Impact of Biochar on Douglas-Fir Tussock Moth (Orgyia pseudotsugata Lepidoptera: Erebidae) Larvae Reared on Synthetic Die

The use of biochar as a soil amendment in forest ecosystems can be beneficial in the restoration of degraded soils. Forest insects such as the Douglas-fir tussock moth, Orgyia pseudotsugata (McDonnough) (Lepidoptera: Erebidae), may be exposed to biochar when the material is applied. Two experiments were conducted using biochar either (1) applied to the surface of the diet at three rates (0, 5, and 10 mg) or (2) incorporated into synthetic diet at four rates (0, 10, 20, and 40% volume/volume). The objective of both experiments was to determine if biochar on the surface or incorporated into a synthetic diet affected development and survival of O. pseudotsugata larvae. In both experiments, there was a significant decrease in estimated time to larval mortality in all biochar treatments compared to untreated controls. In the surface-applied biochar experiment, there was a significant difference in larval weight gain at day 12 between the control and 10 mg biochar treatments. In the experiment with biochar incorporated into the diet, mean larval weight at day 12 was highest in the low (10%) biochar treatment compared to all other treatments, although weight gain was only significantly different between the low- and high-concentration (40%) biochar treatments. Our results suggest that larvae, feeding on a low amount of biochar in the synthetic diet, may respond by engaging in compensatory feeding behavior. Fewer surviving larvae in the biochar treatment groups may contribute to the lack of significance found in the comparison of weight gain at day 24 in each experiment.

Evaluating the effects of Bt protein Vip3Aa on immature Propylea japonica (Thunberg) (Coleoptera: Coccinellidae)

Background Genetically modified (GM) crops have become a common tool for managing insect pests of economic importance. However, before their commercialization, bio-safety evaluation on non-target arthropods such as pollinators and biological control agents is a pre-requisite to save services rendered by them in agro-ecosystem. Results In the present experiment, the potential adverse effects of Bt protein (Vip3Aa) were studied on the life table parameters (pupation and emergence rates, 7-day larval weights, larval development time, and adult weight) of a predatory beetle, Propylea japonica (Thunberg) (Coleoptera: Coccinellidae) in the laboratory. P. japonica was exposed to Bt protein incorporated in synthetic diet at the rate of 200 µg/g of fresh weight of diet. Temporal stability, bioactivity and the uptake of insecticidal protein were confirmed by enzyme-linked immunosorbent assay and a sensitive insect bioassay. The results indicated that pupation and adult emergence rates did not differ significantly from that of negative control (pure synthetic diet). Similarly, the fresh weight of male and female adults emerged in Vip3Aa treatment (2.87 mg and 3.86 mg, respectively) did not vary significantly from that of the negative control treatment (2.66 mg, 3.75 mg). However, the time taken by the larvae to complete their development (12.70 days) was significantly extended than that of the negative control (10.21 days). In contrast, the tested life-table parameters of P. japonica were adversely affected when fed on synthetic diet containing boric acid (positive control) indicating experimental fitness to detect adverse effects. Conclusions On the basis of the results, it is suggested that GM crops expressing Bt protein (Vip3Aa) are safe for non-target insects such as P. japonica and are compatible with other biological programs for the integrated management of insect pests.

Short communication: the effects of a semi-synthetic diet with inclusion of black soldier fly larvae meal on health parameters of healthy adult cats

In recent years, black soldier fly larvae meal (Hermetia illucens; BSFLM) has gained attention as a high value alternative protein source that is of great interest to the pet food industry. However, little is known regarding the effects of BSFLM on health parameters in adult cats. Thus, the objective of the current study was to determine the short-term effects of a semi-synthetic diet containing 4.6% inclusion of BSFLM on complete blood count (CBC) and serum biochemistry profile of healthy adult cats. Healthy adult male cats (n=8; 1.4 years) were fed the experimental diet for 21d (experimental period) to maintain BW. Cats were washed in on a commercial diet and blood samples were collected before the start and at the end of the experimental period to measure gross health parameters. Results were analysed as one-way ANOVA using the GLIMMIX procedure in SAS with cat as a random effect (SAS v. 9.4, The SAS Institute, Cary, NC). Cats lost an average of 5% of their BW (P=0.0003) due to a concurrent decrease in food intake. A significant increase of alanine aminotransferase, chloride, potassium, sodium, mean corpuscular hemoglobin and mean corpuscular haemoglobin concentration was observed on d21 vs. baseline (P < 0.05). In contrast, albumin, amylase, calcium, cholesterol, eosinophil, lymphocyte, monocyte, mean platelet volume, red blood cells, total protein, total solid proteins and urea decreased over time (P < 0.05). However, all CBC and serum biochemistry parameters stayed within reference range for adult cats, with exception of glucose and mean corpuscular haemoglobin concentration that were above and below the reference range, respectively. Transient increases in glucose concentrations were likely due to sedation with dexmedetomidine prior to blood collection. The changes observed over time in the aforementioned parameters are likely due to changes in macronutrient composition of the diets offered prior to and during the experimental period (commercial diet vs. semi-synthetic diet, respectively), and cannot be attributed solely to a unique property of BSFLM. In conclusion, cats fed a semi-synthetic diet containing 4% BSFLM inclusion for 21d remained healthy with no clinically relevant changes in CBC and serum biochemistry parameters. Further research should focus on longer term feeding studies and the ability of BSFLM to support the health and well-being of cats.

Age-Stage, Two-Sex Life Table of Chrysodeixis chalcites (Lepidoptera: Noctuidae) at Constant Temperatures on Semi-Synthetic Diet

The golden twin-spot moth or tomato looper, Chrysodeixis chalcites (Esper), is a polyphagous and worldwide pest that causes important aesthetic damages to banana fruits in the Canary Islands. The life history parameters of C. chalcites were determined under laboratory conditions in base on the age-stage, two-sex life table at 15, 20, 25, 30, and 35°C, 65% relative humidity (RH), and a photoperiod of 16:8 (L:D) h, when it was reared on a semi-synthetic diet. The results show that C. chalcites was able to develop and survive from 15 to 30°C, but no development occurred at 35°C. Developmental threshold temperatures of the egg, larval, pupal, and total preoviposition stages were 10.42, 11.73, 11.22, and 9.42°C, respectively, and their effective accumulated temperatures were 58.31, 265.96, 118.57, and 562.39 degree-days, respectively. The adult longevity was reduced with increasing temperature, which ranged between 16.27 and 34.85 d for females and between 14.27 and 35.21 d for males. The highest values of net reproductive rate (R0) and fecundity were observed at 25°C, with 232.70 offspring and 1,224.74 eggs, respectively. Both the intrinsic rate of increase (r) and finite rate of increase (λ) increased significantly and mean generation time (T) decreased significantly with increasing temperature. These results provide useful information that will allow predicting the impact of climate change on the distribution and population dynamics of C. chalcites and developing successful integrated management programs.

Functional state of rat kidneys under the conditions of acetaminophen-induced injury on the background of alimentary deprivation of protein

The article explores the functional state of kidneys in animals with acetaminophen-induced intoxication, which were maintained under the conditions of different protein supply. The research model involved the division of animals into next equal groups: group I – rats, which were maintained on a complete semi-synthetic diet; group II – rats, which were kept on a low-protein diet; ІІІ – rats with acetaminophen-induced injury, maintained on a complete semi-synthetic diet; IV – rats with acetaminophen-induced injury, which were previously kept on the low-protein diet. It was established, that kidney function of animals, which were maintained in conditions of the alimentary deprivation of protein, was characterized by the disturbances of the filtration capacity on the background of a slight decrease in reabsorption capacity. It is evidenced by a minor increase in GGT activity and urine Na+ level, along with significant proteinuria against the background of GFR reduction and preservation of plasma creatinine level. In animals with acetaminophen-induced injury, an increase in GGT activity, urine Na+ level and proteinuria in the absence of GFR and plasma creatinine changes, indicates the primary damage to renal tubular cells, while maintaining the filtration capacity of the kidney. The most significant changes in the filtration capacity of kidney were recorded in animals receiving toxic doses of acetaminophen on the background of alimentary deficiency of protein: a significant increase in plasma creatinine on the background of a 4-fold decrease in glomerular filtration. Proteinuria, increased γ-glutamyltransferase activity, and an increase in urine Na+ level indicates the damage to tubular cells and impaired renal reabsorption capacity. The conclusion was made, that lack of protein in the diet is a factor leading to a worsening of kidney dysfunction in animals with acetaminophen-induced intoxication since under those conditions disturbances of both filtration and reabsorption capacity of the kidney are observed.