Influence of historical land use and modern agricultural expansion on the spatial and ecological divergence of sugarcane borer, Diatraea saccharalis (Lepidoptera: Crambidae) in Brazil.

We assessed agricultural land’s potential as to food supply and biofuel production. Agricultural land use has been steadily increasing worldwide as one means of feeding the burgeoning global population. If this same land, currently in agricultural production for food purposes, is diverted for biofuel production then it is most probably going to have an impact on global food supply. In this study, we first assessed the characteristics of land and where crops can be successfully grown based on the qualifications of weather, land intensification, land quality, and cropping patterns. Use of land in biofuel production, under current existing technologies, would need a significant expansion of agricultural land in both developed and developing countries from their current levels. We assessed the supply potential of the World Bank’s 25 classified regions for biofuel and also for meeting food production needs under the whole grain production, current per capita consumption, and optimal grain consumption based on vegetarian, normal and affluent diets under a variety of scenarios that encompass both increases in productivity and increases in pasture land conversion to grain crop cultivation. Results indicate that under the whole grain need criterion, the world will have a surplus balance of grains by 2050 (even if production is increased at only the 40% level). When requirements for a vegetarian diet are assumed, a productivity increase of 60% at current land levels would be required to meet global grain needs. When a moderate diet requirement assumption is made, expansion of crop production in existing pasture and meadow land would be necessary to meet food demand. An affluent diet requirement would require a fairly substantial increase in productivity and expansion of crop production to marginal land in order to meet world food demand by 2050. Plantings of switchgrass and Miscanthus on marginal lands can produce much more biofuel than needed but stress on land resources, water quality, water quantity, and the need for a huge amount of production inputs may create a hindrance for its implementation in the future. Additionally, it will require advances in cost effective technology that will then be capable of producing biofuel from lignocellulosic feedstocks. Minimally, to meet moderate diet requirements in 2050, there will be need to expand grain crops in 30% pasture land and to meet at least 10% average world biofuel mandated need additional 3.3% pasture land needs to be planted with lignocellulosic crops such as switchgrass.

Core Ideas A short‐term increase in fertility and greater N mineralization were found in agricultural lands. Low plant recovery and soil degradation were found in fallow soils correlated with erosion indexes. In grass‐legume mixture pastures, improved soil structure and N build up increased soil fertility. P was found as the limiting nutrient in the studied agroecosystem. Expansion of crop production into high‐altitude native grasslands is occurring in the Peruvian High‐Andes due to climate change and agricultural intensification, with little understanding of the consequences to the ecosystem. The objective of this study was to determine the impact of land‐use changes on soil fertility and nutrient cycling to guide future land management. Comparisons were made between native grasslands and two alternative farming systems; the first was a system in which native grassland was replaced by an annual cash crop, maca ( Lepidium meyenii Walp.), followed by a long fallow and the second was a long‐standing perennial cultivated pasture. There was greater N mineralization, extractable Bray‐1 P, and K + in recently converted maca soils relative to adjacent native grassland soils most likely caused by tillage‐induced nutrient mineralization and by incorporation of manure and native grassland residue during the first year of land preparation prior to planting maca. Soil fertility, as determined by an ex situ pot trial to measure plant yield, was correlated with plant cover, soil total organic carbon, and water stable aggregates (WSA) under fallow following maca, suggesting that soil erosion might be an issue in the long term. In cultivated pastures, we found an increase in long‐term fertility driven primarily by the build‐up of soil N and improved soil structure in the perennial grass‐legume mixture compared with adjacent native grassland. Responsible management of the Puna agroecosystem requires restoration of plant cover after annual cropping of maca or the establishment of mixed perennial cultivated pasture.

Spatial genetic structure in 21 populations of butternut, a temperate forest tree (Juglans cinerea L.), is correlated to spatial arrangement, habitat, and land-use history

Fall armyworm (Lepidoptera: Noctuidae), southwestern corn borer (Lepidoptera: Pyralidae) and sugarcane borer (Lepidoptera: Pyralidae) damage and grain yield of four maize hybrids in relation to four tillage systems

The sugarcane borer, Diatraea saccharalis Fabricius, is a pest to sugarcane and many other crops. This work aims to characterize morphological variability in the epithelial cells (columnar, goblet and regenerative) along the midgut of D. saccharalis larvae. Fragments of the midgut (anterior, middle and posterior regions) were fixed and processed by light and scanning electron microscopy. There are both cytochemical and ultrastructural differences in the morphology of the epithelial cells, depending on their localization along the midgut. The apical surface of columnar cells shows an increase in both number and size of the apical protrusions from the anterior to the posterior midgut regions. There is an increase in the amount of PAS-positive (Periodic Acid-Schiff Reaction) granules detected in the cytoplasm of both the columnar and regenerative cells, from the anterior to the posterior region. The goblet cell apical surface is narrow in the anterior region, and enlarged in the posterior midgut; the chamber's cytoplasm extrusion are small and thin at the apical cavity surface, being thicker, longer and more numerous at the basal portion of the cavity. Our results suggest that the sugarcane borer midgut has two morphologically different regions, the anterior and the posterior; the middle region is a transitional region.

Formulations of Bacillus thuringiensis Berliner (Bt) with insecticidal activity against the sugarcane borer, Diatraea saccharalis Fabricius (Lepidoptera: Pyralidae), were developed and tested under laboratory and field conditions. The formulations were prepared using biodegradable polymers such as modified corn starch as an encapsulating agent, gelatin as an adherent, powdered sugarcane as a feeding stimulant and a Bt var. kurstaki GM-34 strain from a non-sugarcane region as the active ingredient. The spore-crystal complex of this strain was mixed at three different concentrations (30, 70 and 100 g kg(-1)) with the other ingredients. The blends were prepared as spray-dried and granular formulations, and then submitted to laboratory tests with two day old larvae of D. saccharalis and field tests in sugarcane crops with natural sugarcane borer infestation. Spray-dried formulations in laboratory bioassays caused mortality near 100% with all three concentrations, and granular formulations caused mortality around 84%. The field tests showed that spray-dried formulations at 70 and 100 g kg(-1) concentrations were as effective as a commercial bioinsectide (Lepinox), while granular formulations were ineffective.

Resistance in maize hybrids and inbreds to first-generation southwestern corn borer, Diatraea grandiosella (Dyar) and sugarcane borer, Diatraea saccharalis Fabricius

BACKGROUNDMaize technologies expressing Bacillus thuringiensis (Bt) insecticidal proteins are widely used in Argentina to control sugarcane borer (Diatraea saccharalis Fabricius). Unexpected D. saccharalis damage was observed to Bt maize events TC1507 (expressing Cry1F) and MON 89034 × MON 88017 (expressing Cry1A.105 and Cry2Ab2) in an isolated area of San Luis Province. Diatraea saccharalis larvae were sampled from MON 89034 × MON 88017 fields in the area to generate a resistant strain (RR), which was subsequently characterized in plant and diet bioassays.RESULTSSurvivorship of the RR strain was high on TC1507 leaf tissue, intermediate on MON 89034 × MON 88017, and low on MON 810 (expressing Cry1Ab). The RR strain had high resistance to Cry1A.105 (186.74‐fold) and no resistance to Cry2Ab2 in diet bioassays. These results indicate resistance to Cry1F and Cry1A.105 (and likely cross‐resistance between them) but not to Cry1Ab or Cry2Ab2. Resistance to MON 89034 × MON 88017 was functionally recessive. Reviews of grower records suggest that resistance initially evolved to Cry1F, conferring cross‐resistance to Cry1A.105, with low refuge compliance as the primary cause. A mitigation plan was implemented in San Luis that included technology rotation, field monitoring, and grower education on best management practices (BMPs) including refuges.CONCLUSIONIn the affected area, the resistance to Cry1F and Cry1A.105 is being managed effectively through use of MON 89034 × MON 88017 and MON 810 in combination with BMPs, and no spread of resistance to other regions has been observed. © 2017 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

The Glanville fritillary butterfly (Melitaea cinxia) has been studied in the Aland Islands in Finland since 1991, where it occurs as a classic metapopulation in a large network of 4000 dry meadows. Much ecological work has been conducted on this species, but population genetic studies have been hampered by paucity of suitable genetic markers. Here, using single nucleotide polymorphisms and microsatellites developed for the Glanville fritillary, we examine the correspondence between the demographic and genetic spatial structures. Given the dynamic nature of the metapopulation, the current genetic spatial structure may bear a signal of past changes in population sizes and past patterns of gene flow rather than reflect the current demographic structure or landscape structure. We analyse this question with demographic data for 10 years, using the Rand index to assess the similarity between the genetic, demographic, and landscape spatial structures. Our results show that the current genetic spatial structure is better explained by the past rather than by the current demographic spatial structure or by the spatial configuration of the habitat in the landscape. Furthermore, current genetic diversity is significantly explained by past metapopulation sizes. The time lag between major demographic events and change in the genetic spatial structure and diversity has implications for the study of spatial dynamics.

Sugarcane borer (SCB), Diatraea saccharalis Fabricius, is a serious pest in tropical maize production areas in the Americas. Little is known about the genetic resistance of maize genotypes to this pest. In this study, we mapped and characterized quantitative trait loci (QTL) affecting resistance to the leaf feeding generation of SCB (1SCB), grain yield under both protection (GYP) and infestation (GYI) with SCB larvae, and plant height (PITT). A total of 171 F2 genotypes derived from cross CML131 (susceptible) × CML67 (resistant) 93 RFLP marker loci were used in QTL analyses. F3 lines were evaluated for the above traits and grain yield reduction (GYR) in field experiments with two replications at two or three tropical environments. Resistance was assessed by rating leaf feeding damage after artificial infestation with SCB larvae. The method of composite interval mapping with selected markers as cofactors was used for detection and characterization of QTL. Resistance to 1SCB was significantly affected by 10 putative QTL on Chromosomes 1, 2, 5, 7, 8, 9, and 10. These showed predominantly additive gene action and explained 65.0% of the phenotypic variance and 93.5% of the genetic variance in a simultaneous fit. Six QTL for GYP, five QTL for GYI with primarily dominant genetic effects, and four QTL for PHT with primarily additive genetic effects were identified, explaining in total about one third of the phenotypic variance for the respective trait. No more than one putative QTL was found to be common between different characters. QTL × environment interaction was found to be significant for 1SCB ratings only. Based on these data, prospects for improving 1SCB resistance by marker‐assisted breeding are promising.

Landscape genetic studies typically focus on the evolutionary processes that give rise to spatial patterns that are quantified at a single point in time. Although landscape change is widely recognized as a strong driver of microevolutionary processes, few landscape genetic studies have directly evaluated the change in spatial genetic structure (SGS) over time with concurrent changes in landscape pattern. We introduce a novel approach to analyze landscape genetic data through time. We demonstrate this approach using genotyped samples (n = 569) from a large black bear (Ursus americanus) population in Michigan (USA) that were harvested during 3 years (2002, 2006, and 2010). We identified areas that were consistently occupied over this 9‐year period and quantified temporal variation in SGS. Then, we evaluated alternative hypotheses about effects of changes in landscape features (e.g., deforestation or crop conversion) on fine‐scale SGS among years using spatial autoregressive modeling and model selection. Relative measures of landscape change such as magnitude of landscape change (i.e., number of patches changing from suitable to unsuitable states or vice versa), and during later periods, measures of fragmentation (i.e., patch aggregation and cohesion) were associated with change in SGS. Our results stress the importance of conducting time series studies for the conservation and management of wildlife inhabiting rapidly changing landscapes.

Spatial genetic structure in natural populations of the overexploited tree Eremanthus erythropappus (DC.) macleish (Asteraceae)

Purification and characterization of three β-glycosidases from midgut of the sugar cane borer, Diatraea saccharalis

The habit which the sugar cane moth stalkborer ( Diatraea saccharalis Fabricius) has of spending the greater part of its life in tunnels in the stalks of sugar cane, corn, and certain grasses serves as an admirable protection against direct, or artificial, measures of control (9),[2][1] but does not seem to afford any great amount of protection against the attack of a rather formidable array of natural enemies. Such a condition is indicated in the comprehensive list of sugar cane moth borer parasites recently published by Van Dine (13). In this list, which includes the parasites reported from different parts of the world, there are ten species credited to Cuba. Among these is Bassus ( Microdus ) stigmaterus , described by Cresson from Cuba in 1865 (2), and reported by Holloway and others (3, 5) as being a parasite of Diatraea saccharalis , as well as four other species reported by Cardin in 1915 (1). Since 1915 the remaining five species have been reported by various authors. [1]: #fn-2

The southwestern corn borer (SWCB, Diatraea grandiosella Dyar) and sugarcane borer (SCB, Diatraea saccharalis Fabricius) are two related insect species that cause serious damage in maize production in subtropical and tropical regions of Central and Latin America. We analyzed quantitative trait loci (QTL) involved in resistance to the first generation of both borer species in two recombinant inbred line (RIL) populations from crosses CML131 (susceptible) × CML67 (resistant) and Ki3 (susceptible) × CML139 (resistant). Resistance was evaluated as leaf feeding damage (LFD) in replicated field trials across several environments under artificial infestation. Leaf protein concentration and leaf toughness were evaluated in one environment as putative components of resistance. The method of composite interval mapping was employed for QTL detection with RFLP linkage maps derived for each population of RIL. Estimates of the genotypic and genotype × environment interaction variances for SWCB LFD and SCB LFD were highly significant in both populations. Heritabilities ranged from 0.50 to 0.75. In Population CML131 × CML67, nine and eight mostly identical QTL were found for SWCB LFD and SCB LFD, respectively, explaining about 52% of the phenotypic variance () for each trait. In Population Ki3 × CML139, five QTL for SWCB LFD were detected, explaining 35.5% of . Several of these QTL were found in regions containing QTL for leaf protein concentration or leaf toughness. A low number of QTL in common between the two RIL populations and between RIL and corresponding populations of F2:3 indicated that the detection of QTL depended highly on the germplasm and population type. Consequently, chances of successful application of marker‐based selection (MBS) for corn borer resistance are reduced when QTL are not identified in the germplasm in which the final selection will be carried out.