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Pest attack is an important biotic threat to sorghum productivity, and one of the main insect pests of grain sorghum is sugarcane borer (SCB) Diatraea saccharalis. Despite the importance of this insect species, little is known about the relationship between SCB infestation and reduction in sorghum grain yield, as well as on the gain threshold and economic injury level for decision making of pest control. This study evaluated the influence of SCB infestation on plant performance and grain production in three commercial grain sorghum hybrids. Hybrids AG1090, BRS 373, and DKB 590 were planted in three crop seasons in Sete Lagoas, Brazil, and six treatments were assessed in the experiments, consisting of three grain sorghum hybrids with and without the insecticide chlorantraniliprole at 52.5 g a.i. ha−1 under SCB natural infestation. The parameters evaluated on sorghum plants were the length of tunnels, plant height, length and weight of panicles, stem borer injury, and grain yield. The infestation of SCB was higher when sorghum plants were not treated with insecticide, resulting in lower productivity. The use of insecticide increased plant height, reduced tunnel length, and increased panicle length and weight. Hybrids only affected panicle weight. The hybrid that presented the highest panicle weight when using the insecticide was AG 1090. Hybrids AG 1090 and DKB 590 showed reduced grain production with increasing gallery length, whereas BRS 373 did not show a significant correlation, which may suggest a certain level of tolerance to SCB attack. This is the first study that determines the gain threshold and economic injury level and that effectively shows how much grain yield is lost by SCB attack in grain sorghum hybrids. [ABSTRACT FROM AUTHOR]

Hymenopteran parasitoids strongly associated with the sugarcane borer [Diatraea saccharalis (Lepidoptera: Crambidae)] may be found both in organic and conventional sugarcane farming systems. This study aimed to sample parasitoids associated with sugarcane borer in organic, organic near a forest fragment and conventional systems. Two colors of Moericke traps were used (yellow and white) to collect insect samples, and faunistic analyses were performed to determine the composition of parasitoids in each management type. A total of 287 insects were collected, with the most abundant families being Diapriidae (44.44 %), Eulophidae (37.5 %) and Braconidae (18.06 %). The most abundant genus in the organic system was Omphale (Eulophidae), Omphale (Eulophidae) in the organic system near the forest fragment, and Omopria and Coptera (Diapriidae) in the conventional system. The parasitoids were more abundant in the organic system (43.06 %), followed by the organic system near the forest fragment (36.81 %) and the conventional system (20.14 %). The yellow trap was the most effective in attracting parasitoids, which were generally more abundant in organic systems, regardless of proximity to forest fragments.

BACKGROUND: Herbivory risk is mediated by plant traits related to nutrition and defense that can vary within a species by genotype and age. Prior herbivore damage accrued by a plant can also interact with these traits to alter future herbivory potential by changing plant quantity or quality. Sugarcane (Saccharum spp.) is a perennial crop where aboveground biomass is harvested annually and with varieties differing in nutrition and defenses, making it conducive to evaluating varietal resistance mechanisms. Using data from 16 sugarcane varieties and 28 years, we assessed damage from the primary pest in Louisiana, the sugarcane borer (Diatraea saccharalis, SCB), relative to variety, crop year (ratoon), plant traits, and incidence of prior herbivory. RESULTS: SCB damage differed among varieties but not crop year, mostly following previously established classifications of SCB resistance, and correlated with select nutritional and defense traits. Within a crop year, the probability of SCB damage increased with prior conspecific damage on the same stalk. However, the strength of this prior damage effect did not match known resistance patterns but still differed with variety. CONCLUSIONS: Interactions of plant variety, traits, and prior pest damage but not age impacted sugarcane borer risk. Borer damage was associated with nutritional traits of fiber and sugar content, but not consistently with defensive traits like high stalk wax or hair density, indicating there may be additional resistance traits or indirect impacts of these traits on predators. Published 2023. This article is a U.S. Government work and is in the public domain in the USA. [ABSTRACT FROM AUTHOR]

Sugarcane borer, Diatraea saccharalis, is one of the main insect pests of sugarcane fields, and it has been mainly managed by the use of chemical or biological controls. Considering the benefits of Silicon (Si) fertilization against pests, it was assessed the development of sugarcane borer larvae and sugarcane growth with and without Si. A greenhouse experiment was conducted using a factorial design (2 × 2) with 10 repetitions. Two commercial sugarcane varieties were evaluated: SP80-3280 and IAC91-1099, which have, respectively, susceptibility, and intermediate resistance to D. saccharalis. Si was applied in soil in an equivalent rate of 800 kg of Si ha−1. Before herbivory, Si increased stalk diameter and plant height in both varieties, and number of leaves and leaf width were only increased in IAC91-1099. After 20 days of herbivory, Si increased stalk diameter in both varieties and plant height in IAC91-1099, but decreased the number of leaves and leaf width in SP80-3280. Larval D. saccharalis showed a reduced weight and a greater index for mandible abrasion after feeding Si-treated plants independently of variety. No influence of Si-treated plants was found in immunological parameters of larvae (total number of hemocytes, cell viability, encapsulation capability, lysozyme active). The activity of phenol oxidase, an immunological and stress marker for insects, was greater in larval D. saccharalis fed with IAC 91-1099, independently of Si. In conclusion, Si application improved sugarcane growth of IAC91-1099 and impaired the development of larval D. saccharalis in both sugarcane varieties. [ABSTRACT FROM AUTHOR]

This study is the first report of the stalk borer Diatraea impersonatella (Walker) on sugarcane in Honduras. A total of 167 larvae were collected from sugarcane crops in the Department Francisco Morazán, Municipality Villa de San Francisco, Honduras, during November 2022 to January 2023. The larval specimens were reared with the objective of obtaining adults for the morphological identification of the species through the inspection of male genitalia. [ABSTRACT FROM AUTHOR]

The parasitoid Trichogramma galloi Zucchi (Hymenoptera: Trichogrammatidae) is an effective biocontrol agent of the sugarcane borer, Diatraea saccharalis (Fabricius) (Lepidoptera: Crambidae). Its use is often recommended in integrated pest management (IPM) programs in sugarcane. However, the IPM of this crop also involves the use of chemical and biological insecticides, and little is known about the effects of concomitant use of these products together with T. galloi. In this study, we evaluated the effects of the chemical insecticide chlorantraniliprole (Altacor 350 WG) and the biological agents Beauveria bassiana (Bals.‐Criv.) Vuill. (Granada WP), Metarhizium anisopliae (Metchnikoff) Sorokin (Opala WP), and Bacillus thuringiensis Berliner var. kurstaki (Dipel WP) on the parasitism of T. galloi adult females against D. saccharalis eggs under laboratory conditions, in addition to biological parameters of the offspring. Treatments with chlorantraniliprole and B. thuringiensis reduced the parasitism rate of T. galloi females. The biological agents M. anisopliae, B. thuringiensis, and chlorantraniliprole increased offspring mortality by more than 30%. The use of B. bassiana favored adult female parasitism rates and did not cause significant offspring mortality. None of the treatments had significant effects on the emergence, longevity, and sex ratio of the offspring. Our results suggest that an insecticide based on B. bassiana can be used concomitantly with the parasitoid T. galloi in sugarcane IPM programs. Moreover, M. anisopliae, B. thuringiensis, and chlorantraniliprole had significant undesirable effects on T. galloi; therefore, they should be used with caution to avoid potential suppression of the parasitoid effect. [ABSTRACT FROM AUTHOR]

Background: In tropical sugarcane crops, the fungus Fusarium verticillioides, the agent responsible for the occurrence of the red rot complex, occurs in association with the sugarcane borer Diatraea saccharalis. This fungus, in addition to being transmitted vertically, can manipulate both the insect and the plant for its own dissemination in the field. Due to the complex interaction between F. verticillioides and D. saccharalis, and the high incidence of the fungus in the intestinal region, our objective was to investigate whether F. verticillioides could alter the intestinal structure of the insect. Methods: We combined analysis of scanning electron microscopy and light microscopy to identify whether the presence of the fungus F. verticillioides, in artificial diets or in sugarcane, could lead to any alteration or regional preference in the insect's intestinal ultrastructure over the course of its development, or its offspring development, analyzing the wall and microvillous structures of the mid-digestive system. Results: Here, we show that the fungus F. verticillioides alters the intestinal morphology of D. saccharalis, promoting an increase of up to 3.3 times in the thickness of the midgut compared to the control. We also observed that the phytopathogen colonizes the intestinal microvilli for reproduction, suggesting that this region can be considered the gateway of the fungus to the insect's reproductive organs. In addition, the colonization of this region promoted the elongation of microvillous structures by up to 180% compared to the control, leading to an increase in the area used for colonization. We also used the fungus Colletotrichum falcatum in the tests, and it did not differ from the control in any test, showing that this interaction is specific between D. saccharalis and F. verticillioides. Conclusions: The phytopathogenic host F. verticillioides alters the intestinal morphology of the vector insect in favor of its colonization. [ABSTRACT FROM AUTHOR]

BACKGROUND: Brazil is the largest grower of the world's 26 million ha of sugarcane, Saccharum officinarum. Pest damage mainly by the sugarcane borer, Diatraea saccharalis (F.), is a great challenge to the sugarcane industry. To control D. saccharalis, Brazil launched the world's first commercial use of Bt sugarcane in 2017. As part of the resistance management programs for Bt sugarcane planting, 535 F2 isoline families of D. saccharalis collected from three major sugarcane planting states (Goiás, Minas Gerais and São Paulo) in Brazil during 2019–2020 were screened for resistance to two Bt sugarcane varieties: CTC20BT expressing Cry1Ab and CTC9001BT expressing Cry1Ac. Here we report the results of the first study related to Bt resistance in a sugarcane cropping system. RESULTS: Larval survivorships of these families in an F2 screen on CTC20BT were highly correlated with their survival on CTC9001BT, whereas the Cry1Ac tissues exhibited greater insecticidal activities than Cry1Ab. Resistance allele frequencies (RAFs) for populations from Goiás and Minas Gerais were relatively low at 0.0034 for Cry1Ab and 0.0045 to Cry1Ac. By contrast, RAFs for São Paulo populations were considerably greater (0.0393 to Cry1Ab, 0.0245 to Cry1Ac). CONCLUSIONS: RAFs to Cry1Ab and Cry1Ac varied among Brazilian D. saccharalis populations. Prior selection resulting from an intensive use of single‐gene Bt maize under low compliance of refuge planting could be a main factor contributing to the high RAF in São Paulo. The results suggest that mitigation measures including sufficient non‐Bt maize refuge planting, effective resistance monitoring, and use of pyramided Bt sugarcane traits should be implemented promptly to prevent further increase in the RAF to ensure the sustainable use of Bt sugarcane in Brazil. To control Diatraea saccharalis, Brazil launched the world's first commercial use of Bt sugarcane in 2017. As part of the resistance management programs for Bt sugarcane planting in Brazil, 535 F2 isoline families of D. saccharalis collected from three major sugarcane planting states (Goiás, Minas Gerais and São Paulo) in Brazil during 2019–2020 were screened for resistance to Cry1Ab and Cry1Ac sugarcane plants Resistance allele frequencies (RAFs) for the populations from Goiás and Minas Gerais were relatively low at 0.0034 for Cry1Ab and 0.0045 to Cry1Ac. By contrast, RAFs for the São Paulo populations were considerably greater (0.0393 to Cry1Ab, 0.0245 to Cry1Ac). Prior selection resulting from an intensive use of single‐gene Bt maize under low compliance of non‐Bt maize refuge planting could be a main factor contributing to the high RAF in São Paulo. The results suggest that effective mitigation measures including sufficient non‐Bt maize refuge planting, effective resistance monitoring and use of pyramided Bt sugarcane traits should be implemented promptly to prevent further increase in the RAF to ensure the sustainable use of Bt sugarcane in Brazil. © 2022 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

The southwestern corn borer, Diatraea grandiosella Dyar, and sugarcane borer, Diatraea saccharalis (F.) (Lepidoptera: Crambidae), are two important stalk borers targeted by Bacillus thuringiensis (Bt) maize in the Americas. Practical resistance to Bt maize in D. grandiosella is emerging in the southwest region of the United States. In this study, Bt maize leaf tissue was used to screen F2 family-lines of these two stalk borers for resistance alleles (RA) to Bt maize expressing one or two of the four common Bt proteins: Cry1A.105, Cry2Ab2, Cry1F, and Cry1Ab. The family-lines were developed from single-pairing or group-mating of field-collected D. grandiosella from non-Bt maize in Tennessee and D. saccharalis from sugarcane in Louisiana during 2019–2022. The F2 screen identified one possible major RA to Cry1A.105 maize in 155 D. grandiosella and 198 D. saccharalis individuals collected from fields, while for the maize expressing one or two of the other three Bt proteins examined, no major RAs were detected in 94–208 field-collected individuals of the two species. Bayesian analysis showed that an upper-level resistance allele frequency (RAF) for major alleles to Cry1A.105 maize was 0.0063 in D. grandiosella and 0.0050 in D. saccharalis. With 95% probability, the RAF of major alleles in D. grandiosella was <0.0093 for Cry2Ab2 maize, <0.0155 for Cry1F maize, and <0.0150 for Cry1A/Cry2A maize; and for D. saccharalis , it was <0.0071 for Cry2Ab2 maize and <0.0090 for Cry1Ab maize. These findings suggest that RAFs for major alleles to the common Bt maize are still low in the two stalk borers. However, minor RAs in both species, especially to Cry2Ab2 and Cry1A.105 maize in D. saccharalis , were not rare. The results of this study, together with other data, suggest that, after 25 years of Bt maize use, the technology is still effective and field resistance to maize expressing the Cry proteins has not evolved in these two stalk borers in the mid-south region of the United States. • D. grandiosella and D. saccharalis are two maize stalk borers targeted by Bt maize. • Resistance allele frequency (RAF) in the two insects to Cry Bt maize was examined. • RAF for major alleles to Bt maize in mid-south U.S. is still low in both species. • However, minor Bt maize resistance alleles in the two species are not uncommon. • Practical resistance of the two borers to Bt maize has not evolved in the region. [ABSTRACT FROM AUTHOR]

A country’s biodiversity is a key resource for the development of a sustainable bioeconomy. However, often the most biodiverse countries on the planet hardly profit from their biological diversity. On the contrary, occasionally components of that biodiversity become a threat to society and its food sustainability. That is the case of the sugarcane borer Diatraea saccharalis. Here, the analysis of the bacteria associated with the digestive tract of D. saccharalis reveals a rich and diverse microbiota. Two types of diets were analyzed under laboratory conditions. The metataxonomic analysis revealed a number of taxa common to most of the larval pools analyzed with relative abundances exceeding 5%, and five families of bacteria which have also been reported in the gut of another Lepidoptera. A large fraction of microorganisms detected by amplicon sequencing were considered to be rare and difficult to cultivate. However, among the cultivable microorganisms, 12 strains with relevant biotechnological features were identified. The strain that showed the highest cellulolytic activity (GCEP-101) was genome sequenced. The analysis of the GCEP-101 complete genome revealed that the values of 16S rRNA identity, the Average Nucleotide Identity, and the digital DNA–DNA hybridization place the strain as a candidate for a new species within the genus Pseudomonas. Moreover, the genome annotation of the putative new species evidenced the presence of genes associated with cellulose degradation, revealing the hidden potential of the pest as a reservoir of biotechnologically relevant microorganisms.

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Background: In tropical sugarcane crops, the fungus Fusarium verticillioides, the agent responsible for the occurrence of the red rot complex, occurs in association with the sugarcane borer Diatraea saccharalis. This fungus, in addition to being transmitted vertically, can manipulate both the insect and the plant for its own dissemination in the field. Due to the complex interaction between F. verticillioides and D. saccharalis, and the high incidence of the fungus in the intestinal region, our objective was to investigate whether F. verticillioides could alter the intestinal structure of the insect. Methods: We combined analysis of scanning electron microscopy and light microscopy to identify whether the presence of the fungus F. verticillioides, in artificial diets or in sugarcane, could lead to any alteration or regional preference in the insect’s intestinal ultrastructure over the course of its development, or its offspring development, analyzing the wall and microvillous structures of the mid-digestive system. Results: Here, we show that the fungus F. verticillioides alters the intestinal morphology of D. saccharalis, promoting an increase of up to 3.3 times in the thickness of the midgut compared to the control. We also observed that the phytopathogen colonizes the intestinal microvilli for reproduction, suggesting that this region can be considered the gateway of the fungus to the insect’s reproductive organs. In addition, the colonization of this region promoted the elongation of microvillous structures by up to 180% compared to the control, leading to an increase in the area used for colonization. We also used the fungus Colletotrichum falcatum in the tests, and it did not differ from the control in any test, showing that this interaction is specific between D. saccharalis and F. verticillioides. Conclusions: The phytopathogenic host F. verticillioides alters the intestinal morphology of the vector insect in favor of its colonization.

Immature endoparasitoids develop inside their hosts. Consequently, endoparasitoids need to circumvent the action of the immune system and reprogram the physiology of their hosts to develop successfully. For this, parasitoids release host regulation‐related molecules into their host's hemolymph produced by the parasitoid itself or expressed in specific host cells infected by parasitoid symbiotic viruses. In addition to their roles in host regulation, these molecules may also present biotechnological potentials, such as for insecticidal purposes in crop protection. We performed a survey for the biotechnological potential of compounds present in the hemolymph serum with and without circulating cell contents of Diatraea saccharalis (Fabricius) (Lepidoptera: Crambidae) parasitized by Cotesia flavipes Cameron (Hymenoptera: Braconidae) as insecticides in feeding assays. Hemolymph serum from D. saccharalis larvae at 6 days after the start of the parasitism with and without circulating cell contents were collected and spread over artificial diet or over sugarcane leaves for feeding assays with D. saccharalis neonates. Hemolymph serum with or without circulating cell contents from non‐parasitized D. saccharalis larvae at the same age were used as controls. Subsequently, hemolymph serum plus circulating cell contents was fractioned using molecular filters and fractions with different molecular weight range were used for feeding assays with D. saccharalis neonates. Feeding larvae with leaf disks amended with hemolymph serum plus circulating cell contents from parasitized hosts resulted in an increase of ca. 30% in the mortality of D. saccharalis neonates. After fractioning hemolymph serum plus circulating cell contents, feeding assays with the >100 or 3–10 kDa fractions did not result in the previously observed increase in larval mortality, but resulted in a reduction of leaf consumption by neonates. Finally, we selected a parasitism‐specific protein band observed in the hemolymph >100 kDa fraction for mass spectrometry identification. This parasitism‐specific protein was similar to hymenopteran apolipophorins‐I. We conclude that there is an insecticidal potential in the hemolymph serum plus circulating cell contents of D. saccharalis larvae parasitized by C. flavipes and further investigations will be performed to identify, characterize, and uncover the biotechnological application of these molecules. [ABSTRACT FROM AUTHOR]

Some pathogens can manipulate their host plants and insects to optimize their fitness, increasing the attraction of insects to the infected plant in ways that facilitate pathogen acquisition. In tropical American sugarcane crops, the fungus Colletotrichum falcatum , the red rot causal agent, usually occurs in association with the sugarcane borer Diatraea saccharalis , resulting in large losses of this crop. Considering this association, we aimed to identify the effects of C. falcatum on D. saccharalis host preference and performance as well as the effect of this insect on C. falcatum sugarcane infection. Here, we show that the fungus C. falcatum modulates D. saccharalis behavior to its own benefit. More specifically, C. falcatum -infected sugarcane plants showed a dramatic increase in VOCs, luring D. saccharalis females to lay eggs on these plants. Therefore, sugarcane infection by the fungus C. falcatum increased in cooccurrence with insect herbivory, benefiting the pathogen when associated with D. saccharalis. [ABSTRACT FROM AUTHOR]

Cultivar resistance is a key management strategy for the sugarcane borer, Diatraea saccharalis (F.), the primary pest in Louisiana sugarcane, but mechanisms of resistance are not well understood. This research evaluated the potential mechanisms of cultivar resistance to D. saccharalis among commercially produced sugarcane cultivars and experimental lines through three field screenings, two greenhouse experiments, and one diet incorporation assay. The resistant standards HoCP 85-845, HoCP 04-838, and L 01-299 were among the cultivars with the lowest D. saccharalis injury levels in both field and greenhouse trials. Cultivars HoCP 00-950 and L 12-201 were among the most heavily injured in both trials. Differences in oviposition among cultivars in the greenhouse choice study were not detected, suggesting adult preference is not a key factor in resistance. This was also supported by the no-choice greenhouse experiment in which up to 9-fold differences in neonate establishment among cultivars were detected. Larval injury among cultivars in greenhouse experiments was consistent with field studies suggesting traits that affect neonate establishment (e.g. rind hardness) help to confer resistance in the field. In the diet incorporation assay, lower larval weights and longer time to pupation were observed on resistant cultivar Ho 08-9003, but no differences were found among current commercial cultivars. Continuous evaluation of cultivar resistance to D. saccharalis is important in developing effective integrated pest management strategies for this pest. More research into plant characteristics (e.g. leaf sheath tightness and pubescence) associated with resistance is needed. [ABSTRACT FROM AUTHOR]

The continuous utilisation of an alternative host may influence parasitoid performance across successive generations due to conditioning in natal hosts. Tetrastichus howardi (Olliff) has successfully been reared using Tenebrio molitor L. pupae as a feasible alternative host. However, the extended rearing of T. howardi on this alternative host may impact the biological features of the parasitoids. Parasitoids were reared using T. molitor pupae for 30 consecutive generations. Quality criteria were assessed during the generations F5, F15, and F30, offering pupae of the target pest, Diatraea saccharalis (Fabr.), and compared with the F0 generation (parasitoids reared in D. saccharalis pupae). Criteria included assessments of parasitism performance, host selection, and wing form variation in the parasitoid wasps. Additionally, we examined the fecundity of T. howardi females that emerged from both hosts, considering their age, egg loading before and after one oviposition, as well as parasitism of sugarcane stalk borer pupae. Rearing T. howardi using pupae of T. molitor did not affect its biological traits or preference for the target pest for 30 generations. After parasitism, the parasitoid left the host pupa inside the stalk, and one oviposition was enough to kill D. saccharalis pupae and obtain viable parasitoid progeny. Female sexual maturation and egg loading occurred 72 and 96 h after parasitoid emergence. Egg-loading recovery after parasitism did not happen within 24 h. T. howardi can be reared for up to 30 generations using alternative hosts without compromising its parasitism performance or egg loading.

Endoparasitoid wasps use complex biochemical arsenals to suppress the normal humoral and cellular immune responses of their hosts in order to transform them into a suitable environment for development of their eggs and larvae. Venom injected during oviposition is a key component of this arsenal, but the functions of individual venom toxins are still poorly understood. Furthermore, there has been little investigation of the potential biotechnological use of these venom toxins, for example for control of agricultural pests. The endoparasitoid Cotesia flavipes (Hymenoptera: Braconidae) is a biocontrol agent reared in biofactories and released extensively in Brazil to control the sugarcane borer Diatraea saccharalis (Lepidoptera: Crambidae). The objectives of this work were to reveal venom components produced by C. flavipes and explore the function of a major venom peptide, Cf4. Using a combined proteomic/transcriptomic approach, we identified 38 putative venom toxins including both linear and disulfide-rich peptides, hydrolases, protease inhibitors, apolipophorins, lipid-binding proteins, and proteins of the odorant binding families. Because of its high abundance in the venom, we selected Cf4, a 33-residue peptide with three disulfide bonds, for synthesis and further characterization. We found that synthetic Cf4 reduced the capacity of D. saccharalis hemocytes to encapsulate foreign bodies without any effect on phenoloxidase activity, consistent with a role in disruption of the cellular host immune response. Feeding leaves coated with Cf4 to neonate D. saccharalis resulted in increased mortality and significantly reduced feeding compared to caterpillars fed untreated leaves, indicating that Cf4 is a potential candidate for insect pest control through ingestion. This study adds to our knowledge of endoparasitoid wasp venoms composition, host regulation mechanisms and their biotechnological potential for pest management. [Display omitted] • A combined proteomic/transcriptomic approach was used to reveal 38 components in the venom of Cotesia flavipes. • Disulfide-rich peptides, hydrolases, protease inhibitors, apolipophorins, lipid-binding proteins and others were identified. • Synthetic venom-peptide Cf4 reduces the capacity of Diatraea saccharalis hemocytes to encapsulate foreign bodies. • The ingestion of Cf4 decreases larval viability and leaf consumption by Diatraea saccharalis. [ABSTRACT FROM AUTHOR]

Predators and parasitoids locate herbivore‐infested plants via detection of herbivore‐induced plant volatiles (HIPVs) that are released in response to pest damage. Synthetic HIPVs have been proposed as tools to enhance the biological control of crop pests. The sugarcane borer, Diatraea saccharalis (Fabricius) (Lepidoptera: Pyralidae), is a key herbivore pest of sugarcane, Saccharum spp. (Poaceae), in the Americas. To manage D. saccharalis in Brazil, more than 3 million ha of sugarcane have been treated with the larval parasitoid Cotesia flavipes (Cameron) (Hymenoptera: Braconidae). In this study, the role of sugarcane HIPVs as cues in the host‐finding process of C. flavipes was investigated using a combination of dynamic headspace collection, chemical analysis, and laboratory behavior experiments. Comparison of volatile organic compounds (VOCs) collected from D. saccharalis‐damaged and healthy sugarcane revealed very similar profiles, apart from significantly higher levels of the sesquiterpene (E)‐caryophyllene released from damaged plants. Naive female C. flavipes spent significantly more time in the olfactometer arm containing VOCs from D. saccharalis‐damaged plants but showed no preference for VOCs from healthy plants. When (E)‐caryophyllene was added to VOCs from healthy plants, parasitoids spent more time in the arm containing the combined treatment. Furthermore, in a dose–response experiment with synthetic (E)‐caryophyllene, naive parasitoids preferred the compound across a dose range of 3–300 ng, and experienced parasitoids – preexposed to (E)‐caryophyllene – responded to doses of (E)‐caryophyllene as low as 0.03 ng. These results suggest that C. flavipes can use (E)‐caryophyllene as a cue to locate D. saccharalis‐infested sugarcane plants. Moreover, experienced females appear to respond to lower doses than naive females. These results potentially pave the way for increasing the efficiency of C. flavipes in biological control of D. saccharalis, the most important pest of sugarcane and maize crops in the Western Hemisphere, and also a major pest of rice and sorghum crops. [ABSTRACT FROM AUTHOR]

Trichoderma is a well‐known soil‐borne fungus, highly efficient producer of extracellular enzymes including chitinases. The aim of this study was to recover a chitinase from fermentation waste after harvesting Trichoderma koningiopsis Th003 conidia and assess its potential as an enhancer of Beauveria bassiana insecticidal activity against Diatraea saccharalis. T. koningiopsis was produced by solid fermentation, conidia were harvested, and a crude extract (CE) was recovered by washing the residual substrate (rice:wheat bran). The partially purified chitinase (PPC) (75 kDa product) with N‐acetyl‐β‐glucosaminidase activity was obtained by chromatography to 29.3‐fold with optimal activity at pH 5 and 55°C. Both the CE and the PPC were mixed with B. bassiana Bv062 conidia and assessed in a bioassay against D. saccharalis larvae. The CE and PPC from T. koningiopsis Th003 did not affect the germination or viability of B. bassiana conidia and enhanced its insecticidal activity when used at 0.06 U/ml enzymatic activity with a 24.5% reduction in B. bassiana lethal time (LT90). This study demonstrated the potential of chitinases produced by T. koningiopsis in solid fermentation to be recovered from the waste substrate and used as an additive to enhance B. bassiana, adding value to the main waste from the Trichoderma biopesticide/biofertilizer industries. [ABSTRACT FROM AUTHOR]

Abstract The lower lignin content in plants species with energy potential results in easier cellulose breakdown, making glucose available for ethanol generation. However, higher lignin levels can increase resistance to insect attack. The objective of this work was to evaluate the susceptibility of a bmr-6 biomass sorghum (a mutant genotype with a lower concentration of lignin) to important pests of energy sorghum, Diatraea saccharalis and Spodoptera frugiperda. Experiments were performed in the laboratory and greenhouse to evaluate the development of these pests on the biomass sorghum bmr hybrids BR007, BR008, and TX635 and their respective conventional near-isogenic genotypes (without the bmr gene). The lignin content was higher in non-bmr hybrids, but the evaluated insect variables varied between treatments, not being consistent in just one hybrid or because it is bmr or not. The lowest survival of S. frugiperda was observed in the BR008 hybrid, both bmr and non-bmr. The S. frugiperda injury scores on plants in the greenhouse were high (>7) in all treatments. For D. saccharalis, there was no difference in larval survival in the laboratory, but in the greenhouse, the BR007 hybrid, both bmr and non-bmr, provided greater survival. Due the need to diversify the energy matrix and the fact that greater susceptibility of the bmr hybrids to either pests was not found in this study, these results hold promise for cultivation of these biomass sorghum hybrids for the production of biofuels.

Control of the sugarcane borers, Diatraea saccharalis and Diatraea impersonatella (= D. flavipennella) (Lepidoptera: Crambidae), in Brazil, is based on mass release of the larval parasitoid Cotesia flavipes (Hymenoptera: Braconidae). However, this method does not prevent some pupae of these borers from completing development and recolonizing the crop. Thus, additional control is required. This study investigated the parasitoid Tetrastichus howardi (Hymenoptera: Eulophidae) to control pupae of sugarcane borers, especially D. impersonatella. Regardless of larval instar and species, no larval parasitism occurred within 24 h of exposure. Nevertheless, a longer exposure period (ca. 96 h) resulted in parasitism of older larvae. Approximately 90% of pupae of both borers were parasitized by T. howardi within 24 h of exposure, and the parasitoid produced a similar number of offspring with >90% females. The developmental time of T. howardi parasitizing D. impersonatella pupae was delayed ~2 days from that of in D. saccharalis. No-choice trails revealed that parasitoid females took longer to start probing larvae compared to pupae. Likewise, when larvae and pupae were offered simultaneously (choice test), the latter represented the first choice of about 92% T. howardi females. The elapsed time to first attack was less on pupae than on larvae, whereas the number of attacks and probing time was greater on pupae. In addition, parasitism on D. impersonatella pupae was higher than on larvae feeding on artificially infested sugarcane seedlings. These results suggest that T. howardi prefers to parasitize the pupal stage and has the potential to be used as a biological control agent to complement the control of sugarcane bores. [ABSTRACT FROM AUTHOR]

Background: The sugarcane borer ( Diatraea saccharalis), a widely distributed moth throughout the Americas, is a pest that affects economically important crops such as sugarcane, sorghum, wheat, maize and rice. Given its significant impact on yield reduction, whole-genome information of the species is needed. Here, we report the first draft assembly of the D. saccharalis genome. Methods: The genomic sequences were obtained using the Illumina HiSeq 2500 whole-genome sequencing of a single adult male specimen. We assembled the short-reads using the SPAdes software and predicted protein-coding genes using MAKER. Genome assembly completeness was assessed through BUSCO and the repetitive content by RepeatMasker. Results: The 453 Mb assembled sequences contain 1,445 BUSCO gene orthologs and 1,161 predicted gene models identified based on homology evidence to the domestic silk moth, Bombyx mori. The repeat content composes 41.18% of the genomic sequences which is in the range of other lepidopteran species. Conclusions: Functional annotation reveals that predicted gene models are involved in important cellular mechanisms such as metabolic pathways and protein synthesis. Thus, the data generated in this study expands our knowledge on the genomic characteristics of this devastating pest and provides essential resources for future genetic studies of the species.

The sugarcane borer, Diatraea saccharalis (F.) (Lepidoptera: Crambidae), is the primary pest of sugarcane, Saccharum spp. in Louisiana. Spring populations are not considered economically damaging, but quantifying infestations can provide an indication of the spatial and temporal character of the damaging summer populations. Statewide surveys quantified the density of sugarcane tillers killed by D. saccharalis (deadhearts) from sugarcane fields across the state in spring from 2003 to 2020. Deadheart density varied greatly among years with a high of 1,318/ha in 2003 to a low of 0/ha in 2018. Linear regressions of the 3-yr rolling average showed declines in spring D. saccharalis populations and the percentage of acreage treated with insecticides over 17 yr. Weather factors including minimum winter temperatures and average spring temperatures were poor predictors of D. saccharalis populations. Only total precipitation in the month of April was positively correlated with numbers of deadhearts per hectare. Results suggest overwintering mortality is not a key factor influencing populations of the first generation of D. saccharalis in Louisiana. Total precipitation in the month of July was positively associated with percentage of treated acreage. Spring deadheart density was directly related to percentage of acreage treated with insecticides during the summer. Quantifying first-generation D. saccharalis populations by recording deadheart density can aid in predicting pest pressure later in the growing season. [ABSTRACT FROM AUTHOR]

A espécie Diatraea saccharalis (Lepidoptera: Crambidae), conhecida popularmente por broca-da-cana, destaca-se como praga-chave da cultura da cana-de-açúcar no Brasil devido aos prejuízos que acarreta na produtividade agrícola e industrial. O objetivo da pesquisa foi avaliar a não preferência para oviposição e alimentação de D. saccharalis por cultivares de cana-de-açúcar. Para tanto, foram realizados testes com e sem chance de escolha conduzidos em casa de vegetação e em laboratório, respectivamente, com as seguintes cultivares: RB867515, RB855453, RB855536, CTC 15, CTC 9, SP80-1842, SP79-1011, SP89-1115, SP81-3250 e SP87-365. No teste de não preferência para oviposição, foi avaliado o número de ovos, de posturas e de ovos por postura. Para o teste de alimentação, foi observada a atratividade das lagartas de D. saccharalis em cada tolete das cultivares, anotando-se a quantidade delas e o tempo de atração por meio de observações a 1, 3, 5, 10, 15, 30, 60 e 120 minutos após as liberações. Após 48 horas do início do teste, foi medido o consumo por intermédio da diferença entre a massa seca da alíquota (mg) pela massa seca da sobra do tolete. Conclui-se que a cultivar CTC 15 foi a menos preferida para oviposição e a mais consumida por D. saccharalis, sendo possivelmente portadora de resistência do tipo não preferência para oviposição e suscetível para alimentação à D. saccharalis.

Cellulolytic enzymes have wide use in several industrial segments (e.g. biofuels, pulp and paper, food, and cosmetics). However, one of the challenges is their large-scale production with high specific activity to eliminate the dependence of the purchase of enzymatic cocktails produced by commercial parties. The aims of this study were (1) isolation, selection, and partial characterization of bacterial cellulases present in the intestinal tract of the sugarcane borer and (2) to identify cellulase-producing bacteria by analyzing the 16S rDNA gene. Cellulase production and purification assays resulted in similar electrophoretic profiles between four bacterial strains. These strains were identified as Klebsiella pneumoniae , Klebsiella sp., and Bacillus sp. K. pneumoniae was the main cellulase-producing microorganism. Our results show the possibility of finding cellulolytic microorganisms that inhabit the gut of herbivorous animals, especially those that are predators of important crops of economic value. Furthermore, K. pneumoniae cellulase is of medical importance. In hospitals, health professionals, hospital technicians, patients and visitors wear clothes containing cellulose. Thus, K. pneumoniae within hospitals can contaminate these clothes and be spread to the environment. In that case, it would be important for the hospital's chemical sterilization products to have at least one cellulase inhibitor. • Cellulolytic bacteria from the sugarcane borer were Klebsiella sp. and Bacillus sp. • K. pneumoniae was the main cellulase-producing microorganism. • This enzyme was able to hydrolyze sodium carboxymethylcellulose • K. pneumoniae cellulase is of medical importance. [ABSTRACT FROM AUTHOR]

Copyright of Revista Colombiana de Entomología is the property of Universidad del Valle and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Cotesia flavipes Cameron (Hymenoptera: Braconidae) is often augmented against Diatraea spp. (Lepidoptera: Crambidae) stem borers in the Americas. Diatraea indigenella Dyar and Heinrich, an endemic pest of sugarcane in southern Colombia, represents a novel host for C. flavipes. We examined the development of C. flavipes on D. indigenella and D. saccharalis, a familiar host, when larvae were stung by one, two or three wasps. Host species had no effect on parasitism success, immature parasitoid mortality, parasitoid developmental time, adult emergence, or female size. Superparasitized D. indigenella hosts yielded more cocoons, more adults, and more female wasps than those parasitized with a single sting, or from D. saccharalis hosts. However, wasp survival and longevity declined when host larvae were stung three times. Thus, D. indigenella was a more suitable host for C. flavipes when superparasitized, and appears suitable for augmentation against this emergent pest and other Diatraea species attacking sugarcane. [ABSTRACT FROM AUTHOR]

The sugarcane borer, Diatraea saccharalis (F.), rice stalk borer, Chilo plejadellus Zincken, and Mexican rice borer, Eoreuma loftini (Dyar), are stem borers (Lepidoptera: Crambidae) that infest rice (Oryza sativa L.) in the southern United States. A 2-yr study was conducted to determine stem borer injury, infestation, and parasitism levels in Florida. Thirty commercial rice fields were selected during the 2017 and 2018 growing seasons throughout the rice production region in southern Florida. Sampling for stem borer injury and infestations was conducted in each field between the milk and early maturation stages by observing plants at 10 locations, with three 1-m2 quadrats per location. In addition, monitoring for E. loftini adults was conducted using one pheromone trap adjacent to each field. In 2017, the number of rice tillers exhibiting stem borer injury averaged 0.024 tillers/m2 and infestation levels averaged 0.008 stem borers/m2, with only D. saccharalis being observed. In 2018, injury and infestation levels averaged 0.062 injured tillers/m2 and 0.023 D. saccharalis larvae or pupae/m2, respectively. The solitary parasitoid Alabagrus stigma Brullé (Hymenoptera: Braconidae) parasitized 33 and 40% of the collected D. saccharalis in 2017 and 2018, respectively. In addition, pheromone traps did not capture E. loftini adults. This study shows that D. saccharalis infests rice in Florida but at relatively low levels not threatening production and that rice fields are habitats for D. saccharalis parasitoids. This study also suggests that C. plejadellus and E. loftini do not occur in southern Florida. [ABSTRACT FROM AUTHOR]

This study aimed to investigate genetic parameters and selection strategies for sugarcane resistance to borer and determine the effects of selection for borer resistance on yield traits. The infestation index by borer (IIB) and yield traits were assessed over 3 years in 35 sugarcane clones planted in four locations in southeastern Brazil. There was no genotype × environment (year or location) interaction for borer resistance. Consequently, selection may be performed at only one location and year or by the mean of clones in several locations and/or years. The borer population affected the genotypic variance for borer resistance but when genotypic variance was significant, heritability was elevated and suitable genetic gain was achieved. Selection for borer resistance reduced the genetic gains for tons of cane per hectare, theoretical recoverable sugar, and tons of sugar per hectare; however, satisfactory selection gains for both borer resistance and yield were achieved using selection index. [ABSTRACT FROM AUTHOR]

The endoparasitoid wasp Cotesia flavipes (Cameron) (Hymenoptera: Braconidae) is inundatively released in Brazilian sugarcane plantations to control the sugarcane borers Diatraea saccharalis (Fabricius) and Diatraea flavipennella (Box) (Lepidoptera: Crambidae). In conjunction with these releases, several synthetic insecticides are used to control the neonate larvae of these pests. We assessed the lethal and transgenerational sublethal effects of seven of these insecticides on C. flavipes. Leaf discs were sprayed at the highest field concentrations of chlorantraniliprole, lambda-cyhalothrin + chlorantraniliprole, chlorfluazuron, triflumuron, lambda-cyhalothrin + thiamethoxam, tebufenozide, and novaluron. Distilled water was used as a negative control. Newly emerged females (24 h old) were placed in Petri dishes containing the treated leaves, and the lethal and transgenerational sublethal effects were assessed for the next two generations. Lambda-cyhalothrin + chlorantraniliprole and lambda-cyhalothrin + thiamethoxam caused 100% mortality of the parasitoid and were highly persistent, causing more than 30% mortality at 30 days after spraying. Chlorantraniliprole, chlorfluazuron, novaluron, and triflumuron did not cause significant mortality compared to the negative control, but did have transgenerational sublethal effects. The length of the tibia of the right posterior leg, used as a growth measurement, was reduced in the progeny (F1 generation) of exposed female parasitoids. In addition, chlorantraniliprole increased and chlorfluazuron reduced the proportion of females in the F1 generation, whereas novaluron reduced the proportion of females in the F2 generation. Overall, only tebufenozide was considered harmless to C. flavipes. The results of this study suggest that lambda-cyhalothrin + chlorantraniliprole and lambda-cyhalothrin + thiamethoxam are harmful to C. flavipes, although field studies are needed to obtain results for actual sugarcane crops. [ABSTRACT FROM AUTHOR]

Nitrogen fertilization is essential to raise sugarcane yield in soils deficient in N. The objective of this study was to evaluate the effect of nitrogen application in production and borer attack on sugarcane. The experiment was conducted at Escobar District, State of Paraguarí, Paraguay. Three sugarcane growing seasons were evaluated during 2011-2013. The experimental design was randomized blocks with seven treatments and three repetitions, with annual application of increasing of nitrogen (0, 30, 60, 90, 120, 150 and 180 kg ha-1). At 360 days of each crop cycle, harvest was performed with the following assessments: industrial plant height, number of internodes per plant, infestation intensity index and yield. The nitrogen rate of maximum technical efficiency and maximum economic efficiency was determined. Statistical analysis of variance, means comparison and regression were performed. Nitrogen fertilization did not affect plant height and number of internodes, but increased yield and borer attack. For every kg ha-1 of nitrogen applied 0.25 t ha-1 of yield is added, and 0.27 % of infestation intensity index increase is obtained. The rate of maximum technical efficiency was 157,4 kg N ha-1 for a yield of 73,6 t ha-1, and the rate of maximum economic efficiency was 136.5 kg N ha-1 for a yield of 88,2 t ha-1.

Understanding sugarcane (Saccharum spp.) response to multiple pest injury, sugarcane borer (Diatraea saccharalis) and spittlebug (Mahanarva fimbriolata), is essential to make better management decisions. Moreover, the consequences of both pests on the sugarcane raw material quality have not yet been studied. A field experiment was performed in São Paulo State, Brazil, where sugarcane plants were exposed to pests individually or in combination. Plots consisted of a 2-m long row of caged sugarcane plants. Photosynthesis was measured once every 3 months (seasonal measurement). Yield and sugar production were assessed. The measured photosynthesis rate was negatively affected by both borer and spittlebug infestations. Photosynthesis reduction was similar on plants infested by both pests as well as by spittlebug individual infestation. Plants under spittlebug infestation resulted in yield losses and represented 17.6% (individual infestation) and 15.5% (multiple infestations). The sucrose content and the sucrose yield per area were reduced when plants were infested by multiple pests or spittlebug.

Biocontrol agents can help reduce pest populations as part of an integrated pest management scheme, with minimal environmental consequences. However, biocontrol agents are often non-native species and require significant infrastructure; overuse of single agents results in pest resistance. Native biocontrol agents are urgently required for more sustainable multi-faceted approaches to pest management. Social wasps are natural predators of lepidopteran pests, yet their viability as native biocontrol agents is largely unknown. Here, we provide evidence that the social paper wasp Polistes satan is a successful predator on the larvae of two economically important and resilient crop pests, the sugarcane borer Diatraea saccharalis (on sugarcane Saccharum spp.) and the fall armyworm Spodoptera frugiperda (on maize Zea mays); P. satan wasps significantly reduce crop pest damage. These results provide the much-needed baseline experimental evidence that social wasps have untapped potential as native biocontrol agents for sustainable crop production and food security. [ABSTRACT FROM AUTHOR]

Copyright of Cientifica is the property of Fundacao de Apoio a Pesquisa e Extensao and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The article focuses on the study to evaluate the biology in different thermal conditions of five Cotesia flavipes strains, from different places of origin such as insects from Paraná (Strain PR), Minas Gerais (Strain MG), Alagoas (Strain AL) and two strains from São Paulo. Topics discussed include inundative release of Cotesia flavipes (Cameron) in the country, Saccharum officinarum, and Diatraea saccharalis.

Field studies across four states in maize-producing areas of Brazil were conducted to characterize the efficacy of a new pyramided Bacillus thuringiensis (Bt) Berliner technology in maize, Zea mays L. and compare it to existing single and pyramided commercial Bt technologies, to control Helicoverpa zea Boddie (Lepidoptera: Noctuidae), Elasmopalpus lignosellus Zeller (Lepidoptera: Pyralidae), Agrotis ipsilon (Hufnagel) (Lepidoptera: Noctuidae), and Diatraea saccharalis F. (Lepidoptera: Crambidae). Bt maize expressing Vip3Aa20 protein and pyramided Bt maize expressing proteins Cry1F + Cry1A.105 + Cry2Ab2 + Vip3Aa20 provided excellent protection against kernel feeding by H. zea compared to Bt technologies expressing only Cry1F or Cry1A.105 + Cry2Ab2. Bt maize expressing Cry1F, Cry1A.105 + Cry2Ab2, Cry1F + Cry1A.105 + Cry2Ab2, and Cry1F + Cry1A.105 + Cry2Ab2 + Vip3Aa20 resulted in less than 5% of plants injured by E. lignosellus, significantly less than Bt maize expressing only Vip3Aa20 and a non-Bt maize iso-hybrid with and without a thiamethoxam seed treatment. The highest protection against plant cutting injury caused by A. ipsilon was observed in the pyramid Bt maize technology expressing Cry1F + Cry1A.105 + Cry2Ab2 + Vip3Aa20. However, it did not differ statistically from the Bt maize expressing Vip3Aa20, Cry1F, or Cry1F + Cry1A.105 + Cry2Ab2. All Bt maize hybrids evaluated in our study were highly effective in reducing tunneling injury caused by D. saccharalis. These results show that a new maize technology expressing pyramided Bt proteins Cry1F + Cry1A.105 + Cry2Ab2 + Vip3Aa20 offers a higher level of protection from feeding by the above lepidopteran pest complex compared to maize with a single Bt protein or double pyramided Bt proteins. [ABSTRACT FROM AUTHOR]

Highlights • Diatraea tabernella and D. busckella are novel sugarcane pests in Colombia. • Two tachinids, L. minense and B. claripalpis , are regularly used as biocontrol. • Parasitism was reduced on larvae of novel species compared to ancestral hosts. • Resistance to parasitism explains outbreaks of these pests in sugarcane. Abstract Lydella minense and Billaea claripalpis (Diptera: Tachinidae) are important parasitoids used in augmentation biological control of sugarcane stem borers, Diatraea spp. (Lepidoptera: Crambidae), the primary pests of sugarcane in Colombia. Following the recent discovery of two new Diatraea species in the Cauca River Valley (CRV), D. tabernella and D. busckella , stalk-boring damage to sugarcane has increased and rates of larval parasitism have declined. The present study assessed the suitability of all four stalk-boring Diatraea species now present in the CRV, D. tabernella, D. busckella, D. indigenella and D. saccharalis , as hosts for the two parasitoids. Following manual inoculation of larvae with maggots of L. minense and B. claripalpis , the development, immature survival, sex ratio and longevity of resulting flies were recorded. Both parasitoid species parasitized a lower percentage of D. tabernella and D. busckella larvae compared to larvae of D. saccharalis or D. indigenella. Although host larvae were more likely to yield two puparia of L. minense than of B. claripalpis , the likelihood of a second puparium was reduced when L. minense parasitized D. tabernella and D. busckella. These results suggest these two Diatraea species have resistance to parasitism by the tachinids, which might explain why outbreaks of these pests have occurred in the regions of the CRV where commercial releases of the parasitoids are relied upon as the primary pest management tactic. Although breeding programs may eventually provide flies with improved ability to parasitize these novel host species, additional work is warranted to explore alternative pest management tactics for these stem borers. [ABSTRACT FROM AUTHOR]

Fungal phytopathogens are known to induce changes in plant metabolite profile and defense levels that consequently affect insect herbivores. Although it is expected that fungal plant infection may also affect herbivore natural enemies that are guided by plant chemical cues, few studies have addressed this interaction. Here, we examined the effect of infection in sugarcane by the red-rot fungus, which is usually associated with the injury of the sugarcane-borer Diatraea saccharalis, on plant defenses by assessing borer weight gain and the attractiveness of herbivore-induced plant volatiles to the parasitoid Cotesia flavipes. Olfactometer assays and GC-MS analysis showed that although red-rot-infected plants released a different volatile blend from mock-inoculated, the wasps showed no preference for either of the two treatments. Red-rot disease also caused qualitative and quantitative changes in the volatile blend emitted by herbivore-damaged plants relative to healthy and damaged plants, such as the addition of the fungal-derived 1-octen-3-ol and either a reduction or an increase of volatiles. These differences were detected by C. flavipes, which preferred volatiles released by herbivore-damaged healthy over herbivore-damaged infected plants. When given a choice between mock-inoculated and herbivore-damaged infected plants, the wasps preferred infected ones. Sugarcane-borer larvae were larger when fed on healthy plants relative to red-rot infected sugarcane plants, indicating that parasitoid wasps likely benefit from being attracted to volatiles of healthy over infected damaged sugarcane. Although the infection did not seem to disrupt the parasitoid host-location, red-rot disease attenuates the attractiveness of herbivore-induced sugarcane volatiles to C. flavipes. [ABSTRACT FROM AUTHOR]

Understanding sugarcane (Saccharum spp.) response to multiple pest injury, sugarcane borer (Diatraea saccharalis) and spittlebug (Mahanarva fimbriolata), is essential to make better management decisions. Moreover, the consequences of both pests on the sugarcane raw material quality have not yet been studied. A field experiment was performed in São Paulo State, Brazil, where sugarcane plants were exposed to pests individually or in combination. Plots consisted of a 2-m long row of caged sugarcane plants. Photosynthesis was measured once every 3 months (seasonal measurement). Yield and sugar production were assessed. The measured photosynthesis rate was negatively affected by both borer and spittlebug infestations. Photosynthesis reduction was similar on plants infested by both pests as well as by spittlebug individual infestation. Plants under spittlebug infestation resulted in yield losses and represented 17.6% (individual infestation) and 15.5% (multiple infestations). The sucrose content and the sucrose yield per area were reduced when plants were infested by multiple pests or spittlebug. [ABSTRACT FROM AUTHOR]

Both soil phosphorus (P) and soil acidity are the key factors in soil fertility management and of - ten limits crop production in subtropical agriculture. The objective of this study was to evaluate the response of lime and different P rates on sugarcane variety and their interactive effect on the sugar cane borer attack. A three factorial experiment containing, two sugarcane varieties i. e., (SP81-3250 and RB-956911); with and without application of agricultural lime (3.5 t ha-1) and four P rates i. e., (0, 20, 40 and 60 kg P2O5 ha-1) was ca - rried out at the research field area of Federal University of Santa Maria, RS, Brazil during 2011-12. It assessed a) sugarcane stalk length, b) stem diameter; c) number of internodes, d) number of stalk ha-1, e) stalk yield, f) °Brix and g) Intensity of infestation Index. Results indicated that, the stalk yields of RB-956911 and SP81-3250 was 106.6 and 139.8 Mg ha-1, respectively. The °Brix was between 18.60 % and 18.00 %, respectively. The Intensity of infestation Index was 2.76 % for the RB-956911 and 3.65 % for the SP81-3250. The lime application showed significant results only on the borer attack. Phosphorus application increased the sugarcane yield from 105.9 Mg ha-1 to 136.5 Mg ha-1 with 60 kg of P2O5 ha-1. The application of phosphorus increased sugarcane productivity but it does not contribute which increase the borer attack.

Evolution of resistance to control measures in insect populations is a natural process, and management practices are intended to delay or mitigate resistance when it occurs. During the 2012/13 season the first reports of unexpected damage by Diatraea saccharalis on some Bt maize hybrids occurred in the northeast of San Luis province, Argentina. The affected Bt technologies were Herculex I® (HX-TC1507) and VT3PRO® (MON 89034 × MON 88017*). Event TC1507 expresses Cry1F and event MON 89034 expresses Cry1A.105 and Cry2Ab2, whichr are all Bt proteins with activity against the lepidopterans D. saccharalis and Spodoptera frugiperda (MON 88017 expresses the protein Cry3Bb1 for control of coleopteran insects and the enzyme CP4EPSPS for glyphosate tolerance). The affected area is an isolated region surrounded by sierra systems to the northeast and west, with a hot semi-arid climate, long frost-free period, warm winters, hot dry summers, and woody shrubs as native flora. To manage and mitigate the development of resistance, joint actions were taken by the industry, growers and Governmental Agencies. Hybrids expressing Vip3A protein (event MIR162) and/or Cry1Ab protein (events MON 810 and Bt11) as single or stacked events are used in early plantings to control the first generations of D. saccharalis, and in later plantings date's technologies with good control of S. frugiperda. A commitment was made to plant the refuge, and pest damage is monitored. As a result, maize production in the area is sustainable and profitable with yields above the average.