Ecology and Management of Stink Bugs (Hemiptera: Pentatomidae) in Southeastern Farmscapes

A three-year study (2009-2011) was conducted to examine the spatial and temporal dynamics of stink bugs in three commercial farmscapes in South Carolina and Georgia. Crops included wheat, Triticum aestivum (L.), corn, Zea mays (L.), soybean, Glycine max (L.), cotton, Gossypium hirsutum (L.), and peanuts, Arachis hypogaea (L.). Farmscapes were sampled weekly using whole-plant examinations for corn, with all other crops sampled using sweep nets. The predominant pest species of phytophagous stink bugs were the brown stink bug, Euschistus servus (Say), the green stink bug, Chinavia hilaris (Say), and the southern green stink bug, Nezara viridula (L.). Chi-square tests indicated a departure from a normal distribution in 77% of analyses of the variance to mean ratio, with 37% of slopes of Taylor\u27s power law and 30% of coefficient β of Iwao\u27s patchiness regression significantly greater than one, indicating aggregated distributions. SADIE indices indicated aggregated patterns of stink bugs in 18% of year-end totals and 42% of weekly counts, with 80% of adults and nymphs positively associated using the SADIE association tool. Peak stink bug densities were linked to crop phenology, following the fruiting pattern of crops in the farmscape. Stink bugs exhibited higher densities in crops adjacent to soybean in Barnwell and Lee Counties, SC, compared with crops adjacent to corn or fallow areas. Efficacy of applications of insecticide limited to the borders of fields to mitigate injury by stink bugs in cotton was evaluated from 2007 to 2011 in South Carolina and Georgia. Stink bug densities and boll injury were greater around the exterior compared with the interior portions of fields based on ANOVA models and interpolation maps of SADIE aggregation indices. Border and whole-field applications had no significant effect (P \u3e 0.05) on average numbers of stink bugs, but boll injury was significantly lower (P \u3c 0.05) in both border and whole-field insecticide treatments compared with untreated controls. No significant difference (P \u3e 0.05) was found between injury levels in fields receiving border or whole-field treatments. Fields receiving no insecticide treatments exceeded economic thresholds 55% of the time. Fields receiving whole-field and border applications of insecticide exceeded thresholds 41% and 30% of the time, respectively. Treated area was 4.4-fold smaller in fields receiving border applications than in fields receiving whole-field applications, indicating substantial savings in insecticide. Results suggested that border treatments of insecticides provided protection from stink bug injury similar to whole-field insecticide treatments, but with considerable savings in application costs. Studies of stink bugs in the field could be improved if movement could be monitored in real time. Harmonic radar tagging was investigated as a method for monitoring the movement of N. viridula. Because adhesive toxicity and tag weight limit the use of this technology, initial efforts focused on selection of the optimal adhesive and design of harmonic radar tags to reduce influence on movement of stink bugs. A design consisting of a 6-cm long 0.10-mm thick silver-plated copper monopole on the anode terminal of a three-contact Schottky barrier diode attached with a rubberized cyanoacrylate (Gorilla super glue) provided a compromise between unimpaired movement and tracking range, adding an additional 8% to the weight of the stink bug while not significantly (P \u3e 0.05) reducing walking or flying mobility in the laboratory. Recovery of tagged stink bugs in cotton and fallow fields ranged from 10-75% after 24 hours, while marked stink bugs were recovered at rates of 0-35% using sweep-net or drop-cloth sampling. The distance dispersed in the field was not influenced (P \u3e 0.05) by crop, tagged status, or gender of the insect. Future research should examine improvements to the harmonic radar transceiver and the wire antenna to decrease encumbrance. Laboratory studies were conducted to determine host preference of the tachinid parasitoid fly Trichopoda pennipes (F.) for E. servus and N. viridula. In choice and no-choice tests, 8-fold fewer eggs were laid on E. servus, compared with N. viridula. Twenty-four T. pennipes emerged from 100 N. viridula, whereas only two larvae emerged from 100 laboratory-parasitized E. servus. Post-mortem dissections of egg-bearing stink bugs without larval emergence revealed 20 T. pennipes larvae inside N. viridula but only one inside E. servus. These results confirmed that T. pennipes prefers N. viridula as a host and is likely an infrequent parasitoid of E. servus. While gathering T. pennipes for the selection trials, Cylindromyia euchenor (Walker), previously found in E. servus, was collected. Unlike most tachinids, which deposit eggs on or near the hosts, members of the genus Cylindromyia have an ovipositor formed from an abdominal sternite, which, assisted by serrated curved claspers, implants eggs directly into hosts. No research has been done on the behavior or host preferences of C. euchenor. My observations were limited to three females over approximately two weeks. Female parasitoids directly injected eggs into E. servus exclusively, ignoring N. viridula. The sequence of oviposition was recorded and described, demonstrating the ovipositional behavior for the first time and indicating a host preference for E. servus

Mediation and Moderation of Intergenerational Epigenetic Effects of Trauma

Trauma and early-life stress have been linked to poor mental and physical health outcomes. In fact, research has identified trauma and stress can influence epigenetic marks on genes that can alter gene activity. It is suspected that epigenetically altered gene activity is involved in behavior and mental health. This may help explain why some individuals don’t experience great benefit from treatment for the effects of stress, and severe mental health symptoms can be chronic for decades or a lifetime. Moreover, some trauma-related mental health symptoms have shown generational patterns that appear linked to epigenetic marks. Therefore, this study sought to investigate the potential inter-generational influence of mother’s trauma history and mental health on her offspring’s DNA methylation and gene expression in umbilical cord blood. Standardized measures were used to assess mother’s trauma history and cumulative experienced fear (TLEQ), as well as mother’s mental health status during pregnancy (BSI). Genome-wide and candidate gene analyses were conducted after standard quality control data cleaning procedures. Batch and chip adjustments were made using the Combat package in R software, and the False Discovery Rate was employed to control for multiple comparisons. Results indicate mother’s exposure to trauma in childhood predicts DNA methylation and gene expression in offspring. Additionally, mother’s mental health status during pregnancy significantly predicts differential gene expression on 245 genes in males only. Finally, mother’s fear completely mediates the influence of trauma on her mental health functioning. In conclusion, a mother’s traumatic experience has potential to influence gene regulation in her offspring. Most importantly, mother’s mental health during pregnancy appears to exert a great influence on gene regulation in males compared to female offspring

Maternal trauma and fear history predict BDNF methylation and gene expression in newborns

Trauma and related fear exert significant influence on mental and physical health throughout the lifespan and are associated with intergenerational patterns of development, health, and behavior. DNA methylation and gene expression are involved in our developmental adaptations to our experiences and can be influenced by social interventions. Patterns of DNA methylation and expression of a gene involved in neurodevelopment and psychiatric risk (BDNF) have been linked with childhood trauma. Given the intergenerational patterns of health and behavior, and previous links between childhood trauma and BDNF methylation and expression, this study investigated the potential for maternal history of traumatic experiences to influence development in her newborn, via changes in her newborn's BDNF methylation and expression. We found that mothers' trauma history was associated with epigenetic regulation of BDNF in their newborns. Moreover, the association between maternal trauma and BDNF methylation and expression patterns were moderated by newborn sex. Male newborns showed increased BDNF expression with maternal exposure to child abuse (p = .001), and increased BDNF methylation with greater maternal fear (p = .001). Female newborns showed reduced BDNF expression with greater maternal fear (p = .004). Practitioners strive to identify prevention and intervention avenues that will reduce the harmful effects of trauma. Future research should consider the potential for maternal historical trauma experiences to influence offspring DNA methylation and gene expression in a manner that could alter development and inform novel prevention strategies

SLC6A4 gene variants moderate associations between childhood food insecurity and adolescent mental health

Abstract Background Food insecurity is a persistent concern in the United States and has been shown to affect child mental health and behavior. The SLC6A4 gene has been indicated as a moderator of the effects of chronic stress on anxiety in adolescents aged 14–21. However, it is unclear if SLC6A4 may also play a role in the effects of childhood food insecurity, a form of chronic stress, on adolescent mental health. This study aimed to identify effects of food insecurity on adolescents’ mental health and delinquent behavior when both mom and child go hungry in the child's early years, and the potential interaction with SLC6A4 variants (SS/LL). Methods The data and sample for this research are from the Future of Families and Child Wellbeing Study. The cohort consists of 4898 children (age 1–15 years, male = 47%, African American = 50%) and their respective caregivers sampled from large cities in the United States from 1998 to 2000. Results The SLC6A4 serotonin transporter short/short allele emerged statistically significant as a moderator of childhood food insecurity and adolescent mental health. Specifically, the presence of the short/short allele increased anxiety symptoms in adolescents with exposure to food insecurity in childhood. Conclusion The SLC6A4 short/short allele amplifies risk of anxiety‐related mental illness when children experience food insecurity. The gene–environment interaction provides insight into the mechanistic pathway of the effects of poverty‐related adversity, such as food insecurity, on developmental trajectories of mental health