By
S.T. Murphy
International Institute of Biological Control
Silwood Park, Buckhurst Road
Ascot, Berks
SL5 7TA, UK
The International Institute of Biological Control (IIBC) is a non-profit, fully international organization dedicated to providing a world service in biological control. IIBC is an institute of CAB International. It has its headquarters in the UK and African stations in Kenya and Benin.
In March 1991, IIBC began a programme of biological control for the three conifer aphid pests in collaboration with the Forest research Institute of Malawi (FRIM). The project is supported by the Overseas Development Administration (ODA) of the UK Government.
A substantial part of the project will support IIBC scientists, based in the UK, to undertake exploration, research and quarantine of biological control agents for the three aphid species. This work will be focused in Europe. In addition, IIBC scientists will provide a training course and bench training to FRIM scientists in relevant areas of biological control. FRIM scientists will undertake pre and post-release studies on the natural enemies and their impact. The project is for five years.
The IIBC-FRIM project will generate information useful to other affected countries in the region. Assistance to those countries, however, will require expansion of the exploration programme and, of course, support for strengthening of their own national programmes.
The principle objective of the proposed project is to achieve long-lasting control of the exotic aphid pests, Pineus pini, Eulachnus rileyi and Cinara cupressi in conifer plantations in Malawi. This objective will be achieved through a programme of classical biological control involving exploration for specific natural enemies into Malawi, and release and monitoring in forest plantations.
A secondary objective of the project is to establish the capability of the Forest Department and Forest Research Institute in Malawi to carry out biological control by training local staff in biological control methods and establishing a local biological control facility.
The project would be carried out through a collaborative programme by the International Institute of Biological Control (IIBC) of CAB International and the Forestry Research Institute of Malawi (FRIM).
Surveys would be carried out in UK and Europe by entomologists based at IIBC's UK Station at Silwood Park, to determine the range of natural enemies associated with each of the three aphids.
The surveys would not only determine the natural enemy complexes of the aphids but would also indicate the location of suitable field sites for the collection of specific natural enemy species for further investigation.
The natural enemies collected during the surveys would be evaluated and reared using the facilities of the IIBC UK Station.
Investigations of the biology of the natural enemies is an essential step in the selection of the most appropriate species for use in a release programme. The specificity of the natural enemies needs to be determined to ensure selection of species that will concentrate their action on the target pest. The synchronization of the natural enemies with their host is important in ensuring that their control potential is maximized. The environmental requirements of the natural enemies must be investigated to determine the most appropriate sites for their release. Finally, methods for the laboratory handling of the natural enemies are a prerequisite for the rearing of the selected species in sufficient numbers for field release.
Once suitable natural enemies have been selected for each of the target aphid pests, laboratory or insectary rearing can be developed by IIBC to ensure a sufficient supply of insects for local rearing and field release in Malawi.
Additional local staff need to be taken on in Malawi in the middle of year 2 to start on the local rearing and monitoring. A 2 week training course, based at FRIM, would take place during the second half of year 2. The course would be taught by IIBC/FRIM to provide local technical staff with the skills required to ensure successful rearing, release and monitoring of the natural enemies in Malawi.
Following provision of guidelines, training and advice by IIBC, monitoring of pest abundance would be undertaken by FRIM staff prior to release of the natural enemies to provide baseline data for assessing the effectiveness of the biocontrol programme.
Following Phase 1, further developments in rearing techniques will be required in UK and selected natural enemies would be processed for shipment in Malawi in years 3 and 4. One of the most important steps is the quarantining of natural enemies prior to shipment to ensure that the material does not harbour associated hyperparasitoids or pathogens, including plant pathogens.
Guidelines and advice would be provided by IIBC for rearing of natural enemies at FRIM and the selection of field sites for their release. FRIM staff would carry out large scale rearing and would be responsible for the rearing programme in Malawi. Successive releases of natural enemies would be carried out during years 3 to 5 of the project.
Monitoring of pest and natural enemy abundance by FRIM staff will continue after release of the natural enemies. The monitoring of the release programme is a particularly important aspect of the project as it provides the necessary feedback for assessing the establishment and effectiveness of the natural enemies; this in turn permits evaluation of the success of the project in achieving its primary objective.
By
J. G. Mwangi
Manager,
National Cypress Aphid Project
Kenya
Integrated pest management (IPM) is defined as the optimization of pest control in an economically and ecologically sound manner (Apple 1979). It is a recipe of biological, cultural, genetic, mechanical and chemical tactics used individually or in combination to maintain pest damage below the economic injury level* while providing protection against hazards to humans, animals, plants and the environment.
Components of the Kenyan IPM are enumerated as follows:
With the exception of item 1, these activities are yet to be carried out and that crystallizes the bulk of the Kenyan IPM as will be described in the subsequent text.
In Kenya, so far, the most severely affected tree is Cupressus lusitanica. Kenya, which has the largest area of industrial forest plantations of Cupressus lusitanica is planted on about 86,000 ha. Out of this, about 5,153 ha has been infested by the aphid to variable damage levels ranging from slight to severe.
Damage levels for other members of the Cupressaceae, Juniperus procera, Thuja occidentalis and Callitris robusta has, in the first year of attack, been slight in most parts of Kenya. It is not known whether this will be the same after the second year of attack. Juniperus procera, which covers about 200,000 ha, mainly in water catchment areas, is currently a great source of national concern.
The activities of this management objective comprise identification and survey of the infested areas, screening and application of pesticides and salvage.
Ground surveys are ongoing but are inadequate because of the lack of adequate transport. Aerial survey, using low flying aircraft techniques is intended to begin in September 1991 through FAO funding. Both aerial and ground surveys for identification of infested areas is scheduled to be completed within eight months of the project.
Screening of locally available pesticides has been carried out and relative toxicities (LC90) determined (Fig 1). These are categorized in the broad spectrum range and selective, environmentally friendly aphicides are yet to be screened. Chemicals are currently being used to control the aphid on people's hedges and nurseries. Plans are to also use chemicals in high value seed orchards and arboretums but not in conventional plantations because this would be prohibitively expensive and socially and environmentally unacceptable.
Various modes of pesticides application have been tested at the Kenya Forestry Research Institute (KEFRI). Soil applications of systemic pesticides have failed to produce good results.
Regarding the tools for pesticide applications, high volume back mounted warm fog generators were tested. Results show that fog generators reduced the man hours for spraying by two thirds. The fog, which is a carrier of active ingredient, rises to the top of the crown and drifts to cover all portions of the tree. Motorized sprayers need a lot of water and spray droplets cannot reach the tops of tall trees.
Salvaging of severely damaged plantations is ongoing but guidance on the criteria for salvage is urgently needed by resource managers. It is suggested that a two year observation of the damaged trees should be done before salvage is recommended. This is because some trees recover after the first year of infestation.
Biological control may offer a long term solution to the aphid problem. Ecobiological studies are a prerequisite to biological control. These studies are short term and are intended to be completed within the next three years.
Aphid population studies are ongoing at Muguga and the results obtained so far are shocking all resource managers. The results show that population density is highest during the hot dry season and lowest during the season of heavy rains (Fig 2). The decline in population density results in some recovery of damaged trees. This recovery is probably not sufficient to carry a tree through another dry period. At the time of writing this paper, many Kenyans were complacent that the evident recovery of trees was an indicator that the aphid was not a threat to trees any more. They were yet to learn that this was not true.
Another activity which is ongoing is exploration of natural enemies in Europe by IIBC. A Kenyan is already in Europe working with IIBC in this programme. Further exploration in North America and other places is yet to be carried out. Exploration is intended to continue up to the fourth year but mass rearing and release will start in the second year.
Examples of natural enemies that may be explored are Pauesia cupressobii and P. juniperorum (Hymenoptera: Braconidae), which have been found attacking Cinara juniperi. Aphidus sp, also a parasitoid, has been found attacking Cinara cupressi in Germany.
Silvicultural control has already been recommended to resource managers. This consists of thinning to reduce the density of trees and resultant shady conditions which the aphid seems to prefer, restricting planting of cypress to rich, deep soils in cool areas and planting of alternative species, for example Grevillea robusta, which are not attacked by the aphid.
Better than the aforementioned, would be to seek trees which have some degree of genetic tolerance or resistance to aphid feeding. A compendium of activities has been planned for this objective. the expected result would be to have a substantial stock of strains of cypress resistant to attack by the aphid which would be made available to foresters and farmers for planting.
Fig 1. Relative toxicity of pesticides tested against Cinara cupressi (LC 90 - 24 hrs. ppm. ai.)
Fig. 2 Population trends of Cinara cupressi, Muguga, Kenya (November 1990 - April 1991)
All activities will be monitored and evaluated during the five year period of this project. This will ensure proper accountability on success or failure of each activity and changes may be instituted at the appropriate time.
Apple, J.L., 1979. Integrated pest management - a programme of research for the State Agricultural Experiment Stations and the colleges of 1890. A study conducted by the Intersociety Consortium for Plant Protection.
Stern, V.M., R.F. Smith, R. Van den Bosch and K.S. Hagen. 1959. The integrated control concept. Hilgardia 29:81.
By
Melvyn J. Weiss
Assistant Director
Forest Pest Management
USDA Forest Service
Washington, D. C. USA
Protecting U.S. Forests from pests is the joint responsibility of the national government, state governments and private landowners. National leadership and coordination to protect forests from pests is provided by the U.S. Department of Agriculture, Forest Service. The Forest Service staff assigned to carry out these responsibilities is Forest Pest Management (FPM).
FPM is responsible for providing pest information and program direction for protection of National Forests, National Parks and other Federal lands. FPM also provides technical and financial assistance, on a cost-share basis, to state agencies who, in turn are responsible for direct assistance on state and private lands. Individual resource managers and private landowners make the final decisions on any action taken against pests.
Authority for nationally organized surveys and actions against forest pests dates to 1947 when the U.S. Congress passed the Forest Pest Control Act. Most of the original provisions in the Forest Pest Control Act continue in effect and are included in the Forest Health Protection Section of the Cooperative Forestry Assistance Act of 1978, as amended. Each of the state legislatures has passed a similar law which provides the necessary authority for the state to cooperate with the Forest Service, conduct surveys and take action against pests on state and private lands.
The FPM program objective is to reduce the adverse impacts of pests on forests to levels consistent with management objectives. The major components of the FPM program are prevention, detection, evaluation, suppression, and technology development. Prevention includes activities like stand hazard rating, and modification of forest management practices that will lessen risk of future pest outbreaks. Aerial and ground detection surveys are carried out annually over U.S. forests to discover and map pest damage. Biological evaluations are carried out to determine
the trend and seriousness of pest outbreaks and need for suppression. Suppression includes the use of cultural measures or pesticides to control damaging pests and protect forest values. Technology development includes pilot projects and demonstrations of promising survey and suppression methods prior to full-scale implementation.
After detection surveys and biological evaluations are completed, Forest Service or state pest management specialists work closely with the resource manager or landowner in making a decision on conducting suppression. The resource manager or landowner has the final decision-making responsibility in prevention and suppression. Pest management specialists have an advisory or support role. The pest management specialist's responsibility is to advise the landowner on the seriousness of pest problems and treatment alternatives.
A key element of the FPM program is cooperation between the national and state governments. Forest Service and state pest management specialists work in close cooperation. When a pest outbreak threatens Federal, state and private lands, this coordinated approach provides effective protection strategies and minimizes costs. Coordination also prevents damage to the environment that can result when pest management activities are not coordinated.
FPM decisions and actions are guided by national laws and policies, and are carried out with considerable deliberation. Forest Service policy requires that suppression be biologically sound, economically efficient and environmentally acceptable. Integrated pest management policy must also be followed. Forest Service policy is to develop, practice and encourage integrated pest management tactics and strategies that protect forest resources in a manner that presents the least hazard to humans and their possessions, wildlife, fish and other components of the environment. The requirements of the National Environmental Policy Act (NEPA) must also be met. NEPA requires full public disclosure of proposed actions, consideration of all reasonable alternatives including a no- action alternative, analysis of the environmental consequences of each alternative, monitoring to compare actual with predicted environmental impacts of the selected alternative.
In 1991, the national budget for FPM is 60 million dollars, which consisted of 17 million dollars for surveys and technical assistance by Forest Service specialists, 11 million dollars for development and application of pest management technology, 15 million dollars for pest suppression on Federal lands, 3 million dollars provided to states for surveys and technical assistance by state specialists on state and private lands, and 14 million dollars available to states for pest suppression on state and private lands. On state and private
lands, program costs are shared by the Federal and state governments. Each state's share is equal to or higher than the Federal share.
FPM has about 150 specialists in entomology, pathology or related disciplines. Of this number, 135 are in nine Forest Service regions and 16 are on the national headquarters staff. In addition to the Forest Service FPM specialists, each state has one or more pest management specialists. State specialists number about 100.
FPM is one of two Forest Service staffs concerned with protecting forests from pests. The other staff is Forest Insect and Disease Research (FIDR). Both FIDR and FPM fill essential roles. FIDR investigates the biology and control of pests. FPM is concerned primarily with operations against pests using basic knowledge developed by FIDR and other scientists. FPM works with FIDR to identify high priority research needs, and to implement FIDR findings.
A recent major change in the U. S. is the growing awareness by scientists, the U.S. Congress and the general public of the importance of healthy forests. Evidence of this growing awareness is found in the Forest Service's Forest Health Strategic Plan completed in 1988, and in recent Congressional action which included forest health in the title and language of the enabling legislation for the FPM program. FPM actions to enhance forest health will continue for the foreseeable future following recommendations in the Forest Health Strategic Plan, and in response to Congressional intent in the recently amended legislation.
We increasingly recognize situations in the U.S. in which forest management practices have created forest conditions which are conducive to pest outbreaks and deterioration of forest health. Consequently, FPM is placing much greater emphasis on prevention and is working with land managers to ensure that management practices lessen rather than increase the hazard of pest damage.
In cooperation with the states, Forest Service Research and the U.S. Environmental Protection Agency, FPM is implementing a nation-wide system to monitor changes in the health of our forests. The monitoring system will provide an early warning of change in forest condition related to pests of other factors, and help guide national strategic planning and policy development. We anticipate that the system will be fully implemented by about 1996. When fully implemented in the U.S., monitoring data will be available annually for most of North America. Canada has already implemented a monitoring system called the Acid Rain National Early Warning System (ARNEWS).
Numerous pests threaten the health and productivity of U.S. forests. These pests include the gypsy moth, southern pine beetle, western spruce budworm, Douglas-fir tussock moth, mountain pine beetle, dwarf mistletoes, root diseases, and air pollutants. In 1991, suppression is being carried out against southern pine beetle, Douglas-fir tussock moth, mountain pine beetle and dwarf mistletoes. The largest costs are for suppression of the gypsy moth. The gypsy moth, an introduced pest, continues to spread to new areas in the eastern U.S. and to occur in isolated infestations elsewhere. From 1981 through 1990, gypsy moth defoliated and average of about 1.7 million hectares annually. In 1990, it defoliated 2.9 million hectares. In 1991, suppression of gypsy moth to protect high value forests is planned on 554,000 hectares. Two pesticides are being used against gypsy moth in 1991, the bacterium, Bacillus thuringienses (Bt) on 152,000 hectares and the insect growth regulator, diflubenzuron, on about 402,000 hectares.
FPM continues to make significant progress in development and application of new technology for managing pests. Major developments include the shift from conventional pesticides to use of Bt for suppression of gypsy moth and western spruce budworm. This shift was made possible through technology development to improve application of Bt. We increasingly use behavioral chemicals to monitor insect populations, and are testing these chemicals for control of insect populations. Pest damage simulation models are being used to help forest managers consider the consequences of their decisions. Geographic information systems are being used to manage and analyze spatial information on pest damage and forest health conditions. Other technology under development or in use include expert systems, an aerial video camera system for assessing pest damage, and simulation models to predict spray deposit form aerial insecticide applications.
I see two major continuing emphasis items ahead for our U.S. program. One emphasis item is further cooperation and sharing between governmental agencies, landowners, and the public. Cooperation is essential because pests do not respect political or ownership boundaries, the job is too big for anyone to do alone, and no one, alone, has all the knowledge and information needed. The second continuing emphasis item is forest health. We must strive to make forest health a consideration in everything we do. This means focusing more on the forest, instead of the insects and diseases, and preventing or avoiding forest conditions that lead to pest damage. It means focusing on the long-term while at the same time being prepared to deal with threatening outbreaks. It means continuing to improve technology for all aspects of forest pest management.
William M.
Ciesla
Forest Protection Officer
FAO, Rome
Discussion
Leader
Two hours have been allocated on the program for a discussion of the desirability and need for a regional approach to the management of conifer aphids. As the discussion leader, I do not plan to say a great deal. However I hope that my few words of introduction will stimulate some discussion.
One of the advantages of taking a regional approach to the management of conifer aphids is the potential synergy which might be generated. Just what is synergy? It can be defined as the additional energy, productivity or efficiency which results from people working as a team to achieve a common goal or objective as opposed to working as individuals. Another way of describing synergy is to say that instead of two plus two equaling four, it might equal five or perhaps even six.
A relevant example is the case of two scientists, working independently in two countries on similar projects. It makes no real difference what the nature of the project is. It could involve the development of a pest management system or a new formula for jet fuel. Assuming that both individuals are competent in their field and given enough time, they will each eventually come up with an answer. Think, for a moment, how much more effective each scientist would be if they were able to meet occasionally and compare notes or even talk to on another on the telephone.
This workshop has brought together scientists and practitioners from eastern and southern Africa who are trying to deal with a crisis in African forestry; the recent introduction of three species of destructive conifer aphids. And, as it turns out, this meeting is something of an historic event. It is the first regional meeting ever to have been held in Africa on a forest pest. There has been a wealth of information presented. This information has inspired a great deal of discussion. A number of similarities and some differences has surfaced in the behaviour and damage caused by these insects in different parts of the region. Hopefully all of you have benefited from these discussions as much as I have. Even more important, I hope that as a result of this workshop you have some new ideas to take home with you.
Now that we are approaching the end of a very successful workshop, it seems appropriate to begin a discussion on "where do we go from here?" To start this discussion, I would like to list the following points:
