Fly Pupae Research Articles

A multispectral imaging system developed based on the spectral feature selection method for identification of housefly pupae

Hyperspectral imaging systems can simultaneously obtain spectral and spatial information of fly pupae, especially achieving a large area of spectral information collection in a short period. However, hyperspectral imaging systems are expensive and require much computation. This study attempts to develop a four-channel spectral imaging system composed of a camera and four filters to achieve spectral discrimination of housefly pupae over a large area. It also aims to verify the feasibility of using spectral feature selection methods to guide the development of low-cost specialized spectral systems. Meanwhile, a strategy combining spectral degradation with the traversal method was proposed for determining the parameter indicators of optical components. Firstly, use a microspectrometer to acquire the spectra of fly pupae. Secondly, the successive projections algorithm (SPA) extracts four feature wavelengths related to fly pupa recognition from the full spectrum variables. Then, based on the strategy of spectral degradation combined with the traversal method, the parameters of the four filters are determined. Finally, a 4-channel spectral imaging system was constructed, and a prediction model was built with random forest (RF), while the spectral index (SI) method was used to improve model performance. The results indicate that this low-cost multispectral imaging system can achieve high-performance discrimination of housefly pupae (accuracy = 97.44 %). At the same time, SPA, spectral degradation, and traversal methods can provide effective central wavelength and resolution indicators for constructing low-cost multispectral imaging systems, offering a practical and feasible example to guide the development of specialized low-cost spectral devices using spectral feature selection methods.

Evaluation of the Entomopathogenic Fungus Beauveria bassiana on Different Stages of Phlebotomus papatasi (Diptera: Psychodidae), Vector of Zoonotic Cutaneous Leishmaniasis in Iran

Background: Zoonotic cutaneous leishmaniasis is a major public health problem in Iran with the main vector of Phlebotomus papatasi. The use of entomopathogenic fungi for biological control of the vector is a potential substitute for the current methods which are being used. The purpose of the current study was to assess the virulence of two local isolates of Beauveria bassiana (OZ2 and TV) against Ph. papatasi.
 Methods: To perform the bioassay test, fungal suspensions were applied for every stage of the sand fly life cycle. The mortality rate, longevity, and number of eggs laid were determined. Also, the probability of fungal survival on the sur­face of rodent’s body was assessed.
  Results: The longevity of infected adult sand flies with both isolates of B. bassiana was significantly lower (P< 0.05) in comparison to the negative control. The estimated Lethal concentration 50 (LC50) values for adult female and male sand flies treated with OZ2 isolate were 1.4×106 and 2.2×107 conidia/ml, respectively, while they were 6.8×106 and 2.3×108 conidia/ml for TV iso­late, respectively. Both isolates of B. bassiana exhibited nonsignificant mortality rates in sand fly larvae and pupae and fecundity rate (P> 0.05). According to our findings for both isolates, the fungus continued to spread throughout the sur­face of the rodent's body for 144 hours after spraying.
 Conclusion: The current study demonstrated that both isolates of B. bassiana have considerable biological control ca­pacity against adult sand flies.

Exploring the impact of culture media on life history characteristics of the house fly, Musca domestica L. (Diptera: Muscidae)

Insects, particularly house fly pupae (M. domestica L.), are increasingly promoted as a rich and sustainable protein source, presenting a practical solution for organic waste management. These insects possess the capability to transform animal waste into valuable biomass, underscoring the necessity to evaluate housefly larval growth on diverse waste mixtures. The primary objective was to comprehend how different culture media influence the life history traits of this species. To address this, the research aimed to assess the growth and development performance of housefly larvae reared on various waste mixtures. Adult house flies (M. domestica) were sourced from meat and fish markets in Rajshahi city, Bangladesh, employing systematic sampling from different market sections for a representative selection. Experimental diets were formulated with combinations of cattle blood, cattle manure, rice bran, wheat bran, and kitchen waste, categorized into Diet-A (kitchen waste:cattle manure:wheat bran), Diet-B (cattle blood:rice bran), Diet-C (cattle manure:wheat bran), and Diet-D (cattle blood:kitchen waste:rice bran). Additionally, a control group comprised a mixture of waste materials, including yeast, egg white, milk powder, and wheat bran. The findings revealed that larvae, pupae, and adults reared on Diet-B, incorporating cattle blood and rice bran, demonstrated increased length compared to other diets. This varied diet also produced the heaviest larvae, pupae, and adults, exhibiting the highest morphometric parameters. The moisture content of pupae varied across the different diets, ranging from 53.23±0.17 % to 65.47±1.32 %. The pupae reared on Diet-B had the highest levels of crude protein (53.44±0.05 %, p < 0.05), while those reared on Diet-C had the highest levels of fat (18.56±0.05 %, p < 0.05 except for diet A). The findings demonstrate that housefly larvae can be reared on diets containing rice bran and cattle blood, which have different nutritional profiles and biological capacities. However, the ideal rearing strategy should depend on how M. domestica will be utilized in the future. The study highlights insects, especially housefly pupae, as a sustainable protein source and an organic waste management solution. Therefore, the results of this study contribute to the broader understanding of Musca domestica and offer practical implications for both scientific research and pest management practices.

Functional response and mutual interference in the parasitoid Coptera haywardi (Oglobin) (Hymenoptera: Diapriidae) attacking Anastrepha ludens (Loew) (Diptera: Tephritidae) pupae.

Functional response and mutual interference are important attributes of natural enemies that should be analysed in species with the potential to be used as biological control agents in order to increase the predictive power of the possible benefits and/or consequences of their release in the field. Our main objective was to determine the functional response and mutual interference of Coptera haywardi (Oglobin), a pupal parasitoid of economically important fruit flies (Diptera: Tephritidae). The functional response of C. haywardi on A. ludens pupae corresponded to a type II model, with an attack rate of 0.0134 host pupa/h and a handling time of 1.843 h, which reveals a meticulous selection process of pupal hosts. The effect of mutual interference among foraging females was negatively correlated with increased parasitoid density in the experimental arena, showing a gradual decline in attack rate per individual female. The increase in the number of foraging females also had an impact on the number of oviposition scars per pupa and the number of immature parasitoids per dissected pupa, but not on the percentage of adult emergence or the sex ratio. Our results suggest that C. haywardi could act as a complementary parasitoid in the control of fruit fly pupae, since the random distribution of these pupae in the soil would decrease the possibility of aggregation and mutual interference between foraging females.

The relationship between overwintering peach fruit fly pupae Bactrocera zonata (Saunders) (Diptera: Tephritidae) and some pathogenies in citrus orchard soils in Diyala province

A field and laboratory study was conducted for soil samples in citrus orchards in the Muqdadiya region - Diyala province in year 2021, for three depths (3, 5, and 7) cm, to detect overwintering peach fruit fly pupae Bactrocera zonata (Saunders) its infecting by Beauveria bassiana (Bals) Vuill. . The results showed that inverse (negative) correlation between the rates of the numbers of fungal colonies and the different soil depths, as the correlation value was (-0.906).

Green Production of Chitin from Black Soldier Fly Pupae Using a Natural Deep Eutectic Solvents

Natural deep eutectic solvents (NADES) are eco-sustainable, non-toxic, non-volatile, renewable, reusable, and biodegradable, and are composed of natural compounds. NADES were developed as a new-generation solvent for extracting chitin from black soldier fly (BSF) pupae, and its effectiveness for demineralization and deproteinization was determined. Here, two promising NADES, consisting of mixtures of choline chloride-betaine-xylitol (NADES A) and choline chloride-malic acid-water (NADES B), were tested. Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), X-ray diffraction (XRD), and scanning electron microscopy (SEM) were used to investigate the changes in the chemical composition of the extracted chitin. α-chitin revealed at wavenumbers 1660-1500 cm-1, in the amide group and decomposed at 330-350°C. NADES A and NADES B have a crystalline index of 91.65% and 90.65%, respectively. The chitin-NADES A and chitin-NADES B surfaces reveal the repetition of square, pentagonal, and hexagonal units (250× magnification) and fibrils (25,000× magnification). This study provides a green approach for chitin production from BSF and reveals the potential of NADES for extracting bio-polymers from natural sources.

Effect of X-ray Irradiation on Pupal Development of Bactrocera zonata and Bactrocera dorsalis under Laboratory Conditions

The studies were performed to check the effect of X-ray doses such as 20, 40, 60, 80 and 100 Gy on the Bactrocera zonata (Saunders) and Bactrocera dorsalis (Hendel) pupae reared on different diets. The laboratory strains of the Peach fruit fly and Oriental fruit fly reared on Guava, Mango and artificial diets.  Results showed a significantly (P&lt;0.05) greater number of deformed adults (Males and Females) of B. zonata at 100 Gy dose of x-ray irradiation followed by B. dorsalis obtained from artificial diets. Less deformity in adults of both fruit fly species was found at the same dosage of irradiation when maggots tended on mango. Similarly, a reduced number of normal adults of both fruit flies were recorded at 100 Gy dose of X-rays reared on an artificial diet.  Reduced pupal emergence was recorded on an artificial diet. From the above results, it is determined that B. zonata is more tolerant to different irradiation doses. Results of the present investigation would be useful to control or target fruit fly pupae in fruits of trade commodities as these pests are universally regulated as quarantine pests.

Automatic classification of parasitized fruit fly pupae from X-ray images by convolutional neural networks

The parasitoid wasp Diachasmimorpha longicaudata (Hymenoptera: Braconidae) has been used for the biological control of fruit fly larvae in many countries. Due to the large scale of production, quality control systems must be utilized to assess insect quality to optimize prerelease activities. However, the parasitism rate, and the unparasitized puparia, which become waste pupae, can only be known after waiting for the emergence of the adults from sampled pupae (ca. 16 days at 25 °C). This waiting time can result in resources being wasted. A way to speed up the quality control of pupal batches and increase the accuracy of the production process would be to combine digital radiography of the parasitized pupae and deep learning methods for the automatic classification of images. Therefore, the purpose of this work was to discriminate parasitized from waste pupae through X-ray images and to test the suitability of 7 Convolutional Neural Networks to classify the pupal images. Radiographic images from 11-day-old pupae allowed the in vivo identification of immature stages of the parasitoid, preserving the viability of the wasp. A positive correlation was found between the number of emerged parasitoids and the ones identified in the X-ray images. In terms of performance metrics, the accuracies achieved by all CNN-based neural architectures were higher than 97%, indicating a high predictive classification power. At least three of the CNNs tested showed great potential as classifiers of X-ray images of parasitized pupae and can be indicated for practical applications in quality control programs.

Chemical and population genetic analysis show no evidence of ecotype formation in a European population of the parasitoid wasp Nasonia vitripennis

Ecotypes, subpopulations or strains of a single species locally adapted to divergent ecological conditions within the same habitat are often considered to be the first steps in sympatric speciation. It has been suggested that two ecotypes are distinguishable in Nasonia vitripennis, a prominent model organism for parasitic Hymenoptera, with one ecotype parasitizing fly pupae in bird nests, and the other one parasitizing fly pupae on carrion. This differentiation into two ecotypes has been hypothesized to indicate incipient sympatric speciation in populations of this globally distributed species. In the present study, we investigated the differentiation into these two distinct ecotypes focusing on chemical profiles and the population genetic divergence in a wild N. vitripennis population from the Netherlands. Isofemale lines were obtained from bird nest boxes and from deer carrion, respectively, representing both microhabitats. To test for phenotypic differentiation, we determined the surface cuticular hydrocarbon (CHC) profiles from wasps of both host patches. Using a panel of 14 microsatellites, we concordantly determined the population genetic structure and tested for genetic differentiation between foundresses obtained from both microhabitats. Both the phenotypic as well as the genetic datasets show no evidence for any kind of separation based on the postulated two ecotypes, but rather suggest free interbreeding with no gene flow interruption between the two distinct host patches. Our findings challenge previous assumptions on clearly distinguishable ecotypes in N. vitripennis, and demonstrate how a chemical ecological assessment coupled with population genetics can be instrumental in re-evaluating the potential of ecological differentiation and incipient speciation mechanisms in parasitoid wasps.

Identification of fruit fly (Tephritidae) pupae parasitized by hymenoptera parasitoids

AbstractOne of the major problems in orchards is the presence of Tephritidae fly maggots, especially in Mirtaceae species. Various biological control tools include the use of Hymenoptera parasitoids, which naturally control fly populations. However, identification of the host species of parasitoids is challenging, because only the puparium remains after the parasitoid hatches. Therefore, the aim of this work was to determine the host species of Hymenoptera parasitoids, through the puparium. Host species were identified by amplification and sequencing of cytochrome C oxidase subunit I (COI) of mitochondrial DNA. The results of the present study show that COI DNA sequencing was able to reliably identify host pupae to the genus level, allowing the identification of the Anastrepha genus in this study. This suggests that this method can be used to identify agriculturally relevant hosts through its puparium remains, since this genus has already been described as a pest of Campomanesia adamantium. Knowledge of the species that cause damage to crop is extremely important to study the biological and ecological aspects of these pests and their control. In this way, our results suggest that this method can be used to identify economically relevant host pupal species since the genus identified in this study has already been described as a pest of C. adamantium.

Upper thermal limits of Rhagoletis indifferens (Diptera: Tephritidae) pupae and pteromalid parasitoids (Hymenoptera: Pteromalidae) inside fly puparia.

Determining upper thermal limits of tephritid fly pupae can have practical implications for disinfesting soils and for predicting differential impacts of global warming on flies and their parasites. Here, upper thermal limits of Rhagoletis indifferens Curran (Diptera: Tephritidae) pupae and pteromalid wasps (Hymenoptera: Pteromalidae) inside puparia were determined. Puparia receiving sufficient chill to terminate pupal diapause were exposed to temperatures ramped linearly over 6 h from 21 °C to 47.8, 49.4, 51.1, 55.0, or 60.0 °C for a 0-h hold time. Flies eclosed when pupae were exposed to 47.8 °C but not to 49.4, 51.1, 55.0, or 60.0 °C nor in a separate test to 47.8 °C for 1-3 h hold times. All fly pupae in treatments where no eclosion occurred were dead based on puparial dissections. In contrast, adult wasps eclosed when puparia were exposed to 49.4 and 51.1 °C for 0 h and to 47.8 °C for 1- and 2-h hold times. Despite the greater upper thermal limits of wasps, heat delayed eclosion times of both adult flies and wasps, in 47.8 and 51.1 °C treatments, respectively. In separate tests, longevity of flies exposed as pupae to 47.3-48.6 °C was greater than of control flies, while longevity of control wasps and wasps exposed as immatures to 47.8-51.1 °C did not differ. Flies exposed as pupae to 47.2-48.6 °C produced as many eggs and puparia as control flies. Results suggest heat could be used to disinfest soils of puparia while sparing parasitoids. In addition, extreme heat waves due to global warming might be more detrimental to fly pupae than immature wasps.

The son-killer microbe Arsenophonus nasoniae is a widespread associate of the parasitic wasp Nasonia vitripennis in Europe

Heritable microbes that exhibit reproductive parasitism are common in insects. One class of these are the male-killing bacteria, which are found in a broad range of insect hosts. Commonly, our knowledge of the incidence of these microbes is based on one or a few sampling sites, and the degree and causes of spatial variation are unclear. In this paper, we examine the incidence of the son-killer microbe Arsenophonus nasoniae across European populations of its wasp host, Nasonia vitripennis. In preliminary work, we noticed two female N. vitripennis producing highly female biased sex ratios in a field study from the Netherlands and Germany. When tested, the brood from Germany was revealed to be infected with A. nasoniae. We then completed a broad survey in 2012, in which fly pupal hosts of N. vitripennis were collected from vacated birds’ nests from four European populations, N. vitripennis wasps allowed to emerge and then tested for A. nasoniae presence through PCR assay. We then developed a new screening methodology based on direct PCR assays of fly pupae and applied this to ethanol-preserved material collected from great tit (Parus major) nests in Portugal. These data show A. nasoniae is found widely in European N. vitripennis, being present in Germany, the UK, Finland, Switzerland and Portugal. Samples varied in the frequency with which they carry A. nasoniae, from being rare to being present in 50% of the pupae parasitised by N. vitripennis. Direct screening of ethanol-preserved fly pupae was an effective method for revealing both wasp and A. nasoniae infection, and will facilitate sample transport across national boundaries. Future research should examine the causes of variation in frequency, in particular testing the hypothesis that N. vitripennis superparasitism rates drive the variation in A. nasoniae frequency through providing opportunities for infectious transmission.

Establishment of a multiplex PCR-CE assay for the simultaneous and rapid analysis of age markers for Calliphora vicina pupae.

Insects, especially blow flies, are forensically relevant to determine the minimal postmortem interval (PMImin), based on the fact that they are usually the first colonisers of a body. By estimating the age of immature blow flies, interferences can be made about the time since death. Whilst morphological parameters are valuable for age estimation of blow fly larvae, gene expression profiling is more applicable for blow fly pupae. Here, the age-dependent changes in the gene expression levels during the development are analysed. 28 temperature-independent markers have already been described for the age estimation of pupae of the forensically important blow fly Calliphora vicina and are analysed by RT-qPCR. To allow simultaneous analysis of these age markers, a multiplex assay was developed in the present study. After reverse transcription, the markers are analysed simultaneously in an endpoint PCR and subsequently separated by capillary electrophoresis (CE). This method is highly attractive due to its quick and easy procedure and interpretation. The present age prediction tool was adapted and validated. The multiplex PCR assay reproduced the same expression profiles as the RT-qPCR assay based on the same markers. The statistical evaluation shows that the new assay has a lower precision but a better trueness for age determination compared to the RT-qPCR assay. Since the new assay is also qualified to estimate the age of C. vicina pupae and is practical, cost-effective and, even more importantly, time-saving, it is attractive for use in forensic casework.

Descriptive analyses of differentially expressed proteins during intrapuparial stage based on the label-free proteomics technique between Chrysomya megacephala and Synthesiomyia nudiseta

The lack of rapid and accurate species identification methods on pupae restricts the practical application of forensic entomology. It is a new idea to construct portable and rapid identification kits based on the principle of antigen/antibody interaction. Screening differentially expressed proteins (DEPs) of fly pupae is a basis of solving the problem. Here, we used the label-free proteomics technique to discover the DEPs and further validate using the parallel reaction monitoring technique (PRM) in the common flies. In this study, we reared the Chrysomya megacephala and Synthesiomyia nudiseta at constanttemperature, and then we sampled at least four pupae at 24 h intervals until the end of the intrapuparial stage. We found 132 DEPs between Ch. megacephala, and S. nudiseta groups, with 68 and 64 proteins being up-regulated and down-regulated between the two groups. Among the 132 DEPs, we selected five proteins having potential for further development and utilization, such as C1-tetrahydrofolate synthase, Malate dehydrogenase, Transferrin, Protein disulfide-isomerase, and Fructose-bisphosphate aldolase, for further validation using PRM-targeted proteomics, with the trends of PRM results being consistent with the label-free data for corresponding proteins. The present study investigated DEPs via the label-free technique during the pupal development in the Ch. megacephala, and S. nudiseta and provided reference data for development of rapid and accurate identification kits.

Efficacy of Abiotic Factors on Population Dynamics of Fruit Fly (Bactrocera dorsalis) Larva and Pupa

The fruit fly B. dorsalis is a serious fruit and vegetable pest in South-East Asia. It causes 25-100% loss of horticultural crops by laying eggs under the skin of mangoes, peaches, guava, apricots and figs. Abiotic factors are ecological factors including temperature, humidity, and rainfall. These factors adversely affect the population dynamics of fruit fly larvae and pupae. Plants were randomly selected and installed with methyleugenol pheromone traps to study the population dynamics of Bactrocera dorsalis and correlate with abiotic factors. The fruits that had fallen were retrieved after a gap of 7-8 days. The contaminated fruit samples were exposed in the lab after a 9-10 days incubation period, and the larvae were counted. To ascertain the relationship between the larval and pupal populations of fruit flies in citrus, the one-way ANOVA technique was used. Bactrocera dorsalis larvae and pupae populations were the greatest at high temperatures and low humidity.

Combination of 3D printing and electrospinning to develop chitin/gelatin/PVA scaffolds.

In this study, novel scaffolds based on natural polymers were developed by combining 3D printing (3DP) and electrospinning (ES) techniques. ES ink was prepared with gelatin and poly(vinyl alcohol) (PVA), while 3DP ink was prepared with gelatin and chitin. Different biopolymers were used to confer unique properties to each ink and obtain a multilayered scaffold suitable for tissue regeneration. First, gelatin is able to exhibit the characteristics needed for both inks since gelatin chains contain arginineglycine-aspartic (RGD) motifs, an important sequence in the promotion of cell adhesion, which gives gelatin an improved biological behavior in comparison to other polymers. Additionally, PVA was selected for ES ink to facilitate gelatin spinnability, and chitin was incorporated into 3DP ink as reinforcement to provide mechanical support and protection to the overall design. In this work, chitin was extracted from fruit fly pupae. The high extraction yield and purity of the chitin obtained from the fruit fly pupae confirmed that this pupa is an alternative source to produce chitin. Once the chitin was characterized, both inks were prepared and rheological analysis was carried out in order to confirm the shear thinning behavior required for additive manufacturing processes. The combination of 3DP and ES processes resulted in porous scaffolds, which were proven biocompatible, highlighting their potential for biomedical applications.

Atomic crystal structure and sugar specificity of a β-trefoil lectin domain from the ectomycorrhizal basidiomycete Laccaria bicolor

Lectins from fruiting bodies are a diverse group of sugar-binding proteins from mushrooms that face the biologically relevant challenge of discriminating self- from non-self carbohydrate structures, therefore providing a basis for an innate defence system. Such a system entails both detection and destruction of invaders and/or feeders, and in contrast to more complex organisms with immense immune systems, these two functions normally rely on multitasking lectins, namely, lectins with different functional modules. Here, we present a novel fungal lectin, LBL, from the basidiomycete Laccaria bicolor. Using a diverse set of biophysical techniques, we unveil the fine details of the sugar-binding specificity of the N-terminal β-trefoil of LBL (LBL152), whose structure has been determined at the highest resolution so far reported for such a fold. LBL152 binds complex poly-N-Acetyllactosamine polysaccharides and also robust LBL152 binding to Caenorhabditis elegans and Drosophila melanogaster cellular extracts was detected in microarray assays, with a seeming preference for the fruit fly adult and pupa stages over the larva stage. Prediction of the structure of the C-terminal part of LBL with AlphaFold reveals a tandem repeat of two structurally almost identical domains of around 110 amino acids each, despite sharing low sequence conservation.

Parasite-host relationships of water mites (Acari: Hydrachnidia) and black flies (Diptera: Simuliidae) in southeastern Spain

BackgroundDocumentation on water mites in Spain is scarce, as is information on the parasite-host relationship between certain water mite species and representatives of the dipteran family Simuliidae. The discomfort caused to humans and animals by black flies seems to be increasing in recent years. In this context, an investigation of parasitic water mites is of great importance, not only from the point of view of biodiversity, but also in terms of their potential to control black fly populations.MethodsRivers across a wide region of eastern Spain were sampled to determine the specific richness of simuliid dipterans and to investigate their possible parasites, such as water mites, mermithid nematodes and microsporidia (fungal microbes). Data on environmental variables, abundance, prevalence and intensity of parasitism on the collected specimens were analyzed.ResultsIn 10 streams, 15,396 simuliid pupae were collected and checked for the presence of water mite larvae; 426 pupae in seven streams were found to be associated with water mite larvae. Of the 21 simuliid species identified based on morphological characters, eight were found to be associated with water mite larvae. Water mite infection was not equally distributed among black fly species. Also, the prevalence of parasitism was low and differed among simuliid species, ranging from one to 13 water mites per black fly pupa. Variation at the intra- and interspecific levels was detected in terms of the number of water mites inside the black fly cocoons. Free-living deutonymphal and adult water mites representing 15 different species of six genera and five families were morphologically identified. The taxonomic identity of the parasitic mite larvae is unclear at present. Morphologically, they fit descriptions of larval Sperchon (Hispidosperchon) algeriensis Lundblad, 1942, but the possibility cannot be excluded that they represent Sperchon algeriensis, the most abundant species at the adult stage in this study and unknown at the larval stage, or even another species of the genus. A molecular analysis produced for the first time cytochrome oxidase I gene sequences for S. algeriensis.ConclusionsOur results contribute to current knowledge on Spanish Hydrachnidia and their relationships with simuliids as hosts. However, further research is needed to evaluate the diversity, distribution, bioecology and prevalence of this parasitism.Graphical

Influence of ground beetles (Carabidae) as biological agent to control of the Mediterranean fruit fly pupae, Ceratitis capitata, in Iranian citrus orchards

• High diversity and density of Carabidae observed with eliminated pesticide spray. • Instead pesticide, mineral oil spray led conserving the carabids species. • Seasonal density fluctuation of Carabidae was observed, increasing in spring. • Highest population of Carabidae with the peak of fruit fly damage in September. • H. rufipes, B. karelinii and Pterostichus macer were the most voracious predators. Damage by Mediterranean fruit fly, Ceratitis capitata (Wiedemann) (Diptera: Tephritidae) in the northern Iranian citrus orchards has been led to spray by different chemical pesticides. The present study was conducted in the citrus orchard in Mazandaran province of Iran where with the exception of mineral oil treatments for scale insects, had not been sprayed with synthetic insecticides for six years. The purpose of this study was initially to investigate faun and seasonal activity of predaceous ground carabid beetles in the citrus orchards. Additionally, their role as predators of Ceratitis capitata (Wiedemann) pupae was evaluated under laboratory and field conditions. Predation in laboratory was evaluated by no choice feeding experiments while predation under field conditions was evaluated by molecular detection of the pest DNA in the gut contents of field-collected Carabids. A total of 3,437 beetles of ten carabid species were collected from a non-chemical treatment citrus orchard. The results of the seasonal density fluctuation indicated increasing population in spring reaching the highest in September, simultaneously with the peak of fruit fly damage, and thereafter decreasing during winter when the pest was overwintering. However, three species, Harpalus rufipes, Broscus karelinii and Brachinus brevicollis were most abundant in the field collection but the results of no-choice experiments in the laboratory indicated H. rufipes, B. karelinii and Pterostichus macer were the most voracious predators on pupae. Results of gut content analysis of the voracious species indicated the positive testing for pest DNA in 79.16 % of H. rufipes , 76.92% of B. karelinii and 75% of P. macer of analyzed beetles. The results of the study strongly indicated that in citrus orchards where intensive spraying is eliminated, natural enemies such as Carabid beetles could play an important role in reducing pests such as medfly.

Characterization of polar and non-polar lipids of Hermetia illucens and Tenebrio molitor meals as animal feed ingredients

Although increasingly used in animal feeding, the black soldier fly (Hermetia illucens - HI) and mealworm (Tenebrio molitor - TM) larvae and pupae require the characterization and modulation of their fat profile for use in the feed industry. In this study, we provide a comprehensive fatty acid profile of the total lipid triglycerides and phospholipids, and sterol composition. For a more detailed characterization of the nutritional properties, we defined the profile of esterified fatty acids (FAs) in the sn-2 position of the triglycerides, which represents the most adsorbed fraction by animals during digestion. Twenty-four batches (12 batches per species divided into 6 batches of larvae and 6 batches of pupae) of 70 subjects were used for the analysis. For each of the developmental stages, individuals in the intermediate stage were considered (2 months and 8 days for TM larvae and pupae respectively; 9 days and 7 days for HI larvae and pupae respectively). Some fatty acids (decanoic, lauric, or myristic acid) were more abundant in HI than in TM. These FAs were produced de novo, indicating that HI produce them from carbohydrates as a source of acetyl-CoA. Hermetia illucens showed a higher level of conjugated linoleic acid (CLA) isomers, a class of fatty acids with positive health effects. In contrast, TM showed a similar fatty acid profile to the plant lipid source (such as soy and sunflower) due to the high level of linoleic acid. Analysis of the triglyceride fraction showed a different affinity for the three glyceride positions. In particular, lauric acid, polyunsaturated fatty acids n-3 and CLA isomers esterified preferentially in sn-2, and therefore were the most adsorbed by the animal during digestion. As for the phospholipids, HI showed a higher level, above all in terms of the phosphatidylethanolamine fraction. Interestingly there was no sphingomyelin in the pupae of both species. The high level of phospholipids is a useful feature for the emulsion of fats in animal feed diets. Lastly, we observed a considerable amount of phytosterol in the sterol profile of both species, which makes these insects a valid alternative to other food sources of plant origin for animal nutrition. We believe that our findings provide new nutritional information for the use of TM and HI in the animal diet.