Characterization of antibiosis to the silverleaf whitefly Bemisia tabaci biotype B (Hemiptera: Aleyrodidae) in cowpea entries

The silverleaf whitefly, Bemisia tabaci (Gennadius) biotype B (Hemiptera: Aleyrodidae), is considered one of the most important pests of cowpea (Vigna unguiculata L. Walp.), limiting the productivity of this crop worldwide. Chemical control is still the main strategy for the management of populations of this insect. However, due to the harmful effects of pesticides on the environment and to humans, less injurious alternatives have been investigated. Along this line, the use of resistant genotypes can be a valuable tool for the control of the silverleaf whitefly. In this paper, we investigate some biological aspects of B. tabaci biotype B confined on 14 genotypes of cowpea. We evaluated the incubation period, egg viability, duration of nymphal stages, total duration of the juvenile phase, instar mortality and total mortality of the immature stage. The genotype MNC 99-541 F21 exhibited antibiosis against the whitefly, prolonging the lifecycle of the insect. The genotypes Canapu, BRS-Urubuquara and TE97-304 G-4 also exhibited antibiosis, causing high nymphal mortality. These results may help in breeding programmes to develop cowpea lines with resistance to B. tabaci biotype B.     

Genetic diversity in natural populations of Gmelina arborea: implications for breeding and conservation

Gmelina arborea is a valuable plantation tree species that is native to South and Southeast Asia. In this study, 534 samples representing 19 natural populations in India, China, Thailand and Myanmar were analyzed with 10 polymorphic microsatellite markers. The genetic diversity analysis revealed highly polymorphic loci (N_a?=?16.4), a good level of genetic diversity (H_o?=?0.56; H_e?=?0.83) and the deficiency of heterozygotes in G. arborea populations evidenced by positive fixation index and deviation from Hardy?CWeinberg Equilibrium in all loci and most populations. The Analysis of Molecular Variance attributed 21, 10 and 69% of total genetic diversity to among-region, among-population (within region) and within-population variation. Unweighted Pair Group Method with Arithmetic Mean dendrogram and Principle Coordinate Analysis revealed three separate clusters composed of China, India and Thailand/Myanmar that were consistent with geographical distance and the presence of natural barriers to gene flow. Populations from within India grouped together genetically consistent with geographical locations, with the exception of the Nowgong population (eastern India), that might have originated from the Kasa area (western India) with which it has high genetic similarity. Understanding genetic diversity and structure of G. arborea populations serve as an important reference for tree breeding programs and conservation strategy. Breeding populations of G. arborea should include selections from each of the major geographic regions to maximize genetic diversity and heterosis. Vegetative propagated clones of elite trees can be used for plantation to address the issue of high level of segregation among seed derived plants.     

苏州市高中校园植物多样性调查分析

通过对苏州市3所高中校园植物种类、数量的调查,分析了校园绿化植物的应用频率和物种丰富度。结果表明:这些高中校园共有144种植物,隶属于65科131属,其中乔木31种,占21.5%;灌木37种,占25.7%;草本73种,占50.7%;藤本3种,占2.1%。人工栽培的绿化植物92种,占植物总数的63.9%;杂草51种,占35.4%,其中狗牙根(Cynodon dactylon)、马尼拉草(Zoysia matrella)为主要杂草种。整体上校园植物资源丰富,但结构相对简单,布局不合理,建议增加植物种类,提高美化效果。     

石泉县园林绿化植物主要害虫种类及危害性研究

选设6个具有代表性的调查样点对石泉县园林绿化植物主要虫害进行了调查,研究了叶部害虫、枝干害虫、刺吸害虫等主要害虫的危害性,最后分析了园林绿化植物主要害虫对县城环境的影响,并提出了相应的害虫防控建议。     

Genetic diversity of the myrtle rust pathogen (Austropuccinia psidii) in the Americas and Hawaii: Global implications for invasive threat assessments

Since the myrtle rust pathogen (Austropuccinia psidii) was first reported (as Puccinia psidii) in Brazil on guava (Psidium guajava) in 1884, it has been found infecting diverse myrtaceous species. Because A. psidii has recently spread rapidly worldwide with an extensive host range, genetic and genotypic diversities were evaluated within and among A. psidii populations in its putative native range and other areas of myrtle rust emergence in the Americas and Hawaii. Microsatellite markers revealed several unique multilocus genotypes (MLGs), which grouped isolates into nine distinct genetic clusters [C1–C9 comprising C1: from diverse hosts from Costa Rica, Jamaica, Mexico, Puerto Rico, and USA‐Hawaii, and USA‐California; C2: from eucalypts (Eucalyptus spp.) in Brazil/Uruguay and rose apple (Syzygium jambos) in Brazil; C3: from eucalypts in Brazil; C4: from diverse hosts in USA‐Florida; C5: from Java plum (Syzygium cumini) in Brazil; C6: from guava and Brazilian guava (Psidium guineense) in Brazil; C7: from pitanga (Eugenia uniflora) in Brazil; C8: from allspice (Pimenta dioica) in Jamaica and sweet flower (Myrrhinium atropurpureum) in Uruguay; C9: from jabuticaba (Myrciaria cauliflora) in Brazil]. The C1 cluster, which included a single MLG infecting diverse host in many geographic regions, and the closely related C4 cluster are considered as a “Pandemic biotype,” associated with myrtle rust emergence in Central America, the Caribbean, USA‐Florida, USA‐Hawaii, Australia, China‐Hainan, New Caledonia, Indonesia and Colombia. Based on 19 bioclimatic variables and documented occurrences of A. psidii contrasted with reduced sets of specific genetic clusters (subnetworks, considered as biotypes), maximum entropy bioclimatic modelling was used to predict geographic locations with suitable climate for A. psidii which are at risk from invasion. The genetic diversity of A. psidii throughout the Americas and Hawaii demonstrates the importance of recognizing biotypes when assessing the invasive threats posed by A. psidii around the globe.     

Persistence of soil and foliar azadirachtin treatments to control sweetpotato whitefly Bemisia tabaci Gennadius (Homoptera: Aleyrodidae) on tomatoes under controlled (laboratory) and field (netted greenhouse) conditions in the humid tropics

Persistence of neem-based products against sweetpotato whitefly Bemisia tabaci Gennadius (Homoptera: Aleyrodidae) was tested in air conditioned rearing rooms and tropical netted greenhouses (GHs). Two commercial neem products, NeemAzal^®-T/S (1% azadirachtin) and NeemAzal^®-U (17% azadirachtin), were used. Foliar application, under room conditions at dose-rates of 7 and 10 ml NeemAzal^®-T/S, induced an immature mortality of 32 and 44%, respectively, whereas 7 days post-application, under GH conditions, mortality rates declined to 5 and 7%, respectively. This result indicated rapid dissipation of the active ingredients. However, systemic application by soil drenching resulted in more stable effects under both laboratory and GH conditions. After soil drenching with solutions of 3.0 g NeemAzal^®-U until 7-day, immature mortality declined from 88% for the first day to almost half (45%) by day-7 in the GH, and from 90% on first day to 64% by day-7 under laboratory condition. Similar response trends for B. tabaci were obtained for other parameters such as adult colonisation, egg deposition, and egg hatch. The loss of efficiency of the neem products was clearly related to dose-rate, methods of application, and environment (temperature and UV). Soil application is therefore, a convenient approach to achieve high efficiency and persistence with neem products under the conditions in tropical GH environments for whitefly management.     

The effect of season on the levels of predation by the ladybird <Emphasis Type="Italic">Serangium parcesetosum</Emphasis> Sicard (Coleoptera: Coccinellidae) on the cotton whitefly <Emphasis Type="Italic">Bemisia tabaci</Emphasis> (Genn.) (Homoptera: Aleyrodidae), a serious pest of eggplants

The whitefly Bemisia tabaci is a serious pest of eggplants, especially those grown undercover in polytunnels and greenhouses. Due to increasing levels of resistance of B. tabaci to a wide range of insecticides, there is now an urgent need to explore other non-chemical methods of control. In this study, Serangium parcesetosum, a ladybird, was evaluated as a possible biological control agent of B. tabaci’s winter and spring populations which infests eggplants grown undercover in Turkey. It was found that in winter, S. parcesetosum failed to control B. tabaci, even when the ladybird population was augmented six times over the course of the experiment. This contrasted with that observed in spring when, with only one introduction of the ladybird, control of the pest was gained within 3 weeks after release. In spring, the B. tabaci population in the cages receiving two and four S. parcesetosum adult per plant showed 56 and 53% reduction, respectively. The percent reduction in B. tabaci population rose to 98.6 and 98.3% in both cages, respectively, by the end of experiment. It is suggested that release of S. parcesetosum against B. tabaci during spring months may be offered as an alternative solution to increase implementation of biologically based B. tabaci management. In winter other biological control agents are needed and these need to be further explored.     

Use of non-timber forest products from invasive alien Prosopis species(mesquite) and native trees in South Africa: implications for management

Background: Prosopis species have been introduced to many areas outside their native range to provide benefits to local communities. Several Prosopis species and their hybrids(hereafter mesquite) have, however, become naturalised and invasive and now generate substantial costs. Management options are limited because of the complex conflicts of interest regarding benefits and costs. Management policies and strategies must take account of such conflicts, but further insights are needed on the dimensions of uses and impacts before such information can be usefully applied. Current policy in South Africa allows for the growth and use of mesquite in one province,but not in others where its control is mandatory. We report on a study to quantify the direct use and perceptions of non-timber forest products(NTFPs) from mesquite and native trees in South Africa.Methods: Semi-structures household interviews were conducted with various stakeholder groups to identify what tree products are used, to ascertain amounts used as well as to gauge perceptions of natural resource use between different tree species and use over time.Results: The direct household use value of native trees was higher than that of mesquite, and local stakeholders attached greater value to products from native trees than from mesquite. Therefore, native trees are and will still be preferentially harvested, and mesquite is unlikely to offer protection to native species by providing an alternative source of products. Mesquite pods do, however, provide valuable additional resources(fodder and medicinal products). The use of both native trees and mesquite is decreasing as the incomes of poorer households rise and as alternative energy sources become available. The benefits and reliance on mesquite are not as high as previously assumed and the impacts from mesquite invasions create large problems for local communities.Conclusion: This study provides further evidence that the impacts of mesquite exceed the benefits, lending support for a policy to reduce negative impacts.     

Seed dispersal and its implications for silviculture of African mahogany (Entandrophragma spp.) in undisturbed forest in the Central African Republic

The study of seed dispersal has received considerable attention in tropical ecology with emphasis placed on its role in the maintenance of species diversity. Since seeds of numerous high-value tropical timber trees are nominally or actively wind dispersed, the subject is also of interest to tropical foresters. In central Africa, up to 70% of harvested timber trees are wind dispersed, including African mahoganies of the genus Entandrophragma. The dual goals of managing many remote areas in central Africa for both biodiversity and timber production values has led to the consideration of low impact logging techniques. In the Central African Republic, increasing light downwind of Entandrophragma has been proposed as a way of increasing regeneration and recruitment of these trees. Mean wind direction at the time of dehiscence of Entandrophragma angolense and Entandrophragma cylindricum was compared with compass orientation of seed shadows for five individuals in mature, undisturbed forest. Mean wind direction was found to be toward the northeast for morning, afternoon, and daily winds and was significantly different from the orientation of seed shadows for all trees. Mean branch direction did not vary significantly from a random pattern, but matched the direction of the seed shadow better than wind direction did. It is concluded that harvesting interventions aimed at increasing light downwind of Entandrophragma will not necessarily benefit seedlings of the species at the study site and further silvicultural research is needed to determine appropriate management interventions, particularly in remote areas of Africa where conservation values are important.     

Silvicultural systems for plantation mahogany in Africa: Influences of canopy shade on tree growth and pest damage

Overexploitation of the African mahoganies, Khaya anthotheca and K. ivorensis, could lead to their commercial extinction in the near future. Efforts to establish plantations to sustain supply have been discouraged by the shoot borer Hypsipyla robusta Moore. We hypothesized that there is a shade level at which Hypsipyla attack and branching are reduced, but height growth is adequate. We report on the growth of these African mahoganies and Hypsipyla attack under three different forest canopy shade levels: open (55% open sky), medium shade (26% open), and deep shade (11% open). Hypsipyla attack on K. anthotheca was 85%, 11%, and 0% attack in the open, medium, and deep shade treatments, respectively. However, growth in medium and deep shade was slow. Mean tree height for K. anthotheca was 413.8, 126.2, and 54.5 cm in the open, medium and deep shade treatments, respectively. K. ivorensis showed similar trends. The reduced growth under these shade levels limit the use of this strategy for controlling Hypsipyla attack.     

桃源洞自然保护区观赏植物多样性及其主要种类观赏效果评价

采用踏查的方法对桃源洞自然保护区的观赏植物进行了系统的调查和研究,结果认为:①本区观赏植物种类繁多,有355种;②本区观赏植物类型多样,有2大类10小类,即:观赏树木和观赏草本2大类,观赏树木类又分为赏树形树木类、赏叶树木类、赏花树木类、赏果树木类、观赏木质藤本类,观赏草本类又分为观叶草本类、观花草本类、观果草本类、观赏草质藤本类和混合观赏草本类。③重点对金线兰、小果冬青等18种观赏植物进行了介绍和观赏效果评价。     

Short rotation coppice willow in Northern Ireland since 1973: development of the use of mixtures in the control of foliar rust (Melampsora spp.)

A review is given of the use of clonal mixtures in the development of disease control strategies in short rotation coppice willow in Northern Ireland. Salix burjatica‘Korso’ had been grown successfully for over 10 years when, in 1985, Melampsora epitea var. epitea caused serious problems. Although fungicides were effective, their use was not practical for environmental and economic reasons. Therefore, in 1987 large scale field experiments were initiated to investigate the use of clonal mixtures as a disease control strategy. Increased yields were consistently recorded from mixed stands when compared to either the mean yield of component clones or the individual yields of any of the component clones grown in monoculture. Part of this increased yield was due to a reduction in the impact of rust disease. Investigations are currently being conducted on the effect of number of clones within a mixture, the best clones to use and the optimum planting density. It is essential that there is a range of susceptibilities to M. epitea var. epitea pathotypes within the components of the mixture.     

Genetic diversity of Castanopsis acuminatissima (Bl.) A. DC. in northern Thailand and the selection of seed trees for forest restoration

Castanopsis acuminatissima (Bl.) A. DC. is one of a number of framework species which are being planted to restore seasonally dry tropical forests in northern Thailand. This study describes the level of microsatellite variation within and among three populations of this species in three National Parks in northern Thailand: Doi Suthep-Pui, Doi Inthanon and Jae Sawn, using published primers developed for Castanopsis cuspidata var. sieboldii Nakai. The five microsatellite loci employed in this study detected a total of 54 alleles (n = 72). The informativeness of the microsatellite loci varied from six to 18 alleles, with an average of 10.8 alleles found over all loci. The mean observed heterozygosities in the three populations showed no significant deviations from Hardy-Weinberg expectations. The vast majority of genetic diversity was contained within the populations, with no significant differentiation between them (F_ST = 0.006). Algorithms were designed to capture microsatellite diversity, and the rationale for using microsatellite markers to inform genetic conservation is discussed. The implications for seed collection of C. acuminatissima for forest restoration are also discussed.     

Genetic variation in fruitfulness in a hinoki (Chamaecyparis obtusa Endl.) seed orchard and its impact on the maintenance of genetic diversity in seedlots

Genetic variation in seed/cone production among clones was studied in a hinoki (Chamaecyparis obtusa Endl.) seed orchard containing 25 plus-trees by analyzing the number of cones, the yield of cones and seeds of individual ramets for 5 successive years (1982 to 1986). There was significant variation among clones each year and parental contribution in the seed orchard. Specifically, in the years 1982, 1983, 1984, 1985, and 1986, 20% of the clones produced 37.2, 60.6, 36.0, 44.3, and 44.8% of the total cones, respectively. The size of the crop greatly influenced the parental balance in the resulting seed/cone crops. The product moment correlation coefficients and Spearman’s coefficients of rank correlation were small and insignificant between consecutive years, but large and highly significant between alternate years, suggesting the presence of carry-over effects in seed/cone production. The broad-sense heritability on a clone mean basis was 0.74 ± 0.15 for the number of cones, 0.72 ± 0.14 for the yield of cones, and 0.68 ± 0.13 for the yield of seeds. The corresponding heritabilities from analyses combined over all years were 0.24, 0.558, and 0.724, respectively. These results indicate that seed/cone production in hinoki is under strong genetic control. Several managerial measures are discussed that maintain the genetic diversity in seedlots used for reforestation, by reducing the variation in seed/cone production among clones and producing seed crops with equal contributions from all parents.     

Studies on the parasitoid complex of Choristoneura murinana (Hbn.) (Lep.: Tortricidae) in Turkey

The parasitoid complex of Choristoneura murinana (Hbn.), a pest of Abies cilicica Carr., was studied in Isparta, Turkey. Shoots and needles of A. cilicica with C. murinana larvae and pupae were collected and examined under laboratory conditions in 2002 and 2003. As a result of this study, 14 parasitoid species of C. murinana were determined: Apanteles obscurus Nees. (Hym.: Braconidae), Brachymeria intermedia Nees (Hym.: Chalcididae), Mesopolobus mediterraneus Mayr, Mesopolobus dubius Walker, Pteromalus chrysos Walker, Pteromalus sp. (Hym.: Pteromalidae), Monodontomerus aereus Walker (Hym.: Torymidae), Itoplectis maculator (Fabricius), Apophua bipunctoria Thunberg, Triclistus globulipes Desvignes, Dirophanes maculicornis Stephens, Hyposoter sp., Dusona sp. (Hym.: Ichneumonidae) and Aprostocetus sp. (Hym.: Eulophidae). In the studied parasitoid complex, A. obscurus, B. intermedia and I. maculator were the most important in reducing pest numbers. The level of total parasitism of the C. murinana was 19.4% in 2002 and 22.3% in 2003.     

Influence of host plant species of Bemisia tabaci (Genn.) (Hom., Aleyrodidae) on some of the biological and ecological characteristics of the entomophagous Serangium parcesetosum Sicard (Col., Coccinellidae)

The entomophagous Serangium parcesetosum Sicard (Col., Coccinellidae) is an effective predator of some whitefly species. However, information on the influence of the preys host plant species on its biological and ecological characteristics is still lacking in the literature. Therefore, the current study focuses on the possible influence of three greenhouse and two field host plant species of Bemisia tabaci (Genn.) (Hom., Aleyrodidae) on the number of eggs laid by S. parcesetosum. In addition, because of the economic importance and widespread planting of cucumber in greenhouses and cotton in the field, these plants were selected for further investigation into the development, mortality, longevity and reproduction of S. parcesetosum at a high temperature in the laboratory. Results showed that S. parcesetosum was able to lay eggs on all five host plant species of B. tabaci, whether greenhouse or field plants. However, among the three greenhouse plant species studied, S. parcesetosum females laid the highest number of eggs on cucumber followed by tomato and then sweet pepper. Of the two field plant species, significantly higher numbers of eggs were laid on tobacco than on cotton. S. parcesetosum could develop either on cucumber or on cotton as preferable host plant species for B. tabaci. There were significant differences in mean developmental duration of larval instars of the same sex between both host plant species; the duration was significantly shorter on cucumber than on cotton. There were no significant differences for mean total developmental duration from egg to adult emergence between both host plant species within the same sex; females showed a mean of 15.9 days and males of 15.1 days on cucumber, while on cotton the means were 17.2 days for females and 16.2 days for males. Total mortality percentage of S. parcesetosum during development from egg to adult stage was lower on cucumber than on cotton, 20.6 and 23.8%, respectively. Longevity of S. parcesetosum varied according to host plant species and sex with a mean of 63.4 days for females and 50.3 days for males on cucumber, and 92.4 days for females and 52.5 days for males on cotton. On cucumber, mean period of oviposition of S. parcesetosum was significantly longer than on cotton. Mean total fecundity was significantly higher on cucumber than on cotton, with means of 97.7 and 31.0 eggs/female, respectively.     

Floristic diversity and composition of the Biteyu forest in the Gurage mountain chain (Ethiopia): implications for forest conservation

The Afromontane forests of Ethiopia have been under a serious degradation threat. Assessment of floristic diversity and species composition in Biteyu forest of Gurage mountain chain in the central Ethiopia was conducted to examine the pattern of forest structure. Thirty plots of 30 m×30 m were used to record the vegetation and environmental data using systematic sampling technique. The local name, plant scientific names, DBH, height,species abundance and percentage canopy cover of plant species were recorded. Shannon diversity index and Sorensen's coefficients was used for comparison among communities and similar forests in the country. Threats to the forest biodiversity in Biteyu were determined by counting cattle interference and wood stumps as disturbance indicators. Relative Euclidean Distance measures by using Ward's method(linkage) was applied for cluster analysis. Environmental variables were also recorded in each plot. Woody species population structure, basal area and importance value index were analyzed using spreadsheet programs. Data on species distribution and environmental variables in the forest were analyzed by canonical correspondence analysis. A total of 190 species in 154 genera under 73 families were identified. Twenty species were found to be endemic taxa to the Flora Area. Only three plant community types were identified from the cluster analysis due to the high human influence. The Sorensen's coefficient showed the resemblance of the Biteyu forest with other Dry Evergreen Afromontane forests in the country. Moreover, altitude and slope strongly affect the species composition and structure of Biteyu forest. Given the high anthropogenic influence, high endemism, high dependence of the local community on the forest resources, forest conservation and restoration measures should be done by stakeholders.     

Post-logging regeneration and recruitment of shihuahuaco (Dipteryx spp.) in Peruvian Amazonia: Implications for management

Over the past decade, shihuahuaco timber - comprising several species of Dipteryx (Fabaceae) traded internationally as “cumarú” or “Brazilian teak” - has become one of the most highly demanded types of hardwood from Peruvian Amazonia, particularly in the Chinese market. Dipteryx is an ecologically important canopy-emergent genus with widespread distribution in neotropical forests. To assess the response of Dipteryx to logging, we conducted inventories in three logging areas in the Regions of Ucayali and Loreto, Peru. The size-class distributions of Dipteryx populations in recently logged sites showed that initial post-logging conditions enhance recruitment of residual seedlings. These conditions are created by a combination of logging gaps and the activities of farmers migrating into logged lands. Through protection and liberation of shihuahuaco seedlings in post-logged forest as well as within and around agricultural fields, local residents and timber companies could favor the recovery of this valued resource. However, as logged land is increasingly converted to agriculture and pastureland, the reestablishment of mature seed trees is not assured.     

The role of saltbushes (Atriplex spp.) in arid land rehabilitation in the Mediterranean Basin: a review

Arid lands in the Mediterranean Basin harbour populations of saltbushes over substantial areas. These have been grazed for centuries and often cleared. There are also some 100,000 hectares of artificially established saltbushes, both native and exotic; they include no more than half a dozen species, when large scale plantations are concerned. Another dozen of exotic species, introduced from Australia, Southern and Northern America, have successfully undergone field trials and could be used on a large scale in a near future. The present paper attempts to review the current state of knowledge on Atriplex spp. in the Mediterranean Basin as a means of Arid Land rehabilitation at a time where huge areas in the region have undergone processes of severe degradation or have been subjected to desertization, particularly over the past four decades. In spite of a number of constraints in their establishment, management and utilization, the plantation of Atriplex spp. appears as one of the best way, if not the best one, to rehabilitate desertized areas and restore them to production, under the present state of knowledge on arid land rehabilitation. They, in particular, are amenable to inclusion into new, man-made agro-sylvo-pastoral systems of production well adapted to arid lands and to the needs of their populations.     

Genetic control of the tree-ring response of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) to the 2003 drought and heat-wave in France

The genetic control of tree ring growth in Douglas-fir in response to the drought and heat-wave that occurred in 2003 in Europe was studied with microdensity profiles in three clonal experiments located in three different French regions. The drought and heat-wave significantly affected Douglas-fir wood formation. The Chassenoix site (Northeast of Massif-Central) was more severely affected that the other two: the 2003 year-ring was narrower and less dense than in the other sites and than the previous (2002) and following (2004) year-rings in the same site: ring growth stopped earlier and latewood did not develop completely. The year-rings 2004 and 2002 were very similar in this site. There was a significant genetic control for all ring parameters in the three sites and during the three years. The heritability was highly variable between years and among sites, without any clear pattern in this variability, except in Chassenoix where it was slightly lower in the 2003 year-ring. Variables measuring the response of trees to the 2003 event, i.e., the difference in ring width between 2002 and 2003, or between 2003 and 2004, showed a very variable degree of genetic control, from very low to relatively high. Douglas-fir seemed plastic enough to acclimate to the drought and heat-wave and then to recover during 2004. Furthermore the level of heritability estimated demonstrates that Douglas-fir has an adaptive potential that could be useful for multi-generation long-term response.