy moth is permanently established in New
Gypsy Moth
England, the mid-Atlantic States, Virginia, West Virginia,
Ohio, and Michigan. Eradication of isolated infestations
Gypsy Moth Digest (GM Digest)
in places like Arkansas, Wisconsin, and Washington are
Gypsy Moth Suppression and Eradication attempts to slow the westward spread. Eradication is not
Projects, 1993 a new effort. Various government agencies have been
attempting to eradicate the gypsy moth for about 100
Arkansas' New Residents Eradicated
years. At this point in time, no one expects to eliminate
New Publication the gypsy moth from North America. Present eradication
of isolated infestations (those away from the main body)
are viewed as an attempt to prevent new infestations and
slow the spread. The Animal and Plant Health Inspection
Service (APHIS), a regulatory arm of the USDA has
Editor Daniel B. Twardus
primary responsibility for this effort.
Managing Editor Helen A, Machesky
You can read about one of these eradication projects
Production Melissa A. Emerson
taking place in Arkansas on page 12 of this issue. How
on earth did the gypsy moth get to Arkansas? The same
Circulation Stephen C. Smith
way it got to Salt Lake City, Utah--someone carried them.
The gypsy moth egg mass is well suited for travel. The
Gypsy Moth News 1s a service of the USDA
egg mass, attached to the underside of a camper, trailer,
Forest Service, Northeastern Area State and
firewood, or lawn furniture, requires neither food nor
Private Forestry.
water. Come Spring, the eggs hatch, and the wee little
The News is distributed quarterly to individuals larvae crawl out to discover America.
and organizations. Products mentioned by
name within articles are not necessarily -DBT
endorsed by the USDA. Use of graphics or
reprints of articles should cite the Gypsy Moth
News as their source.
Address correspondence to the Editor, USDA
Forest Service, Forest Health Protection,
Morgantown, WV 26505.
LETTERS TO THE EDITOR
W. K. from Rhinelander, WI asks: I think you will find in the Hajek B.S. in Princeton, NJ, writes:
report that results are inconclusive
"Has sufficient research been at this time. However, based "I'd like copies of reports on
completed to prove that E. upon conidial production, E. Entomophaga maimaiga listed
maimaiga does not infect maimaiga infected larvae in three in the April Gypsy Moth
native North American of the five suborders tested: News".
lepidoptera?" Noctuoidea, Bombycoidea, and
Geometroidea. Infection levels Dan Twardus responds:
Dan Twardus responds: though, were very low. In answer
to your question, "Has sufficient All of the titles listed are studies
I have sent a progress report of research been completed to prove that are underway and reports do
on-going studies by Drs. A. Hajek that E. maimaiga does not infect not exist. However, Dr. Ann
and L. Butler which you may native North American Hajek has been kind enough to
find helpful (see page 2). In lepidoptera?", I would have to say forward to me progress reports of
addition, you should be aware that that on-going research appears to her studies which I have sent to
the Wisconsin Department of indicate that native North you for your use. I suggest that
Agriculture published an American lepidoptera can be if you require more definitive
"Environmental Assessment for a infected, though the significance information about E. maimaiga,
Permit to Release Entomophaga of the infection level is yet to be you contact Dr. Ann Hajek.
maimaiga for the Biological determined. I also suggest that
Control of Gypsy Moth". Quoting more definitive information As reports of these studies are
from the Decision Document of relating to the topic can be completed, I will publish their
this Assessment: obtained by writing to: Dr. Ann availability in the News.
Hajek, Boyce Thompson Institute Information about the actual
"Published host range studies for Plant Research, Tower Road, cooperative agreements
indicate that Entomophaga Ithaca, NY 14853; or Dr. Linda authorizing these studies can be
maimaiga infects only larvae Butler, West Virginia University, obtained by contacting Dr.
of certain families in the order 1090 Agricultural Sciences Richard Reardon, USDA Forest
Lepidoptera, or butterflies and Building, Morgantown, WV Service in Morgantown, WV, at
moths. However, the 26506. 304-285-1566. W
Department feels that there is
not enough information on the
pathogenicity of E. maimaiga
to certain families of
Lepidoptera to assess whether
and the extent to which it may
be able to infect threatened and
endangered species of
butterflies and moths in
Wisconsin.”
Apparently, as a result of this lack
of information, the Department of
Agriculture, Trade and Consumer
Protection of Wisconsin therefore
denied a permit for release of the
fungus.
EFFECTS OF THE FUNGAL PATHOGEN
ENTOMOPHAGA MAIMAIGA ON NON-TARGET
LEPIDOPTERA
By Ann E. Hajek and Linda Butler
n recent years, spores began causing
concern has been infections approximately
expressed over the Presented at the 1993 USDA Interagency two weeks before gypsy
impact of gypsy moth Gypsy Moth Review in Annapolis, Maryland moth eggs began hatching.
suppression programs Larvae became infected
on non-target until the end of July, when
arthropods. The gypsy all gypsy moths pupated
moth fungal pathogen, and the group that demonstrated and many adults had emerged.
Entomophaga maimaiga Humber, infection in trials with the Therefore, the activity of this
Shimazu & Soper, has caused Japanese strain of E. maimaiga. fungus appears to be quite finely
epizootics in North American E. maimaiga infected larvae in tuned to the seasonal appearance
gypsy moth populations since its three of the five suborders tested: of gypsy moth larvae and pupae,
discovery in 1989. Previous work Noctuoidea, Bombycoidea, and although it appears to be active
with a Japanese strain of E. Geometroidea. In all families for a relatively brief period before
maimaiga demonstrated that the beside Lymantriidae, infection was egg hatch and for a time after
fungus only infects Lepidoptera. not uniform and infection levels most larvae had pupated. *
We asked what impact E. were low. The four species of
maimaiga will have on the lymantriids treated became
endemic North American infected at levels from 60-100
lepidopteran fauna. percent. As a caveat, our results
at this time reflect only bioassays Ann Hajek is an Entomologist
We challenged lepidopteran larvae conducted in the laboratory where with Boyce Thompson Institute,
with E. maimaiga, emphasizing infection by E. maimaiga was Tower Road Ithaca, New Yo rk
field-collected larvae from West optimized. However, we know 14853-1801.
Virginia where E. maimaiga is not that the activity of E. maimaiga is
well established. Lepidopteran partially dependent upon weather Linda Butler is a Professor with
species for experiments were conditions and we hypothesize the Division of Plant and Soil
either reared from eggs, field- that the gypsy moth-specific larval Sciences, P.O. Box 6108
collected as larvae, or obtained movements and aggregations West Virginia University,
from a laboratory colony. All promote infection. Therefore, it is Morgantown, WV 26506-6108
larvae were reared on their not known whether our bioassay
preferred host plant species. results are any indication of levels
Larvae were challenged with E. of infection of alternate hosts
maimaiga by dipping them into a under field conditions.
conidial suspension of known
dose. Bioassays were successfully To determine the seasonality of
conducted using 43 species in 5 resting spore germination, resting
lepidopteran suborders: spores were placed in replicated
Papilionoidea (1 species), bioassay boxes in the field and,
Pyralidoidea (1), Geometroidea beginning April 7, each week
(12), Bombycoidea (5), and fourth-instar larvae were
Noctuoidea (24). We emphasized challenged until the end of
the Noctuoidea because this is the August. Results from field
suborder that includes gypsy moth bioassays indicate that resting
TFECHNOLOG Y OPDATE
GYPSY MOTH REARING PROBLEM LINKED TO IRON
(Fe) IN DIET
By Thomas M. ODell, Melody A. Keena, John A. Tanner and Raymond B. Willis
Laboratory-reared gypsy moth are essential for research and for the production of the gypsy moth nuclearpolyhedrosis virus, Fl-sterile egg
masses, and sterile males used in operational programs, Until 1985, the New Jersey Standard Strain (NJSS) was an excellent production insect,
It provided competitive adults for the sterile insect program, large larvae for virus production and consistent, relatively disease free larvae for
research. However, beginning in late 1985, the Standard Strain, as well as other lab-reared gypsy moth strains, were subject to unpredictable
periods of poor hatch, reduced survival, and slow asynchronous development. This was affectionately named, Abnormal Performance Syndrome,
or APS.
In 1989, aresearch team developed a problem analysis and research action plan for solving the gypsy moth rearing problem (APS). The research
objectives were: 1) to determine the cause of APS, 2) to develop methods for eliminating APS rearing problems from gypsy moth production
systems, and 3) develop management protocols for preventing the reoccurrence of APS. The goal was to complete the research required to
achieve our objectives within 3 years. This was accomplished.
Laboratory-reared gypsy moths produced at the USDA's Forest Service Insect Rearing Facility, Hamden, CT, and the Animal and Plant Health
and Inspection Service's Methods Development Center, Otis Air National Guard Base, MA, account for approximately 95 percent of the gypsy
moths used for RD&A im the United States. The New Jersey Standard Strain, produced at both facilities and now. in its 39th generation, has
become the white rat for scientists investigating methods for controlling this forest pest. The success of the APS research was due primarily
io excellent cooperation between the Hamden and Otis research staffs and the support provided by each Agency. Scientists using Forest Service
or APHIS produced gypsy moth can now be confident that they are once again receiving consistent, relatively disease free insects. Vendors
of gypsy moth diet ingredients, cooperators, and others rearing gypsy moth, now have specific protocols for diet ingredients and methods for
assessing the effects of changing diet ingredients.
fter three years of intensive ingredients of Wesson Salt When the NJSS was reared for two
research, the cause of a Mixture, a commercial mineral generations on WSM-B, APS did
gypsy moth rearing problem supplement. Between 1989 and not affect production. Alternating
called Abnormal Performance 1992, the USDA Forest Service's WSM-A and WSM-B by
Syndrome (APS), has been Insect Rearing Facility, Hamden, generation almost eliminated APS
determined. Symptoms associated Connecticut, and the USDA in the second generation; i.e., some
with APS are expressed when Animal and Plant Health symptoms were observed but
there is a dietary deficiency of Inspection Service's (APHIS) production was not significantly
available iron (see Table 1). This Methods Development Center, affected. Subsequent chemical
discovery has made it possible to Otis ANGB, Massachusetts, analysis of the two WSMs
eliminate APS as a significant purchased Wesson Salt Mixture indicated that they differed
problem in the production of (WSM) from two different primarily in the structure of ferric
gypsy moth for research, NPV vendors. These are identified here phosphate (FePO,); WSM-A
production, and the development as WSM-A and WSM-B. When contained crystalline FePO,, WSM-
of the Fl-sterile technique. two consecutive generations of the B contained amorphous FePQ,.
New Jersey Standard Strain
Iron is added to the standard (NJSS), i.e., parents and progeny, To determine if crystalline FePO,
gypsy moth high wheat germ diet were reared on diet containing in WSM-A was the cause of APS,
(Bell et al. 1981) as ferric WSM.-A, APS had a significant bioassays were conducted using
phosphate (FePO,), one of 12 negative impact on production. diet containing FePO,, and Wesson
Salt Mixture without FePO,, each be prescribed (see * When both parents and
purchased separately from vendors Recommendations), amorphous
progeny are reared on diet
A and B. FePO,-A and FePO,-B FePO, as a mineral supplement in
containing crystalline FePO,,
were mixed independently with gypsy moth diet does not appear
the incidence of APS varies
each WSM prior to diet to be a stable source of iron.
between and within families (egg
processing. APS symptoms were Methods to stabilize and/or
masses).
expressed only when gypsy moth enhance the bioavailability of iron
were reared on diets containing in gypsy moth diet are being
> Progeny reared from field
FePO, purchased from Vendor A. investigated.
collected eggs on diet containing
Chemical analysis showed that
FePO, from vendor A was CONCLUSIONS RELATED TO crystalline FePO, express
crystalline and FePO, from vendor SMALL SCALE AND MASS significant APS symptoms, but
siblings reared on diet containing
B was amorphous. Bioassays REARING OF GYPSY MOTH
amorphous FePO, do not. This
using other ferric compounds as
substitutes for FePO, (e.g. ferric - The potential for significant indicates that induction occurred in
citrate, FeC,H,O,) confirmed that problems related to APS, the parent in the field and that
iron was the component mediating including poor egg hatch and slow successful establishment of new
laboratory colonies is likely to
the expression of APS. asynchronous growth (straggling),
is induced in the parent by a depend on the bioavailability of
iron in the laboratory diet.
In physical appearance, crystalline deficiency in available iron.
FePO, is salt-like in texture; Induction occurs when parents are
amorphous FePO, is more reared on diet which contains * Consistent use of Wesson
powdery or flour-like. When crystalline FePO, as the only Salt Mixture which contains the
added to water, amorphous FePO, supplementary source of iron. amorphous form of FePO, can
forms a cloudy dispersion, significantly reduce and/or
crystalline FePO, settles rapidly to * Poorer quality and often eliminate the rearing problems
the bottom as crystals. Neither is associated with APS in the standard
reduced numbers of egg masses
soluble in water. Our studies laboratory production strains.
are produced for use in the
indicate that the bioavailability of
next generation when gypsy moth
iron in gypsy moth diet is greater
are reared continually on diet RECOMMENDATIONS
when FePO, is in the amorphous
deficient in available
form, and that it may be possible Wesson Salt Mixture is widely
iron.
to substitute other iron compounds used in insect diets because it has
for FePO,. In addition, we have given satisfactory results, despite
found that the expression of APS - Straggling, the most visible its recognized imbalance of salts
in the second generation can be expression of APS, is manifested for insects. Commerical Wesson
affected by the method of diet only in progeny of induced Salt Mixtures are modifications of
production. The iron availability
parents and will significantly the original formula and, as we
of amorphous FePO, appears to reduce production of gypsy moth have found, these modifications
differ between diet batches made
when progeny are reared on diet may vary between vendors and
using an autoclave and a blender, which contains crystalline FePO, may significantly effect production
hot plate and blender, and open or as the only supplementary source of insects.
closed kettles with built-in mixers. of iron.
For example, slow, asynchronous
Of equal importance, APS research
growth was observed when diet - APS is significantly reduced has demonstrated that the effects of
containing amorphous FePO, was or eliminated when progeny of changes in diet formulation may
processed using an autoclave and parents reared on diet containing not be expressed and/or detected in
blender.
crystalline FePO, (induced) are the first generation and that
reared on diet containing either sensitivity to dietary changes has a
While the cause of APS has been amorphous FePO, or FeC,H;0,. genetic basis. To ensure these
identified, and a method for variables and other APS research
reducing or eliminating APS can
findings are accounted for, the
* Each change in diet formu- * The recommendations noted
following production management
lation should be tested independ- above should be used routinely to
actions should be followed:
ently for a minimum of two make decisions on all proposed
generations. changes in standard production/
* To eliminate or significantly rearing procedures.
reduce the occurrence of APS,
* Bioassays to determine
orders for Wesson Salt Mixture This research was initiated in 1990
effect of diet modification on
should specify that FePO, meets following a "high priority" request
production of NJSS or wild strains
by the USDA Gypsy Moth
should include a
Working Group. The success of
minimum of 25
the APS research was due to the
families, 20
excellent interagency cooperation
Table 1.--Quantitative Assessment of insects/family (see
and the support provided by each
APS Symptoms
Table 2), with each
agency. For more information, call
family treated as a test
low as rowth (s li Tom ODell or Melody Keena at
variable.
- mean larval stage at 10 days
203-773-2024 or 202-773-2297,
. % pupation at 34 days
respectively.
; Mean days to adult eclosion
* Variables used to
Reedmucebd rhatych oof natedeg gs
. 9% hatch of embryonated eggs quantify expression of BIBLIOGRAPHY
ed surviv APS should be
, 9% \arval mortality at 10 and 34 days sufficient for detecting Bell, R.A., Owen, C., Shapiro,
- % pupal mortality
most diet deficiencies M., Tardiff, J.R. 1981.
as e al de i
. mean female pupal banding (Table 1). Development of mass-rearing
technology. pp. 599-655 In C.C.
> Variability in Doane and M.L. McManus, eds.
gypsy moth laboratory The Gypsy Moth: Research
the Food Chemicals Codex (FCC) colonies should be conserved toward integrated pest
specifications as provided for in and/or increased so that management. U.S. Dep. Agric.
the FCC, 3rd Edition (1981). inadvertent selection for more Tech. Bull. 1584.
sensitive genotypes and inbreeding
> Specifications (standards) for depression are avoided. National Research Council.
1981. Food Chemicals Codex,
all diet ingredients should be used
3rd Edition. National Academy
consistently in purchasing. For
Press, 2101 Constitution
example, the 12 minerals in
Avenue, NW, Washington, D.C.
Wesson Salt Mixture should be
20418.
specified by formula (also see
first recommendation).
Thomas M. ODell and Melody A.
Insects;
Keena are Research Entomologists
25 families (egg masses),
* Storage of diet ingredients
20 neonates/family/treatment and Raymond B. Willis is a
should ensure that specifications Containers: Chemist with the USDA Forest
are maintained. Suppliers indicate 6 oz fluted plastic cups with
Service, Northeastern Forest
that placing ingredients in plastic cardboard lids, 10 insects/eup
Experiment Station in Hamden, CT.
2Hamily/treatment
bags to exclude moisture, and John A. Tanner is an Entomologist
Diet:
storing in a freezer is adequate for Standard wheat germ diet (Bell with the USDA Animal and Plant
maintaining ingredients for up to et al. 1981), 40 or 80 ml Health Inspection Service, Otis
1 year. However, as a general diet/cup ANGB, MA.
rule, wheat germ should not be Environment;
Walk-in chamber set at 25°C,
stored for more than 6 months.
50-60% RH, and 16:8 L:D
Update on the National Gypsy Moth EIS
By Jill Cherpack
n the February 1992 issue of July 1992, the public affairs con- an organized picture of the public
Gypsy Moth News, Robert D. tacts from as far as Alaska met in issues emerges.
Wolfe of the USDA Forest Ser- Philadelphia, reviewed the team's
vice, Forest Health Protection Staff, draft public involvement plan, and Work has begun on some of the
reported that the Forest Service and discussed coordination needs and technical requirements of the project,
Animal and Plant Health Inspection ideas for reaching target groups. including an updated assessment of
Service (APHIS) had formed a risks to human health from approved
team to review the 1985 In November 1992, the team pub- insecticides. Risks to nontarget
environmental impact statement lished in the Federal Register a organisms from both gypsy moth
(EIS) for gypsy moth suppression Notice of Intent to prepare a new defoliation and treatment methods
and eradication projects and set a EIS. The notice kicked off a 120- will also be assessed. Computer
course for action. Here's what's day public comment period, which modeling will map forests at risk and
occurred since that time, and what closed in March 1993, estimate the effects of gypsy moth
happens next. defoliation on short and long term
Public involvement efforts were changes in forest vegetation for all
An EJS is an analytic document extensive. Informational items susceptible U.S. forest types.
that is legally required for Federal were developed to explain the
actions that may affect the envi- gypsy moth problem and the EIS The next part of the project is de-
ronment. The team’s first challenge process in plain language. Dozens veloping the draft EIS, which will
was deciding whether to do a new of presentations were made to examine alternative ways to manage
EIS or a supplement to the 1985 groups across the country. Over the gypsy moth problem. Comments
EIS. After meeting with 22,000 letters were mailed re- and concerns raised by the public will
cooperators, scientists, resource and questing public comment on the shape much of the draft EIS. The
agency managers, it was decided gypsy moth problem and ways to merits, pitfalls, social, economic and
that a fresh look at the gypsy moth manage it. Employees of the For- environmental effects of each way
problem was needed and a new EIS est Service and APHIS were also will be explored, and a preferred
should be done. The new EIS will invited to comment. The team's alternative will be recommended.
be national and programmatic, with national network was vital in sup- The option of no action--meaning no
the objective of controlling porting the information campaign, Federal gypsy moth program--will
unacceptable damage to high value providing mailing lists, reaching also be explored.
forests and shade trees. It will be the media, answering questions and
strategic, giving general Federal providing public involvement The draft will be available for public
guidelines and leaving site-specific opportunities. Over 800 public review in summer 1994 and will be
decisions to resource managers who comment letters were received, accompanied by another major public
will implement the guidelines. many with detailed recommenda- outreach effort. Public response to
Both the European and Asian tions. the draft will be analyzed and
gypsy moth will be addressed. incorporated into the final EIS.
Eleven analysts and clerical staff
The next step was forming a were detailed to the EIS team for 3 For more information, call John
network of Forest Service and weeks in spring 1993, to review the Hazel, EIS Team Leader, at (215)
APHIS public affairs and forest public's letters. In this process, 975-4150. W
pest managers to reach the inter- substantive comments from each
ested public nationwide. This letter are identified and coded Jill Cherpack is a Public Affairs
network also provides the tech- according to subject matter. Each Specialist with the USDA Forest
nical direction needed to ensure comment is entered into a database, Service, National Gypsy Moth EIS
that the EIS reflects conditions in a computer program groups all Team, in Radnor, PA.
all parts of the United States. In comments on a given subject, and