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Simple Summary: Predator–prey population dynamics is one of the most studied problems in population biology. Parasitoids' reproductive behaviour is crucial in shaping host population dynamics and plays a key role in determining their reproductive strategies. Along with many biotic and abiotic parameters, the age of the adult parasitoids plays an important role in their performance. This research focuses on the variation in some biological parameters related to the fecundity of the parasitoid A. ervi, as a function of female age at the first oviposition. The results of the present study provide key elements on the effects of the time elapsed between parasitoid emergence and first oviposition, making it possible to predict the behaviour and performance of the parasitoid following its release in the field. The study of parasitoid reproductive behaviour is crucial to understanding how parasitoids influence host population dynamics, and the strategies used by parasitoids to maximize their reproductive success. Studying how the parasitoid optimizes its reproductive resources is important as it provides information to improve the efficiency of a biological control programme. Many studies have been carried out on Aphidius ervi to assess the foraging behaviour of the parasitoid, but how the age of the parasitoid affects its foraging behaviour is still poorly understood. In the present study, the influence of the time elapsed between adult parasitoid emergence and the first oviposition in A. ervi was evaluated. Correlations between the parasitoid size and other fitness components were also investigated. Our results show how the parasitoid senescence is associated with the loss of reproductive capacity, as the late field release of parasitoids reduces their total parasitism. We also observed a parasitization rhythm independent of the parasitoid age. Possible explanations for the observed phenomena are discussed. [ABSTRACT FROM AUTHOR]

Rapid urbanization has heightened the urgency of the necessity for sustainable water management in agriculture. This review focuses on the impacts of using reused wastewater in agricultural practices, specifically highlighting the nutrient benefits and consequences of pollutants on important environmental elements. It investigates the impact of contaminants on agricultural ecosystems by assessing the soil composition and nutrient equilibrium. This research also examines the impact of pollution exposure on plants and insects, elucidating the behavioural adaptations and their broader ecological consequences in agricultural environments. Eventually, a comprehensive analysis was conducted to consolidate these findings, emphasizing the challenges and significance of implementing sustainable practices. This study highlights the necessity of addressing the health and environmental concerns associated with the agricultural reuse of wastewater, while also giving valuable information to guide future regulations. [ABSTRACT FROM AUTHOR]

Organisms could be exposed to several heat waves during their life, and their ability to survive a heat wave strongly depends on the effects of the previous one. Exposure to extreme temperatures can have important effects on the outcome of host-parasitoid interactions, as the ability of the parasitoid to survive depends on the ability of its host to cope successfully with these stresses. In the present study we address the impact of repeated exposure to heat stress on the survival of the pea aphid Acyrthosiphon pisum (Harris) (Hemiptera Aphididae) and its endoparasitoid Aphidius ervi Haliday (Hymenoptera Braconidae). The first treatment consisted of a heat stress of 35 °C for 30 minutes performed on 4 days old aphids, the second and third heat stresses of 39 °C were performed on 5 days old and on adult aphids, respectively. The three treatments were applied alone or in all their combinations. We found that aphid thermal tolerance is positively influenced by heat hardening if a severe stress occurs a few days after the first event. Adult parasitized aphids show significantly higher survival than unparasitized ones; however, the effects of parasitization and hardening on host survival after heat shock are not additive. We also found that A. ervi has a lower thermotolerance capacity than its host and does not show apparent hardening effects. In addition, parasitoid survival after mummification is not affected by the previously experienced heat shock. The possible explanations of the observed phenomena are discussed. [ABSTRACT FROM AUTHOR]

Genetic diversity in crop plants is the conditio sine qua non for sustainable agriculture and long-term food security. Our research carried out the morphological, agronomic, and physico-chemical characterization and resistance to late blight of 35 tomato landraces from seven countries. These landraces have been approved and appear in the Official Catalog of Varieties. The International Plant Genetic Resources Institute (IPGRI) descriptors have been used to describe the tomato's morphological and agronomic characteristics. For the physico-chemical characteristics, the dry matter, the pH, and the carotenoid content (lycopene, lutein, and β-carotene)) were analyzed. Carotenoids were monitored by high-performance liquid chromatography (HPLC). The results showed that the morphological diversity of landraces was very high. Three landraces of remarkable commercial value have shown increased resistance to late blight caused by Phytophthora infestans, one of the most damaging diseases of tomato. Also, six landraces had a lycopene content exceeding 100 µg/g sample. The carotenoid content ranged between 0.769 (Marmande-FR 166) and 140.328 mg kg−1 FW (Răscruci). The landrace with the highest β carotene content was PT 308 with 65.499 mg kg−1 FW, while the lowest values were registered for Marmande-FR 166 with 0.105 mg kg−1 FW. The present study provides essential information on the morphological and agronomic qualities of these tomato landraces and their lycopene and other carotenoid content. The results are discussed in light of the importance of tomato landraces in meeting the preferences of different producers and consumers, the choice of the most suitable landraces for specific pedoclimatic conditions, and the supply of carotenoid pigment sources for the pharmaceutical industry. Our research responds to humanity's great global challenges: preserving agricultural biodiversity, protecting the environment by identifying pest-resistant varieties, and also protecting consumer health by finding important sources of antioxidants. [ABSTRACT FROM AUTHOR]

The plain along the Ionian coast and the Matera hills are close to the border of the Apulia region, where, since 2013, the bacterium Xylella fastidiosa has been causing the death of olive trees. During 2016-2018 a study was conducted on the potential insect vectors of X. fastidiosa in eight olive groves, located in three areas of the province of Matera (Basilicata, Italy), characterized by different agricultural landscapes. We captured three spittlebug species, Philaenus spumarius (L.), Neophilaenus campestris (Fallen) and Lepyronia coleoptrata (L.), in addition to the cicadellid Cicadella viridis (L.). Among them, P. spumarius was by far the most prevalent species in 2016, while in 2017 and 2018 catch rates were modest for all the candidate vector species. The population trend of the four insect species in the June-October period was reported about the three study areas in the years considered. [ABSTRACT FROM AUTHOR]

Abstract Background Despite its pervasiveness, the genetic basis of adaptation resulting in variation directly or indirectly related to temperature (climatic) gradients is poorly understood. By using 3-fold replicated laboratory thermal stocks covering much of the physiologically tolerable temperature range for the temperate (i.e., cold tolerant) species Drosophila subobscura we have assessed whole-genome transcriptional responses after three years of thermal adaptation, when the populations had already diverged for inversion frequencies, pre-adult life history components, and morphological traits. Total mRNA from each population was compared to a reference pool mRNA in a standard, highly replicated two-colour competitive hybridization experiment using cDNA microarrays. Results A total of 306 (6.6%) cDNA clones were identified as 'differentially expressed' (following a false discovery rate correction) after contrasting the two furthest apart thermal selection regimes (i.e., 13°C vs . 22°C), also including four previously reported candidate genes for thermotolerance in Drosophila (Hsp26, Hsp68, Fst, and Treh). On the other hand, correlated patterns of gene expression were similar in cold- and warm-adapted populations. Analysis of functional categories defined by the Gene Ontology project point to an overrepresentation of genes involved in carbohydrate metabolism, nucleic acids metabolism and regulation of transcription among other categories. Although the location of differently expressed genes was approximately at random with respect to chromosomes, a physical mapping of 88 probes to the polytene chromosomes of D. subobscura has shown that a larger than expected number mapped inside inverted chromosomal segments. Conclusion Our data suggest that a sizeable number of genes appear to be involved in thermal adaptation in Drosophila, with a substantial fraction implicated in metabolism. This apparently illustrates the formidable challenge to understanding the adaptive evolution of complex trait variation. Furthermore, some clustering of genes within inverted chromosomal sections was detected. Disentangling the effects of inversions will be obviously required in any future approach if we want to identify the relevant candidate genes.

Abstract Background Populations of Drosophila melanogaster show differences in many morphometrical traits according to their geographic origin. Despite the widespread occurrence of these differences in more than one Drosophila species, the actual selective mechanisms controlling the genetic basis of such variation are not fully understood. Thermal selection is considered to be the most likely cause explaining these differences. Results In our work, we investigated several life history traits (body size, duration of development, preadult survival, longevity and productivity) in two tropical and two temperate natural populations of D. melanogaster recently collected, and in a temperate population maintained for twelve years at the constant temperature of 18°C in the laboratory. In order to characterise the plasticity of these life history traits, the populations were grown at 12, 18, 28 and 31.2°C. Productivity was the fitness trait that showed clearly adaptive differences between latitudinal populations: tropical flies did better in the heat but worse in the cold environments with respect to temperate flies. Differences for the plasticity of other life history traits investigated between tropical and temperate populations were also found. The differences were particularly evident at stressful temperatures (12 and 31.2°C). Conclusion Our results evidence a better cold tolerance in temperate populations that seems to have been evolved during the colonisation of temperate countries by D. melanogaster Afrotropical ancestors, and support the hypothesis of an adaptive response of plasticity to the experienced environment.

This work investigates the intraguild predation (IGP) between the predator Macrolophus pygmaeus Rambur (Hemiptera Miridae) and the aphid parasitoid Aphidius ervi Haliday (Hymenoptera Braconidae). In particular, predation on parasitized Acyrthosiphon pisum (Harris) (Hemiptera Aphididae) aphids was studied at two different stages of parasitism. It is known that A. pisum parasitized by A. ervi exhibits a 'suicidal' behaviour in presence of a coccinellid. This behaviour may be linked to an increased risk of being preyed, since it has been observed that parasitized A. pisum suffers greater predation rate by Harmonia axyridis (Pallas). The escape response in A. pisum is affected by predator species and hemipterans cause a small disturbance of aphid colony. We hypothesize that parasitized A. pisum at an early stage of parasitization would suffer higher predation risk also if the predator is a hemipteran. We used the generalist predator M. pygmaeus to test this hypothesis. Predation on newly parasitized aphids was tested by offering groups of twenty 2nd instar aphids composed of parasitized and unparasitized individuals in different proportions to the predator. The relative proportion of the healthy and parasitized aphids did not change the total prey consumption. Increased susceptibility to predation for parasitized aphids at an early stage of parasitism was observed. This result is discussed on the basis of the kin selection theory. Predation on pre-mummified and mummified A. pisum aphids was also studied. Our results show that M. pygmaeus preys, on average, about two A. pisum mummies in 24 h, which is fully in line with the consumption of fourth instar aphids. Pre-mummies killed by M. pygmaeus always showed visible damage while mummies did not always show visible signs of the predator feeding activity. The possible consequences of the mass release of generalist predators on parasitoid natural populations are briefly discussed. [ABSTRACT FROM AUTHOR]

Macrolophus pygmaeus (Hemiptera: Miridae) is an important predator of pests of horticultural crops and here its ability as a predator of Acyrthosiphon pisum (Hemiptera: Aphididae) is addressed for the first time. The percentage predation of the different aphid instars and the number partially consumed were studied. Our results, obtained using choice and no-choice tests, revealed that M. pygmaeus caught and consumed more young than later instars of A. pisum, which confirms results of previous studies using other species of aphids. We also studied the interactions between predators (male/female) foraging in the same patch. When the prey/predator ratio is kept constant at 10: 1 the average percentage of aphids completely consumed by individual females or males does not change with increase in the number of foraging predators. However, the number of partially consumed aphids decreased when females shared the same patch. In contrast, there was an increase in the number of aphids partially consumed when two males shared the same patch. The results were discussed in terms of potential predator foraging strategies since intraspecific competition is a key factor modulating the dynamics of prey-predator systems. [ABSTRACT FROM AUTHOR]