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.

Effect of Entomopathogenic Fungi to Eggs and Nymphs Survival of Halyomorpha halys (Hemiptera: Pentatomidae) Under Laboratory Conditions.

Halyomorpha halys (Stål) (Hemiptera: Pentatomidae) is becoming a major pest of Greece's agricultural production, including tree fruit. Until now, the control of this pest has been based on conventional methods, with the application of chemical insecticides being the primary option. However, the wide distribution of H. halys, in combination with the large area of tree fruit production in Greece, raise the need for alternative control methods. In this study, we investigated the possibility of implementing microbial control agents for managing H. halys. Eggs and nymphs of H. halys were treated with 15 native entomopathogenic fungal isolates and their virulence was evaluated in the laboratory. After treatment, egg hatching time was recorded for 7 days and ranged from 4.5 to 7.0 days. Nymphal survival was recorded daily for 7 days following application and ranged from 2.1 to 6.6 days for second instar nymphs and 3.7 to 6.8 days for fourth instar ones. Beauveria varroae isolate displayed the highest toxicity to all H. halys stages that were tested and could be considered a promising biocontrol agent of this insect. Please check and confirm that the authors and their respective affiliations have been correctly identified and amend if necessary.οκ.

Analyzing On-Farm Spatiotemporal Distribution of Halyomorpha halys (Stål) (Hemiptera: Pentatomidae) Populations from a Precision Agriculture Perspective.

The brown marmorated stink bug, Halyomorpha halys Stål (Hemiptera: Pentatomidae), is native to Japan, China, Taiwan, and Korea. Its dispersion from Asia to the United States of America and Europe caused serious damage to fruit, vegetables, and high-value crops. In Greece, damages are reported in kiwi orchards in the regions of Pieria and Imathia, which are the main production areas of kiwifruit. Greek kiwifruit production is expected to increase twofold within the next years. The aim of this research is to study the terrain and canopy properties that may have an impact on the development of H. halys populations. Thus, five kiwi orchards in total were selected in the regions of Pieria and Imathia. Τen traps were installed from early June to late October within each selected kiwi orchard-two types of traps at every side of the orchards and the center. The installed traps were examined weekly and the number of the captured H. halys was recorded. During the same days, sentinel satellite images were analyzed to calculate the vegetation index, NDVI (Normalised Difference Vegetation Index), and NDWI (Normalised Difference Water Index). The results showed population variability within the kiwi orchards since the population of H. halys was higher in areas with high NDVI and NDWI values. Additionally, our research revealed that H. halys prefers to develop populations at higher altitudes at both regional and field scales. The results of this research can be used to reduce damages by H. halys in kiwi orchards using different rates of pesticides depending on the prediction of the population size. There are multiple benefits of the proposed practice, such as a reduction in the production cost of kiwifruits, an increase in farmers' profit, and environmental protection.

Age- and Density-Dependent Parasitism Rate and Development Time of the Generalist Egg-Parasitoid Ooencyrtus telenomicida (Hymenoptera: Encyrtidae) on Eggs of the Brown Marmorated Stink Bug, Halyomorpha halys.

Halyomorpha halys (Hemiptera: Pentatomidae) is an invasive pest species that was imported into Greece in 2011 and since then, has caused severe qualitative and quantitative damage to economically important crops. Its management relies mainly on the use of broad-spectrum insecticides, with little to no information available concerning the potential use of native parasitoids in terms of classical biological control. Our study aimed to assess the parasitism rate and development time of the gregarious egg parasitoid Ooencyrtus telenomicida (Hymenoptera: Encyrtidae) on H. halys egg-masses, depending on several factors such as: (i) age of parasitoids, (ii) density of parasitoids, (iii) age of host eggs, and (iv) oviposition experience of parasitoids. According to our results, the younger the host eggs and the more parasitoids, the higher the parasitism rate achieved by adults of O. telenomicida, with the maximum mean value of the parasitism rate observed with 1-day-old host eggs and 4 parasitoid pairs (57.3%). On the contrary, the lowest mean value of the parasitism rate was observed with 4-day-old host eggs and 1 parasitoid pair (6.5%). Similarly, the age of parasitoids significantly affected parasitisation. The older the parasitoids were, the higher the parasitism rate achieved by adults of O. telenomicida, with a three-fold higher parasitism rate observed at 3-4 and 5-6-day-old O. telenomicida, compared to 1-2-day-old (31.8, 32.4, and 12.1%, respectively). Individuals that developed in younger host eggs displayed a shorter development time, and the shortest development time was observed for O. telenomicida laid by 2 parasitoid pairs. Parasitoid age did not affect the development time of O. telenomicida, although there was a tendency for individuals laid by younger female parasitoids to exhibit a shorter development time. Our findings provide valuable information on the potential use of O. telenomicida as a biocontrol agent of H. halys.

Females of Halyomorpha halys (Hemiptera: Pentatomidae) Experience a Facultative Reproductive Diapause in Northern Greece.

Halyomorpha halys (Stål) (Hemiptera: Pentatomidae) is a native pest of East Asia that overwinters as an adult in natural and human-made structures. Adult emergence from overwintering sites starts in spring, whereas females produce offspring in early summer on host plants, where most feeding occurs. In this study, we investigated the reproductive physiology of overwintering females of H. halys in Northern Greece, by determining the duration of the preoviposition period and fecundity of individuals that were left to overwinter in natural conditions and were subsequently transferred to chambers with standard conditions monthly, from December 2020 to March 2021. According to our results, overwintering H. halys females do not initiate egg laying once they emerge from overwintering sites, but rather need some additional time to exit diapause and mature reproductively. The mean preoviposition period of overwintering females that were transferred from their overwintering sites to the chambers in December 2020 was 29.0 days, which was significantly longer by 8.3 days than that of females that overwintered until March 2021, and by 13.2 days than the control (26 °C, 60% RH and a 16:8 h light: dark photoperiod). No significant difference among the average number of eggs per egg mass laid by overwintering individuals brought in the chambers in different time intervals and the laboratory colony was observed. However, females that were left to overwinter until March laid a significantly higher number of eggs in total, compared to the ones whose overwintering was disrupted in February. Based on our findings, overwintering females of H. halys experience a facultative reproductive diapause in Northern Greece. Our study was the first to determine the occurrence of diapause of H. halys in N. Greece and our findings could be very valuable for assessing the damage of this pest to early-season crops and designing successful management practices.

Carob (Ceratonia siliqua) as Functional Feed Is Beneficial in Yellow Mealworm (Tenebrio molitor) Rearing: Evidence from Growth, Antioxidant Status and Cellular Responses.

In terms of sustainability and circular economy, agricultural by-products may be efficiently reused in insects' rearing for high-quality protein sources in human diet and animal feeds. The present study aimed to explore whether the utilization of carob pods as feeding substrate may beneficially affect Tenebrio molitor's growth, nutritional value, antioxidant status and cellular responses. Increasing levels of milled whole carob pods (0, 25, 50, 75, 100%) were used as alternative wheat bran (control) substrates for yellow mealworm rearing, while growth performance, proximate composition, total phenolic content, antioxidant enzyme activity and the expression of stress- and apoptotic-related proteins were evaluated in larvae. The results showed that carob pods' content up to 75% did not significantly differentiate larvae weight, development time and total dry matter. Larvae total phenolic content and antioxidant activity exhibited a significant increase at 75% content. Although the antioxidant enzymes' activity decreased at both 25 and 50% levels, higher carob content levels (75 and 100%) resulted in no significant changes compared to the control. Carob pods led to decreased apoptotic indicators and the low expression of most stress-related proteins compared to the control. The present findings demonstrate that carob pods and their antioxidant properties exert beneficial effects on T. molitor's rearing and nutritional status, although 100% carob content may impact adversely the larvae due to the high amounts of carob tannins.

Reactive Oxygen Species Initiate Defence Responses of Potato Photosystem II to Sap-Sucking Insect Feeding.

Potato, Solanum tuberosum L., one of the most commonly cultivated horticultural crops throughout the world, is susceptible to a variety of herbivory insects. In the present study, we evaluated the consequence of feeding by the sap-sucking insect Halyomorpha halys on potato leaf photosynthetic efficiency. By using chlorophyll fluorescence imaging methodology, we examined photosystem II (PSII) photochemistry in terms of feeding and at the whole leaf area. The role of reactive oxygen species (ROS) in potato's defence response mechanism immediately after feeding was also assessed. Even 3 min after feeding, increased ROS generation was observed to diffuse through the leaf central vein, probably to act as a long-distance signalling molecule. The proportion of absorbed energy being used in photochemistry (ΦPSII) at the whole leaf level, after 20 min of feeding, was reduced by 8% compared to before feeding due to the decreased number of open PSII reaction centres (qp). After 90 min of feeding, ΦPSII decreased by 46% at the whole leaf level. Meanwhile, at the feeding zones, which were located mainly in the proximity of the leaf midrib, ΦPSII was lower than 85%, with a concurrent increase in singlet-excited oxygen (1O2) generation, which is considered to be harmful. However, the photoprotective mechanism (ΦNPQ), which was highly induced 90 min after feeding, was efficient to compensate for the decrease in the quantum yield of PSII photochemistry (ΦPSII). Therefore, the quantum yield of non-regulated energy loss in PSII (ΦNO), which represents 1O2 generation, remained unaffected at the whole leaf level. We suggest that the potato PSII response to sap-sucking insect feeding underlies the ROS-dependent signalling that occurs immediately and initiates a photoprotective PSII defence response to reduce herbivory damage. A controlled ROS burst can be considered the primary plant defence response mechanism to herbivores.