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"Woolley, James"
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Sugarcane Aphid Population Growth, Plant Injury, and Natural Enemies on Selected Grain Sorghum Hybrids in Texas and Louisiana
In response to the 2013 outbreak of sugarcane aphid, Melanaphis sacchari (Zehntner) (Hemiptera: Aphididae), on sorghum, Sorghum bicolor (L.), in North America, experiments were conducted at three southern U.S. grain sorghum production locations (Corpus Christi, TX; Winnsboro, LA; Rosenberg, TX). The objectives were to authenticate yield decline on susceptible hybrids (2014 and 2015) and to measure aphid population growth and natural enemy prevalence on susceptible and resistant hybrids with similar genetic background (2014).Yield decline on susceptible hybrids (Tx 2752/Tx430 and DKS53-67) was more substantial when aphid population growth accelerated quickly and peaked above 300 aphids per leaf (50 to nearly 100% yield decline). Location and year variation in maximum aphid density and cumulative aphid-days was high, with doubling time values on the susceptible hybrids ranging between 3.9 and 7.9 d. On resistant Tx2752/Tx2783, leaf injury and yield decline were not seen or less severe than on its paired susceptibleTx2752/Tx430. Aphids declined onTx2752/Tx2783 after initial colony establishment (Corpus Christi) or took about 60% longer to double in population size when compared with Tx2572/Tx430 (Winnsboro). The predominant natural enemy taxa were aphelinid mummies (Hymenoptera: Aphelinidae), ladybird beetles (Coleoptera: Coccinellidae), and sryphid flies (Diptera: Syrphidae), and they were more prevalent during flowering than prior to flowering.They were generally responsive to changes in aphid density of both susceptible and resistant hybrids, but variability points to need for further study. In future research, full season observations should continue as well as more detailed study of potential compatibility of sorghum resistance and biological control.
Journal Article
New records of three parasitoids, Pteroptrix chinensis, Aphytis hispanicus, and Marlattiella prima
A survey for parasitoids of Lopholeucaspis japonica Cockerell (Hemiptera: Diaspididae), an exotic scale of woody ornamentals, resulted in the discovery of 3 species of aphelinid parasitoid wasps, Pteroptrix chinensis (Howard), Aphytis hispanicus (Mercet), and Marlattiella prima Howard. This serves as the first report of these parasitoids reared from a host in the state of Tennessee, USA. Despite routine pesticide applications in the surveyed nursery and directed treatments of the infested plants to control the scale outbreak, the percentage of parasitized scale in privet and euonymus shrubs averaged 70% and 79%, respectively. These parasitoids may be useful in the natural or managed control of this pest in the United States, but additional research is needed to understand how these parasitoids contribute to the control of L. japonica in the landscape and how nursery production practices can be modified to promote parasitoid populations.
Journal Article
New records of three parasitoids, Pteroptrix chinensis , Aphytis hispanicus , and Marlattiella prima (Hymenoptera: Aphelinidae) associated with an exotic scale, Lopholeucaspis japonica (Hemiptera: Diaspididae) in Tennessee
A survey for parasitoids of Lopholeucaspis japonica Cockerell (Hemiptera: Diaspididae), an exotic scale of woody ornamentals, resulted in the discovery of 3 species of aphelinid parasitoid wasps, Pteroptrix chinensis (Howard), Aphytis hispanicus (Mercet), and Marlattiella prima Howard. This serves as the first report of these parasitoids reared from a host in the state of Tennessee, USA. Despite routine pesticide applications in the surveyed nursery and directed treatments of the infested plants to control the scale outbreak, the percentage of parasitized scale in privet and euonymus shrubs averaged 7.0% and 7.9%, respectively. These parasitoids may be useful in the natural or managed control of this pest in the United States, but additional research is needed to understand how these parasitoids contribute to the control of L. japonica in the landscape and how nursery production practices can be modified to promote parasitoid populations.
Journal Article
Gender Differences in White Matter Microstructure
Sexual dimorphism in human brain structure is well recognised, but little is known about gender differences in white matter microstructure. We used diffusion tensor imaging to explore differences in fractional anisotropy (FA), an index of microstructural integrity.
A whole brain analysis of 135 matched subjects (90 men and 45 women) using a 1.5 T scanner. A region of interest (ROI) analysis was used to confirm those results where proximity to CSF raised the possibility of partial-volume artefact.
Men had higher fractional anisotropy (FA) in cerebellar white matter and in the left superior longitudinal fasciculus; women had higher FA in the corpus callosum, confirmed by ROI.
The size of the differences was substantial--of the same order as that attributed to some pathology--suggesting gender may be a potentially significant confound in unbalanced clinical studies. There are several previous reports of difference in the corpus callosum, though they disagree on the direction of difference; our findings in the cerebellum and the superior longitudinal fasciculus have not previously been noted. The higher FA in women may reflect greater efficiency of a smaller corpus callosum. The relatively increased superior longitudinal fasciculus and cerebellar FA in men may reflect their increased language lateralisation and enhanced motor development, respectively.
Journal Article
Counties not countries: Variation in host specificity among populations of an aphid parasitoid
Parasitic wasps are among the most species‐rich groups on Earth. A major cause of this diversity may be local adaptation to host species. However, little is known about variation in host specificity among populations within parasitoid species. Not only is such knowledge important for understanding host‐driven speciation, but because parasitoids often control pest insects and narrow host ranges are critical for the safety of biological control introductions, understanding variation in specificity and how it arises are crucial applications in evolutionary biology. Here, we report experiments on variation in host specificity among 16 populations of an aphid parasitoid, Aphelinus certus. We addressed several questions about local adaptation: Do parasitoid populations differ in host ranges or in levels of parasitism of aphid species within their host range? Are differences in parasitism among parasitoid populations related to geographical distance, suggesting clinal variation in abundances of aphid species? Or do nearby parasitoid populations differ in host use, as would be expected if differences in aphid abundances, and thus selection, were mosaic? Are differences in parasitism among parasitoid populations related to genetic distances among them? To answer these questions, we measured parasitism of a taxonomically diverse group of aphid species in laboratory experiments. Host range was the same for all the parasitoid populations, but levels of parasitism varied among aphid species, suggesting adaptation to locally abundant aphids. Differences in host specificity did not correlate with geographical distances among parasitoid populations, suggesting that local adaption is mosaic rather than clinal, with a spatial scale of less than 50 kilometers. We sequenced and assembled the genome of A. certus, made reduced‐representation libraries for each population, analyzed for single nucleotide polymorphisms, and used these polymorphisms to estimate genetic differentiation among populations. Differences in host specificity correlated with genetic distances among the parasitoid populations.
Journal Article
Neural correlates of executive function and working memory in the ‘at-risk mental state’
People with prodromal symptoms have a very high risk of developing psychosis.
To use functional magnetic resonance imaging to examine the neurocognitive basis of this vulnerability.
Cross-sectional comparison of regional activation in individuals with an'at-risk mental state' (at-risk group: n=17), patients with first-episode schizophreniform psychosis (psychosis group: n=10) and healthy volunteers (controls: n=15) during an overt verbal fluency task and an N-back working memory task.
A similar pattern of between-group differences in activation was evident across both tasks. Activation in the at-risk group was intermediate relative to that in controls and the psychosis group in the inferior frontal and anterior cingulate cortex during the verbal fluency task and in the inferior frontal, dorsolateral prefrontal and parietal cortex during the N-back task.
The at-risk mental state is associated with abnormalities of regional brain function that are qualitatively similar to, but less severe than, those in patients who have recently presented with psychosis.
Journal Article
Seek and Ye Shall Not Find (Yet): Searching Clinical Trial Registries for Trials Designed With Patients—A Call to Action
Clinical trial registries were designed to help patients search for potentially suitable clinical trials. When our family faced another serious cancer diagnosis, we searched multiple international clinical trial registries. Despite increasing evidence that trials designed with patients can be better for trial participants (eg, they can have more relevant outcome measures and fewer burdens), it is currently impossible to search registries for these specific types of trials. In this Patient Perspective article, we make the first “call to action” for clinical trial registries to include (1) a filter that allows for efficient searching for clinical trials designed with patients and (2) structured information, in plain language, on how patients were involved. We propose how these two innovations could help reduce barriers to clinical trial participation. We also highlight how new regulatory and ethical guidelines are encouraging patient involvement in trial design, and we identify the benefits to many of doing so. Given the pressing need to improve clinical trial participation, we respectfully call on the clinical trial community to respond to our call to action and consider our proposed action plan. Ideally, when patients want to search for clinical trials designed with patients for patients, we should be able to find them. A plain language summary for this publication is available in the supplementary material for this paper.
Journal Article
First report in Colombia and diagnosis of Diaphorencyrtus aligarhensis (Hymenoptera: Encyrtidae), a parasitoid wasp of Diaphorina citri (Hemiptera: Liviidae)
Diaphorencyrtus aligarhensis (Hymenoptera: Encyrtidae) is herein reported for the first time from Colombia based on specimens collected in the municipality of Palmira, department of Valle del Cauca. Adult male and female wasps of this endoparasitoid are diagnosed based on published literature and character states taken from specimens collected in the present study. The adult parasitoids were extracted from parasitized nymphs (mummies) of the Asian citrus psyllid, Diaphorina citri (Hemiptera: Liviidae). Information is provided on the differences in the morphology of parasitized nymphs of D. citri with exit holes made by the two main primary parasitoids, i.e., Tamarixia radiata (Hymenoptera: Eulophidae) and D. aligarhensis. Rates of parasitization on D. citri ranged from 1.5 to 24.2 % for T. radiata and 0.3 to 1.0 % for D. aligarhensis. With the present study, the presence of D. aligarhensis in Colombia becomes the second confirmed report of the species in South America, after Ecuador.
Diaphorencyrtus aligarhensis (Hymenoptera: Encyrtidae) se reporta por primera vez en Colombia con base en especímenes recolectados en el municipio de Palmira, departamento del Valle del Cauca. Los machos y hembras adultos del endoparasitoide D. aligarhensis se diagnostican con base en la literatura publicada y los estados de carácter tomados de las muestras recolectadas en el presente estudio. Los parasitoides adultos se extrajeron de ninfas parasitadas (momias) del psílido asiático de los cítricos, Diaphorina citri (Hemiptera: Liviidae). También se proporciona información sobre las diferencias en la morfología de las ninfas parasitadas de D. citri con orificios de salida de los dos principales parasitoides primarios, i.e., Tamarixia radiata (Hymenoptera: Eulophidae) y D. aligarhensis. Las tasas de parasitismo en D. citri variaron entre 1,5 y 24,2 % para T. radiata y entre 0,3 y 1,0 % para D. aligarhensis. Con el presente estudio, la presencia de D. aligarhensis en Colombia se convierte en el segundo reporte confirmado de la especie en América del Sur después de Ecuador.
Journal Article
Evolution of glandular structures on the scape of males in the genus Aphelinus Dalman (Hymenoptera, Aphelinidae)
The pores and associated glands on male antennae in species of Hymenoptera are involved in mate recognition and are diverse and widespread among taxa. However, nothing has been published about these structures in species of Aphelinus (Chalcidoidea: Aphelinidae), a genus of parasitoid wasps with a long history in biological control. Images from scanning electron microscopy (SEM) and transmission electron microscopy (TEM) of Aphelinus varipes revealed pores on the ventral side of the male scape that were connected to glands. A survey of the scapes of male antennae in 16 species in six species complexes of Aphelinus , as well as two outgroup species, Aphytis melinus and Centrodora sp., showed that pores were present in all except Centrodora sp. The pores varied in several characters: the shape of the structures that carried them, pore size, elevation of the cuticle surrounding the structures, the extent of a carina delimiting the area around the structures, and the number and position of pores. The shape of the pore-bearing structures, the elevation of cuticle around these structures, and the extent of the carina around them map well onto a molecular phylogeny of these Aphelinus species. Combinations of pore characters are diagnostic of species complexes, and in some cases, species of Aphelinus .
Journal Article