Since taking over as Editor-in-Chief of Insect Science and its Application with Volume 16, major changes have been undertaken by the editorial and production teams to improve the journal's quality, presentation, format, timeliness and overall coverage. In Volume 17, these changes are more visible, with the new cover design and layout. In terms of quality, the relevance and originality of the content of the accepted articles is being constantly improved. Inevitably, this has led to increased rejection of papers which no longer meet the new standards. On the editorial side, we have set in place a broadened team of scientific editors and given additional training to existing staff. The process of regionalising the editorial activities in Latin America, Asia and Africa is also progressing and we hope to have the regional offices in place in the not too distant future.

During the last decade damage to stone-and pome-fruit orchards in Israel caused by bark beetles has increased. We present data on injury by Scolytus amygdali Geur. and S. rugulosus Muller to nine rosaceous fruit trees of Prunus spp., Malus silvestris, Pyrus malus, Cydonia oblonga and Eriobotrya japonica in 6 major regions in Israel. Approximately 64 and 18% of the sampled areas planted with stone- and pome-fruits, respectively, were damaged by bark beetles. The heaviest damage occurred on apricot, almond, peach, plum and cherry. Most of the area planted with stone fruits, and large areas planted with apple and pear, were damaged by bark beetles. The most widespread beetle damage occurred in the central mountain range and the southern coastal region, with approximately 96 and 92% of the sampled area damaged, respectively and the least occurred in the northern mountain range. Stone fruits are more susceptible to damage by bark beetles than apple and pear, while quince and loquat are virtually resistant. The level of damage appears to be influenced by grove management, host plant resistance to Capnodis spp. (Coleoptera: Buprestidae), climatic conditions and conditions in plots neighbouring the orchard.

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.

We monitored abundance, population dynamics and damage impacts of the leucaena psyllid Heteropsylla cubana Crawford (Homoptera: Psyllidae) in a maize-leucaena agroforestry system. The abundance of local ladybird beetle predator populations were also evaluated. The studies were conducted between June 1993 and November 1995 at Mtwapa and Amoyo in coastal and western Kenya respectively. Alley-cropping leucaena with maize had no effect on the abundance of the leucaena psyllid or its coccinellid predators. Therefore, neither the ‘resource concentration’ hypothesis nor the ‘enemies’ hypothesis corroborated for the psyllid-leucaena system within the spatial scale of this study. Psyllid populations were generally much higher at Mtwapa than at Amoyo, suggesting possible environmental effects on population growth. Psyllid populations were influenced by weather (mainly rainfall) and availability of suitable shoots. New growth of young shoots following rainfall encouraged psyllid abundance as long as weather conditions were not extreme. Though population of the generalist ladybird beetles was correlated with that of its psyllid prey, beetles did not appear to have significant effect on prey populations.

Several species of stemborers attack sorghum and pearl millet in Africa and Asia. The commonest species on sorghum are Chilo partellus (Swinhoe) and Busseola fusca (Fuller) and on pearl millet, Contesta ignefusalis (Hampson). This paper discusses control options and the extent to which farmer perceptions of stemborers and associated crop losses have been considered. Examples of research aimed at developing IPM strategies are presented in the context of their impact or lack of it, on the farming community. Research efforts have traditionally focused on the development of resistant cultivare and only recently are they being targeted towards a combination with cultural and biological tactics. Conventional breeding procedures have not produced adequate levels of resistance to stemborers and natural enemies are not effective in regulating borer populations. The prospects of applied biological control and improved intercropping configurations are discussed. Reference is also made to progress in the role of semiochemicals in parasitoid activity on Ch. partellus and sex pheromones in the control of Con. ignefusalis. Unless resistance levels to stemborers are increased through biotechnological approaches, optimisation of the yield potential in existing cultivars requires that IPM research should focus on the improvement of cultural and biological components and should incorporate farmers' perceptions and an assessment of traditional pest management practices.

A systematic account of the lepidopterous cereal stemborers in Africa is presented. The identification and distribution of the economically important species is discussed. Systematic problems are pointed out.

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.

Populations of surface-living Collembola of a 5-year-old fallow were monitored with pitfall traps before and after clearing of vegetation, after ploughing and harrowing and during the different growth phases of cowpea (Vigna unguiculata L. Walp.) with and without weed-control measures. Overall, 8 genera of Collembola were identified in the study site. Songhaica nigeriana was the most abundant species in the study site before clearing. After clearing, the relative abundance of the different genera of Collembola was altered and after ploughing and harrowing, fewer species were recorded. After ploughing, Songhaica nigeriana, Dicyrtoma, Cryptophygus and Sminthurinus spp. were not obtained in the study site. During the vegetative growth phase, Collembola populations remained low in the herbicide-treated plots. The community structures of Collembola varied among the treatments, and temporal changes in the relative abundance of the different genera of Collembola were observed.

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.

Stemborers in Africa are attacked by a complex of about 120 species of hymenopteran parasitoids, including about 15 species which are either facultative or obligatory hyperparasitoids. Several dipteran parasitoids also attack stemborers. An overview of hymenopteran stemborer parasitoids is here presented by superfamily and family, giving numbers of genera and species involved, their biologies (where known) and distributions.

The blue biliverdin pigment in the haemolymph of Schistocerca gregaria Forskål (Orthoptera: Acrididae) was shown to be associated with all the stages and ages of the solitary-reared (solitarious) insects, irrespective of their origin or diet. The pigment was absent or present in very small quantities in the crowd-reared (gregarious) insects. The ratio of absorbance at 460 nm and 680 nm, the former representing the λmax for the carotenoid pigment and the latter for the biliverdin, provides a clear-cut index for partitioning the phases. The mean value of the index for the gregarious group fell in the range 3.69 to 4.78. That of the solitarious group ranged from 0.64 to 1.67. The absorbance ratio at 460/680 nm appears to represent a simple and convenient means of differentiating the two phases of the desert locust, Schistocerca gregaria.

The noctuids Busseola fusca and Sesamia calamistis and the pyraloids Chilo partellus, Chilo orichalcociliellus and Eldana saccharina are the most important stemborers of maize in East Africa. A wide range of egg, larval and pupal parasitoids of stemborers have been identified, but information on predators, nematodes and microbial pathogens is less extensive. The most abundant and widespread parasitoids in the East African region are the egg parasitoids Telenomus spp. and Trichogramma spp., the larval parasitoids Cotesia sesamiae and Sturmiopsis parasitica and the pupal parasitoids Pediobius furvus and Dentichasmias busseolae. Predators, such as ants, spiders and earwigs can cause high mortality of eggs and young larvae in some areas. Nematodes and microbial pathogens have been reported to infect all life stages, but their impact is low under natural conditions. The abundance of natural enemies can vary considerably between locations and seasons. In general, indigenous natural enemies are not able to keep stemborer populations below economic injury levels. This paper summarises what is currently known of the natural enemies of cereal stemborers in East Africa.

Three designs of pheromone-baited flight trap for the larger grain borer, Prostephanus truncatus (Horn) were compared in a daily-trapping trial in Ghana. Japanese-beetle (JB)-type traps, composed of a funnel surmounted by a cross-vane, captured two to three times more beetles than delta- and box-type sticky traps, which are currently the most commonly used designs. Japanese beetle traps have now been adopted by the Ghana National Trapping Network for P. truncatus. The higher efficiency of the JB traps has led to the discovery of the borer in two important maize-growing areas which had previously recorded zero catches using sticky delta-type traps. Analysis of correlation between replicates suggested that JB traps were the most consistent of the three trap designs (r = 0.88). The mode of entry of P. truncatus adults into different trap types, which may explain variations in catches from the different traps, is discussed.

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.

Patterns of stemborer life history and the foraging patterns exhibited by a taxonomically diverse array of stemborer parasites are described. Foraging strategies provide functional descriptions of natural parasite groupings and include elements of the guild concept plus ecological, behavioural, and morphological adaptations that enable a parasite to locate and exploit a particular host effectively. Elements of the foraging strategy include: host stage attacked, microhabitat of the host, cues employed to locate and identify the host, and method of host attack. Possible constraints presented by the crop plants to the success of different foraging strategies exhibited by groups of parasites are explored.

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.

Competition between Dermestes maculatus Degeer (Coleoptera: Dermestidae) and Necrobia rufipes Degeer (Coleoptera: Cleridae) in Clarias gariepinus (Burchell), was studied at four population levels (16,30,48 and 60), three moisture-content levels (12,15 and 20%) and three temperatures (20, 27 and 32°C). Experiments were carried out using adult insects of both species in mixtures of equal and unequal numbers. Interspecific competition between N. rufipes and D. maculatus was found to have an effect on the population growth of both beetles but to different extents. The intensity of competition is dependent on temperature, moisture content and the initial density ratio. Using the replacement series approach, it was predicted that at high adult population and moisture content, N. rufipes becomes extinct and D. maculatus dominates a mixed culture. At a temperature of 20°C, D. maculatus outcompetes N. rufipes while at 32°C, both species co-exist. This observation possibly accounts for the low occurrence or absence of N. rufipes relative to D. maculatus in commercial dried fish in areas with temperatures of 20 to 30°C.

A basic study of the behavioural responses of the harvester termite, Hodotermes mossambicus (Hagen) to poison baits was undertaken. Laboratory trials revealed that the collected baits were not incorporated into the termite nest food stores. The baits were never eaten because the nest-bound larval caste selects the food to be consumed by the entire colony, from the material collected by the foraging caste. Moreover, field observations have shown that the commercial bait, Kamikaze®, bears no resemblance to the grass collected by the termite foragers. This study revealed that observations of foraging and feeding behaviour of the termites are necessary before designing control measures.

One tactic of importation of natural enemies for biological control of stemborers and other pests is the use of parasite species that have had no previous association with the pest. This ‘novel association’ approach offers the possibility of using parasites that have proven effective against a stemborer species other than the target stemborer pest. Nevertheless, creation of a novel host-parasite association requires that the novel host be ecologically and physiologically equivalent to the ancestral host. Selecting natural enemies based on ecological and physiological equivalence offers the best possibility of temporal, behavioural, nutritional and immunological compatibility in the host-parasite interaction, and reduces the chances of failure with the imported parasite species.