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  1. Article ; Online: Diapause Termination and Postdiapause in Lygus hesperus (Heteroptera: Miridae).

    Brent, Colin S

    Journal of insect science (Online)

    2021  Volume 21, Issue 1

    Abstract: The western tarnished plant bug, Lygus hesperus Knight, overwinters as a diapausing adult in response to short day lengths. Once environmental conditions are favorable, the bugs revert to an active reproductive state. To determine the impact on life- ... ...

    Abstract The western tarnished plant bug, Lygus hesperus Knight, overwinters as a diapausing adult in response to short day lengths. Once environmental conditions are favorable, the bugs revert to an active reproductive state. To determine the impact on life-history traits of diverting resources toward diapause rather than oogenesis during early adulthood, diapausing and nondiapausing L. hesperus females were reared from the same cohorts. Body mass, ovarian maturation, ovipositional activity, and survivorship were monitored starting either at the time of release from diapause-inducing conditions or at adult eclosion for diapausers and nondiapausers, respectively. Females that had gone through 2 wk of diapause were larger and able to mobilize the resources necessary for oogenesis faster than nondiapausers, initiating oogenesis and ovipositing sooner and at a faster initial rate. However, lifetime egg production and average daily rates were similar for both groups. Postdiapausers lived longer than nondiapausers by an average of 19 d, which is five more than the 2-wk period when they were reproductively senescent. Overall, the results indicate that short-term diapause does not have a negative impact on life history. Furthermore, the extra endogenous resources stored during diapause may be able to enhance the alacrity with which the female can take advantage of improved environmental conditions and may prolong life by shielding the females against environmental stressors such as temperature extremes, oxidative agents, or food deficits.
    MeSH term(s) Animals ; Diapause, Insect ; Female ; Heteroptera/growth & development ; Heteroptera/physiology ; Life History Traits ; Oogenesis ; Oviposition
    Language English
    Publishing date 2021-01-04
    Publishing country United States
    Document type Journal Article
    ZDB-ID 2049098-7
    ISSN 1536-2442 ; 1536-2442
    ISSN (online) 1536-2442
    ISSN 1536-2442
    DOI 10.1093/jisesa/ieaa142
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  2. Article ; Online: Nutritional and Physiological Regulation of Glassy-Winged Sharpshooter Oogenesis.

    Sisterson, Mark S / Brent, Colin S

    Journal of economic entomology

    2022  Volume 115, Issue 2, Page(s) 526–538

    Abstract: The glassy-winged sharpshooter (Homalodisca vitripennis (Germar); Hemiptera: Cicadellidae: Cicadellinae) is an invasive insect that transmits the plant pathogenic bacterium Xylella fastidiosa Wells et al. (Xanthomonadales: Xanthomonadacae). While adult ... ...

    Abstract The glassy-winged sharpshooter (Homalodisca vitripennis (Germar); Hemiptera: Cicadellidae: Cicadellinae) is an invasive insect that transmits the plant pathogenic bacterium Xylella fastidiosa Wells et al. (Xanthomonadales: Xanthomonadacae). While adult glassy-winged sharpshooter must feed to produce eggs, the role of nutritional status on initiating oogenesis is poorly understood. To determine the effects of glassy-winged sharpshooter nutrition on nymphal development, oogenesis, and fecundity, glassy-winged sharpshooter were reared on cowpea, sunflower, sorghum, and a mixture of the three plant species. Adults emerging from cowpea, sunflower, or plant mixture treatments had shorter development times, attained larger size, and had greater estimated lipid reserves than females reared on sorghum. In choice tests, nymphs avoided sorghum and preferentially fed on cowpea and sunflower. Adult females provisioned with a single plant species during the nymphal stage were provided with either the same host plant species or a mixture of host plant species (cowpea, sunflower, sorghum) for a 9-wk oviposition period, with 37% of females initiating oogenesis. Ovipositing females had greater juvenile hormone and octopamine levels than reproductively inactive females, although topical application of the juvenile hormone analog Methoprene did not promote oogenesis. Across nymphal diets, reproductively active females produced more eggs when held on plant mixtures than on single plant species. In choice tests, adult females were observed most frequently on cowpea, although most eggs were deposited on sorghum, the host least preferred by nymphs. Results suggest that fecundity is largely determined by the quality of the adult diet, although the stimulus that initiates oogenesis does not appear to be related to nutrition.
    MeSH term(s) Animals ; Female ; Helianthus ; Hemiptera/physiology ; Juvenile Hormones ; Nymph ; Oogenesis ; Oviposition ; Vigna
    Chemical Substances Juvenile Hormones
    Language English
    Publishing date 2022-04-06
    Publishing country England
    Document type Journal Article ; Research Support, U.S. Gov't, Non-P.H.S.
    ZDB-ID 3031-4
    ISSN 1938-291X ; 0022-0493
    ISSN (online) 1938-291X
    ISSN 0022-0493
    DOI 10.1093/jee/toab260
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  3. Article: Nutritional and Physiological Regulation of Glassy-Winged Sharpshooter Oogenesis

    Sisterson, Mark S. / Brent, Colin S.

    Journal of economic entomology. 2022 Jan. 13, v. 115, no. 2

    2022  

    Abstract: The glassy-winged sharpshooter (Homalodisca vitripennis (Germar); Hemiptera: Cicadellidae: Cicadellinae) is an invasive insect that transmits the plant pathogenic bacterium Xylella fastidiosa Wells et al. (Xanthomonadales: Xanthomonadacae). While adult ... ...

    Abstract The glassy-winged sharpshooter (Homalodisca vitripennis (Germar); Hemiptera: Cicadellidae: Cicadellinae) is an invasive insect that transmits the plant pathogenic bacterium Xylella fastidiosa Wells et al. (Xanthomonadales: Xanthomonadacae). While adult glassy-winged sharpshooter must feed to produce eggs, the role of nutritional status on initiating oogenesis is poorly understood. To determine the effects of glassy-winged sharpshooter nutrition on nymphal development, oogenesis, and fecundity, glassy-winged sharpshooter were reared on cowpea, sunflower, sorghum, and a mixture of the three plant species. Adults emerging from cowpea, sunflower, or plant mixture treatments had shorter development times, attained larger size, and had greater estimated lipid reserves than females reared on sorghum. In choice tests, nymphs avoided sorghum and preferentially fed on cowpea and sunflower. Adult females provisioned with a single plant species during the nymphal stage were provided with either the same host plant species or a mixture of host plant species (cowpea, sunflower, sorghum) for a 9-wk oviposition period, with 37% of females initiating oogenesis. Ovipositing females had greater juvenile hormone and octopamine levels than reproductively inactive females, although topical application of the juvenile hormone analog Methoprene did not promote oogenesis. Across nymphal diets, reproductively active females produced more eggs when held on plant mixtures than on single plant species. In choice tests, adult females were observed most frequently on cowpea, although most eggs were deposited on sorghum, the host least preferred by nymphs. Results suggest that fecundity is largely determined by the quality of the adult diet, although the stimulus that initiates oogenesis does not appear to be related to nutrition.
    Keywords Helianthus annuus ; Homalodisca vitripennis ; Xylella fastidiosa ; adults ; cowpeas ; diet ; entomology ; fecundity ; host plants ; invasive species ; juvenile hormones ; lipids ; methoprene ; nutritional status ; octopamine ; oogenesis ; oviposition ; physiological regulation ; plant pathogenic bacteria ; topical application
    Language English
    Dates of publication 2022-0113
    Size p. 526-538.
    Publishing place Entomological Society of America
    Document type Article
    ZDB-ID 3031-4
    ISSN 0022-0493
    ISSN 0022-0493
    DOI 10.1093/jee/toab260
    Database NAL-Catalogue (AGRICOLA)

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  4. Article ; Online: Reproductive Development of Lygus hesperus (Hemiptera: Miridae) Adults Under Constant and Variable Temperatures.

    Brent, Colin S / Spurgeon, Dale W

    Journal of insect science (Online)

    2019  Volume 19, Issue 3

    Abstract: As water for agriculture becomes less available in the semi-arid western United States, alternative irrigation strategies such as deficit irrigation may be necessary for continued crop production. Alternative irrigation practices in cotton (Gossypium spp. ...

    Abstract As water for agriculture becomes less available in the semi-arid western United States, alternative irrigation strategies such as deficit irrigation may be necessary for continued crop production. Alternative irrigation practices in cotton (Gossypium spp. [Malvales: Valvaceae]) can result in episodic drought stress that alters temperature profiles within the crop canopy. These altered temperatures may influence populations of important pests such as Lygus hesperus Knight. Field studies often associate lower population densities of L. hesperus with limited irrigation. Recent studies of the thermal ecology of L. hesperus egg and nymphal development have demonstrated only subtle effects of the high, variable temperatures typical of moderate drought stress in cotton. However, influences of these conditions on L. hesperus adult reproductive development have not been studied. The reproductive development of L. hesperus adults was examined under constant (±0.2°C) and variable (±8°C) regimes at a low (15°C), moderate (22°C), and high (29°C) daily mean temperatures. No developmental differences were demonstrated between temperature regimes under moderate or high temperatures. At the low temperature, only the times to the occurrence of eggs, filled medial accessory glands, and filling seminal vesicles were shorter under variable regime, compared with the constant temperature. These results suggest that temporary, episodic increases in crop canopy temperatures caused by moderate drought stress are unlikely to impact L. hesperus population growth, and may only promote short-term displacement of adults into adjacent crops with preferable conditions.
    MeSH term(s) Animals ; Female ; Hemiptera/growth & development ; Male ; Sexual Maturation ; Temperature
    Language English
    Publishing date 2019-06-21
    Publishing country United States
    Document type Journal Article
    ZDB-ID 2049098-7
    ISSN 1536-2442 ; 1536-2442
    ISSN (online) 1536-2442
    ISSN 1536-2442
    DOI 10.1093/jisesa/iez066
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  5. Article ; Online: Development and Survival of Lygus hesperus (Hemiptera: Miridae) Nymphs Under Constant and Variable Temperatures.

    Spurgeon, Dale W / Brent, Colin S

    Journal of insect science (Online)

    2019  Volume 19, Issue 1

    Abstract: Thermal environments of the arid western United States are often harsh compared with the ranges of temperatures favorable for development and survival of crop insect pests. In cotton [Gossypium spp. (Malvales: Malvaceae)], new irrigation practices such ... ...

    Abstract Thermal environments of the arid western United States are often harsh compared with the ranges of temperatures favorable for development and survival of crop insect pests. In cotton [Gossypium spp. (Malvales: Malvaceae)], new irrigation practices such as deficit irrigation may impact populations of pest and beneficial arthropods by temporarily altering temperature profiles within the plant canopy. Most information regarding the temperature-dependent development and survival of an important cotton pest, the western tarnished plant bug (Lygus hesperus Knight), is derived from constant temperature studies. We examined the development and survival of L. hesperus nymphs under constant (±0.2°C) and variable (±8°C) temperature regimes at daily mean temperatures of 15, 22, and 29°C. Under the low temperature (15°C), stadium lengths and duration of the nymphal stage were shorter when temperatures were variable compared with a constant temperature. No differences in development times were observed between regimes at the medium temperature (22°C). Except for the first stadium, development times under the high variable temperature regime were longer compared with the high constant regime (29°C). Nymph survival was unaffected by temperature regime except at the lowest temperature, where daily thermal fluctuations substantially improved survival compared with the constant conditions. These results suggest that temporarily increased crop canopy temperatures caused by altered irrigation schemes are unlikely to substantially reduce the growth of L. hesperus populations. However, enhanced nymphal development and survival under low variable temperatures likely contribute to the survival of overwintering L. hesperus in the absence of acute, low-temperature mortality.
    MeSH term(s) Animals ; Cold Temperature ; Gossypium/growth & development ; Heteroptera/growth & development ; Hot Temperature ; Longevity ; Nymph/growth & development
    Language English
    Publishing date 2019-01-01
    Publishing country United States
    Document type Journal Article
    ZDB-ID 2049098-7
    ISSN 1536-2442 ; 1536-2442
    ISSN (online) 1536-2442
    ISSN 1536-2442
    DOI 10.1093/jisesa/iez003
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  6. Article ; Online: Identification of Sr67, a new gene for stem rust resistance in KU168-2 located close to the Sr13 locus in wheat.

    Sharma, Jyoti Saini / Che, Mingzhe / Fetch, Thomas / McCallum, Brent D / Xu, Steven S / Hiebert, Colin W

    TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik

    2024  Volume 137, Issue 1, Page(s) 30

    Abstract: Key message: Sr67 is a new stem rust resistance gene that represents a new resource for breeding stem rust resistant wheat cultivars Re-appearance of stem rust disease, caused by the fungal pathogen Puccinia graminis f. sp. tritici (Pgt), in different ... ...

    Abstract Key message: Sr67 is a new stem rust resistance gene that represents a new resource for breeding stem rust resistant wheat cultivars Re-appearance of stem rust disease, caused by the fungal pathogen Puccinia graminis f. sp. tritici (Pgt), in different parts of Europe emphasized the need to develop wheat varieties with effective resistance to local Pgt populations and exotic threats. A Kyoto University wheat (Triticum aestivum L.) accession KU168-2 was reported to carry good resistance to leaf and stem rust. To identify the genomic region associated with the KU168-2 stem rust resistance, a genetic study was conducted using a doubled haploid (DH) population from the cross RL6071 × KU168-2. The DH population was phenotyped with three Pgt races (TTKSK, TPMKC, and QTHSF) and genotyped using the Illumina 90 K wheat SNP array. Linkage mapping showed the resistance to all three Pgt races was conferred by a single stem rust resistance (Sr) gene on chromosome arm 6AL, associated with Sr13. Presently, four Sr13 resistance alleles have been reported. Sr13 allele-specific KASP and STARP markers, and sequencing markers all showed null alleles in KU168-2. KU168-2 showed a unique combination of seedling infection types for five Pgt races (TTKSK, QTHSF, RCRSF, TMRTF, and TPMKC) compared to Sr13 alleles. The phenotypic uniqueness of the stem rust resistance gene in KU168-2 and null alleles for Sr13 allele-specific markers showed the resistance was conferred by a new gene, designated Sr67. Since Sr13 is less effective in hexaploid background, Sr67 will be a good source of stem rust resistance in bread wheat breeding programs.
    MeSH term(s) Humans ; Triticum ; Plant Breeding ; Basidiomycota ; Alleles ; Puccinia
    Language English
    Publishing date 2024-01-24
    Publishing country Germany
    Document type Journal Article
    ZDB-ID 2170-2
    ISSN 1432-2242 ; 0040-5752
    ISSN (online) 1432-2242
    ISSN 0040-5752
    DOI 10.1007/s00122-023-04530-8
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  7. Article: RNAi-Mediated Manipulation of Cuticle Coloration Genes in

    Brent, Colin S / Heu, Chan C / Gross, Roni J / Fan, Baochan / Langhorst, Daniel / Hull, J Joe

    Insects

    2022  Volume 13, Issue 11

    Abstract: Cuticle coloration in insects is a consequence of the accumulation of pigments in a species-specific pattern. Numerous genes are involved in regulating the underlying processes of melanization and sclerotization, and their manipulation can be used to ... ...

    Abstract Cuticle coloration in insects is a consequence of the accumulation of pigments in a species-specific pattern. Numerous genes are involved in regulating the underlying processes of melanization and sclerotization, and their manipulation can be used to create externally visible markers of successful gene editing. To clarify the roles for many of these genes and examine their suitability as phenotypic markers in
    Language English
    Publishing date 2022-10-27
    Publishing country Switzerland
    Document type Journal Article
    ZDB-ID 2662247-6
    ISSN 2075-4450
    ISSN 2075-4450
    DOI 10.3390/insects13110986
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  8. Article: Mating and social contact change egg production and longevity in adult females of the mirid Lygus hesperus

    Brent, Colin S

    Entomologia experimentalis et applicata. 2018 July, v. 166, no. 7

    2018  

    Abstract: There is frequently a tradeoff between fecundity and longevity, but the relationship is inconsistent across species and influenced by various exogenous and endogenous factors. Previous studies of Lygus hesperus Knight (Hemiptera: Miridae) established ... ...

    Abstract There is frequently a tradeoff between fecundity and longevity, but the relationship is inconsistent across species and influenced by various exogenous and endogenous factors. Previous studies of Lygus hesperus Knight (Hemiptera: Miridae) established that egg production is promoted by insemination, at least temporarily, but little is known about the long‐term effects of mating and nonsexual interactions with conspecifics on egg production and female lifespan. To elucidate these relationships, survivorship and oviposition rate were tracked daily in females that were isolated or paired with a fertile male or another female throughout their adult lives. Mating rates were determined by postmortem examination. Results indicate that male‐specific stimuli accelerate female reproductive maturation, and that mating elevates oviposition rate. However, females paired with either a female or male companion had shortened lifespans, suggesting that social contacts exact a significant cost in this solitary species. Despite the negative impact of conspecific interactions and the finding that a singly mated female has sufficient sperm to fertilize a lifetime supply of eggs, many females were found to have mated more than once. Multiply mated females had higher sustained oviposition rates, lived longer, and had greater lifetime fecundities. Collectively, no strong evidence was found of a direct physiological link between fecundity and longevity, but environmental factors and mating were found to significantly influence both traits.
    Keywords adults ; egg production ; eggs ; environmental factors ; fecundity ; females ; insemination ; long term effects ; longevity ; Lygus hesperus ; males ; necropsy ; oviposition ; spermatozoa ; survival rate
    Language English
    Dates of publication 2018-07
    Size p. 545-554.
    Publishing place John Wiley & Sons, Ltd
    Document type Article
    Note JOURNAL ARTICLE
    ZDB-ID 216272-6
    ISSN 0013-8703
    ISSN 0013-8703
    DOI 10.1111/eea.12683
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  9. Article ; Online: RNA interference-mediated knockdown of eye coloration genes in the western tarnished plant bug (Lygus hesperus Knight).

    Brent, Colin S / Hull, J Joe

    Archives of insect biochemistry and physiology

    2018  Volume 100, Issue 2, Page(s) e21527

    Abstract: Insect eye coloration arises from the accumulation of various pigments. A number of genes that function in the biosynthesis (vermilion, cinnabar, and cardinal) and importation (karmoisin, white, scarlet, and brown) of these pigments, and their precursors, ...

    Abstract Insect eye coloration arises from the accumulation of various pigments. A number of genes that function in the biosynthesis (vermilion, cinnabar, and cardinal) and importation (karmoisin, white, scarlet, and brown) of these pigments, and their precursors, have been identified in diverse species and used as markers for transgenesis and gene editing. To examine their suitability as visible markers in Lygus hesperus Knight (western tarnished plant bug), transcriptomic data were screened for sequences exhibiting homology with the Drosophila melanogaster proteins. Complete open reading frames encoding putative homologs for all seven genes were identified. Bioinformatic-based sequence and phylogenetic analyses supported initial annotations as eye coloration genes. Consistent with their proposed role, each of the genes was expressed in adult heads as well as throughout nymphal and adult development. Adult eyes of those injected with double-stranded RNAs (dsRNAs) for karmoisin, vermilion, cinnabar, cardinal, and scarlet were characterized by a red band along the medial margin extending from the rostral terminus to the antenna. In contrast, eyes of insects injected with dsRNAs for both white and brown were a uniform light brown. White knockdown also produced cuticular and behavioral defects. Based on its expression profile and robust visible phenotype, cardinal would likely prove to be the most suitable marker for developing gene editing methods in Lygus species.
    MeSH term(s) Animals ; Eye/metabolism ; Heteroptera/genetics ; Heteroptera/physiology ; Insect Proteins/metabolism ; Pigmentation/genetics ; Pigments, Biological/genetics ; Pigments, Biological/physiology ; RNA Interference ; RNA, Double-Stranded
    Chemical Substances Insect Proteins ; Pigments, Biological ; RNA, Double-Stranded
    Language English
    Publishing date 2018-12-26
    Publishing country United States
    Document type Journal Article
    ZDB-ID 11323-2
    ISSN 1520-6327 ; 0739-4462
    ISSN (online) 1520-6327
    ISSN 0739-4462
    DOI 10.1002/arch.21527
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  10. Article ; Online: Filling in the gaps: A reevaluation of the Lygus hesperus peptidome using an expanded de novo assembled transcriptome and molecular cloning.

    Hull, J Joe / Gross, Roni J / Brent, Colin S / Christie, Andrew E

    General and comparative endocrinology

    2021  Volume 303, Page(s) 113708

    Abstract: Peptides are the largest and most diverse class of molecules modulating physiology and behavior. Previously, we predicted a peptidome for the western tarnished plant bug, Lygus hesperus, using transcriptomic data produced from whole individuals. A ... ...

    Abstract Peptides are the largest and most diverse class of molecules modulating physiology and behavior. Previously, we predicted a peptidome for the western tarnished plant bug, Lygus hesperus, using transcriptomic data produced from whole individuals. A potential limitation of that analysis was the masking of underrepresented genes, in particular tissue-specific transcripts. Here, we reassessed the L. hesperus peptidome using a more comprehensive dataset comprised of the previous transcriptomic data as well as tissue-specific reads produced from heads and accessory glands. This augmented assembly significantly improves coverage depth providing confirmatory transcripts for essentially all of the previously identified families and new transcripts encoding a number of new peptide precursors corresponding to 14 peptide families. Several families not targeted in our initial study were identified in the expanded assembly, including agatoxin-like peptide, CNMamide, neuropeptide-like precursor 1, and periviscerokinin. To increase confidence in the in silico data, open reading frames of a subset of the newly identified transcripts were amplified using RT-PCR and sequence validated. Further PCR-based profiling of the putative L. hesperus agatoxin-like peptide precursor revealed evidence of alternative splicing with near ubiquitous expression across L. hesperus development, suggesting the peptide serves functional roles beyond that of a toxin. The peptides predicted here, in combination with those identified in our earlier study, expand the L. hesperus peptidome to 42 family members and provide an improved platform for initiating molecular and physiological investigations into peptidergic functionality in this non-model agricultural pest.
    MeSH term(s) Animals ; Cloning, Molecular ; Heteroptera/genetics ; Plants ; Polymerase Chain Reaction ; Transcriptome/genetics
    Language English
    Publishing date 2021-01-01
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't ; Research Support, U.S. Gov't, Non-P.H.S.
    ZDB-ID 1851-x
    ISSN 1095-6840 ; 0016-6480
    ISSN (online) 1095-6840
    ISSN 0016-6480
    DOI 10.1016/j.ygcen.2020.113708
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