Lobeatta schneideri gen. and sp. nov., Anegertus cubitalis Handlirsch 1911, and Nectoptilus mazonus gen. and sp. nov., from the deposit of Mazon Creek (IL, USA; Upper Carboniferous), are described. They are shown to be close relatives of the genera Eoblatta Handlirsch 1906 and Ctenoptilus Lameere 1917. The latter genera, from French deposits nearly contemporaneous with Mazon Creek (Commentry, Montceaules-Mines), have been previously assigned to Archaeorthoptera Béthoux and Nel 2000. Additional evidence of archaeorthopterid affinities of the Mazon Creek species is provided. Ongoing reviews of North American and European Upper Carboniferous insect faunas might reveal more similarities than expected in their respective composition, although at a suprageneric taxonomic level.

Nymphal instars of Xyleus discoideus discoideus, a romaleid grasshopper, are described for the first time. The following characters are recorded for each stage: body length, head width, pronotal length, hind femoral length, number of antennomeres, number of longitudinal eye stripes and the morphology of wing pads and external genitalia. Criteria that can be used to distinguish the instars and sexes are identified. Males and females have a 5-instar cycle under laboratory conditions. Females are larger as adults than males and this is linked to a longer nymphal period in females.

Host and geographical ranges are updated for the microsporidium Paranosema locustae; this pathogen was developed in the USA as a long-term microbial control agent of grasshoppers. Currently known to be susceptible to P. locustae, either naturally or experimentally, are 121 species of Orthoptera from North and South America, Africa, Australia, China, and India. Most belong to the Acrididae (112), and within this family, to the Melanoplinae (36), Oedipodinae (35), and Gomphocerinae (35). The host range of P. locustae, as presently understood, is based largely on morphology and could change if molecular techniques revealed cryptic species. The North American isolate is not only the best studied, but the one established after its introduction into Argentina, and produced and used in China: it can be considered a generalist pathogen. As such, P. locustae may have the ability to alter, through differences in host susceptibilities, the structure of grasshopper assemblages in areas where it was not present before. Long-term careful monitoring of key grasshopper species in areas of pathogen introduction/establishment may reveal such effects.

A comparison of hybrid zones between chromosome races of the tree weta Hemideina thoracica (White) found that the chromosomal rearrangements that involved the greatest proportion of the genome apparently had the least effect on fitness of hybrids. In order to further explore the nature of chromosomal rearrangements that differentiate weta races, relative DNA content was compared between 2 races of H. crassidens (Blanchard) (known to differ by 2 Robertsonian (Rb) translocations) and 4 races of H. thoracica, using flow cytometry. Where Rb translocation was the inferred process (H. crassidens 15 vs 19; H. thoracica 17 vs 15′) no change in relative DNA content was detected, as expected. The 19-karyotype of H. thoracica was predicted to have more DNA due to a duplication/loss compared to the 17-karyotype of H. thoracica, but here too, no change in relative DNA content was detected. In contrast, significantly more DNA was found where less was predicted; the 13-karyotype of H. thoracica was thought to have less DNA than the 15′-karyotype, due to a duplication/loss, but in fact this race has significantly more DNA than any of the 3 other races of H. thoracica examined. Due to the differential staining of A-T bases by the stain used in flow cytometry, 4′-6′-diamidino-2-phenylindole (DAPI), it is possible the increased DNA estimate for the 13-karyotye is due to a significant shift in A-T base bias throughout its genome. However, it is more likely that the absence of the very small acrocentric autosomes that characterize many of the karyotypes of H. thoracica, result from translocations to larger autosomes than from a change in total DNA content and a simultaneous change in base ratio.

The arboreal camel cricket, Gammarotettix bilobatus Thomas, is abundant and widespread in California. It emerges in mid to late February, survives into late May and early June, and utilizes 8 host-plant species (coast live oak, barberry, Christmas berry, California lilac, California buckeye, Monterey pine, black locust, and California bay), some of which are toxic. It appears that G. bilobatus switches host plants intraseasonally and possibly acts as an inadvertent pollinator of some of its host plants.

Very little research has been conducted into the impact of grassland management on insect populations of Culm grasslands located in northwest Devon, UK. This paper presents the effects of agricultural improvement and burning on Orthoptera populations of these wet, heathy pastures at Dunsdon National Nature Reserve. The results from this 2-year study should aid conservation management of this important UK habitat. Orthoptera populations and habitat variables of improved (drained and cropped from 1840-1875) and unimproved pastures, were monitored in 2002 and 2003. There was no significant difference in Orthoptera abundance between pasture cropped from 1840-1875 and unimproved grassland, suggesting that mobile grasshopper species such as the meadow grasshopper Chorthippus parallelus, recolonised the improved swards from surrounding pastures, after a lengthy period of arable cropping in the 1800s. Winter burning led to higher numbers of Orthoptera in the post-burn year, perhaps due to the reduced sward height and biomass on the burnt swards, making them more favorable for postdiapause development.

We describe 2 new and closely allied tettigoniid species, recently discovered on mountain slopes in southwestern continental Greece. Though they differ in habitus, coloration, morphology (modified paraprocts) and habitat from most members of Rhacocleis, the new species have been arranged tentatively in this genus. Unknown morphological characters and faunistic data for some other poorly known Greek Rhacocleis species (R. ferdinandi Willemse & Tilmans 1987 and edentata Willemse 1982) are included.

Plague locusts are a major problem in many developing countries. For the desert locust, control by a preventive strategy proved effective, and led to a dramatic decrease in outbreak frequency and duration over the last 40 y. Principal problems are now of an organizational nature. Natural-risk management plans for locust outbreaks, associated with new financial mechanisms, must be implemented in order to ensure early reaction, efficiency of control and sustainability of the preventive approach. Studies of these outbreaks should be based on the ecological mechanisms considered to date, but also be broadened to include economic, social, organizational and cultural mechanisms that have been largely overlooked in the past. New concepts, such as risk-management systems, stakeholder strategies, and governance, should be given serious consideration. A new approach to locust issues is suggested, using techniques derived from sociological and anthropological sciences.

Opinions expressed in this article are entirely those of the author.

Acridid pests, locusts and grasshoppers, pose continuing threats to rural communities in developing countries, including sub-Saharan Africa, where human and material resources for controlling these insects are meager to none. The past 15 y have witnessed invasions, upsurges and/or plague of the desert locust, Schistocerca gregaria, mixed at times with the migratory locust, Locusta migratoria migratorioides, and the Senegalese grasshopper, Oedaleus senegalensis—in outbreak and invasion areas in the Sahel, northwestern Africa, the Red Sea region, and southwest Asia. Strained by lack of resources to develop and implement integrated pest management strategies that embrace effective preventive control alternatives, affected countries often resort to spraying enormous quantities of synthetic chemical pesticides to control these pests. During the 2003–05 and 1993–94 upsurges, and the 1986–89 locust/grasshopper plague, close to 25 million liters of pesticides were sprayed, largely with the help of the international community. At current estimates, that may have meant upwards of US$500 million in control cost alone, not to mention associated environment and nontarget costs. This paper attempts an overview of the challenges, impacts, and implications of the current approach, its perceived and actual benefits to rural communities and the dilemma in donors' actions or inactions. It also tries to capture lessons learned and experiences gained from recent and past campaigns and to draw conclusions and offer recommendations for future directions.

The search for alternatives to the widespread use of chemicals to control locusts and grasshoppers has led to the development of mycoinsecticides based on Metarhizium anisopliae var. acridum. Two products are available commercially: Green Muscle® in Africa and Green Guard® in Australia. Only Green Guard® has been used in large control operations, with nearly 80,000 ha treated since operational use began in 2000. Research, though important, was not sufficient to lead to operational use of Green Guard®: the critical factor was the formation of the Locust and Grasshopper Biocontrol Committee that consisted of research providers, end-users and a commercial partner who together favored the rapid development of a commercial product.

In Australia, M. a. var. acridum is used in environmentally sensitive areas such as near waterways, or where there are rare and endangered species, and on the many properties, in locust-source areas in the interior, that produce organic beef for export. However, an increasingly important use is by landholders, who are now required to list all the chemicals used for pest control when they sell their products. This, potentially very large, use is limited by the myopesticide's slower action and higher price.

Slower action is not a major problem when Metarhizium is used in preventive control programs. The higher price is, in part, a consequence of its narrow host range. M. a. var. acridum is specific to locusts and grasshoppers, so research, development and registration costs must be divided amongst 1 or 2 users, not dozens, as is common with chemical pesticides.

Yet one of the greatest problems is the sporadic nature of locust and grasshopper outbreaks, which results in an intermittent need for Metarhizium and a lack of ready availability when outbreaks do occur. Use of Metarhizium in a number of countries, including those that have more regular outbreaks, may be one way of ensuring high-volume production at a reasonable price. Only then will there be a regular operational use to prove that this mycoinsecticide works under a wide variety of environmental conditions, so that it can take its place as part of the integrated pest management of locusts and grasshoppers throughout the world.

At the time of the major outbreak of desert locust in the late 1980s, FAO convened a meeting to discuss control operations in view of the worldwide ban on the use of dieldrin, hitherto regarded as the most important insecticide to control locusts. An outcome of the meeting was to set up an independent advisory body, the Pesticide Referee Group (PRG), to examine the scientific data obtained from laboratory and field trials submitted to FAO. The PRG was expected to make recommendations on which insecticides were effective and the dosage that should be used, either as a barrier treatment or for full-cover applications. The remit of the PRG was subsequently extended to consider environmental data and indicate the possible risk that the effective insecticides pose to various categories of nontarget fauna.

The aim of the recommendations has been to give locust-affected countries a choice of suitable insecticides, to avoid the previous problems of maintaining stocks of only one insecticide, and to allow flexibility in relation to possible environmental impact. The need for ULV formulations, with specifications that include appropriate volatility and viscosity requirements, is stressed for operational reasons. Stocks of these formulations can be reformulated for use against other pests to avoid long-term storage or obsolesence. Attention has been given to new alternatives, including insect growth regulators and the biopesticide Metarhizium anisopliae var. acridum. The PRG has requested feedback on operational use of insecticides, including these new products, so that the list can be refined and extended.

Sustainable development was defined in 1987 by the World Commission on Environment and Development, as a development that meets the needs of the present without compromising the ability of future generations to meet their own needs. Sustainability has since become a guiding principle and basis for action in all fields of agriculture, including pest management. The principle is stipulated in the Declaration on Environment and Development of 1992 which calls for “research and development into pesticides that are target-specific and readily degrade into harmless constituent parts after use”, as well as in the ‘Plan of Implementation of the World Summit on Sustainable Development’ of 2002 which calls for “promoting programs for the environmentally sound, effective and efficient use of … pest control”. How do these obligations translate into the reality of locust control? The present paper addresses this question from different perspectives, representing the 3 pillars of decision-making for sustainable development: capacity, understanding and willingness. It concludes that substantial progress has been made over the last decade in improving the technological capacity for more target-specific control (application technology, biological control, barrier treatment). However, despite all evidence, these innovations are often perceived with suspicion by locust control practitioners and the public. The paper identifies a lack of confidence in the efficacy of some of the new technologies as a major constraint to their adoption. Improving the understanding of these technologies is key to overcoming this constraint. This may require believing what one does not see immediately. Only then may decision makers be willing to include new and more environmentally sound technologies into their control portfolios—and so progress towards sustainable locust control.

The present paper arose from a symposium at the 9^th International Conference of the Orthopterists' Society held in Canmore, Canada, from 14-19^th August 2005. Most of the major groups working on locust phase polyphenism were in attendance ^{(Table 1)}, offering the opportunity to review the rapid progress that has occurred in this field over recent years. To maintain momentum in this research, areas where results from different groups are at odds were debated, and ways to reconcile such discrepancies proposed. The symposium also provided researchers with a forum to consider how to coordinate core facilities and resources across laboratories, to make best use of national and international funding opportunities. Participants presented their results spanning a range of aspects of phase polyphenism research: molecular analyses, physiology, ecology and phylogenetic reconstruction of the evolutionary history of phase change. The symposium was followed by a detailed discussion session, attended by members of the audience as well as the symposium speakers. The present paper provides a synopsis of that discussion and is structured according to the major issues considered. Unless otherwise stated, the paper concerns the desert locust, Schistocerca gregaria, which has been the subject of most of the recent research.

A better understanding of the mechanisms that underlie phase transformation in a solitarious desert locust population is an important prerequisite for the development of a quantitative gregarization model and for predicting locust outbreaks. Two types of processes are involved: 1) clustering at diminishing spatial scales, which brings dispersed locusts together and which, in patchy micro-environments with a concentrated food resource, gives rise to nuclei of pheromone-emitting, gregarizing insects; and 2) recruitment processes which promote the horizontal spread of gregarious traits from such nuclei. Because of the heterogeneity of typical breeding habitats and divergent behavior of the 2 phases of the insect, there is a dynamic interplay between the forces of crowd formation and those of dispersal. All the key steps in the course of phase change are reversible and for successful development of a viable gregarious population, all must proceed at optimal pace toward the gregarious phase. The process resembles a chemical transformation that involves a series of reversible sequential steps and may, likewise, be treated as a series of equilibria. Such a conceptual model may constitute a useful framework for quantitative studies in desert locust primary breeding areas and in the development of a predictive gregarization model.

A density-dependent change from a cryptic to an aposematic antipredator strategy has recently been suggested as a possible functional explanation for phase change in the desert locust (Schistocerca gregaria Forskål). Predators learn to avoid locusts that have fed on toxic plants faster when they are in the brightly colored gregarious phase than when they are green and solitarious. We review recent work comparing acquisition of a defensive compound via food selection between solitarious, transiens (solitarious locusts in transition to the gregarious phase) and gregarious locusts. Lab experiments showed that solitarious locusts were deterred at first contact with hyoscyamine, a plant compound that protects against predators, but later habituated to the compound and incorporated it into the diet (albeit at a low rate). By contrast, gregarious and transiens locusts fed readily on the compound. A computer simulation showed how low-density, solitarious locusts would not benefit much from consuming the compound, because they escape predation by avoiding detection. However, for high-density transiens and gregarious locusts, for whom crypsis is no longer an option, acquiring toxicity dramatically decreases predation risk. A survey of the literature showed that solitarious locusts exhibit a narrower diet breadth than gregarious locusts, suggesting that solitarious locusts avoid defensive plant compounds, whereas gregarious locusts use a mix of compounds in the gut as a defence against predators. Gut-mediated antipredator defences might be more widespread among Orthopterans, especially brightly colored species, than has previously been realized. In particular, it remains to be investigated whether density-dependent aposematism and changes in food selection toward chemical defense, play a role in phase change in other locust species.

Locust phase polyphenism is a spectacular example of density-dependent phenotypic plasticity. It is generally interpreted as an adaptation to heterogeneous environmental conditions brought on by high population density. However, several nonlocust species are known to express phase-like traits, which is difficult to explain from an adaptive perspective alone. Here I attempt to explain this phenomenon by 1) taking a reaction norm perspective in understanding the mechanisms underlying locust phase and 2) taking a phylogenetic perspective to study how individual reaction norms of locust phase might have evolved. I argue that locust phase polyphenism is a complex syndrome resulting from interactions among different density-dependent plastic reaction norms, each of which can follow a separate evolutionary trajectory, which in turn can be reflected in a phylogeny. Using a phylogeny of Cyrtacanthacridinae (Orthoptera: Acrididae), I explore the evolution of plasticity in density-dependent color change. I demonstrate that locusts and closely related nonlocusts, express similar phenotypic plasticity due to phylogenetic conservatism. Finally, I argue that it is crucial to study the evolution of locust phase polyphenism from both adaptive and phylogenetic perspectives.

The formation of new species involves the evolution of barriers to gene exchange. One such barrier is sexual isolation, where divergent mate preferences prevent copulation between taxa. Sexual isolation can evolve via a number of processes, including natural selection, sexual selection, genetic drift, and reinforcing selection to avoid maladaptive hybridization. Conversely, gene flow between populations generally erodes the evolution of sexual isolation. In Timema cristinae walking stick insects, some sexual isolation between populations evolved through ecological divergence in host-plant use, implicating a role for natural selection. However, reinforcement and gene flow also contribute, such that sexual isolation is strongest when migration between hosts is high enough to result in selection to avoid hybridization, but low enough to prevent gene flow from eroding adaptive divergence in mate choice. Both parallel and contrasting patterns can be seen in other Orthopteroids. This variation among groups might reflect 1) the degree to which different groups are intimately associated with their food resources, 2) the types of traits used in mate choice, and 3) how the geographic arrangement of populations affects the opportunity for reinforcement.

A new species of Miracanthops Roy, 2004 from Tambopata, Peru is described: Miracanthops eseejja n. sp. The diagnosis of the genus Miracanthops is also completed, with the description of the male, which was previously unknown. Based on the characters of the male, Acanthops occidentalis Lombardo & Ippollito 2004 is transferred to Miracanthops as M. occidentalis (Lombardo & Ippollito 2004) n. comb.

Results are presented of a study on the armature of the hind and fore tibiae in 39 species and 4 additional subspecies, out of 54 (formally recognised) species and 9 additional subspecies, belonging to Rhacocleis and Pterolepis. The armature of the hind tibia, traditionally used to separate Pterolepis and Rhacocleis, varies within taxa from very slight in most taxa to extensive in a few. The armature of the upper inner margin of the fore tibia proved a more reliable character than the traditional hind tibial armature to separate Pterolepis and Rhacocleis, indicating that the synonymy of Rhacocleis with Pterolepis proposed in Heller et al. (1998), should be re-evaluated. Observations suggest a possible re-arrangement of species described under Pterolepis and Rhacocleis, but no nomenclatural changes are proposed. It is argued that nomenclatural changes, if any, should only be taken after a much needed review of the generic definitions in the Platycleidini (s.l.). An updated checklist of Pterolepis and Rhacocleis taxa is included. Pterolepis ramburi Serville 1838 is proposed as a species incertae sedis.