Percentage Of Pupae Research Articles

Larval competition between three endemic fruit flies (Diptera: Tephritidae) of differing phylogenetic relatedness

AbstractWithin a fruit, fruit fly larvae can be subject to scramble competition, in which density‐dependent effects can influence the fitness of subsequent adults. While there is significant research on tephritid interspecific larval competition, it has been conducted in invasive situations where the species are evolutionarily novel to each other. There has been no published research investigating larval competitive interactions between naturally coexisting, endemic species. We ran laboratory‐based, intraspecific and interspecific larval competition trials involving three co‐occurring Bactrocera species of differing genetic relatedness and also measured aspects of juvenile development rate to test possible mechanisms of competitive difference. Larval density had an influence on intraspecific competition in Bactrocera tryoni, Bactrocera neohumeralis and Bactrocera jarvisi, with a decreasing percentage of pupation with increasing larval density. Interspecific competition between B. tryoni and B. neohumeralis, and between B. tryoni and B. jarvisi was influenced by the interaction between species and density. The intensity of competition between B. tryoni and B. neohumeralis was minimal but high between B. tryoni and B. jarvisi. B. jarvisi produced larger eggs and had faster initial larval growth rates than the other two species, but it took the longest time for pupation to occur. Our results conflict with theory, as the greatest competition was observed between the two more distantly related species (B. tryoni and B. jarvisi) rather than between the two most closely related species (B. tryoni and B. neohumeralis). Further, and contrary to other studies, egg size, hatch rate and larval growth rate did not provide B. jarvisi with a competitive advantage; thus, larval size does not appear to be a mechanism of larval competition between B. tryoni and B. jarvisi.

Evaluate the effects of seed protectants on pupation percentage and pupal period of C. chinensis

Evaluate the effects of seed protectants on pupation percentage and pupal period of C. chinensis

Cassia tora (L.) Roxb.: An Alternate Host for Offseason Survival of Tobacco Caterpillar, Spodoptera litura (Fabricius, 1775)

Spodoptera litura (Fabricius, 1775) is a serious polyphagous pest causes serious damage to various crops like tobacco, cotton, cabbage etc. in Asia and other Indian subcontinents. Depletion in host plants may lead to adverse effect on the alternate host plants. During survey, observed S. litura larvae were feeding on Cassia tora, in this study third instar larvae of S. litura larvae were reared on the common and most preferred hosts like castor and tobacco. Larval, prepupal and pupal weight were compared with and other two common hosts. Percent pupation and adult emergence rate were also recorded. Among three hosts, insects which fed on Cassia tora have higher larval weight (0.825 mg) and also observed longer larval period compared to other two hosts. No differences were observed in prepupal, pupal (male and female) weight. Percent pupation was higher in S. litura, which were fed on castor and tobacco i.e., 100 % and 96.67 % respectively, and on C. tora recorded lowest per cent pupation (20 %). Adult emergence rate was found to be non-significant on castor and tobacco fed larvae but the lowest adult emergence was recorded on cassia about 18 %. Feeding of newly hatched instars of S. litura confirms that, it uses C. tora as an alternate host during off-season survival and complete its life cycle. Longer larval duration on C. tora may prone larvae to expose more to the external environment, results in less pupation rate.

Sublethal Effects of Chitosan-O-Arginine, a Chitosan Based Insecticidal Compound against Green Lacewing Chrysoperla zastrowi sillemi (Esben-Petersen)

The widespread application of synthetic chemicals leads to the unintended negative impact to non-target organisms both directly or indirectly, as these chemicals can infiltrate new environments, disrupting established ecological niches. Laboratory experiments explored the effects of sublethal doses of Cs-O-Arg to the third instar grubs of Chrysoperla zastrowi sillemi when fed with treated and untreated larvae of diamondback moth (DBM). The results showed that when the untreated third instar C. zastrowi sillemi grub was fed with treated P. xylostella larvae at LC25, LC35 and LC45 concentrations, there was 6.67 per cent mortality of C zastrowi sillemi grub at all the concentrations, after 48 and 72 hours of exposure. but, when the treated C. zastrowi sillemi grubs (LC35 and LC45) were fed with untreated P. xylostella, there was only 3.33 and 10.00 per cent mortality of C. zastrowi sillemi grubs, respectively. Whereas, Cs-O-Arg caused 33.33 per cent mortality when LC45 treated grubs were provided with LC45 treated DBM larvae as feed, whereas the treatment with LC25 concentrations of Cs-O-Arg resulted in the highest pupation percentage (76.67%) and adult emergence rate (73.33%) in C. zastrowi sillemi grubs when fed with DBM larvae treated with the same concentration. Chitosan derivative insecticide causes a mild adverse impact on the survival of the economically significant insect predator C. zastrowi sillemi, which hold valuable implications for guiding decisions regarding the compatible utilization of insecticides alongside C. zastrowi sillemi or other natural predators within integrated pest management strategies.

Toxic effect of cyanobacterial (blue–green algae) extracts as natural pesticides for the control of Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae)

BackgroundThe Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae) is a cosmopolitan polyphagous pest that feeds on nearly 80 species of plants The pest can cause upto 100% damage to crops if neglected. It is also resistant to the most of the chemical molecules available in the market, so it is necessary to identify alternate technology to combat this pest.ResultsThe crude cyanobacterial extracts of hexane, petroleum ether, ethanol and methanol extracts of Spirulina sp. and Nostoc muscorum were evaluated against second instar larvae of S. frugiperda through diet overlay method of bioassay. The results revealed that N. muscorum hexane extract and N. muscorum petroleum ether extract recorded the lowest LC50 value of 49.09 and 61.37 ppm, respectively. This was followed by Spirulina hexane extract, Spirulina petroleum ether extract, N. muscorum ethanol extract, N. muscorum methanol extract, Spirulina ethanol and methanol extract which were recorded 173.16, 227.22, 530, 730, 970 and 1000 ppm, respectively. Further, their potential effects on different biological parameters of S. frugiperda, viz. larval duration, pupal duration, percent pupation, pupal weight, pupal malformation, adult malformation, percent adult emergence, fecundity, and male and female adult longevity, were studied. The significant effects on different biological parameters were recorded by N. muscorum hexane and petroleum ether extract, followed by Spirulina hexane and petroleum ether extract. Similarly, an experiment was repeated for the confirmation of the first set of results, which followed by a similar trend. The first-ever novel study on S. frugiperda concluded that crude extracts of Spirulina sp. and N. muscorum extracts showed significant effects in causing larval mortality and affecting different biological parameters.ConclusionsThe experimental results can be recommended as a potential source of natural pesticides for the control of S. frugiperda.

In vitro Studies on the Biology and Predatory Potential of Commonly Occurring Ant Species in a Selected Agro-ecosystem of the Himalayan Range, India

Four commonly occurring species of queen ants were collected after their nuptial flight from an agroecosystem in Lehri Sarail village of Himachal Pradesh (31°32’03.9”N 76°38’57.7“E) using light traps. Queens named HAC1, HAC2, HAC3, and HAC4 were placed individually in a test tube with water sources. Once the queen started laying eggs, and a few workers emerged, they were transferred to an artificial formicarium. HAC1 and HAC2 were identified as Camponotus compressus, while HAC3 and HAC4 were identified as Polyrhachis thompsoni and Pheidole minor, respectively. In the study period of one year between July 2020 and July 2021, offspring from all colonies were found to be workers. HAC1, HAC2, and HAC4 produced dimorphic workers, the majors and minors. Studies on colony establishment, biology, and behavior were carried out with colonies from HAC1, HAC2, and HAC3, while a colony from HAC4 failed to establish. All species showed similar types of colony founding, nesting, brood management, necrophorosis, and hibernation. C. compressus showed higher fecundity, while percent hatchability was higher in P. thompsoni. Percent pupation and adult emergence were higher in C. compressus and lower in P. thompsoni. P. thompsoni was observed to be more aggressive with a high predation rate, followed by C. compressus. P. minor showed aggressiveness initially but was unable to incapacitate the host larva. Understanding ant biodiversity, biology, behavior, predatory potential, etc., will allow us to use the native ants in the agroecosystem as biological control agents. Methods of rearing ants under the artificial setup described here enable laboratory culturing of ants with biocontrol potential and using ants as model organisms to study the bio-efficacy of agrochemicals and pharmaceutical drugs.

Comparative study of three plant-derived extracts as new management strategies against Spodoptera littoralis (Boisd.) (Lepidoptera: Noctuidae)

Finding innovative eco-friendly agents for pest control may be aided by investigating the plant-derived extracts’ properties on economic pests. Therefore, the insecticidal, behavioral, biological and biochemical effects of Magnolia grandiflora (Magnoliaceae) leaf water and methanol extracts, Schinus terebinthifolius (Anacardiaceae) wood methanol extract, and Salix babylonica (Salicaceae) leaf methanol extract in comparison with a reference insecticide novaluron against S. littoralis were evaluated. The extracts were analyzed by High-Performance Liquid Chromatography (HPLC). The most abundant phenolic compounds were 4-hydroxybenzoic acid (7.16 mg/mL) and ferulic acid (6.34 mg/mL) in M. grandiflora leaf water extract; catechol (13.05 mg/mL), ferulic acid (11.87 mg/mL), and chlorogenic acid (10.33 mg/mL) in M. grandiflora leaf methanol extract; ferulic acid (14.81 mg/mL), caffeic acid (5.61 mg/mL), and gallic acid (5.07 mg/mL) In the S. terebinthifolius extract; cinnamic acid (11.36 mg/mL), and protocatechuic acid (10.33 mg/mL) In the methanol extract from S. babylonica extract. S. terebinthifolius extract had a highly toxic effect against second larvae after 96 h and eggs with LC50 values of 0.89 and 0.94 mg/L, respectively. Despite M. grandiflora extracts didn’t show any toxicity against S. littoralis stages, they had an attractant effect on fourth- and second larvae, with feeding deterrence values of − 2.7% and − 6.7%, respectively, at 10 mg/L. S. terebinthifolius extract significantly reduced the percentage of pupation, adult emergence, hatchability, and fecundity, with values of 60.2%, 56.7%, 35.3%, and 105.4 eggs/female, respectively. Novaluron and S. terebinthifolius extract drastically inhibited the activities of α-amylase and total proteases to 1.16 and 0.52, and 1.47 and 0.65 ΔOD/mg protein/min, respectively. In the semi-field experiment, the residual toxicity of tested extracts on S. littoralis gradually decreased over time compared to novaluron. These findings indicate that extract from S. terebinthifolius is a promising insecticidal agent against S. littoralis.

Diterpenes of Coffea seeds show antifungal and anti-insect activities and are transferred from the endosperm to the seedling after germination

Species of the genus Coffea accumulate diterpenes of the ent-kaurane family in the endosperm of their seeds, of which cafestol and kahweol are the most abundant. The diterpenes are mainly stored in esterified form with fatty acids, mostly palmitate. In contrast to the numerous studies on their effects on human health and therapeutic applications, nothing was previously known about their biological and ecological role in planta. The antifungal and anti-insect activities of cafestol and cafestol palmitate were thus investigated in this study. Cafestol significantly affected the mycelial growth of five of the six phytopathogenic fungi tested. It also greatly reduced the percentage of pupation of larvae and the pupae and adult masses of one of the two fruit flies tested. By contrast, cafestol palmitate had no significant effect against any of the fungi and insects studied. Using confocal imaging and oil body isolation and analysis, we showed that diterpenes are localized in endosperm oil bodies, suggesting that esterification with fatty acids enables the accumulation of large amounts of diterpenes in a non-toxic form. Diterpene measurements in all organs of seedlings recovered from whole seed germination or embryos isolated from the endosperm showed that diterpenes are transferred from the endosperm to the cotyledons during seedling growth and then distributed to all organs, including the hypocotyl and the root. Collectively, our findings show that coffee diterpenes are broad-spectrum defence compounds that protect not only the seed on the mother plant and in the soil, but also the seedling after germination.

Omani Frankincense nanoemulsion formulation efficacy and its latent effects on biological aspects of the spiny bollworm Earias insulana (Boisd.).

Our research shed light on the perspective of formulation technology regarding its responsibility to provide phyto-insecticides that are worthy of research into potential novel applications. There has been an increase in interest in using nanoemulsion as a new formulation in a variety of sectors during the last several decades. Boswellia sacra essential oil (Fam: Burseraceae) from the resin of frankincense trees has been recently proposed as a promising ingredient in a new generation of botanical insecticides. Frankincense nanoemulsion was formulated in 5% ratios comprising frankincense oil, surfactants, and water. A frankincense nanoemulsion was prepared using a high-energy ultra-sonication process and characterized by dynamic light scattering transmission electron microscopy surface tension, viscosity, and zeta potential value. Gas chromatography/mass spectrometry (GC/MS) was used to identify the chemical profiles of frankincense essential oil. Furthermore, insecticidal effects against second instar larvae of the spiny bollworm, Earias insulana, as well as their latent effects on the larvae were studied. In the present study, the formulation was a good nanoemulsion. The surface tension was 53.69, the viscosity was 4.76 cPs, the zeta potential was-10 mV, and the size distribution was 41.30 nm. The polydispersity index (PDI) of the nanoemulsion was found to be 0.26, and the morphology of the frankincense nanoemulsion was visualized in a spherical shape. The main constituents identified in frankincense oil were α-pinene (15.52%); monolinolenin (12.92%); and geranylgeranyl acetate (9.99%). The results showed significant insecticidal activity against the larval stage and considerably decreased the pupation percentage with increasing the volume of the frankincense nanoemulsion. On the other hand, the latent effects of the frankincense nanoemulsion on E. insulana resulted in a higher prolongation of larval and pupal durations as well as a significant reduction in the weight of larvae and pupae of E. insulana. Additionally, frankincense nanoemulsion dramatically influenced the adult emergence percentage. It also caused a significantly lower hatchability percentage compared to the untreated control. The concentrations used and the types of mating combination have a significant effect on the fecundity of E. insulana. This novel frankincense nanoemulsion formulation could be used in strategies to control the spiny bollworm on cotton plants.

Synergistic activity of lemongrass and sesame oils on spinosad: A new approach to control the peach fruit fly; Bactrocera zonata (Saunders, 1841), referring to their effect on the adult biological and protein aspects

The peach fruit fly Bactrocera zonata (Diptera: Tephritidae), is considered a major destructive pest for fruits and some vegetables. Toxicity of Spinosad mixtures with each lemongrass (Cymbopogon citratus Stapf) and sesame (Sesamum indicum L.) oils were evaluated against Bactocera zonata (Saunders, 1841) adults in a lab by feeding method. The study proved that mixing LC25 of spinosad with LC25 of the plant oils showed a high percentage of mortalities than using each compound individually. The mixture of spinosad with each lemongrass and sesame oil strongly affected the longevity of males (39.66 and 35.66 days) and females (54.33 and 53.33 days), respectively. Also treating insects with the tested mixtures adversely affected the egg numbers(28.7, 21.3), hatchability (46.66 and 33.33) of the deposited eggs, percentage of pupation (29.0 and 42.0), and percentage of adult emergence (20.33 and 36.66). Fractionation of proteins by SDS-PAGE showed that some protein bands were missed or expressed under stress of the spinosad, lemon grass, sesame oil and their mixtures.

Appraisal of growth inhibitory, biochemical and genotoxic effects of Allyl Isothiocyanate on different developmental stages of Zeugodacus cucurbitae (Coquillett) (Diptera: Tephritidae)

Allyl isothiocyanate (AITC), a glucosinolates’ hydrolytic product, was studied for its anti-insect potential against an economically important, destructive tephritid pest, Zeugodacus cucurbitae (Coquillett). The first, second and third instar maggots of the pest were fed on artificial diets amended with varied concentrations of AITC viz. 5 ppm, 25 ppm, 50 ppm, 100 ppm, 150 ppm and 200 ppm with DMSO (0.5%) as control. Results revealed high larval mortality, alteration of larval period, prolongation of pupal and total developmental periods in all instars of the maggots treated with AITC as compared to controls. Percent pupation and percent adult emergence decreased in all larval instars. Growth indices viz. Larval Growth Index (LGI) and Total Growth Index (TGI) were negatively affected. Anti-nutritional/post ingestive toxicity of AITC was also revealed by the decrease in Food Assimilation (FA) and Mean Relative Growth rate (MRGR) values with respect to control. Profiles of PO (Phenol oxidase) and other detoxifying enzymes including SOD (Superoxide dismutases), CAT (Catalases), GST (Glutathione-S-transferases), EST (Esterases), AKP (Alkaline phosphatases) and ACP (Acid phosphatases) were also significantly influenced. The genotoxic effect of AITC was also evaluated by conducting comet assays at LC30 and LC50. Significant DNA damage in hemocytes was reflected by increase in Tail length (μm), Percent Tail DNA, Tail Moment (TM) and Olive Tail Moment (OTM) as compared to controls. The results indicated high potential of AITC as biopesticide for pest management.

Chemical composition and bioactivities of Melaleuca alternufolia essential oil and its main constituents against Spodoptera littoralis (Boisaduval, 1833)

BackgroundSpodoptera littoralis is mostly controlled by the use of synthetic insecticides. Nonetheless, the use of these insecticides causes a slew of issues. On this pest, the antifeedant activity of Melaleuca alternifolia essential oil (EO) and its two principal components was investigated.ResultsThe gas chromatography–mass spectrometry (GC/MS) analysis revealed that the M. alternifolia EO was composed of eleven compounds. Terpinen-4-ol (40.1%) and γ-terpinene (21.9%) were chosen as the major constituents. In terms of antifeedant efficacy, treatment with M. alternifolia EO and these components reduced leaf consumption and the efficiency of food conversion in larvae in a concentration-dependent manner. When compared to untreated larvae, weight, growth, and pupation percentage were all significantly lower.ConclusionsThe findings show that M. alternifolia EO and its components, terpinen-4-ol and γ-terpinene can be effectively combined for cotton leafworm management.

Effect of Larval Diets on House Fly (Diptera: Muscidae) Production and Host Suitability for a Pupal House Fly Parasitoid (Spalangia gemina) (Hymenoptera: Pteromalidae).

A larval medium for house fly (Musca domestica L.) suitable for house fly parasitoid production was developed from locally available and inexpensive food ingredients. Biological parameters and life table parameters were estimated for house flies treated with five different diets. It was found that percentage survival of 1st-3rd instar larvae of house fly, percentage of pupation, percentage of hatching adults, growth index, and life table parameters (net reproductive rate [R0] the cohort generation time [T], intrinsic rate of increase [r], and finite rate of increase [λ]) were significantly highest on larvae produced on diet 5 (composed of rice barn and chicken feed). Diet composition and performance of house fly larvae in larval medium are discussed, based on the results. The results of Spalangia gemina Bouček (Hymenoptera, Pteromalidae) parasitization on house fly pupae revealed that the number of total parasitized pupa and number of parasitoids hatched from pupa reared with diet 5 (rice bran and chicken feed) were greater than with diet 1 (rice bran, powdered milk, dry yeast, fish meal, soybean meal, and chicken feed). Additionally, S. gemina offspring from diet 5 treatment had a higher proportion of females. Our results indicated that pupal size resulting from larval diet was an important factor for parasitization.

Nanochitosan to control the red palm weevil Rhynchophorus ferrugineus (Olivier) (Coleoptera: Curculionidae)

The red palm weevil Rhynchophorus ferrugineus infest more than nearly 40 palm species around the world. They damage the internal tissues of palms by the larval stage which is the serious stage. Nanoparticles represent a new generation of environmental remediation technologies that can provide cost-effective solution to some of the most challenging environmental clean-up problems. They also help to produce new pesticides. Nanochitosan is used to control the red palm weevil larvae and adults. The results show that it affects the mortality percentage of R. ferrugineus larvae. The mortality percentage increased by increasing the time and concentrations of nanochitosan, since 100% mortality was obtained at the concentration 80000 ppm after (15–20) days time interval. The percentage of mortality of R. ferrugineus female and male showed that the most effective concentration of nanochitosan was 20000 ppm, where 100% mortality was obtained in time interval 10–20 days. In addition, nanochitosan affects the biology of red palm weevil by decreasing pupation percentage, emergence percentage, pupal duration number of eggs/female, hatchability percentage and longevity of males and females as compared to the control. LC50 and Lc25 of nanochitosan disturbs the total protein and total carbohydrates. The activity of enzymes (protease, invertase and amylase) of larvae and adult (males and females) was disordered. We conclude that nanochitosan can be used as a control tool to the red palm weevil.

Fitness Cost of Sequential Selection with Deltamethrin in Aedes aegypti (Diptera: Culicidae).

In Mexico, Aedes aegypti (L.) is the primary dengue vector, chikungunya, and Zika viruses. The continued use of synthetic pyrethroids has led to the development of resistance in target populations, which has diminished the effectiveness of vector control programs. Resistance has been associated with disadvantages that affect the biological parameters of resistant mosquitoes compared to susceptible ones. In the present study, the disadvantages were evaluated by parameters related to survival and reproduction ('fitness cost') after selection with deltamethrin for five generations. The parameters analyzed were the length of the development cycle, sex ratio, survival, longevity, fecundity, egg viability, preoviposition, oviposition and postoviposition periods, and growth parameters. In the deltamethrin-selected strain, there was a decrease in the development cycle duration, the percentage of pupae, the oviposition period, and eggs viability. Although mean daily fecundity was not affected after the selection process, this, together with the decrease in the survival and fecundity levels by specific age, significantly affected the gross reproductive rate (GRR), net reproductive rate (Ro), and intrinsic growth rate (rm) of the group selected for five generations with deltamethrin compared to the group without selection. Identifying the 'cost' of resistance in biological fitness represents an advantage if it is desired to limit the spread of resistant populations since the fitness cost is the less likely that resistant individuals will spread in the population. This represents an important factor to consider in designing integrated vector management programs.

The effects of ethylparaben and propylparaben on the development and fecundity of Drosophila melanogaster

Parabens are widely used as preservatives in pharmaceuticals, cosmetics, and food products. Ethylparaben (EP) and propylparaben (PP) are particularly preferred because of their bactericidal and fungicidal effects. Although generally described as safe compounds, many studies have reported that parabens have estrogenic and endocrine-disrupting properties. In the present study, the effects of EP and PP (50 mM, 100 mM and 200 mM) on Drosophila melanogaster development and fecundity were investigated. No differences were found in the pupation and maturation percentages in all concentrations of parabens (p > 0.05). However, it was found that the mean pupation and maturation times increased in all treatment groups (p < 0.05). A statistically significant decrease (p < 0.05) in the number of offspring of the 200 mM ethylparaben exposure group was observed. In all paraben groups, a significant reduction in mean fecundity was found compared to the control group (p < 0.05).

Larvicidal Activity of Green Synthesized Silver Nanoparticles and Chitosan Nanoparticles Encapsulated Aloe vera Gel Extract against Musca domestica (Diptera: Muscidae)

Background:There is a worldwide interest in metal nanoparticles synthesized by various chemical reactions for use in biomedical applications. These processes exhibit a broad range of toxicity in non-target organisms. To avoid chemical toxicity, green synthesis of metal nanoparticles is proposed as a cost-effective and eco-friendly alternative. Aloe vera (A. vera) leaf extract is a medicinal agent with multiple properties, including antibacterial effects. Its constituents include lignin, pectin and hemicellulose, which can be used in the reduction of silver ions to produce silver nanoparticles (AgNPs).Objective:The study aimed at the use of naturally occurring compounds as a reducing and stabilizing agent for the biosynthesis of nanoparticles and investigation of the insecticidal activity of these compounds against Musca domestica (M. domestica) larvae.Methods:Phytochemical analysis of A. vera gel extract was done and the phytochemical components were identified by Gas Chromatography–Mass Spectrometry (GC-MS) analysis. AgNPs and encapsulated Chitosan Nanoparticles (CsNPs) were prepared by an eco-friendly method using A. vera gel extract as a reducing and stabilizing agent. A. vera-AgNPs and A. vera encapsulated CsNPs were characterized using Ultraviolet-visible spectrophotometer (UV–vis spectrum), Transmission Electron Microscopy (TEM), Fourier-Transform Infrared Spectroscopy (FTIR) and X-ray Diffraction (XRD). Then the insecticidal activity of these compounds was investigated against late second instar larvae of the house fly.Results:The most active ingredients identified by GC-MS analysis were Terpene and Sesquiterpene hydrocarbons. The synthesized AgNPs were spherical with an average size of about 12-75 nm, as revealed by TEM. While encapsulated CsNPs ranged between 34-75 nm and the shape seemed spherical with dark parts confirming the encapsulated plant extract. FTIR and XRD results confirmed the successful encapsulation of the gel extract within the chitosan nanoparticles. Results proved the insecticidal potential of the tested compounds against M. domestica larvae, and the relative potency of encapsulated CsNPs was nearly 148.51 times more potent than A. vera crude extract whereas AgNPs was nearly 40.65 times more potent than A. vera crude extract. Furthermore, a prolongation of larval duration and reduction in the percentage pupation and adult emergence were observed.Conclusion:Overall, green-synthesized silver and chitosan nanoparticles have the potential for application as a biopesticide for house fly population control through the use of a safer and costeffective approach.

Evaluation of Larval Diets for Mass Rearing of Aedes aegypti L. (Diptera: Culicidae)

The ability to mass-produce quality insects in the laboratory is vital in any sterile insect technique (SIT) program. In mass-rearing Aedes aegypti, optimizing larval diet and conditions is essential as they directly affect adult traits that are important in future sterile male releases. This study aimed to evaluate different mosquito diets and determine the effects of changing parameters in the diet on the growth and development of Ae. aegypti (Old Balara strain). Different diets, densities, diet concentrations and the addition of brewer’s yeast (BY) were evaluated in rearing mosquito larvae. The cat food (CF) diet showed a more synchronized day of pupation at five days, where 80% of males already pupated regardless of larval density. In all three diets, a larval density at 2 larvae/mL of water was comparable to 1 larva/mL, saving more space and reducing the water requirement of Ae. aegypti without affecting its quality. The addition of BY resulted in significantly reduced time to pupation, increased pupation and adult emergence percentages. Among the diet concentrations, 0.2 mg/larva was the ideal concentration for CF and International Atomic Energy Agency diets and 0.3 mg/larva for the commercial fish meal due to shorter larval durations, longer adult longevity and longer adult wing lengths. In rearing Ae. aegypti, it is best to use CF with BY at 0.2 mg/larva/day at 2 larvae/mL.

Effects of soil texture and moisture on the host searching abilities of Steinernema siamkayai against Bactrocera latifrons

Summary Soil texture and moisture have significant effects on the infectivity and persistence of entomopathogenic nematodes (EPN). Both EPN and chili fruit flies (Bactrocera latifrons) spend most of their lifetime in soil, therefore making it possible to consider the successful use of EPN against chili fruit flies. This study aimed to investigate the effects of soil texture and moisture contents on chili fruit fly pupation and adult emergence, and on the infectivity of the EPN, Steinernema siamkayai, against this pest. The results revealed that the highest percentage of pupation occurred at a depth of 2 cm in all soil types. At a depth of 5 cm in the sandy clay loam only, no pupation of B. latifrons was observed. The adult emergence ranged from 51.9 to 82.5%, with significant differences between soil types. The horizontal movement of S. siamkayai showed that the concentration of EPN at a rate of 20 000 dauer juveniles pupa−1 yielded maximum pupae mortality (77.5-91.3%) in all soil types containing 15% moisture. In the vertical displacement test, S. siamkayai was capable of killing pupae up to a distance of 15 cm in all soil types. These results confirmed the potential of S. siamkayai to be used within pest control programmes of various soil textures, as long as the soil moisture contents allow its dispersal and host infection.

3.5-GHz radiofrequency electromagnetic radiation promotes the development of Drosophila melanogaster

With the rapidly increasing popularity of 5G mobile technology, the effect of radiofrequency radiation on human health has caused public concern. This study explores the effects of a simulated 3.5 GHz radiofrequency electromagnetic radiation (RF-EMF) environment on the development and microbiome of flies under intensities of 0.1 W/m2, 1 W/m2 and 10 W/m2. We found that the pupation percentages in the first 3 days and eclosion rate in the first 2 days were increased under exposure to RF-EMF, and the mean development time was shortened. In a study on third-instar larvae, the expression levels of the heat shock protein genes hsp22, hsp26 and hsp70 and humoral immune system genes AttC, TotC and TotA were all significantly increased. In the oxidative stress system, DuoX gene expression was decreased, sod2 and cat gene expression levels were increased, and SOD and CAT enzyme activity also showed a significant increase. According to the 16S rDNA results, the diversity and species abundance of the microbial community decreased significantly, and according to the functional prediction analysis, the genera Acetobacter and Lactobacillus were significantly increased. In conclusion, 3.5 GHz RF-EMF may enhance thermal stress, oxidative stress and humoral immunity, cause changes in the microbial community, and regulate the insulin/TOR and ecdysteroid signalling pathways to promote fly development.