A core reality in wildland conservation is “Use it or lose it”. And when you use it, something has to restore it. Footprints must mostly erase, or the use is not sustainable. The Area de Conservacion Guanacaste (ACG) in northwestern Costa Rica is a 3-decade old and long-term pilot project in tropical wildland biodiversity development and tropical wildland ecosystem development. In summary, it is environmental services development. Some conclusions are already evident:

• Restoring complex tropical wildlands is first and foremost a social endeavor; the technical issues are far less challenging.

• Survival of a large complex wildland, whatever its origin, in the face of humanity's genes and domesticated genomic extensions, requires a major paradigm shift—we cannot afford to perceive the conserved area as “wild”, otherwise known as “up for grabs”.

• Sustainability of a large wildland will only be achieved by bestowing garden status to it, with all the planning, care, investment and harvest that implies.

• All use is impact, all gardens are impacted—restoration is footprint absorption by the garden and occurs at all scales.

• Planning, care, investment and harvest within the wildland garden is achieved through detailed understanding of biodiversity and its ecosystems, AND in simultaneous incorporation of a specific garden's social milieu at local, national and international scales.

• The “achievable” is an ever-shifting and ever-negotiating n-dimensional hyperspace produced by the intrinsic traits of a specific wildland interwoven with the mosaic of social energies and agendas brought to bear on it.

Oedaleus senegalensis is a mainly sahelian non gregarious grasshopper which is today considered as the most important crop pest acridid, especially on millet. The species has three generations per year (rarely four) and spends the dry season as diapausing/quiescent eggs. Both photoperiod and temperature influence the induction of diapause in which O. senegalensis eggs can survive several years. Migratory movements have been reported by many authors; adults may migrate up to 350 km per night. These factors enable the species' adaptation to its natural hostile environment. The current control strategies are based on monitoring of the oviposition sites of the dry season to predict the subsequent outbreaks in order to control early hatchlings during the following rainy season. The present work gives an overview of the current knowledge on the morphology, biology, ecology and control methods of the grasshopper.

The economic injury levels (EIL) of the mustard aphid, Lipaphis erysimi on mustard, Brassica juncea were evaluated in field trials in Tarai, India, during the winters of 1986/87 and 1987/88. The EIL values ranged between 37 and 4, and 48 and 6 aphids per 10 cm terminal shoot per plant during the 1986/87 and 1987/88 trials respectively. A one-day increase in crop exposure to the aphids led to a significant reduction in seed yield per plant, 1000-seed weight, number of siliquae per plant and number of seeds per siliqua. The highest benefit-to-cost ratio was obtained at 3 weeks of exposure, when initiation of insecticide application was most economical.

In the Eduardo Mondlane irrigation scheme in Chokwe, southern Mozambique, land had been allocated in 1983 to approximately 12000 farmers for growing rice (85%) and maize (15%). From the onset, maize production in the warm season was severely constrained by a number of pathogens and pests. During 1984–1988 a study on downy mildew, maize streak virus, stemborers and rodents, was carried out. This resulted in the formulation of a package of recommendations along lines of integrated pest and disease management, which was subsequently disseminated to farmers by the extension service. In order to evaluate the effectiveness of technology transfer, farmers were interviewed just before the new recommendations were disseminated (1988) and again two years after the start of the training and extension programme. Severe constraints in technology transfer to farmers were encountered due to the poor functioning of the extension service. It is concluded that improvements in communication and feedback mechanisms between farmers, extensionists and researchers and substitution of the prevailing ‘top-down’ training and extension methods by a ‘bottom-up’ approach are needed. In addition, rehabilitation and proper maintenance of the irrigation system and better land allocation to smallholders is required before research recommendations can be expected to work.

Surveys for natural enemies of Mexican stemborers and the major biocontrol attempts using indigenous and exotic parasites in Mexico are reviewed. Although biological control of stemborers in Mexico was initiated in the 1920s, parasite explorations were intensified during the 1980s and have continued to date in response to the invasion of Diatraea grandiosella Dyar, D. lineolata (Walker) and Eoreuma loftini (Dyar) into the United States from Mexico. Recent surveys for stemborer parasites in Mexico has led to the discovery and laboratory culturing of the braconids Allorhogas pyralophagus Marsh, Digonogastra solitaria Wharton & Quicke and Macrocentrus prolificus Wharton; the ichneumonid Mallochia pyralidis Wharton and the tachinid Lydella jalisco Woodley. The Asian braconid Cotesia flavipes Cameron was introduced and established in the states of Tamaulipas and Sinaloa against Diatraea spp. Unsuccessful attempts to establish other exotic parasites are also discussed. Stemborer predators and diseases have been poorly studied in Mexico, and their potential as biocontrol agents is unknown. The current biological control programmes of stemborers in Mexico and the potential of indigenous and exotic parasites as biocontrol agents are discussed. National and international collaboration is stressed for optimisation of resources and efficient exchange of natural enemies and their mass rearing technology.

During surveys conducted in 40 maize-cassava intercrops in the humid forest zone of southwestern Nigeria, the following termite species were identified from soil samples: Microtermes spp., Macrotermes nigeriensis (Sjöstedt), Macrotermes subhyalinus (Rambur), Amitermes evuncifer (Silvestri) and Anoplotermes quietus (Fr. Muller). High incidence of Microtermes and Macrotermes spp. was observed. The population density of predominant species was generally higher in the rainy seasons than in the dry seasons, indicating the role of moisture in their spread. The soil texture of surveyed farms did not influence the presence of the subterranean species Microtermes. The level of weeds in the surveyed farms also did not affect the population density of termites. However, Microtermes population increased significantly (P < 0.05) with increase in crop residues and its presence in farms partly depended on the presence of maize in such farms. Microtermes and Macrotermes species inflicted most of the damage observed on maize crops, while that caused by Amitermes evuncifer was low. No termite attack was observed on growing cassava during the surveys. The presence of live cassava in the intercrop did not influence damage by termites. Nasutitermes and Microcerotermes species which attack economic trees such as cocoa, citrus, oil palm, and forest trees did not attack cassava or maize.

One hundred and five okra cultivars were evaluated in the field for resistance to the leafhopper Amrasca biguttula biguttula (Ishida) during the 1989–1990 season. On the basis of nymphal abundance and leafhopper injury index two resistant (Siswal Local and IC 7194) and nine moderately resistant [IC 6653, IC 8899, IC 13617, Sel. 1, HB 94, IC 6316,6 Dhari, Sel. 2–2 and Line 6(1)] genotypes were identified. Both of the resistant, two moderately resistant (Line 6(1) and IC 13617) and two highly susceptible (Pusa Sawani and Pusa Reshmi) genotypes were retested in 1990–1991. Resistant genotypes had significanlty (P < 0.05) fewer nymphs (18.5 to 22.0 nymphs/leaf) and lower values of injury index (2.2) compared with the other varieties. Nymphal duration was also longer (9.3 to 9.8 days) and nymphal survival lower (41.7 to 47.5%) in resistant cultivars. Higher trichome density, longer trichome length and higher concentration of sugars, silica, potassium, tannins and phenols in the leaves of resistant cultivars were associated with resistance to leafhopper.

Combining ability of resistance to the sorghum shootfly, Atherigona soccata and spotted stemborer, Chilo partellus in grain sorghum was analysed on a seven-parents diallel in a field trial at the ICIPE Mbita Point Field Station, western Kenya during the 1990 long rainy season. Lines with best performance for each of the four measured resistance parameters were also found to be the best general combiners. Resistance to leaf damage and number of holes/metre were controlled by additive gene effects whereas resistance to deadheart and stem tunnelling were controlled by additive and non-additive gene effects. Parents IS-1044, IS-12308 and IS-2269 with their good level of resistance, and desirable general combining ability (GCA) effects are proposed for utilisation as resistant combiners in breeding programmes for shootfly and stemborer resistance in grain sorghum.

The functional response in terms of prey consumption and numerical response in terms of number of eggs laid by individual female adult predators of Coccinella transversalis Fab. and Cheilomenes (Menochilus) sexmaculatus Fab. (Coccnellidae: Coleoptera) at varied prey (Aphis gossypii Glover) (Aphididae: Homoptera) densities were investigated under laboratory conditions. The feeding rate by individual predators increased at increased prey densities, with both the coccinellids showing the Type II functional response. One hundred percent prey consumption was observed up to an initial prey density of 50 and 20 for Co. transversalis and Ch: sexmaculatus respectively. The fecundity of Co. transversalis increased at higher prey densities, but that of Ch. sexmaculatus remained unchanged.

The temperature, pH, moisture, carbon and nitrogen contents of soils at oviposition sites of Zonocerus variegatus (L.) (Orthoptera: Pyrgomorphidae) located around cassava farms at Aiyepe, southwestern Nigeria, were compared with those of soils at non-oviposition sites (control) during different months. Although oviposition site soils did not differ in particle composition from control soils, their temperatures were, generally, significantly lower. Soils at oviposition sites lost significantly less organic carbon to oxidation and nitrogen to leaching. They also contained significantly more moisture than soils at control sites during February-April when oviposition occurred and newly deposited eggs, lacking the serosal cuticle, would be prone to desiccation in dry soils. Conditions at oviposition sites are a key factor in the selection of egg deposition by gravid Z. variegatus.

At Alemaya in eastern Ethiopia, tef (Eragrostis tef) was found to be attacked by a complex of seven shootfly species, five species belonging to the family Chloropidae and two to Muscidae. Atherigona hyalinipennis (Diptera: Muscidae) was economically the most important species in the shootfly complex of the crop. It caused 42–58% damage to growing panicles in different varieties of tef, which resulted in an estimated loss of 378–522 kg/ha. The average incubation period of eggs, developmental periods of larvae and pupae of A. hyalinipennis were 3.0, 12.7 and 9.6 days respectively, and the total life cycle was completed in less than a month in the laboratory. Larval parasitism by Neotrichoporoides nyemitawus ranged from 6.7 to 18.5%. Peak activity of A. hyalinipennis in the region was in August to September.

Intraspecific competition in the rice weevil, Sitophilus oryzae (L.) and the angoumois grain moth, Sitotroga cerealella (Oliv.) in grain sorghum was studied in laboratory experiments. Progeny production per female of each of the two species when reared separately, decreased as the initial parent population density increased. The number of progeny produced by Sitophilus oryzae increased to a peak, and then declined sharply with a further increase in initial parent population density, characteristic of a scramble competition. In contrast, the progeny produced by Sitotroga cerealella increased with an increase in parental density to reach a fairly constant maximum (flat topped curve), characteristic of a contest competition. It is concluded that intraspecific competition will not limit the potential of the grain moth S. cerealella of becoming a major pest of stored sorghum.

The searching behaviour of two coccinellid predators, Coccinella transversalis Fab. and Cheilomenes (Menochilus) sexmaculatus Fab. at different hunger levels and larval stage was studied on eggplant infested with Aphis gossypii Glov. Females of both predators required more prey to return to a state of complete satiation. As the period of starvation increased, more aphids were consumed by both the beetles, reaching a maximum at 24 h starvation. In first, second, third and fourth instars of both the predators, the searching time and the number of eggplant leaf veins visited increased with increasing hunger levels. A high positive correlation between searching time and hunger level of tested predators was obtained.

Studies were conducted on the spatial distribution of the sugarcane shoot borer, Chilo infuscatellus Snellen. Distribution was aggregated and described by the negative binomial model with a fixed mean size. Aggregated distribution probably resulted from environmental heterogeneity. The five quadrants of the field, i.e. north, south, east, west and central did not differ significantly in borer population. The optimum sample size, based on Iwao's formula, was 126 plants of 6 tillers each. The relevance of these findings to the management of C. infuscatellus is discussed.

Bioassays were carried out in Petri dishes with body washings of larvae, male and female moths and scale extract of Corcyra cephalonica St. in hexane to observe their kairomonal effect on Trichogramma brasiliensis (Ashmead) and T. japonicum Ashmead. The mean parasitoid activity index (PAI) and mean parasitisation were recorded. Trichogramma brasiliensis and T. japonicum recorded the highest mean parasitisation in the eggs treated with scale extract. Mean parasitisation recorded by T. japonicum in cards treated with female moth and male moth body washings were considerably lower than the corresponding values for T. brasiliensis. Both the parasitoids recorded significantly lower levels of parasitisation in cards treated with larval body washings. Gas chromatographs of host body washings / extract recorded a large number of similar hydrocarbons in the body washings of male and female moths and the scale extract. Pentadecane, heneicosane, eicosane, tetracosane, pentacosane and hexacosane were recorded in scale extracts. Female moth body washings recorded the presence of eicosane, tetracosane and pentacosane while heneicosane and eicosane were indicated in the male moth body washings.

Haemolymph from the locusts Schistocerca gregaria and Locusta migratoria contains humoral factors such as lectin and phenoloxidase system. In vitro studies demonstrated that phenoloxidase system can be activated by LPS, laminarin, Malamoeba locustae cysts, trypsin and methanol. Haemolymph showed agglutination activity for mammalian erythrocytes and protozoa (M. locustae, Leishmania major and Trypanosoma brucei). A purified lectin was isolated from haemolymph by affinity chromatography. Analysis by SDS-PAGE gave a single band at 80 kD while on native PAGE, it gave a single band at 650 kD. Inhibitors of the two humoral factors were investigated. Lectin activity was inhibited by nitrophenyl a α D-galactopyranoside in both cases and by lectin antiserum. Inhibitors of the phenoloxidase system were found in plasma. Prospects for use of such inhibitors are discussed. They could be incorporated in biopesticide formulations in such a way that they could depress locust immune reaction and stimulate biocide activity.

Acute toxicity tests were conducted to determine the biological effects of partially purified extracts of four different plants on the juveniles of Culex quinquefasciatus. The active ethyl acetate extract of Solarium suratense leaf produced a 24h LC50 of between 23.53 ppm for the second instars and 46.04 ppm for the third instars. This was followed by the defatted methanol fraction of Abrus precatorius seed coat extract with the LC50 values ranging from 59.82 ppm for the second instar to 77.34 ppm for the third instar. The petroleum ether fraction of Solatium trilobatum and the ethyl acetate fraction of Lencas aspera were less toxic to the larvae. The active fractions of the plant extracts disrupted moulting and metamorphosis, induced malformation, extended the larval duration and inhibited adult emergence. At concentrations of less than 37.64 ppm, they inhibited emergence of 50% of the larvae. The insecticidal activity of these extracts persisted for up to four days.

The effects of various concentrations of Neem Azal-T and Neem Azal-T/S as natural insecticides on the biology and percentage mortality of adult Aphis craccwora Koch were studied under laboratory conditions. Both extracts had an aphicidal effect against the adults and significantly decreased their fecundities and longevities. Addition of synergists such as ethyl oleate, sesame oil and dimethyl sulphoxide (DMSO) improved the aphicidal effects of both insecticides. The biological activity of Neem Azal-T/S only could be enhanced with suitable additives as they adversely affected the fecundity and longevity in comparison to the extract alone. Addition of CaCO3 to the above extracts had no clear effect on either neem seed extract formulation.

Studies were carried out from 1990 to 1993 to identify termite species associated with cocoa and coffee in Ghana. Ten genera/species, belonging to the families Termitidae and Rhinotermitidae, were recorded from cocoa and coffee trees aged from 6 to 36 months. The commonest was Ancistrotermes sp., followed by Amitermes sp., Microtermes subhyalinus, Microtermes sp. and Nasutitermes sp. Others were Macrotermes bellicosus, Pseudacanthotermes sp., Cubitermes sp., Schedorhinotermes putorius and Coptotermes sp. All species except M. bellicosus, Pseudacanthotermes sp. and Cubitermes sp. caused damage to cocoa and/or coffee. The shade tree, Gliricidia sp. was attacked by Pseudacanthotermes sp. whereas Macrotermes bellicosus and Cubitermes sp. were harmless. The relative abundance of these termites is discussed.