Transovarial effect of novaluron: persistence and residual effects on Stephanitis pyrioides (Hemiptera: Tingidae)

Stephanitis pyrioides (Scott) (Hemiptera: Tingidae) is an important insect pest of azaleas, Rhododendron Linnaeus spp. (Ericaceae), in the United States of America. Because neonicotinoids, insecticides traditionally used against S. pyrioides, pose a risk to pollinators and natural enemies, nursery growers have reduced neonicotinoid use and are seeking alternative management options. Novaluron, an insect growth regulator, elicits a transovarial effect by reducing the viability of eggs after exposure to S. pyrioides adults. However, stability and persistence of transovarial effects on adults following exposure are not clear. The objectives of this study were to determine (1) the persistence of the transovarial effect of novaluron for up to three weeks after a single adult exposure and (2) the residual activity of aged novaluron residues eliciting a transovarial effect against S. pyrioides after a single application. Stephanitis pyrioides density was significantly lower in the novaluron-treated adults than in the nontreated controls for up to 21 days. The novaluron residues deposited on azalea foliage aged up to 32 days significantly reduced the number of S. pyrioides nymphs compared to that of the nontreated control. There was no significant difference in the number of nymphs among the 7-, 17-, and 32-day-old novaluron treatments relative to the nontreated control.

Context in Continuity: The Enduring Legacy of Neighborhood Disadvantage Across Generations

Neighborhoods may contribute to the maintenance of inequality in well-being across generations. We use 35 years of restricted geo-coded NLSY 1979 and NLSY Children and Young Adults data to estimate the association between multigenerational exposure to childhood neighborhood disadvantage and subsequent adult exposure. Invoking cousin fixed effects models that adjust for unobserved legacies of disadvantage that cascade across generations, we find that families where both parents and their children are exposed to childhood neighborhood disadvantage are likely to pass on the legacy of neighborhood disadvantage to successive generations, net of observed and unobserved confounders. Second, we find a direct intergenerational neighborhood association, net of observed and unobserved confounders. Third, we find that unobserved confounders nested in previous generations explain away the intragenerational neighborhood association. These findings reorient neighborhood theory to more seriously attend to the interdependence of neighborhood level and individual level antecedents of inequality across generations.

Evaluating the Levels and Human Health Risks of Heavy Metals in Soils around Onne Landfill, Rivers State, Nigeria

This study evaluated selected heavy metals’ levels in soil around the landfill in Onne Rivers State, Nigeria. It also examines potential human health risks due to exposure to the contaminated soil. Composite samples of soils from the northern, southern, eastern and western domains of the landfill were collected, processed, and analysed for heavy metals using atomic absorption spectrophotometry, and their human health risks were evaluated. The heavy metals’ levels in the soils around the four domains were in the order Pb>Cr>Ni>Cd>As. Children and adult ingestion, inhalation and dermal hazards quotients for the selected metals in the four domains were below unity ranging from {(HQchildren 2.71 x 10-10 As inhalation in the eastern domain to 9.24 x 10-1 Pb ingestion in the northern domain); HQadult 1.55 x 10-10 As inhalation in the eastern domain to 9.90 x 10-2 Pb ingestion in the northern domain)}. Adult ingestion, inhalation and dermal cancer risks (CRadult) were within acceptable limits, ranging from 1.99 x 10-13 As inhalation in the eastern domain to 4.68 x10-5 Cr ingestion in the northern domain. However, ingestion cancer risk for children (CRchildren) due to exposure to Ni and Cr in the four domains were above tolerable limit ranging from {(Ni - 2.00 x 10-4 in the southern domain to 3.11 x 10-4 in the northern domain); Cr – 2.95 x 10-4 in the southern domain to 4.37 x 10-4 in the northern domain)}. Children and adult hazards index due to exposure to the selected metals were also less than 1.0, ranging from children exposure to Ni (5.91 x 10-3) in the southern domain and Pb (9.25 x 10-1) in the northern domain to adult exposure to Ni (6.50 x 10-4 in the southern domain and Pb (9.94 x 10-2) in the northern domain. Total cancer risks (TCRadult) due to adult exposure to the metals were within tolerable limit, ranging from Cd (4.93 x 10-7) in the southern domain to Cr (5.01 x 10-5) in the northern domain. And total cancer risk (TCRchildren) due to children exposure to Ni and Cr were above tolerable limit, ranging from {Ni (2.40 x 10-4 in the southern domain to 3.74 x 10-4 in the northern domain); Cr (3.54 x 10-4 in the southern domain to 5.24 x 10-4 in the northern domain)}. The values for both non carcinogenic and carcinogenic risks were higher for children than those for adult. Reasons for this attributes and improvement actions were suggested.

Adult exposure to ocean acidification and warming remains beneficial for oyster larvae following starvation

Climate change is expected to warm and acidify oceans and alter the phenology of phytoplankton, creating a mismatch between larvae and their food. Transgenerational plasticity (TGP) may allow marine species to acclimate to climate change; however, it is expected that this may come with elevated energetic demands. This study used the oysters, Saccostrea glomerata and Crassostrea gigas, to test the effects of adult parental exposure to elevated pCO2 and temperature on larvae during starvation and recovery. It was anticipated that beneficial effects of TGP will be limited when larvae oyster are starved. Transgenerational responses and lipid reserves of larvae were measured for 2 weeks. Larvae of C. gigas and S. glomerata from parents exposed to elevated pCO2 had greater survival when exposed to elevated CO2, but this differed between species and temperature. For S. glomerata, survival of larvae was greatest when the conditions experienced by larvae matched the condition of their parents. For C. gigas, survival of larvae was greater when parents and larvae were exposed to elevated pCO2. Larvae of both species used lipids when starved. The total lipid content was dependent on parental exposure and temperature. Against expectations, the beneficial TGP responses of larvae remained, despite starvation.

Knockdown-Mortality Responses of Six Stored-Product Beetle Species on Different Surfaces Treated With Thiamethoxam, Using a Standardized Lethality Index

Bioassays were conducted to evaluate the effectiveness of thiamethoxam in different surfaces, against six stored-grain insects, Sitophilus granarius (L.) (Coleoptera: Curculionidae), Sitophilus oryzae (L.) (Coleoptera: Curculionidae), Tribolium confusum Jacquelin du Val (Coleoptera: Tenebrionidae), Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae), Cryptolestes ferrugineus (Stephens) (Coleoptera: Laemophloeidae), and Oryzaephilus surinamensis (L.) (Coleoptera: Silvanidae). Six different surfaces (concrete, plywood, galvanized steel, linen, plastic, and ceramic tile) treated with thiamethoxam at 0.05 and 0.1 mg/cm2 were used as substrate for adult exposure. Knockdown was recorded after 1, 3, and 7 d of exposure to the treated surface, in order to calculate a Standardized Lethality Index (SLI). Knockdown counts were ranked from ‘0’ to ‘4’, with ‘0’ representing adult insects ‘moved generally’ and ‘4’ representing dead insects. Based on the results, insect knockdown seems leading to mortality than to recovery and the SLI ranking of the target species according to their susceptibility to thiamethoxam showed that S. granarius being more susceptible and decreasing susceptibility in an order of S. oryzae > T. castaneum ≥ O. surinamenis ≥ C. ferrugineus ≥ T. confusum. In general, among the surfaces, thiamethoxam efficacy was lower on linen, wooden, and concrete surfaces, as compared to metallic and plastic surfaces. Nevertheless, at the end of 7-d exposure, all surfaces equally affected thiamethoxam toxicity.