Chitosan Films Obtained from Brachystola magna (Girard) and Its Evaluation on Quality Attributes in Sausages during Storage.

High molecular weight chitosan (≈322 kDa) was obtained from chitin isolated from Brachystola magna (Girard) to produced biodegradable films. Their physicochemical, mechanical and water vapor permeability (WVP) properties were compared against commercial chitosan films with different molecular weights. Brachystola magna chitosan films (CFBM) exhibited similar physicochemical and mechanical characteristics to those of commercial chitosans. The CFBM films presented lower WVP values (10.01 × 10-11 g/m s Pa) than commercial chitosans films (from 16.06 × 10-11 to 64.30 × 10-11 g/m s Pa). Frankfurt-type sausages were covered with chitosan films and stored in refrigerated conditions (4 °C). Their quality attributes (color, weight loss, pH, moisture, texture and lipid oxidation) were evaluated at 0, 5, 10, 15 and 20 days. Sausages covered with CFMB films presented the lowest weight loss (from 1.24% to 2.38%). A higher increase in hardness (from 22.32 N to 30.63 N) was observed in sausages covered with CFMB films. Compared with other films and the control (uncovered sausages), CFMB films delay pH reduction. Moreover, this film presents the lower lipid oxidation level (0.10 malonaldehyde mg/sample kg). Thus, chitosan of B. magna could be a good alternative as packaging material for meat products with high-fat content.

The Effects of Structural Alterations in the Polyamine and Amino Acid Moieties of Philanthotoxins on Nicotinic Acetylcholine Receptor Inhibition in the Locust, Schistocerca gregaria.

Alterations in the polyamine and amino acid (tyrosine) moieties of philanthotoxin-343 (PhTX-343) were investigated for their effects on the antagonism of nicotinic acetylcholine receptors (nAChRs) isolated from the locust (Schistocerca gregaria) mushroom body. Through whole-cell patch-clamp recordings, the philanthotoxin analogues in this study were shown to cause inhibition of the inward current when co-applied with acetylcholine (ACh). PhTX-343 (IC50 = 0.80 µM at -75 mV) antagonised locust nAChRs in a use-dependent manner, suggesting that it acts as an open-channel blocker. The analogue in which both the secondary amine functionalities were replaced with methylene groups (i.e., PhTX-12) was ~6-fold more potent (IC50 (half-maximal inhibitory concentration) = 0.13 µM at -75 mV) than PhTX-343. The analogue containing cyclohexylalanine as a substitute for the tyrosine moiety of PhTX-343 (i.e., Cha-PhTX-343) was also more potent (IC50 = 0.44 µM at -75 mV). A combination of both alterations to PhTX-343 generated the most potent analogue, i.e., Cha-PhTX-12 (IC50 = 1.71 nM at -75 mV). Modulation by PhTX-343 and Cha-PhTX-343 fell into two distinct groups, indicating the presence of two pharmacologically distinct nAChR groups in the locust mushroom body. In the first group, all concentrations of PhTX-343 and Cha-PhTX-343 inhibited responses to ACh. In the second group, application of PhTX-343 or Cha-PhTX-343 at concentrations ≤100 nM caused potentiation, while concentrations ≥ 1 µM inhibited responses to ACh. Cha-PhTX-12 may have potential to be developed into insecticidal compounds with a novel mode of action.

High-Strength Nanostructured Films Based on Well-Preserved α-Chitin Nanofibrils Disintegrated from Insect Cuticles.

The α-chitin nanofibril is an alternative to nanocellulose as a building-block for strong films and other nanomaterials. The hypothesis of high film strength for films based on mildly treated insect cuticles was tested. Fibrils from the cuticle of Ruspolia differens (a long-horned bush cricket grasshopper locally known as senene) are disintegrated by a mild process, subsequently characterized by transmission electron microscopy, NMR, Fourier transform infrared spectroscopy, and XRD, and used to prepare strong and transparent films. A mild process (with 20% NaOH treatment for 2 weeks and at room temperature) was used to largely remove the strongly bound protein associated with chitin. The purpose was to reduce chitin degradation. The native structure of chitin was indeed well preserved and close to the native state, as is supported by data for degree of acetylation, molar mass, crystallinity, and crystallite dimensions. The diameter of the smallest chitin fibrils was as small as 3-7 nm (average 6 nm) with lengths larger than or around 1 µm. A stable and well-dispersed colloidal chitin fibril suspension in water was achieved. A nanostructured chitin film prepared by filtration showed high optical transmittance (∼90%) and very high tensile strength (220 MPa). The high tensile strength was attributed to the well-preserved chitin structure, high intrinsic fibril strength, and high colloidal stability of the fibril suspension. Strong, transparent insect chitin films offer interesting alternatives to nanocellulose films because of different resource origins, surface chemistries, and potential antimicrobial properties.

Protective effects of Oxya chinensis sinuosa Mishchenko against ultraviolet B-induced photodamage in hairless mice.

BACKGROUND: Edible insects, including Oxya chinensis sinuosa Mishchenko (Oc), which is consumed as food in Asia, are considered as a human food shortage alternative, and also as a preventive measure against environmental destruction. Ultraviolet B (UVB) irradiation, which causes skin photodamage, is considered as an extrinsic skin aging factor. It reduces skin hydration, and increases wrinkle formation and reactive oxygen species (ROS) and inflammatory cytokine expression. Thus, the objective of this study was to investigate the anti-aging effects of an ethanol extract of Oc (Oc.Ex). METHODS: A UVB-irradiated hairless mouse model was used to examine relevant changes in skin hydration, wrinkle formation, and skin epidermal thickness. Also, antioxidant markers such as superoxide dismutase (SOD) and catalase (CAT) were analyzed, and Oc. Ex skin protective effects against UVB irradiation-induced photoaging were examined by determining the levels of skin hydration factors. RESULTS: Oc.Ex improved epidermal barrier dysfunctions such as increased transepidermal water loss (TEWL) and capacitance reduction in UVB-irradiated mice. It upregulated skin hydration-related markers, including hyaluronic acid (HA), transforming growth factor (TGF)-ß, and pro-collagen, in UVB-irradiated mice, compared with the vehicle control group. It also reduced UVB-induced wrinkle formation, collagen degradation, and epidermal thickness. Additionally, it remarkably suppressed the increased expression of matrix metalloproteinases (MMPs), and restored the activity of SOD and CAT in UVB-irradiated mice, compared with the vehicle control group. Furthermore, Oc. Ex treatment downregulated the production of inflammatory cytokines and phosphorylation of the mitogen-activated protein kinases (MAPKs) signaling pathway activated by UVB irradiation. CONCLUSION: This study revealed that Oc. Ex reduced skin thickness and the degradation of collagen fibers by increasing hydration markers and collagen-regulating factors in the skin of UVB-irradiated mice. It also inhibited UVB-induced antioxidant enzyme activity and inflammatory cytokine expression via MAPK signaling downregulation, suggesting that it prevents UVB-induced skin damage and photoaging, and has potential for clinical development in skin disease treatment.

Schistocerca piceifrons piceifrons (Orthoptera: Acrididae) as a Source of Compounds of Biotechnological and Nutritional Interest.

The Central American locust, Schistocerca piceifrons piceifrons (Walker) is a major agricultural pest in Mexico and Central America. Control measures against this pest have generated much environmental damage and substantial financial costs because chemical insecticides are used. Yet various Orthoptera species also appear to be a potential source of nutrients and a source of bioactive metabolites. Here, we studied the presence of secondary metabolites in the adult stage of S. p. piceifrons by applying different colorimetric techniques. Adults were collected from the southern region of Tamaulipas, Mexico, during September-December 2017. These samples were subjected to sequential processes of eviscerating, drying, pulverizing, extracting, and detecting of metabolites. Extractions were carried out in water, 50% ethanol, and absolute ethanol. The presence of phenolic compounds, alkaloids, tannins, saponins, flavonoids, and quantity of antioxidants against the DPPH (2, 2-diphenyl-1-picrylhydrazyl) and ABTS (2, 2'-azino-bis, 3-ethylbenzothiazoline-6-sulfonic acid) radicals were determined and reported. Proximate analysis showed that S. p. piceifrons has a high protein content (80.26%), low fat content (6.21%), and fiber content (12.56%) similar to other Orthoptera species. Chitin and chitosan contents of S. p. piceifrons were 11.88 and 9.11%, respectively; the recovery percentage of chitosan from chitin was 76.71%. Among the Orthoptera, the protein content of this pest is among the highest while its contents of chitin and chitosan are similar to those of other insect species (e.g., Bombix mori Linnaeus [Lepidoptera: Bombycidae]). Our results suggest this pest species is a potential source of bioactive compounds of biotechnological interest for use by pharmaceutical and food industries.

Transfer of C-terminal residues of human apolipoprotein A-I to insect apolipophorin III creates a two-domain chimeric protein with enhanced lipid binding activity.

Apolipophorin III (apoLp-III) is an insect apolipoprotein (18kDa) that comprises a single five-helix bundle domain. In contrast, human apolipoprotein A-I (apoA-I) is a 28kDa two-domain protein: an α-helical N-terminal domain (residues 1-189) and a less structured C-terminal domain (residues 190-243). To better understand the apolipoprotein domain organization, a novel chimeric protein was engineered by attaching residues 179 to 243 of apoA-I to the C-terminal end of apoLp-III. The apoLp-III/apoA-I chimera was successfully expressed and purified in E. coli. Western blot analysis and mass spectrometry confirmed the presence of the C-terminal domain of apoA-I within the chimera. While parent apoLp-III did not self-associate, the chimera formed oligomers similar to apoA-I. The chimera displayed a lower α-helical content, but the stability remained similar compared to apoLp-III, consistent with the addition of a less structured domain. The chimera was able to solubilize phospholipid vesicles at a significantly higher rate compared to apoLp-III, approaching that of apoA-I. The chimera was more effective in protecting phospholipase C-treated low density lipoprotein from aggregation compared to apoLp-III. In addition, binding interaction of the chimera with phosphatidylglycerol vesicles and lipopolysaccharides was considerably improved compared to apoLp-III. Thus, addition of the C-terminal domain of apoA-I to apoLp-III created a two-domain protein, with self-association, lipid and lipopolysaccharide binding properties similar to apoA-I. The apoA-I like behavior of the chimera indicate that these properties are independent from residues residing in the N-terminal domain of apoA-I, and that they can be transferred from apoA-I to apoLp-III.

Identification of a hypertrehalosemic factor in Spodoptera exigua.

Trehalose is a major blood sugar in insects with a range of physiological functions, including an energy source and a cryoprotectant. Hemolymph trehalose concentrations are tightly regulated according to physiological conditions. An insulin-like peptide, SeILP1, downregulates hemolymph trehalose concentrations in Spodoptera exigua. Here, we identified a factor that upregulates hemolymph trehalose concentration in S. exigua. Hemolymph trehalose concentrations were significantly increased after immune challenge or under starvation in a time-dependent manner. To determine endocrine factors responsible for the upregulation, stress-associated mediators, such as octopamine, serotonin, or eicosanoids were injected, but they did not upregulate hemolymph trehalose. On the other hand, injection with Schistocerca gregaria adipokinetic hormone (AKH) significantly increased hemolymph trehalose concentration in S. exigua. During upregulation of hemolymph trehalose by AKH injection, trehalose degradation appeared to be inhibited because expression of trehalase and SeILP1 were significantly suppressed while that of trehalose phosphate synthase was not significantly changed. Interrogation of a Spodoptera genome database identified an S. exigua AKH-like gene and its expression was confirmed. During starvation, its expression concentrations were increased, although RNA interference specific to the AKH-like hypertrehalosemic factor (SeHTF) gene significantly prevented the upregulation of hemolymph trehalose concentrations during starvation. A synthetic peptide of SeHTF was prepared and injected into S. exigua larvae. At nanomolar concentration, the synthetic SeHTF peptide effectively upregulated hemolymph trehalose concentrations. Here we report a novel hypertrehalosemic factor in S. exigua (SeHTF).

First protein and peptide characterization of the tarsal adhesive secretions in the desert locust, Schistocerca gregaria, and the Madagascar hissing cockroach, Gromphadorhina portentosa.

Peptides and proteins have been largely neglected in the analysis of insect tarsal adhesives. After extraction of the protein fraction of the tarsal secretion of the desert locust, Schistocerca gregaria, and Madagascar hissing cockroach, Gromphadorhina portentosa, we combined Fourier transform infrared spectroscopy (FTIR), sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) and matrix-assisted laser desorption/ionization mass spectrometry (MALDI-TOF MS) analyses for protein mass detection. In both these insects, SDS-PAGE analysis revealed several protein bands ranging from 8-190 kDa in both the tarsal secretion and the tibia control sample. Two (S. gregaria) and one (G. portentosa) protein bands exclusively occurred in the tarsal secretion and can be considered to belong to peptides and proteins specific to this secretion. MALDI-TOF analyses revealed 83 different proteins/peptides of 1-7 kDa in S. gregaria, and 48 of 1-11 kDa in G. portentosa. 59 (S. gregaria) and 27 (G. portentosa) proteins exclusively occurred in the tarsal secretion. In G. portentosa, a characteristic series of signal peaks occurred in the range of c. 10-12 kDa, each peak being approximately 160 Da apart. Such a pattern is indicative of proteins modified by glycosylation. Our approach demonstrates that extensive sampling involving considerable time and manpower to sample the adhesive fluid directly from the tarsi opens up a perspective for extracting peptides and proteins in sufficient quantities. This makes them accessible to the field of proteomics and thus to elucidate their possible function in the adhesive process.

Abiotic, biotic, and evolutionary control of the distribution of C and N isotopes in food webs.

Ecosystem functioning depends on nutrient cycles and their responses to abiotic and biotic determinants, with the influence of evolutionary legacies being generally overlooked in ecosystem ecology. Along a broad elevation gradient characterized by shifting climatic and grazing environments, we addressed clines of plant N and C∶N content and of δ(13)C and δ(15)N in producers (herbs) and in primary (grasshoppers) and secondary (birds) consumers, both within and between species in phylogenetically controlled scenarios. We found parallel and significant intra- and interspecific trends of isotopic variation with elevation in the three groups. In primary producers, nutrient and isotope distributions had a detectable phylogenetic signal that constrained their variation along the environmental gradient. The influence of the environment could not be ascribed to any single factor, and both grazing and climate had an effect on leaf stoichiometry and, thus, on the resources available to consumers. Trends in consumers matched those in plants but often became nonsignificant after controlling for isotopic values of their direct resources, revealing direct bottom-up control and little phylogenetic dependence. By integrating ecosystem and mechanistic perspectives, we found that nutrient dynamics in food webs are governed at the base by the complex interaction between local determinants and evolutionary factors.

RELATIONSHIP BETWEEN SUPERCOOLING CAPABILITY AND CRYOPROTECTANT CONTENT IN EGGS OF PARARCYPTERA MICROPTERA MERIDIONALIS (ORTHOPTERA: ACRYPTERIDAE).

BACKGROUND: Grasshoppers are major agricultural pests throughout the world. The egg stage is important for the low temperature resistance, and almost all grasshoppers overwinter in the egg stage. OBJECTIVE: To study the relationship between cold hardiness and cryoprotectant content in Pararcyptera microptera meridionalis eggs. MATERIALS AND METHODS: The supercooling point (SCP) of the eggs was measured, along with the contents of water, fat, amino acids, low molecular sugars and polyols. RESULTS: SCP, water content and glucose concentration decreased during egg development, whereas the contents of fat, trehalose, glycerol, inositol and sorbitol increased. SCP is negatively correlated with the concentrations of fat, trehalose, glycerol, inositol and sorbitol, but positively with water content and glucose concentration. Among low molecular weight sugars and polyols tested in eggs, trehalose concentration was highest, followed by glycerol. Although total content of free amino acids did not change much, of the tested 17 free amino acids in eggs, proline and glutamine had increased by 46.3 % and 13.2 %, respectively, and both showed a negative correlation with SCP. Stepwise regression analysis showed that proline, glycerol, trehalose and inositol contribute most to the SCP depression. Cold acclimation at 0 degree C increased the contents of trehalose and glycerol, and decreased SCP. CONCLUSION: The increase of the supercooling capacity in P. microptera meridionalis eggs during development could be attributed mainly to proline, glycerol, trehalose and inositol. Cold acclimation enhances supercooling capacity via glycerol and trehalose.

Identification of methyl farnesoate from the hemolymph of insects.

Methyl farnesoate, [methyl (2E,6E)-3,7,11-trimethyldodeca-2,6,10-trienoate (1)] has not been thought be present in the hemolymph of insects, although it is the immediate biosynthetic precursor of the circulating insect hormone juvenile hormone III (methyl (2E,6E)-10,11-epoxy-3,7,11-trimethyl-2,6-dodecadienoate) (2). Compound 1 was identified from the hemolymph obtained from five orders of insects. Identification of 1 from the American bird grasshopper was facilitated using both electron impact and chemical-ionization GC-MS, GC-FTIR, and 2D NMR techniques. The identifications from other insects were made using GC-MS, and the amounts of all were quantified using LIM-CI-GC-MS. The ratios of 1 and 2 varied in these insects during different developmental stages. The present results underscore the need for further studies on methyl farnesoate (1) as a circulating hormone in insects.

Supercooling capacity and cold hardiness of band-winged grasshopper eggs (Orthoptera: Acrididae).

The band-winged grasshopper, Oedaleus asiaticus Bei-Bienko, is one of the most dominant and economically important grasshopper species in the steppe grasslands and farming-pastoral ecotone in northern China. It is a univoltine species and overwinters as eggs in soil. The cold hardiness of its eggs was examined in the laboratory. Water content in soil significantly affected the supercooling points (SCPs), water content and fat content of prediapause eggs. With the increase of water content in soil, the SCP, and water content of prediapause eggs rose whereas the fat content declined. There was a significant relationship between the SCP and water content or fat content of prediapause eggs. The SCPs of prediapause and diapause eggs varied from -7.6 to -28.4°C and the SCPs of eggs 30 d after oviposition could be divided into two groups. The means of high SCP group (-11.0 to -11.9°C) were much higher than those of low SCP group (-21.8 to -21.9°C), and the majority belonged to the latter (90.48-93.33%). The SCPs of prediapause eggs and early-diapause eggs 30 d after oviposition were significantly higher than those of deep-diapause eggs 60 d after oviposition. The survival rates of diapause eggs were significantly different among different temperature treatments. The survival rate was higher than 88% at greater than -20°C and declined significantly to 57% at -25°C, and suddenly dropped to zero at -30°C. The lower lethal temperature (Ltemp50) for 12 h exposure was -25.3°C and the lower lethal time (Ltime50) at -20°C was 32.8 d. As the mean SCPs of diapause eggs were similar to their Ltemp50, the SCP of eggs can be considered as a good indicator of cold hardiness for O. asiaticus and that this grasshopper is a freeze-intolerant insect.

Bioaccumulation of zinc, lead, copper, and cadmium from contaminated sediments by native plant species and Acrida cinerea in South China.

This research was conducted to search and identify spontaneously growing heavy metal-tolerant plant species that are potentially useful for phytoremediation in contaminated sediment. Five sites were selected for collection of plants growing on polluted shore (river bank) sediment of the Xiang River, China. The concentrations of Zn, Pb, Cu and Cd in plants, sediments, and grasshoppers were determined using flame atomic absorption spectrophotometer (AAS700, Perkin-Elmer, USA). Considering translocation factor and bioaccumulation factor, Rumex crispus (Polygonaceae), Rumex dentatus (Polygonaceae), and Lagopsis supina (Labiatae) could be potentially useful for phytostabilization of metals. R. crispus can be considered potentially useful for phytoextraction of Cd. In light of the biomagnification factors, grasshoppers are deconcentrators for Pb and Cd, microconcentrators for Zn and macroconcentrators for Cu to the plants, respectively. To the best of our knowledge, the present study is the first report on Zn, Pb, Cu and Cd accumulation in R. crispus and L. supina, providing a pioneer contribution to the very small volume of data available on the potential use of native plant species from contaminated sediments in phytostabilization and phytoremediation technologies.

Bioaccessibility of trace elements and Fe and Al endogenic nanoparticles in farmed insects: Pursuing quality sustainable food.

This study investigated the in vitro bioaccessibility of aluminum, copper, iron, manganese, lead, selenium, and zinc in three important species of farmed insects: the yellow mealworm (Tenebrio molitor), the house cricket (Acheta domesticus) and the migratory locust (Locusta migratoria). Results show that all three insect species constitute excellent sources of essential elements (Fe, Cu and Zn) for the human diet, contributing to the recommended dietary allowance, i.e., 10%, 50%, and 92%, respectively. A higher accumulation of Se (≥1.4 mg Se/kg) was observed with increasing exposure concentration in A. domesticus, showing the possibility of using insects as a supplements for this element. The presence of Al and Fe nanoparticles was confirmed in all three species using single particle-inductively coupled plasma-mass spectrometry and transmission electron microscopy. The results also indicate that Fe bioaccessibility declines with increasing Fe-nanoparticle concentration. These findings contribute to increase the nutritional and toxicological insights of farmed insects.

Phytal: a candidate sex pheromone component of the moroccan locust dociostaurus maroccanus.

Outbreaks of locusts cause enormous economic losses to agriculture in many countries. To develop environmentally friendly strategies for their control, much research has been focused on the factors that influence locust biology, particularly infochemical-mediated interactions. We present herein the identification and synthesis of both Z and E isomers of phytal (3,7,11,15-tetramethylhexadec-2-enal, 1), which are involved in chemical communication and behaviour of the Moroccan locust, Dociostaurus maroccanus, a serious agricultural pest. The compound was identified by comparison of its chromatographic and spectrometric features and microchemical reactions with those of a synthetic sample. The natural compound was shown to have the R,R configuration by chiral HPLC analysis, and its structure is unique as an insect pheromone component. Both isomers of phytal are produced by sexually mature adult males and elicit electroantennographic responses in antennae of both sexes. In two-choice olfactometer bioassays, males and females significantly preferred the stream enriched with racemic phytal to the control. In contrast, hydrogenated phytal was behaviourally inert. Both isomers of phytal are specific to D. maroccanus as they are absent in the closely related, habitat-sharing species Dociostaurus jagoi and Calliptamus wattenwylianus. Legs and wings are the main release sites of the compound: approximately 90 % of that emitted by living individuals. In biosynthetic studies, phytal appears to proceed from oxidation of phytol (2) after injection of deuterated phytol into the abdomen of the insect or after administration in the diet. Our results demonstrate that phytal is a candidate sex pheromone component of the Moroccan locust; it is produced by mature males, and might be eavesdropped upon by conspecific males.

Characterization of genome methylation patterns in the desert locust Schistocerca gregaria.

DNA methylation is a widely conserved epigenetic modification. The analysis of genome-scale DNA methylation patterns in various organisms suggests that major features of animal methylomes are widely conserved. However, based on the variation of DNA methyltransferase genes in invertebrates, it has also been proposed that DNA methylation could provide a molecular mechanism for ecological adaptation. We have now analyzed the methylome of the desert locust, Schistocerca gregaria, which represents an organism with a high degree of phenotypic plasticity. Using genome-scale bisulfite sequencing, we show here that the S. gregaria methylome is characterized by CpG- and exon-specific methylation and thus shares two major features with other animal methylomes. In contrast to other invertebrates, however, overall methylation levels were substantially higher and a significant fraction of transposons was methylated. Additionally, genic sequences were densely methylated in a pronounced bimodal pattern, suggesting a role for DNA methylation in the regulation of locust gene expression. Our results thus uncover a unique pattern of genome methylation in locusts and provide an important foundation for investigating the role of DNA methylation in locust phase polyphenism.

Meat fatty acid and cholesterol level of free-range broilers fed on grasshoppers on alpine rangeland in the Tibetan Plateau.

BACKGROUND: Meat safety and nutrition are major concerns of consumers. The development of distinctive poultry production methods based on locally available natural resources is important. Grasshoppers are rich in important nutrients and occur in dense concentrations in most rangelands of northern China. Foraging chickens could be used to suppress grasshopper infestations. However, knowledge of the fatty acid content of meat from free-range broilers reared on alpine rangeland is required. RESULTS: Rearing conditions and diet did not significantly (P > 0.05) affect concentrations of saturated fatty acid (SFA), arachidonic acid, docosahexaenoic acid or the ratio of total n-6 to total n-3 fatty acids. Breast muscle of chickens that had consumed grasshoppers contained significantly (P < 0.05) less monounsaturated fatty acid, but the ratio of polyunsaturated fatty acids (PUFA)/SFA and contents of total n-3, total n-6 and PUFA were significantly (P > 0.05) higher than intensively reared birds. Compared with meat from intensively reared birds, meat from free-range broilers had less cholesterol and higher concentrations of total lipid and phospholipids. CONCLUSION: Chickens eating grasshoppers in rangeland produce superior quality meat and reduce the grasshopper populations that damage the pastures. This provides an economic system of enhanced poultry-meat production, which derives benefits from natural resources rather than artificial additives.

[Identification of the meiotic events in grasshopper spermatogenesis].

The grasshoppers are ideal materials to study various meiotic stages of spermatogenesis due to their easy availability, fairly large chromosomes, and fewer numbers of chromosomes. It is easy to make temporary squash preparation of grasshopper testes; however, it is usually difficult for the beginners to differentiate between stages of meiosis. In view of this, we demonstrated the method of identification of meiotic stages by chromosome number and chromosome conformation, taking spermatogonial meiosis of Locusta migratoria manilensis as an example. We described briefly the mitosis of spermatogonia and the spermatogenesis of this species as well.

Effects of diet on the chemical composition of migratory locusts (Locusta migratoria).

An experiment was conducted to determine the effects of diet on the chemical composition of migratory locusts (Locusta migratoria L.). Fresh and dry weight and the contents of dry matter, ash, lipid, protein, Ca, K, Mg, Na, P, Cu, Fe, Zn, retinol, lutein, zeaxanthine, cryptoxanthin, carotenes, lycopene and gross energy were determined in penultimate instar and adult locusts, that had been fed three different diets. The locusts received a diet of grass or grass+wheat bran or grass+wheat bran+carrots. Adding wheat bran decreased the protein content and increased fat content (633 vs. 583 and 182 vs. 231 g/kg DM, respectively). Addition of carrots to the diet increased fat content further from 231 to 271 g/kg DM. Mineral concentrations of Ca, K, Mg, and Na, were significantly affected by diet. P, K, Cu, and Fe concentrations were significantly different in penultimate migratory locusts compared with adults. Wheat bran decreased the α-carotene content, which did not change by incorporating carrots in the diet. However, carrots did result in higher ß-carotene concentrations. Retinol concentrations were increased by incorporating both wheat bran and carrots in the diet compared with the diet containing only grass. This study shows that the chemical composition of migratory locusts can be manipulated through the diet. As such, it enables nutritionists to adapt the chemical composition of live feeder insects to better meet the nutritional demands of predators.

Ultrasound-assisted extraction of protein from Bombay locusts and its impact on functional and antioxidative properties.

Impact of ultrasound-assisted process (UAP) on yield, functional properties, antioxidant properties and molecular characteristics of protein extracted from Bombay locusts (BL) (Patanga succinta L.) was studied. Different conditions of UAP were implemented for different amplitudes (40-60%) and times (10-30 min) during aqueous extraction. Notably, UAP could enhance yield and protein recovery, compared with those from typical process (TP) (continuously stirred at 100 rpm at room temperature for 1 h). UAP conditions used governed the change of surface hydrophobicity and free α-amino content of BL. UAP could improve solubility of BL, especially at pH levels higher than 2. UAP had no significant (p > 0.05) detrimental effects on foaming capacity and stability of BL. Nevertheless, UAP, particularly at 50-60% amplitudes, affected the emulsion activity and stability of BL. UAP provided BL with high radical scavenging activities and good electron donating ability, especially that from 60% amplitude for 20 min (UAP-60/20). UAP-60/20 showed the impact on change of isoelectric point and molecular characteristic monitored by Fourier transform infrared (FTIR) of BL, compared to those from TP. In addition, BL was also an excellent source of both essential and nonessential amino acids. Therefore, UAP potentially enhanced BL extraction efficiency, resulting the BL with good functional and antioxidative properties.