Insect Larvae Research Articles

Productivity and Nutritive Value of Black Soldier Fly (Hermetia illucens) Larvae Fed with Different Waste Substrates

Due to the unavailability and rising market price of fishmeal and soybean meal, insect larvae, such as black soldier fly larvae (BSFL: Hermetia illucens), are currently being investigated as an alternate source of protein for swine and poultry. The productivity and nutritional value of BSFL were examined in this study together with the effects of various waste substrates.
 There were two experimental containers for every treatment and were replicated three times and laid out using a Completely Randomized Design (CRD). A total of twenty-four (24) plastic containers (12 x 8.5 x 3 inches) were used which per container contained 100 grams/1000 of 4 days old BSF larvae.
 The results showed that BSF larvae fed with T2-Fruit remains and T3 -Vegetable scraps yielded the highest production of 1230-1312 grams and an early maturation period of 18-19 days. Both T2-Fruit remains and T3 -Vegetable scraps have the highest nutritional value of around 43% to 47% of crude protein content, respectively as compared to the rest of the treatments. The nutritional profile of BSF larvae fed fruit and vegetable waste suggests that it may be used as a less expensive and more sustainable source of protein for pigs and poultry.

Mulching time of forest meadows influences insect diversity

Abstract The diversity in meadows is affected by numerous aspects, such as the amount and type of fertilisation and the timing and frequency of cutting. The effects of mowing on the diversity of plants and insects have been studied in detail. However, the effect of mulching (vegetation is cut, shredded, and left in place, instead of being removed) on insects in small forest meadows has received limited scrutiny to date. In this study, we examined how different mulching times influenced insect diversity of forest meadows. We sampled insect larvae and observed flower‐visiting insects at 24 sites in the Northern Black Forest in south‐west Germany. We applied four treatments with six replicates each: (i) mulching in June, (ii) mulching in September, (iii) mulching in June and September, and (iv) no mulching as a control. The overall larval community was dominated by Symphyta (45%, Hymenoptera) and Lepidoptera (44%). The flower‐visiting insect community was dominated by Syrphidae (80%, Diptera). The insect larvae were negatively influenced by all mulching treatments. The abundance and species richness of flower visitors was reduced by mulching in June only and by mulching in both June and September. Summary: Given that meadow management is required for conserving grassland diversity our results indicate that for insect larvae other mulching methods, than those we tested, such as mulching with an arthropod‐friendly mulching machine, strip‐mulching, or delayed mulching may help this crucial stage of insect development. For insect flower visitors mulching in September is beneficial.

Structural Diversity Design, Synthesis, and Insecticidal Activity Analysis of Ester-Containing Isoxazoline Derivatives Acting on the GABA Receptor.

To explore insecticides targeting the γ-aminobutyric acid (GABA) receptor, two series of novel isoxazoline derivatives containing sulfonic and carboxylic esters were designed and synthesized. Their insecticidal activities against Plutella xylostella, Mythimna separata, and Aedes aegypti larvae and their structure-activity relationship were investigated. The sulfonate-containing isoxazoline derivatives (10k-q) exhibited promising insecticidal activities against the three insect larvae. Compound 10o displayed excellent activities with LC50 values of 8.32, 5.23, and 0.35 μg/mL at 48 h against P. xylostella, M. separata, and A. aegypti larvae, respectively, which were better than or similar to those of avermectin. Furthermore, compound 10o exhibited a faster insecticidal effect than avermectin against M. separata. The mode of action of 10o was preliminarily verified by molecular docking, theoretical calculations, and measurement of glutamate decarboxylase and glutamic pyruvic transaminase activities. Compound 10o is a novel insecticidal candidate acting on GABA receptors, which could guide the discovery of isoxazoline insecticides.

Activity of Nerium oleander leaf extract on the larvae of Crocidolomia binotalis Zell.

The active compound of Nerium oleander L. leaf extract is toxic to insect larvae. It is used to control pests but information on the activity of N. oleander leaf extract was not yet known in detail. This research aimed to determine mortality, lethal concentration (LC50), feeding inhibition, larval and pupal fitness weights and imago morphological perfection of Crocidolomia binotalis Zell. The research was done at the Laboratory of Pests and Plant Diseases, Faculty of Agriculture, Tadulako University from May 2021 to October 2021. This research used a completely randomized design with five treatments and four replications. Each treatment used 20 tails sample of third instar C. binotalis larvae from East Lore Sub-district, Poso Regency. Concentrations for the treatment of N. oleander leaf extract were as follows: P0 = 0%, P1 = 1.25%, P2 = 2.5%, P3 = 5%, and P4 = 10%. The results show that the concentrations of N. oleander leaf extract that were effective in causing mortality of C. binotalis larvae, were from 1.25% to 2.5%. The LC50 concentration of N. oleander leaf extract, which killed 50% of C. binotalis larvae, was 1.915% (0.01915ml/ml), with a minimum concentration of 1.425% (0.01425ml/ml) and a maximum concentration of 2.375% (0.02375ml/ml). The higher the concentration of N. oleander leaf extract, the higher the feeding inhibition, causing the decrease in the feeding of C. binotalis larvae. In addition, the fitness weights of C. binotalis larvae and pupae also decreased, so that fewer larvae developed into imago (adult individuals). A 10% concentration of N. oleander leaf extract caused abnormal (rudimentary) morphological forms of C. binotalis imago.

Intra-Population Alteration on Voltinism of Asian Corn Borer in Response to Climate Warming.

The Asian corn borer (ACB) Ostrinia furnacalis (Guenée) can occur in one to seven generations annually from cool (48°00' N) to warm (18°10' N) region of corn cultivation in China. Although ACB is commonly known as a facultative larval diapause insect, the co-existence of various voltinism suggests that intra-population variation may have evolved for the nature of diapause, i.e., voltinism plasticity. Here, we conducted recurrent selection efforts to establish three strains of, respectively, univoltine (with obligate diapause), multivoltine (with facultative diapause), and non-diapausing ACB under various temperature and photoperiod environments. The univoltine (Lu) strain has evolved a stable univoltinism under a diapause suppressing condition (16 h daylength at 28 °C), with the diapause incidence constantly over 80% after three generations of selection. The multivoltine strain (Lm) under the high temperature (28 °C) was shown to have a typical facultative diapause induced by a range of short-day lengths (11-13.5 h). Diapause incidence was constantly <2.6% under the long day length (16 h) when the temperature was from 18 to 28 °C, i.e., low temperature could not enhance the diapause response in the Lm strain. However, the development was prolonged from 14.2 ± 0.3 d to 46.0 ± 0.8 d when the temperature was reduced from 28 °C to 18 °C. The majority (94.4%) of the developed Ln strain still maintained the non-diapausing nature under a diapause enhancing condition, i.e., a short (13 h) daylength at a low temperature (22 °C). Lm and Ln were able to complete their second generation in Heihe (50°14' N) if the first-generation moth oviposits before 18 June. The study suggests that ACB has evolutionary intra-population variation in voltinism. Under the climate change scenario warmer spring and summer might affect the proportion of sympatric voltine biotype populations that evolve toward being multivoltine.

Retrogressive moulting in khapra beetle, Trogoderma granarium (Coleoptera: Dermestidae)

AbstractInsect larvae typically moult to grow, but here we investigate insect larvae that moult to shrink; that is, retrogressive moulting or retrogressive development. We demonstrate this phenomenon in khapra beetle, Trogoderma granarium Everts (Dermestidae), among the world's most invasive pests of stored grains and cereal products, and a quarantine pest of interest for many countries. Larvae survived a 3‐month period of starvation, moulting up to six times and reducing their body mass by about half, on average. When reprovisioned with food, most larvae resumed the normal trajectory of development and pupated within a month. Thus, retrogressive development is a mechanism that may favour species whose resources exhibit feast‐or‐famine dynamics. By enabling survival during periods of privation, retrogressive development contributes to the invasiveness of the khapra beetle by allowing them to persist for long periods in empty storage facilities or empty containers used for international grain shipments.

Modelling and optimal control of growth, energy, and resource dynamics of Hermetia illucens in mass production environment

Mass production of Hermetia illucens insect larvae is now being adopted in many countries and is taking an industrial production approach. Despite abundant literature on factors that affect larvae growth and the optimal static parameters identified in laboratory setup, for an industrial production process it is necessary to identify the trajectories such that the growth as well as the production process is optimal. To achieve this in this work, some of the important requirements and challenges involved thereof are identified and objectives of the automation process are formulated within a model based optimal control setup. Mechanistic models necessary for the optimization framework are derived as differential equations that describe the dynamic variation of resources (feed, water, O2 etc.), energy, and larval biomass. In addition, the elevated metabolic activity of larvae corresponding to the final instar development is identified and also modelled based on the observation from experiments. The mass and energy balance approach used in modelling enables the quantification and distinction of the mass and energy flux components in various levels (e.g. larvae body, growing medium, production environment, and external environment) while holding its applicability for both open and closed/reactor based production setups. Finally, the trajectories generated using the synthesized optimal controller are tested under different scenarios showcasing significant reduction in resource consumption compared to a constant set-point operation of the production setup. Results presented in this work not only showcase the potential of the mechanistic models and their application in identifying the relevant process parameters (e.g. reactor properties such as volume, thermal conductivity, actuator capacities), but most importantly in optimizing the process dynamically and tuning the process objectives as desired (e.g. maximize larvae mass, reduce energy).

First Record of the Elusive Ant Parasitoid Horismenus floridensis (Hymenoptera: Eulophidae) in Mexico and New Association with an Ant Host.

Most eulophid wasps are primary parasitoids, mainly of endophytic insect larvae (Diptera, Coleoptera, Lepidoptera, Hymenoptera, Hemiptera, and Thysanoptera), but can also attack spider eggs, gall-forming mites, or nematodes. A few species are known to parasitize ants. Here we report on the occurrence of Horismenus floridensis (Schauff and Bouček) attacking Camponotus atriceps (Smith) in southern Mexico (Campeche), expanding the distribution for this eulophid species and the range of its potential hosts. We also provide an updated list of the Horismenus Walker species found in Mexico, which currently includes 21 identified species. This is the second host ant ever recorded for H. floridensis and the first reliable record of C. atriceps as a host for this eulophid wasp. The first host ant reported from Florida 35years ago was the closely related valid species, C. floridanus (Buckley), erroneously synonymized at that time with C. atriceps (formerly, C. abdominalis (Fabricius)).

Microplastics occurrence, detection and removal with emphasis on insect larvae gut microbiota

Microplastics have been identified in all living forms including human beings, the present need is to restrain its spread and devise measures to remediate microplastics from polluted ecosystems. In this regard, the present review emphasizes on the occurrence, sources detection and toxic effects of microplastics in various ecosystems. The removal of microplastics is prevalent by various physico-chemical and biological methods, although the removal efficiency by biological methods is low. It has been noted that the degradation of plastics by insect gut larvae is a well-known aspect, however, the underlying mechanism has not been completely identified. Studies conducted have shown the magnificent contribution of gut microbiota, which have been isolated and exploited for microplastic remediation. This review also focuses on this avenue, as it highlights the contribution of insect gut microbiota in microplastic degradation along with challenges faced and future prospects in this area.

Inferring feeding habits of Carabidae (Coleoptera) larvae based on mandible morphology: Case studies of Lesticus magnus and Chlaenius costiger

AbstractIn the beetle family Carabidae, feeding habits are important life history traits that determine their role in ecosystems and suitability as bioindicators. However, they have not been elucidated for most species, especially in the larval stages. Using laboratory‐rearing experiments, this study examined the larval feeding habits of two large carabid species: Lesticus magnus (tribe Pterostichini) and Chlaenius costiger (tribe Chlaeniini). Although previous studies failed to rear these larvae on insect larva diets, the mandible morphology of the first instars described in those studies, together with subsequently obtained knowledge of the relationship between mandible morphology and feeding habits in other carabid larvae, suggests that they are earthworm feeders. Rearing experiments with three types of animal diet (insect larvae, mixed snail and slug, and earthworm diets) showed that as expected, their larvae are earthworm feeders. In L. magnus, although the larvae accepted the mixed snail and slug diet and the earthworm diet, only larvae reared on the earthworm diet reached adulthood. In C. costiger, the larvae accepted only the earthworm diet and reached adulthood. This is the first report of earthworm feeding during the larval stage for the genus Lesticus (tribe Pterostichini) and tribe Chlaeniini. The importance of these results is discussed from ecological and evolutionary perspectives.

Analysis of nutrients in Apriona germari and treatment of diarrhea in mice fed with insect powder

The insect larvae of Apriona germari, Apriona swainsoni and other closely related species are related to the insects that bore through the stems of the Caesalpinia decapetala. Because of therich nutritional as well as medicinal value of edible A. germari, it is often used to nourish the body, enhance immunity, and to treat ailments such as diarrhea. The soluble protein content of A. germari was determined using Kjeldahl and Soxhlet extraction methods. The crude fat content and the content of various fatty acids was determined by the normalization method, normalization method refers to that after the fat in the sample is extracted by hydrolysis ether solution, it is saponified and methylated under alkaline conditions to generate fatty acids and methyl esters, which are analyzed by capillary column gas chromatography and quantitatively measured by area normalization method. Amino acid content determined using an amino acid analyzer after acid hydrolysis showed 17 kinds of amino acids. A diarrhea mouse model was established by injecting a suspension of Escherichia coli into the abdominal cavity of mice. The mice were then fed with A. germari fodders at dose concentrations of 12%, 8%, 4% and 0%. The number of E. coli was determined from the intestinal tracts of mice; the activities of antioxidant enzymes and digestive enzymes in the serum were determined. Eleven kinds of fatty acids were detected in A. germari; unsaturated fatty acids accounted for 71.87% of the total fatty acids. A. germari is an edible resource insect with high nutritional value. Mice fed with A. germari showed an increase in the activity of antioxidant enzymes and digestive enzymes in the serum, which helped in the effective inhibition and reduction in the total number of intestinal bacteria and E. coli. The results indicate that A. germari has high nutritional value; A. germari also has a certain therapeutic effect on diarrhea caused by E. coli in mice.

Assessment of macrozoobenthos quality in the Bolshaya River (Western Kamchatka) in connection with escapements of Pacific salmon spawners

The paper shows mechanisms of influence of organic matter of marine origin entering the Bolshaya River basin with spawning escapement of Pacific salmon on the quality of freshwater macrozoobenthos. It has been found out that larvae of amphibiotic insects can receive marine nutrients through direct consumption of benthos in summer-autumn period and indirectly through trophic chains for a long time (till spring of the next year). The effect of Pacific salmon spawning escapements on such invertebrate characteristics as body weight, content of lipids and fatty acid-markers of food sources (phytoplankton, bacterioplankton or detritus) has been established. It is concluded that the trophic conditions of macrozoobenthos organisms, the food items of juvenile fish, have improved due to the intake of more marine nutrients.

Effects of edible insect extracts on the antioxidant, physiochemical, and microbial properties of Tteokgalbi during refrigerated storage

In this study, Tteokgalbi, a meat product, was prepared with edible insect larvae extracts and its antioxidant, physiochemical, and microbial properties were evaluated during refrigerated storage. Tteokgalbi prepared with 2% A. dichotoma and 2% P. brevitarsis showed the highest radical-scavenging activity and metal-chelating activity, but the lowest thiobarbituric acid reactive substance (TBARS) value, among the treatments (P < 0.05). In addition, those antioxidant activities were the lowest and the TBARS value was the highest in control Tteokgalbi (P < 0.05) during all storage days. Tteokgalbi prepared with 2% A. dichotoma showed the highest brownness index, pH, and cooking yield, but the lowest shear force value (P < 0.05). During all storage days, the total aerobic bacteria level did not differ significantly among the treatments. In conclusion, A. dichotoma extracts (2%) were effective as antioxidants, inhibiting lipid oxidation, and improving the quality properties of Tteokgalbi, without negatively affecting microbial counts. These results confirmed that the edible insect extracts have industrial value as a food additive.

A major conformational change of N-terminal helices of Bacillus thuringiensis Cry1Ab insecticidal protein is necessary for membrane insertion and toxicity.

Pore forming toxins rely on oligomerization for membrane insertion to kill their targets. Bacillus thuringiensis produces insecticidal Cry-proteins composed of three domains that form pores that kill the insect larvae. Domain I is involved in oligomerization and membrane insertion, whereas Domains II and III participate in receptor binding and specificity. However, the structural changes involved in membrane insertion of these proteins remain unsolved. The most widely accepted model for membrane insertion, the 'umbrella model', proposed that the α-4/α-5 hairpin of Domain I swings away and is inserted into the membrane. To determine the topology of Cry1Ab in the membrane, disulfide bonds linking α-helices of Domain I were introduced to restrict their movement. Disulfide bonds between helices α-2/α-3 or α-3/α-4 lost oligomerization and toxicity, indicating that movement of these helices is needed for insecticidal activity. By contrast, disulfide bonds linking helices α-5/α-6 did not affect toxicity, which contradicts the 'umbrella model'. Additionally, Föster resonance energy transfer closest approach analyses measuring distances of different points in the toxin to the membrane plane and collisional quenching assays analysing the protection of specific fluorescent-labeled residues to the soluble potassium iodide quencher in the membrane inserted state were performed. Overall, the data show that Domain I from Cry1Ab may undergo a major conformational change during its membrane insertion, where the N-terminal region (helices α-1 to α-4) participates in oligomerization and toxicity, probably forming an extended helix. These data break a paradigm, showing a new 'folding white-cane model', which better explains the structural changes of Cry toxins during insertion into the membrane.

The efficacy of new oral vaccine feeds against Salmonid novirhabdovirus in rainbow trout

Salmonid novirhabdovirus (IHNV) causes infectious haematopoietic necrosis (IHN) in salmonid species. Despite an injectable plasmid-based DNA vaccine of the glycoprotein (G) gene is effective, there are no oral vaccines for mass vaccination of rainbow trout (Oncorhynchus mykiss) fry. Recombinant baculoviruses were generated, used in cabbage looper (Trichoplusia ni) insect larvae to produce IHNV G and IHNV G-C5a proteins. Western blotting and chemiluminescence assays confirmed the expression of recombinant proteins, which were added to the fish feeding and top-coated with unflavored gelatin binder. Commercial rainbow trout were fed with experimental diets containing either IHNV G or IHNV G-C5a proteins for 2 weeks, and boosted 4 weeks after. Four weeks post-booster, fish were challenged with IHNV by immersion. Survival upon the infection challenge was evaluated. Spleen were sampled at 7 and 14 days post infection (dpi). Non-vaccinated and IHNV G fed trout reached a mortality of 91.7 and 97.6%, and 70.9 and 88.4%, respectively at 8 and 15 dpi. The IHNV G-C5a fed group exhibited a reduced mortality of 51.2% at 8 dpi, reaching 81.7% at 15 dpi, suggesting some level of antiviral protection. The individual viral load was measured by RT-qPCR detection of IHNV N gene, showing no significant difference across experimental groups. The transcription modulation of selected immune response markers was evaluated across experimental groups, including Type I IFN-a, Mx-1, CD4, and IgM. Further study is needed to assess how new oral vaccines may become effective to mitigate IHNV pathogenesis in juvenile trout by modulating the host immune response to protect towards IHNV exposure.

Presence of the European bone-skipper fly Thyreophora cynophila (Panzer, 1798) (Diptera: Piophilidae) larvae in the cerebral cavity of large mammals and report of different insect larvae living inside mammal bones

Summary The iconic fly Thyreophora cynophila has long attracted the interest of entomologists but, despite its re-discovery in Spain and France, its biology is still poorly known. The larvae and puparium have been described in detail but their feeding habits on large carcasses remain largely unknown. Here, we took advantage of a carrion pile containing the remains of wild boar (Sus scrofa) and red deer (Cervus elaphus) as well as of two cow (Bos taurus) carcasses to search for T. cynophila larvae inside the bones and skulls. We document the occurrence of T. cynophila inside the cerebral cavity of dead animals, containing the brain. From the carrion pile, out of seven skulls, T. cynophila larvae could be found in five of them, and identified on the basis of their size, the shape and arrangement of the ventral tubercles, prothoracic spiracle and cephalopharyngeal skeleton. In contrast, no T. cynophila larvae could be found inside the nine bones we inspected. From the cow carcasses, no T. cynophila larvae could be found in the bones but one larva was found inside the cerebral cavity of one cow. In addition, other Diptera and Coleoptera larvae were found inside the bones.

The results of the study of the amino acid composition of compound feeds during the extrusion of wheat grain with the addition of Black Soldier Fly Larvae (Hermetia illucens L.)

The production of quality and inexpensive feed based on agricultural raw materials is the main way to increase the profitability and competitiveness of livestock production, ensuring its import substitution and high quality. It is known that in the structure of the cost of livestock products, 50-70% of all costs are accounted for by feed. Three variants of a mixture of crushed wheat grain and biomass of the black soldier fly larvae (Hermetia illucens) were extruded with the content of the latter 10, 15, and 20% by weight at different temperatures. The content of amino acids in raw materials and finished extrudate was determined. It was found that the feed mixture of crushed grain and black soldier fly larvae can be successfully extruded at a temperature of 121-135 °C. With an increase in the extrusion temperature in the range of 115-140 °C, the amino acid content in the finished extrudate decreases. The change in the content of insect larvae in the feed mixture does not affect the nature of the dependence of the amino acid content in the extrudate on the extrusion temperature and the course of the process. It was found that the content of amino acids in the extruded feed decreases with increasing speed with increasing temperature, regardless of the content of insect biomass. The rational range of the extrusion temperature of the feed mixture from wheat grain and insect larvae was determined – 121-127 °C, which ensures a reduction in the content of essential amino acids in the extrudate by no more than 30%. The extruded feed, which includes 15% of the biomass of insect larvae, contains 9.6 ± 0.13% amino acids, including 4.38 ± 2.01% of essential amino acids. The extrusion of insect larvae in a mixture with seeds of grain crops is a promising direction for improving the production of feed for fish and farm animals.

Agrobacterium rhizogenes-Mediated Transformation of Crotalaria ochroleuca: Production of Flavonoids from Hairy Roots

Crotalaria ochroleuca (Fabaceae) is rich in bioactive compounds used for nematode control. Transformed root culture allows the production of a large amount of hairy root biomass, conditioned by auxin biosynthesis-related genes integrated via the process of Agrobacterium rhizogenes infection, which is known to cause a hairy root phenotype. We transformed A. rhizogenes to increase the biomass of hairy roots and optimized the process of production of bioactive compounds. The transformed nature of hairy roots was confirmed by polymerase chain reaction, which confers kanamycin resistance. The transformed roots were cultured in full-strength in liquid media to realize the growth of hairy roots and the production of bioactive compounds. The transformed roots were grown in a culture medium supplemented with elicitors to produce total phenols, and flavonoids. Chromatographic analysis of transformed roots revealed the presence of flavonoids apigenin-6,8-C-diglucoside and luteolin-6-C-glucoside. The results were obtained by conducting physiological and biochemical studies with the flavonoids and studying the pathways that led to the production of large amounts of bioactive compounds from the hairy roots of C. ochroleuca. It was observed that the extraction of the compounds significantly affected nematodes and insect larvae, resulting in significantly high levels of economic damage to crops.

Assessment of ichthyofaunal diversity of family Cyprinidae in River Panjkora Dir, Khyber Pakhtunkhwa, Pakistan.

The study explores the Ichthyofaunal diversity of freshwater Cyprinidae fish in the Panjkora River of Dir, Khyber Pakhtunkhwa, Pakistan. A total of 911 fish samples were collected from 5 different sites along the river and identified using standard identification keys. Out of the 911 fish samples, 204 were related to family Cyprinidae, having 4 sub families, i.e Cyprininae representing 3 species i.e Carassius auratus, Cyprinus carpio, Cyprinus watsoni, Danioninae representing 6 species i.e Barilius modestus, Barilius vagra, Barilius pakistanicus, Amblypharangodon mola, Salmophasia punjabensis, Rasbora daniconius, Labeoninae representing 5 species i.e Tor putitora, Crossocheilus diplocheilus, Gara gotyla, Labeo rohita, Labeo diplocheilus, and Barbinae representing 6 species i.e Puntius ticto, Puntius sophore, Puntius chonchonius, Schizothorax esocinus, Schizothorax labiatus and Schizothorax plagiostomus. This study adds 6 new species i.e Amblypharangodon mola, Salmophasia punjabensis, Labeo rohita, Labeo diplocheilus, Puntius chonchonius and Rasbora daniconius for the 1st time which are not reported earlier. EXCEL 2019 and XLSTAT were used for principal components analysis to study richness and correlation of fish diversity. Eigenvalues obtained from Sheringal to Zulam are 3.72, 0.511, 0.37, 0.29 and 0.09 respectively. The higher eigenvalue of Sheringal site shows higher diversity. Water quality study shows that the mean values of water temperature was 16.8°C, pH 7.08, total hardness134.6 mg/L, alkalinity 89.3 mg/L, Nitrate 5.93 mg/L, Chlorine 0.87 mg/L, Nitrite0.02 mg/L and Copper 0.04 mg/L, Iron 0.07 mg/L, Lead 0.002 mg/L. The physicochemical parameters of river Panjkora during the study time remained within the permissible limits as prescribed by the WHO (2005). Gut analysis revealed the presence of algae, nymphs insect's larvae, macroinvertebrates and protozoans.

ИЗУЧЕНИЕ ЭФФЕКТИВНОСТИ БИОЛОГИЧЕСКОГО ЛАРВИЦИДНОГО ПРЕПАРАТА

The article provides information about tests of the preparation containing spores and cells of the culture-producer Bacillus thuringiensis var. thuringiensis, endotoxin (delta-endotoxin) and thermostable β-exotoxin. The tests were carried by the method of processing of the tested drug of organic substrate (manure) in which there were larvae of various insects out in as close to production conditions as possible in the vivariums of the Institute of Veterinary Medicine, Veterinary and Sanitary Expertise and Agro-Safety of the Federal State Budgetary Educational Institution of Higher Education and All-Russian Research Institute of Veterinary Sanitation, Hygiene and Ecology – branch of the Federal State Budgetary Scientific Research Center of the Russian Academy of Sciences. It was found that an average of 15-18 fly larvae of various ages and 6-10 pupae of various insects were found in a manure substrate with a volume of 10 cm3.The results of semi-reproducible studies have shown that the preparation when used at a concentration of 3% and a flow rate of 3000- 5000 ml/ m2, reduces the number of flies flying out of the treated substrate by an average of 5.32-6 times during 30 days. The treatment interval was 30 days.