Larval performance of Zophobas morio (F.) (Coleoptera: Tenebrionidae) on various diets enriched with post-distillation residues and essential oils of aromatic and medicinal plants.

The increasing demands for resources driven by the global population necessitate exploring sustainable alternatives for affordable animal protein over the use of traditional protein sources. Insects, with their high protein content, offer a promising solution, especially when reared on agricultural post-distillation residues for enhanced sustainability and cost-effectiveness. We assessed the development of Zophobas morio (F.) (Coleoptera: Tenebrionidae) larvae on diets enriched with essential oils and post-distillation residues from Greek aromatic and medicinal plants. Two aromatic plant mixtures (A and B) were examined. Mixture A consisted of post-distillation residues, while Mixture B incorporated these residues along with essential oils. Insect rearing diets were enriched with different proportions (10, 20, and 30 %) of these mixtures, with wheat bran serving as the control. Enrichment positively influenced larval development without compromising survival. Larval weight remained unchanged with Mixture A, but improved with Mixture B. No adverse effects were detected in the case of the enriched diets, although higher concentrations of Mixture B prolonged development time.

Go local: Enhancing sustainable production of Tenebrio molitor through valorization of locally available agricultural byproducts.

Insects receive increasing attention as an alternative source of protein for animals and humans, and thus, the production of low-cost insects for meeting the dietary demand on sustained basis is an ever-growing concept. This study aims to design dietswith locally available agricultural byproducts from Greece as feed for larvae of the yellow mealworm, Tenebrio molitor L. (Coleoptera: Tenebrionidae). This will considerably reduce the cost of insect feed and the environmental impact of insect farming by using locally available agricultural byproducts as economic insect feedstock. More specifically, five agricultural byproducts derived from the production of cereals and legumes were utilized to design twelve different diets at two protein levels, i.e., 17.4 and 22.5% protein content. All diets were evaluated both at laboratory scale, but also at pilot scale. Based on the obtained results, both bioassays revealed that the diets contained one legume and one cereal byproduct (i.e., lupin and triticale as well as lupin and oat) supported more efficiently the growth and performance of the larvae, irrespective of the protein level. Indicatively, individual larval weight of the best performed larvae from both groups ranged from 132 to 142 mg. Moreover, our results highlight the fact that data derived from laboratory scale bioassays are not always easy to be extrapolated to industrial production. For instance, the total harvest of larvae, a parameter assessed in the tray scale bioassay, exhibited a disparity between diet A2 (910 g) and diet A3 (749 g), despite both being deemed optimal in the laboratory-scale experiment. Our study aims to promote a circular approach for the industrial rearing of insects through integration of local agricultural byproducts into specific diets for T. molitor larvae.

Diet replacement with whole insect larvae affects intestinal morphology and microbiota of broiler chickens.

Insect-based diets are gaining interest as potential ingredients in improving poultry gut health. This study assessed the dietary treatment with whole dried Tenebrio molitor larvae (TM) on broiler chickens' gut microbiota and morphology. 120 Ross-308 broilers received treated diets with 5% (TM5) and 10% (TM10) replacement ratio in a 35-day trial. Intestinal histomorphometry was assessed, as well as claudin-3 expression pattern and ileal and caecal digesta for microbial community diversity. Null hypothesis was tested with two-way ANOVA considering the intestinal segment and diet as main factors. The TM5 group presented higher villi in the duodenum and ileum compared to the other two (P < 0.001), while treated groups showed shallower crypts in the duodenum (P < 0.001) and deeper in the jejunum and ileum than the control (P < 0.001). Treatments increased the caecal Firmicutes/Bacteroidetes ratio and led to significant changes at the genus level. While Lactobacilli survived in the caecum, a significant reduction was evident in the ileum of both groups, mainly owed to L. aviarius. Staphylococci and Methanobrevibacter significantly increased in the ileum of the TM5 group. Results suggest that dietary supplementation with whole dried TM larvae has no adverse effect on the intestinal epithelium formation and positively affects bacterial population richness and diversity.

Effects of low temperatures on quiescence in Trichogramma evanescens Westwood and T. chilonis Ishii reared on Plodia interpunctella (Hübner): implications for mass rearing.

The egg parasitoids of the genus Trichogramma are important potential biological control agents for a wide range of lepidopteran pests. Cold storage of host eggs has been proposed as a valuable technique for ensuring the release of sufficient parasitoid numbers whenever it is needed. In this context, the impact of low temperatures to induce quiescence in T. evanescens Westwood and T. chilonis Ishii was studied using eggs of Indian meal moth Plodia interpunctella (Hübner). Prepupae of the parasitoids were stored for 15, 30, 45, 60 and 75 d at 4 °C, following a 7 d period of acclimation at 10 °C. Both parasitoid species seem to survive unfavorable temperature conditions by entering a state of quiescence. Parasitism, adult emergence, sex ratio and progeny quality were not affected by cold storage in either parasitoid species for up to 30 d of storage. Parasitized host eggs of P. interpunctella can be stored for up to 60 d at 4 °C for both parasitoids, but there was no emergence at 75 d. General productivity values gradually decreased as the duration of storage lengthened for both species. Our results clearly reveal that the eggs parasitized by these species can be stored for up to 30 d at 4 °C in a state of quiescence without much loss of their performance compared to the control eggs.

Development, application and evaluation of three novel TaqMan qPCR assays for phosphine resistance monitoring in major stored product pests Tribolium castaneum and Rhyzopertha dominica.

BACKROUND: Stored product protection from insect pests relies heavily on the use of phosphine. The most serious drawback of phosphine is the development of resistance in major stored product insects worldwide, including the red flour beetle, Tribolium castaneum (Herbst) and the lesser grain borer, Rhyzopertha dominica (F.). Two genetic loci are responsible for phosphine resistance: the rph1 (S349G mutation in the cyt-b5-r homolog) in T. castaneum and the rph2 (P45/49S mutation in the dihydrolipoamide dehydrogenase (dld) gene) in T. castaneum and R. dominica. RESULTS: In this study, we have developed and applied high-throughput, practical and specific molecular diagnostics (TaqMan qPCR) for monitoring mutations S349G, P45S and P49S. In our pilot monitoring application, we have included phosphine-resistant and susceptible populations from different parts of the world (USA, Australia, Brazil) and European strains from Greece and Serbia. Our results for the resistant T. castaneum showed a P45S mutant allele frequency (MAF) of 100% and 75.0% in the populations from Serbia and Brazil, respectively. Regarding the susceptible T. castaneum, P45S was detected in Greece (MAF = 62.5%) and was absent in Australia (MAF = 0.0%). Additionally, the S349G mutation was found to be fixed in all resistant populations, while it was also detected in susceptible ones (frequencies: 65.0% and 100.0%). The only case where both mutations were fixed (100%) was a resistant population from Serbia. In R. dominica, the P49S mutation was found only in the two resistant R. dominica populations from Serbia and Greece (50.0% and 100%) and was absent from the susceptible one from Greece; thus, P49S seems to be a satisfactory indicator for monitoring phosphine resistance. CONCLUSIONS: Our P49S detection assay in R. dominica seems to be a viable option in this direction, yet its utilization needs additional large-scale confirmatory work. The identification of additional resistance markers also should be prioritized. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Competition of Rhyzopertha dominica and Sitophilus oryzae on six sorghum varieties.

We tested the effect of simultaneous infestation by adults of the lesser grain borer, Rhyzopertha dominica (F.) and the rice weevil, Sitophilus oryzae (L.) on six sorghum varieties. For this purpose, vials containing sorghum and either each species alone or both species were placed at 30 °C and 65% relative humidity. After ten days, all parental adults were removed and the vials were returned to the same conditions. Five weeks later the vials were emptied, to record adult emergence, the percentage of insect damaged kernels (IDK), and frass weight. Our results indicated that progeny production capacity for both species was not affected by the simultaneous presence of R. dominica and S. oryzae, and that adult emergence was more of a variety- mediated parameter. Both species had previously shown similar preferences towards specific sorghum varieties. IDK and frass were higher in vials containing R. dominica alone rather than S. oryzae alone, but these indicators were not always related to progeny production. Specifically, the most and the least frass production was noted on Sumac and PE sorghum varieties for both species, respectively. When the two species were placed together in the same vial, the most frass production was noted in the Non-Waxy Burgundy and Sumac varieties. Our results suggest that varietal resistance in sorghum could be utilized to help reduce post-harvest infestations by S. oryzae and R. dominica.

Breeding Substrate Containing Distillation Residues of Mediterranean Medicinal Aromatic Plants Modulates the Effects of Tenebrio molitor as Fishmeal Substitute on Blood Signal Transduction and WBC Activation of Gilthead Seabream (Sparus aurata).

This work assesses the dietary use of two insect meals of Tenebrio molitor (TM) larvae reared in conventional (TM-10) or MAP-enriched substrates (MAP-TM-10) as fish meal replacements (10%) in the diets of gilthead seabream (Sparus aurata). Fish (n = 4500; 207.19 ± 1.47 g) were divided into three groups with triplicates: control (fed conventional diet), TM-10, and MAP-TM-10 groups. The fish were reared in floating cages for 12 weeks and the dietary effects on white blood cell activation, heat shock proteins, MAPKs, and apoptosis of the fish were evaluated. The MAP-TM-10 group exhibited the highest eosinophilic induction. Phosphorylated levels of p38 MAPK, p44/42 MAPK, HSP70, and HSP90 increased in the TM-10 and MAP-TM-10 groups. In terms of apoptosis, Bax levels were lower in the TM groups compared to the control, and the MAP-TM-10 group showed even lower levels than the TM-10 group. Bcl-2 levels increased in the TM-10 group compared to the control, and further increased in the MAP-TM-10 group. The Bax/Bcl-2 ratio, an apoptosis indicator, decreased in the TM groups, with the MAP-TM-10 group showing a further decrease compared to TM-10. These findings suggest that insects' breeding substrate being enriched with MAPs modulated the effect of TM on cellular stress and apoptosis.

Mating compatibility and offspring traits evaluation among different strains of Tenebrio molitor.

The fast-growing sector of insects for food and feed stimulates researchers and the industry to explore uncharted territories, such as insect breeding, to improve economically important insect fitness traits. The yellow mealworm, Tenebrio molitor L., is one of the most thoroughly studied insect species as food and feed. However, data on mating compatibility and the effect of cross-breeding between different strains on the performance and fitness of the hybrids are scarce. In the present study, we comparatively evaluated the mating compatibility between two T. molitor inbred strains (Greek and Italian) and their outbred strains, i.e., Italian (♀)-Greek (♂) and Greek (♀)-Italian (♂), as well as the performance of their hybrid offspring. Based on the results, there is good mating compatibility among adults of the strains tested. Offspring performance, quantified as larval survival and final larval weight, followed a similar pattern among the crossings examined. Even though differences were insignificant, the outbreeding of females of the Italian strain resulted in a higher cumulative number of eggs and hatching rate and higher offspring weight. The present study sheds light on the mating compatibility of different T. molitor strains and their hybrids' economically important life table characteristics to take the mass production of insects one step further.

Enhancing the Nutritional Profile of Tenebrio molitor Using the Leaves of Moringa oleifera.

Nowadays, more and more research is being carried out on various feeds of Tenebrio molitor larvae, in order to increase their nutritional value and render them a valuable component of the human diet. In this study, Moringa oleifera leaves were used in different proportions (up to 50%) to substitute wheat bran (the usually employed feed), in order to evaluate their effect on the growth and development of the larvae, as well as on their composition in crude protein, fat and fatty acids, ash, vitamins, and antioxidants. It was found that the addition of M. oleifera leaves in the feed had no negative impact on the development and survival of the insects, while an increase in their nutritional value was recorded. More specifically, an increase in the crude protein of up to 22.61% and vitamin C and A contents of up to 40.74% and 491.63%, respectively, was recorded. Therefore, the use of M. oleifera leaves as a feed additive is highly recommended for rearing T. molitor larvae to enhance the nutritional value of the insects.

Insecticidal Effect of Diatomaceous Earth Formulations for the Control of a Wide Range of Stored-Product Beetle Species.

Diatomaceous earth (DE) formulations are promising alternatives over the use of traditional insecticides. In the present study, a series of laboratory bioassays was carried out to assess the efficacy of three diatomaceous earth formulations, i.e., Silicid, Celatom® MN-23, and SilicoSec®, for the control of a wide range of stored-product insect species in soft wheat. The species tested were Tribolium confusum, Tribolium castaneum, Sitophilus oryzae, Sitophilus granarius, Rhyzopertha dominica, Oryzaephilus surinamensis, and Alphitobious diaperinus. Different dose rates, i.e., 0 (control), 100, 300, 500, and 1000 ppm, were used for each of the aforementioned dust formulations. Mortality levels of the exposed individuals were assessed after 3, 7, 14, and 21 days of exposure. Moreover, progeny were counted 65 days later. Based on our results, dust formulations were effective for the control of most of the stored-product beetle species tested. Among the DE formulations tested, Silicid could adequately control the stored-product insect species. Complete suppression of offspring was observed only for secondary species (T. confusum, T. castaneum, O. surinamensis, and A. diaperinus). For primary species (S. oryzae, S. granarius, and R. dominica), the lowest number of progeny was observed in wheat treated with Silicid. For instance, in the case of R. dominica, significantly fewer individuals were produced in Silicid-treated wheat at the highest dose rate. The results of the present study aim to encourage the utilization of DE in stored-product protection as an integrated pest management tool. Additional experimentation is required to apply the tested DE formulations in the field and on different surfaces.

Effect of Nitrogen on Stored-Product Insect Control at Industrial Scale.

In this study, we evaluated the insecticidal effect of nitrogen against Sitophilus granarius (L.), Sitophilus oryzae (L.), Rhyzopertha dominica (F.), Prostephanus truncatus (Horn), Tribolium confusum Jacquelin du Val, and Oryzaephilus surinamensis (L.). Four trials were conducted in chambers containing flour in bags or sacks with >99% nitrogen level. Adults of all the above species, as well as immature life stages (eggs, larvae, and pupae) of T. confusum were used in the trials. Our results showed that nitrogen caused high mortality for all species and life stages tested. Some survival was recorded for R. dominica and T. confusum pupae. Low progeny production was recorded for S. granarius, S. oryzae, and R. dominica. In conclusion, our trials indicated that a high nitrogen environment can provide satisfactory control of various primary and secondary stored-product insect species.

Comparison of different traps and attractants in 3 food processing facilities in Greece on the capture of stored product insects.

Certain lures are marketed toward particular pests or classes of pests, while others might be multi-species lures. Investigative aims for this study included both which trap was most sensitive and whether different combinations of traps and attractants were delivering novel information about the stored product insect community. Comparisons were made for all combinations of 3 commercial traps and 4 different attractants plus an untreated control on the capture of stored-product insects for 2 consecutive years in 3 food processing facilities in Central Greece. The traps used in the experiments were Dome Trap (Trécé Inc., USA), Wall Trap (Trécé) and Box Trap (Insects Limited, Ltd., USA). The attractants that were evaluated were 0.13 g of (i) PantryPatrol gel (Insects Limited), (ii) Storgard kairomone food attractant oil (Trécé), (iii) wheat germ (Honeyville, USA), and (iv) Dermestid tablet attractant (Insects Limited). The traps were inspected approximately every 15 days and rotated. A total of 34,000+ individuals were captured belonging to 26 families and at least 48 species. The results indicated that Indian meal moth, Plodia interpunctella (Hübner), red flour beetle, Tribolium castaneum (Herbst), and cigarette beetle, Lasioderma serricorne (F.) were the most abundant. Although there were noticeable differences among the different traps and attractants for specific species, all combinations provided similar information on population dynamics. Generally, Dome traps baited with either the oil or the gel, were found to be the most sensitive. The results of the present study demonstrate the importance of long-term trapping protocols, as a keystone in IPM-based control strategies in food processing facilities.

Efficacy of deltamethrin and pirimiphos-methyl in proportionally layer-treated maize against the larger grain borer and the maize weevil.

Two insecticides (deltamethrin and pirimiphos-methyl) were evaluated in laboratory assays as grain protectants when applied as a total percentage of a maize mass to control adult Prostephanus truncatus and Sitophilus zeamais. All experiments were conducted at the University of Thessaly in Greece at 30°C and 65% RH under continuous darkness. Either insecticide was applied to 20 g of maize placed in a vial or to the upper one half, one fourth, or one-eighth layer of the maize, then insects were either added to the vials before or after the maize in a completely randomized block design CRBD with n = 9 replicates. Mortality, progeny production, and insect damaged kernels (IDK) were then evaluated for each vial. Insect introduction method (before or after) did not have any impact on any of the variables. Mortality was nearly 100% for all treatments for both insecticides for P. truncatus. Subsequently, progeny production and the number of insect damaged kernels were very low or zero for P. truncatus. Mortality of S. zeamais remained low across layer treatments for deltamethrin. However, S. zeamais was easily controlled by pirimiphos-methyl. The results of this laboratory study show that while deltamethrin and pirimiphos-methyl have some effectiveness as a layer treatment on a column of maize, efficacy will be dependent on the target species, and the depth of the treated layer, as well as the location on which the insects are present.

Quick knockdown results in high mortality: is this theory correct? A case study with phosphine and the red flour beetle.

BACKGROUND: The fumigant phosphine is used all over the world for disinfestation of stored grains and commodities. Adults of 23 different populations of Tribolium castaneum from 10 different countries were evaluated for phosphine resistance using a modification of the Detia Degesch Phosphine Tolerance Test Kit (DDPTTK). Adults were exposed to 3000 ppm and recorded for 5-270 min for their mobility. RESULTS: Among the tested populations, high levels of phosphine resistance were recorded in populations from Brazil, Serbia, and Spain. No survivals were recorded after 7 days post exposure for eight of 23 in a tested population. CONCLUSIONS: Our work revealed four scenarios: 1, quick knockdown-low (or no) recovery; 2, Slow knockdown-high recovery; 3, Quick knockdown-high recovery; and 4, Slow knockdown-low recovery. Our data indicate that post exposure period is critical for the evaluation and characterization of phosphine resistance. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Improved Quality Management of the Indian Meal Moth, Plodia interpunctella (Hübner) (Lepidoptera: Pyralidae) for Enhanced Efficacy of the Sterile Insect Technique.

The sterile insect technique (SIT) is considered an environmentally friendly, autocidal control tactic to manage insect pests. This work dealt with the improvement of quality management of the Indian meal moth Plodia interpunctella (Hübner) for enhanced efficacy of the SIT. The results indicated that egg hatching of irradiated mature eggs of P. interpunctella was higher than that of younger eggs, indicating that mature eggs were significantly more tolerant than younger eggs. Moreover, our data revealed that a dose of 500 Gy completely prevented pupal formation in irradiated young and mature larvae. Crosses between irradiated and non-irradiated adults resulted in considerable variations in fecundity. The mating competitiveness index (CI) value was higher for a ratio of 5:1:1 (sterile male, fertile male, and fertile female, respectively) as compared with the ratio 1:1:1 for the irradiated individuals of all life stages. Low temperature (5 °C) maintenance of irradiated pupae significantly affected adult emergence. Using cylinders to assess flight ability, we found that the flight performance of adults that were developed from cold treated irradiated pupae was influenced by cylinder diameter, cylinder height and the number of hours the insects were in the cylinders. The percentage of DNA damage of the reproductive organs of adults developed from cold treated pupae that were irradiated with 100 and 150 Gy varied significantly. The results of this study should be used to implement pilot-scale field tests aiming at a sterile- to-fertile male ratio of 5 to 1.

Growth performance, welfare traits and meat characteristics of broilers fed diets partly replaced with whole Tenebrio molitor larvae.

The role of insects in animal nutrition has been reconsidered during recent years, paving the way for an increasing market for edible insects. Their protein and amino acid balance make them a promising source of protein for replacing high value proteins. Yellow mealworm, Tenebrio molitor L. (TM; Coleoptera: Tenebrionidae) larvae, have shown positive effects on broiler performance in several research studies and have a strong potential as a sustainable alternative protein source for monogastric animals. This study aimed to assess the effect of replacing various ratios of basal diets with T. molitor larvae on broiler performance as well as on several meat and welfare characteristics. For the study, 120 one-day-old male chicks (Ross 308) were randomly allocated in 3 treatments and 4 replications (10 birds per pen). Birds of the control group (basal diet) were fed with typical commercial maize and soymeal-based rations in mash form. The other 2 groups were treated with the same diet, after replacing 5% and 10% with dried TM larvae, respectively. On d 35 (end of trial), meat samples were collected and analysed. Body weight, feed intake, body weight gain and feed conversion ratio during the periods of 1 to 10 d (starter period), 11 to 24 d (grower period), 25 to 35 d (finisher period) and 1 to 35 d (total period) were assessed. Pododermatitis, diarrhoea, feather score and litter conditions were also assessed during the trial. The results indicated that TM larvae inclusion in the broilers' diet positively affected body weight gain values, as well as the carcass yield, the meat composition and various welfare traits. Additionally, the dietary treatments with TM larvae favourably affected meat composition and colour parameters, whereas there were also some positive effects on lipid and protein oxidation. Saturated fatty acids were decreased by the dietary supplementation whereas the polyunsaturated fatty acids to SFA ratio increased. In general, the study showed that whole TM larvae addition can provide a promising alternative to soybean meal in the diet of broilers, demonstrating a positive impact on growth, welfare and meat characteristics.

Development and Immature Mortality of the Sawtoothed Grain Beetle (Coleoptera: Silvanidae), on Different Sorghum Fractions and Different Temperatures.

Developmental ability of Oryzaephilus surinamensis (L.) (Coleoptera: Silvanidae) was examined on six different sorghum milling fractions: Bran, Shorts, Cgrits, Fgrits, Red dogs, Flour, and also on a standard diet of Oat Flakes. For this purpose, a 1-day-old egg was placed in a vial containing 1 g of one of the sorghum fractions and exposed to three temperatures: 25, 30, or 32°C. All vials were checked daily for pupal and adult emergence and mortality of immatures. The developmental time was significantly affected by the type of sorghum fraction. After two weeks, for most of the temperatures examined, the longest developmental times in most cases for both pupation and adult emergence were observed in Flour and Oat flakes. Increasing the temperature from 25 to 30 accelerated the development, while adult emergence time did not differ between 30 and 32°C for all fractions except Flour. Egg mortality ranged from 11 to 78%, while larval and pupal mortality ranged from 0 to 22 and 0 to 45%, respectively for all sorghum fractions and different temperatures tested. Moreover, the mean overall immature mortality occurred at 30°C was 49.2, 39.7, and 65.1% at 25, 30, and 32°C for all the diets examined. The findings of the present work show that O. surinamensis can develop and survive in sorghum milling fractions and that the optimal temperatures for growth enhancement are 30 and 32°C. The temperatures within sorghum milling facilities could support O. surinamensis development on milling fractions if they are not addressed through phytosanitary measures.

Direct competition and potential displacement involving managed Trogoderma stored product pests.

The establishment of an exotic pest may require displacing local species with a similar niche. The potential of Trogoderma granarium to displace Trogoderma inclusum was explored in a stored product setting. We performed direct competition experiments varying commodity and temperature over different durations. At nine weeks T. inclusum outproduced T. granarium on all commodities at any temperature. However the proportion of T. granarium versus T. inclusum was greater at 32 °C compared to 25 °C. The nine-week production of T. granarium was best on wheat, while rice was optimal for T. inclusum. After 25 weeks, when adults were used at the start of competition, T. inclusum maintained an advantage in the direct competition. If larvae were used to initiate the competition for 25 weeks, the two species coexisted well at 25 °C, but T. granarium nearly excluded T. inclusum at 32 °C. Thus T. inclusum performs better in competition over shorter intervals when resources are plentiful, but T. granarium can be more successful over longer time periods, particularly when late instar larvae are involved. The finding suggests a real threat of introductions of T. granarium larvae to establish populations within grain storage infrastructure where T. inclusum is common.

Population growth of phosphine resistant and susceptible populations of Lasioderma serricorne (F.) (Coleoptera:Anobiidae) exposed to different temperatures and commodities.

The aim of this work was to investigate the population growth of Lasioderma serricorne (F.) with two populations with different susceptibility to phosphine (one resistant and one susceptible). Population growth was recorded on different days (35 days, 50 days, 65 days, 80 days, 95 days, and 110 days) in two different commodities: (a) mixed food consisted of wheat flour (10 parts) + cornmeal (10 parts) + brewers' yeast (1.5 parts) and (b) wheat flour. Our results clearly indicate that both populations preferred mixed food compared to wheat flour for all combinations tested. Moreover, the increase in temperature from 25 to 30 °C showed a positive effect in some combinations in the population growth of both populations. In general, we found some differences in the production of offspring between the susceptible and the resistant population. Based on the results of the present study, population growth may provide critical information for the fitness advantages or disadvantages of each population.

Waste Orange Peels as a Feed Additive for the Enhancement of the Nutritional Value of Tenebrio molitor.

Lately, additional attention is being placed on edible insects, since they constitute an excellent, cost-efficient source of proteins with a low ecological footprint. Tenebrio molitor was the first insect that was considered edible by EFSA in 2021. This species can replace conventional protein sources and thus, it has the potential to be used in many different food products. In the present study, a food by-product that is commonly produced (i.e., albedo orange peel waste) was used as a feed additive for T. molitor larvae, in an effort to further improve the circular economy and enhance the nutritional value of the insects. To this end, bran, which is commonly used as feed for T. molitor larvae, was fortified with the albedo orange peel waste (up to 25% w/w). Larval performance, in terms of larval survival and growth, as well as the larval nutritional value, i.e., the content of protein, fat, carbohydrates, ash, carotenoids, vitamins A and C, and polyphenols, was evaluated. Based on the results, the increase in the percentage of orange peel albedos in T. molitor feed resulted in a subsequent increase in the content of larvae in carotenoids and vitamin A up to 198%, in vitamin C up to 46%, and an increase in the protein and ash content up to 32% and 26.5%, respectively. Therefore, the use of albedo orange peel waste for feeding of T. molitor larvae is highly recommended, since it results in larvae with enhanced nutritional value and at the same time, the utilization of this feeding substrate further lowers the cost of insect farming.