Integrating adverse effect analysis into environmental risk assessment for exotic generalist arthropod biological control agents: a three-tiered framework

Environmental risk assessments (ERAs) are required before utilizing exotic arthropods for biological control (BC). Present ERAs focus on exposure analysis (host/prey range) and have resulted in approval of many specialist exotic biological control agents (BCA). In comparison to specialists, generalist arthropod BCAs (GABCAs) have been considered inherently risky and less used in classical biological control. To safely consider exotic GABCAs, an ERA must include methods for the analysis of potential effects. A panel of 47 experts from 14 countries discussed, in six online forums over 12 months, scientific criteria for an ERA for exotic GABCAs. Using four case studies, a three-tiered ERA comprising Scoping, Screening and Definitive Assessments was developed. The ERA is primarily based on expert consultation, with decision processes in each tier that lead to the approval of the petition or the subsequent tier. In the Scoping Assessment, likelihood of establishment (for augmentative BC), and potential effect(s) are qualitatively assessed. If risks are identified, the Screening Assessment is conducted, in which 19 categories of effects (adverse and beneficial) are quantified. If a risk exceeds the proposed risk threshold in any of these categories, the analysis moves to the Definitive Assessment to identify potential non-target species in the respective category(ies). When at least one potential non-target species is at significant risk, long-term and indirect ecosystem risks must be quantified with actual data or the petition for release can be dismissed or withdrawn. The proposed ERA should contribute to the development of safe pathways for the use of low risk GABCAs

Mitochondrial physiology

As the knowledge base and importance of mitochondrial physiology to evolution, health and disease expands, the necessity for harmonizing the terminology concerning mitochondrial respiratory states and rates has become increasingly apparent. The chemiosmotic theory establishes the mechanism of energy transformation and coupling in oxidative phosphorylation. The unifying concept of the protonmotive force provides the framework for developing a consistent theoretical foundation of mitochondrial physiology and bioenergetics. We follow the latest SI guidelines and those of the International Union of Pure and Applied Chemistry (IUPAC) on terminology in physical chemistry, extended by considerations of open systems and thermodynamics of irreversible processes. The concept-driven constructive terminology incorporates the meaning of each quantity and aligns concepts and symbols with the nomenclature of classical bioenergetics. We endeavour to provide a balanced view of mitochondrial respiratory control and a critical discussion on reporting data of mitochondrial respiration in terms of metabolic flows and fluxes. Uniform standards for evaluation of respiratory states and rates will ultimately contribute to reproducibility between laboratories and thus support the development of data repositories of mitochondrial respiratory function in species, tissues, and cells. Clarity of concept and consistency of nomenclature facilitate effective transdisciplinary communication, education, and ultimately further discovery

Uptake and transfer of a Bt toxin by a Lepidoptera to its eggs and effects on its offspring.

Research on non-target effects of transgenic crop plants has focused primarily on bitrophic, tritrophic and indirect effects of entomotoxins from Bacillus thuringiensis, but little work has considered intergenerational transfer of Cry proteins. This work reports a lepidopteran (Chlosyne lacinia) taking up a Bt entomotoxin when exposed to sublethal or low concentrations, transferring the entomotoxin to eggs, and having adverse effects on the first filial generation (F1) offspring. Two bioassays were conducted using a sublethal concentration of toxin (100.0 ng/µl Cry1Ac) for adults and a concentration equal to the LC10 (2.0 ng/µl Cry1Ac) for larvae. Cry1Ac is the most common entomotoxin expressed in Bt cotton in Brazil. In the adult diet bioassay there was no adverse effect on the parental generation (P0) adults, but the F1 larvae had higher mortality and longer development time compared to F1 larvae of parents that did not ingest Cry1Ac. For the 3rd instar larvae, there was no measurable effect on the P0 larvae, pupae and adults, but the F1 larvae had higher mortality and longer development time. Using chemiluminescent Western Blot, Cry1Ac was detected in F1 eggs laid by P0 butterflies from both bioassays. Our study indicates that, at least for this species and these experimental conditions, a ∼65 kDa insecticidal protein can be taken up and transferred to descendants where it can increase mortality and development time

Cry1Ac detection (dashed square) in the egg masses of the lepidopteran <i>Chlosyne lacinia</i> by ECL Western Blot.

<p>Lanes: 1. Biotin Amersham ECL Ladder (GE Healthcare Life Science, USA); 2. One F₁ egg mass corresponding to around 100 eggs from the control group (parents without exposure to Cry1Ac); 3. One F₁ egg mass from P₀ adults exposed to Cry1Ac protein in the adult diet bioassay; 4. One F₁ egg mass from P₀ parents exposed to Cry1Ac protein in the third instar in the leaf dip bioassay.</p

Cry1Ac ligand blot receptors in the lepidopteran <i>Chlosyne lacinia</i> isolated from midgut BBMV.

<p>For each lane 10 µg of BBMV were used (<i>N</i> = 10 individuals). Lanes: 1. Larval BBMV without binding assay with biotinylated-Cry1Ac (control-group); 2. Larval BBMV binding assay with biotinylated-Cry1Ac; 3. Male butterfly BBMV without binding assay with biotinylated-Cry1Ac (control-group); 4. Male butterfly BBMV with binding assay with biotinylated-Cry1Ac; 5. Female butterfly BBMV without binding assay with biotinylated-Cry1Ac (control-group); and 6. Female butterfly BBMV with binding assay with biotinylated-Cry1Ac.</p

Adult diet bioassay with Cry1Ac on adult <i>Chlosyne lacinia</i> and their offspring.

<p>*The means are followed by standard deviations. Values followed by the same letter are not significantly different.</p><p>^†ns: not significantly different.</p

Mortality (%) of <i>Chlosyne lacinia</i> (Lepidoptera: Nymphalidae) larvae exposed to Cry1Ac on wild sunflower leaves after immersion for 30 s in a solution containing the indicated concentration of Cry1Ac and 0.02% Tween (<i>N</i> = 10 larvae per instar for each toxin concentration, and were replicated three times).

<p>*Values followed by the same letter are not significantly different. The first letter indicates the difference in the same column (related to the mortality in each Cry1Ac concentration in one instar) and the second letter indicates the difference in the same line (related to the mortality in one concentration of Cry1Ac among the instars). The comparison was made by GLM (P<0.01).</p