@article{magalhaes_kretschmar_donohue_roe_2013, title={Pyrosequencing of the adult tarnished plant bug, Lygus lineolaris, and characterization of messages important in metabolism and development}, volume={146}, ISSN={["1570-7458"]}, DOI={10.1111/eea.12035}, abstractNote={The adoption of Bt transgenic cotton has practically eliminated lepidopteran pests from this crop and has produced a secondary pest problem, with pierce-sucking insects such as the tarnished plant bug, Lygus lineolaris (Palisot de Beauvois) (Hemiptera: Miridae). The future of cotton genetic pest management is threatened by these insects and their development of resistance to chemical insecticides. Lygus lineolaris is also a pest of more than 100 other crops. The development of transcriptome data for this insect should be transformative in essentially all aspects of research on plant bug biology and the development of control strategies. The first 454 tarnished plant bug whole body (WB) and gut (G) transcriptomes were constructed (half plate for each). A total of 116 163 527 bases were obtained, representing 262 555 WB and 229 919 G reads (SRA048217) of which 232 058 (SRS280903) and 168 069 (SRS280894) reads, respectively, were available for assembly. The average read length was 233.1 and 208.5 bp for WB and G, respectively. The whole body and gut reads were assembled together (WB-G) to produce the most complete transcriptome possible from our sequencing effort and resulted in 6 970 contigs with an average length of 393 bp. The gut transcriptome alone was assembled into 3 549 contigs with an average length of 349 bp. The smallest contig was 55 bp and the largest was 3 466 bp, and there were 62 484 sequences that could not be assembled (singletons) among both transcriptomes. Overall transcriptome analysis was organized according to the Gene Ontology consortium, enzyme commission, and InerPro using the Blast2GO® program. We further characterized metabolic systems and messages associated with development.}, number={3}, journal={ENTOMOLOGIA EXPERIMENTALIS ET APPLICATA}, author={Magalhaes, Leonardo C. and Kretschmar, Jaap B. and Donohue, Kevin V. and Roe, R. Michael}, year={2013}, month={Mar}, pages={364–378} } @article{magalhaes_van kretschmar_barlow_roe_walgenbach_2012, title={Development of a rapid resistance monitoring bioassay for codling moth larvae}, volume={68}, ISSN={["1526-4998"]}, DOI={10.1002/ps.3246}, abstractNote={BACKGROUND: The codling moth, Cydia pomonella (L.), is one of the most important pests of apple worldwide. Use of insecticides for management of this insect has been extensive and has resulted in resistance development. There are a number of different bioassay methods to monitor for codling moth resistance; however, many are not applicable to new insecticides and most are time consuming. A novel 16-well plasticware bioassay plate containing lyophilized diet was developed for rapid resistance monitoring of codling moth. RESULTS: The contact insecticides acetamiprid and azinphosmethyl were significantly more toxic to neonates than to fourth instars. However, there was no significant difference in LC50 values between neonates and fourth instars to the ingestion insecticides chlorantraniliprole, methoxyfenozide, novaluron and spinetoram. Field colonies of codling moth were significantly more resistant to methoxyfenozide than susceptible populations. A diagnostic dose of 20 µg mL−1 (LC99) was established to monitor for codling moth resistance to methoxyfenozide. CONCLUSIONS: The results presented here demonstrate that a novel and rapid bioassay can be used to monitor for codling moth resistance to methoxyfenozide. The bioassay method is relevant to both ingestion and contact insecticides, but a single diagnostic dose, regardless of larval age, is only relevant to ingestion insecticides. Age-dependent diagnostic doses are likely necessary for contact insecticides. Copyright © 2011 Society of Chemical Industry}, number={6}, journal={PEST MANAGEMENT SCIENCE}, author={Magalhaes, Leonardo C. and Van Kretschmar, Jaap B. and Barlow, Vonny M. and Roe, R. Michael and Walgenbach, James F.}, year={2012}, month={Jun}, pages={883–888} } @article{magalhaes_walgenbach_2011, title={Life Stage Toxicity and Residual Activity of Insecticides to Codling Moth and Oriental Fruit Moth (Lepidoptera: Tortricidae)}, volume={104}, ISSN={["1938-291X"]}, DOI={10.1603/ec11070}, abstractNote={The codling moth, Cydia pomonella (L.), and oriental fruit moth, Grapholita molesta (Busck), are two key pests of apple (Malus domestica Borkh.) in North Carolina. Growers extensively relied on organophosphate insecticides, primarily azinphosmethyl, for >40 yr to manage these pests. Because of organophosphate resistance development and regulatory actions, growers are transitioning to management programs that use new, reduced-risk, and OP-replacement insecticides. This study evaluated the toxicity of a diversity of replacement insecticides to eggs, larvae, and adults, as well as an assessment of their residual activity, to codling moth and oriental fruit moth. Laboratory-susceptible strains of both species were used for all bioassays. Fresh field-harvested apples were used as a media for assessing the ovicidal activity of insecticides. For larval studies, insecticides were topically applied to the surface of lima bean-based diet, onto which neonates were placed. Toxicity was based on two measures of mortality; 5-d mortality and development to adult stage. Ovicidal bioassays showed that oriental fruit moth eggs were generally more tolerant than codling moth eggs to insecticides, with novaluron, acetamiprid, and azinphoshmethyl having the highest levels of toxicity to eggs of both species. In contrast, codling moth larvae generally were more tolerant than oriental fruit moth to most insecticides. Methoxyfenozide and pyriproxyfen were the only insecticides with lower LC50 values against codling moth than oriental fruit moth neonates. Moreover, a number of insecticides, particularly the IGRs methoxyfenozide and novaluron, the anthranilic diamide chlorantriliprole, and the spinosyn spinetoram, provided equal or longer residual activity against codling moth compared with azinphosmethyl in field studies. Results are discussed in relation to their use in devising field use patterns of insecticides and for insecticide resistance monitoring programs.}, number={6}, journal={JOURNAL OF ECONOMIC ENTOMOLOGY}, author={Magalhaes, Leonardo C. and Walgenbach, James F.}, year={2011}, month={Dec}, pages={1950–1959} } @article{esteves magalhaes_cao_lucia_2009, title={Cellulose Nanocrystals/Cellulose Core-in-Shell Nanocomposite Assemblies}, volume={25}, ISSN={["0743-7463"]}, DOI={10.1021/la901928j}, abstractNote={We report herein for the first time how a co-electrospinning technique can be used to overcome the issue of orienting cellulose nanocrystals within a neat cellulose matrix. A home-built co-electrospinning apparatus was fabricated that was comprised of a high-voltage power supply, two concentric capillary needles, and one screw-type pump syringe. Eucalyptus-derived cellulose was dissolved in N-methylmorpholine oxide (NMMO) at 120 degrees C and diluted with dimethyl sulfoxide (DMSO) which was used in the external concentric capillary needle as the shell solution. A cellulose nanocrystal suspension obtained by the sulfuric acid hydrolysis of bleached sisal and cotton fibers was used as the core liquid in the internal concentric capillary needle. Three flow rate ratios between the shell and core, four flow rates for the shell dope solution, and four high voltages were tested. The resultant co-electrospun composite fibers were collected onto a grounded metal screen immersed in cold water. Micrometer and submicrometer cellulose fiber assemblies were obtained which were reinforced with cellulose nanocrystals and characterized by FESEM, FTIR, TGA, and XRD. Surprisingly, it was determined that the physical properties for the cellulose controls are superior to the composites; in addition, the crystallinity of the controls was slightly greater.}, number={22}, journal={LANGMUIR}, author={Esteves Magalhaes, Washington Luiz and Cao, Xiaodong and Lucia, Lucian A.}, year={2009}, month={Nov}, pages={13250–13257} } @article{guedes_magalhaes_cosme_2009, title={Stimulatory Sublethal Response of a Generalist Predator to Permethrin: Hormesis, Hormoligosis, or Homeostatic Regulation?}, volume={102}, ISSN={["1938-291X"]}, DOI={10.1603/029.102.0124}, abstractNote={The assessment of pesticide effects in arthropods historically have relied heavily on acute lethal effects. Although the sublethal responses to such compounds are sometimes neglected, stimulatory effects associated with low doses of compounds toxic at higher doses, such as pesticides, have been widely reported in recent years and recognized as a general toxicological phenomenon. Evidence of such stimulatory response has also been reported among mites and a few insect pest-species exposed to pesticides and recognized as a one of the potential causes underlying pest resurgence and secondary pest outbreaks. However, fitness parameters and its implications were seldom considered in these studies and natural enemies are not usually target of attention. Here, we reported the stimulatory effect of sublethal doses (ranging from 0.02 to 172.00 ppb in addition to the control) of the pyrethroid permethrin topically applied to third instar nymphs of the spined soldier bug, Podisus distinctus (Stål) (Heteroptera: Pentatomidae). The parameters estimated from the fertility tables of insects exposed to the increasing doses of insecticide indicated a slight increase in the mean survival time for doses > or = 0.20 ppb and a peak in the net reproductive rate at 1.72 ppb. This trend is coincident and correlated with the intrinsic rate of population growth (n = 18, r = 0.78, P = 0.0001), which also shows a peak at 1.72 ppb, leading to higher reproductive values of insects exposed to this dose. The phenomenon is consistent with insecticide-induced hormesis, for which the potential implications are discussed.}, number={1}, journal={JOURNAL OF ECONOMIC ENTOMOLOGY}, author={Guedes, R. N. C. and Magalhaes, L. C. and Cosme, L. V.}, year={2009}, month={Feb}, pages={170–176} }