Insects can be found in most of the planet's ecosystems and are capable of utilizing virtually any food source. They are the most diverse group of animals, with an estimated five million species. All insects share a common body plan consisting of three segments (head, thorax, and abdomen), three pairs of legs, one pair of antennae, and compound eyes; however, each species has specialized parts according to its lifestyle. Although insects can utilize multiple food sources, they often depend on microbial companions to obtain nutrients scarce in their diet. Therefore, symbiosis plays a crucial role in the development and evolution of this group of animals. The ecological unit resulting from these associations is called a holobiont, and the genomes of the participants in the relationship are known as the hologenome. These hologenomes are prone to suffer losses of duplicated genes among the interaction participants and can also undergo gene transfers from one genome to another. In many cases, these interactions also lead to the development of specialized organs and novel mechanisms to regulate the growth of their endosymbionts. In addition to keeping their endosymbionts under control, insects must be able to face numerous infections. For this, they have a first barrier, their exoskeleton, which protects them from the invasion of most pathogens. However, when this protection fails, pathogens face another barrier: the immune system. Although insects only have an innate immune system, it is capable of protecting insects against most infections. However, a poorly studied phenomenon is how the insect immune system is regulated to protect them against pathogens but tolerate their endosymbionts. Among insects, there is no doubt that beetles are the most successful order, with an estimated 400,000 described species. The success of this group is due to numerous factors, including their short life cycles, high fertility, highly resistant exoskeleton, and low extinction rates. Of all the families in this order, the Curculionidae family is the largest, with more than 51,000 described species, possibly being the family with the most species among all animals. The Dryophthoridae family contains some of the most destructive pest insects, including the granivorous Sitophilus (Coleoptera, Dryophthoridae), which can cause losses in stored cereals of between 25 and 40% of the total weight. Of the species in this genus, the rice weevil, S. oryzae, is the most destructive. In addition to the losses caused by these weevils, the dust released during their feeding attracts secondary pests that can carry mycotoxins. Like other holometabolous insects, the life cycle of S. oryzae is divided into four stages: egg, larva, pupa, and adult. The first three stages occur inside the grains. Females make a small hole in the grain using their mandibles and deposit an egg, which they later cover with a secretion. Upon hatching, the larva begins to develop inside the grain, consuming it from the inside. Later, it pupates inside the grain and emerges as an adult. An important characteristic of weevils of the genus Sitophilus is their permanent association with endosymbionts that provide them with nutrients scarce in the grains. Currently, S. oryzae maintains a mutualistic relationship with Candidatus Sodalis pierantonius (hereafter S. pierantonius). These endosymbionts are transmitted maternally and induce the formation of bacteriocytes in the larvae. This interaction was established recently (less than 30,000 years ago), replacing Nardonella, the previous symbiont. Numerous studies have shown that S. pierantonius increases the invasive capabilities of S. oryzae by increasing its fertility and flight capacity. Additionally, having the genome sequence of its genome, its metabolism has been inferred, and it has been determined that the endosymbiont is capable of providing its host with all amino acids except methionine, tryptophan, and histidine. The study of its genome also allowed determining that, unlike other genomes of older endosymbionts, this one has not yet experienced such a drastic reduction in size. It has a high GC content, numerous pseudogenized genes, and a large number of mobile elements that cover 18% of its genome. Another important point is that it was determined that S. pierantonius plays a very important role in the synthesis of the exoskeleton of adults through the tyrosine and phenylalanine it provides to the host. Interestingly, the host is capable of precisely controlling the growth stages of S. pierantonius, allowing its proliferation when it requires larger amounts of tyrosine. On the other hand, aphids (Hemiptera, Aphididae) are part of a group of insects with more than 5,000 described species. Being hemipterans, they do not have complete metamorphosis and only have three stages: egg, nymph, and adult. However, their life cycles are far from simple and have adults with different morphologies. Most of them present a holocyclic life cycle in which there are several generations of parthenogenetic females. With the arrival of cold, they produce a generation of sexual forms that lay eggs capable of resisting the extreme temperatures of winter. With the arrival of spring, these eggs hatch, and the cycle begins again. This characteristic is undoubtedly one of the reasons for their success. Aphids also harbor endosymbionts; most of them have Buchnera as their primary endosymbiont. However, they are capable of harboring multiple primary endosymbionts, and the subfamily Lachninae seems to be especially prone to this. In their case, in addition to harboring Buchnera, they also have Serratia, which makes them excellent models for studying endosymbiotic complementation and the process by which a secondary endosymbiont can become co-primary. The genus Cinara, and especially the cedar aphid Cinara cedri, is one of the best-studied within this subfamily. The sequencing of both primary endosymbionts of C. cedri determined that they had established a co-obligate relationship with their host. It was observed that Buchnera had lost the ability to produce riboflavin and tryptophan. While Serratia is entirely responsible for the production of riboflavin, it was discovered that the synthesis of tryptophan was shared between both endosymbionts. This involved the biosynthesis of anthranilate by Buchnera and its transfer to Serratia, which is responsible for converting it into tryptophan. Subsequently, the sequencing of other endosymbionts of members of the subfamily Lachninae confirmed that the Buchnera-Serratia consortium was established before the diversification of the lineage, as in all cases, Buchnera had a small genome and had lost the ability to synthesize riboflavin. Although we are primarily interested in identifying the differences between both models due to the age of the relationship between the host and its endosymbiont, it is evident that there are multiple differences we must consider. Among them are the habitat in which they are found, their diet, their taxonomic position, and whether they are holo- or hemimetabolous. For this, we include 19 other arthropods with complete genomes available. As outgroups, we included a crustacean, the water flea Daphnia pulex, and an arachnid that, although known as the red spider, is actually a mite, Tetranychus urticae. Regarding hemimetabolous insects, we included several hemipterans: (i) the cedar aphid C. cedri, which, as mentioned earlier, harbors Buchnera and Serratia; the pea aphid Acyrthosiphon pisum and the green peach aphid Myzus persicae, which only harbor Buchnera; and the Asian citrus psyllid Diaphorina citri, which harbors Candidatus Carsonella ruddii DC, all four belonging to the suborder Sternorrhyncha and feeding on phloem; (ii) the brown planthopper Nilaparvata lugens of the suborder Auchenorrhyncha, which harbors a yeast as an endosymbiont and also feeds on phloem; (iii) the bed bug Cimex lectularius, which harbors Wolbachia and feeds on blood; and (iv) the human louse Pediculus humanus, which harbors Candidatus Riesia pediculicola and also feeds on blood. From the class Hymenoptera: (i) the Florida carpenter ant Camponotus floridanus; and the red fire ant Solenopsis invicta, both omnivorous; (ii) the European honey bee Apis mellifera, which feeds exclusively on pollen and nectar; and (iii) the parasitoid wasp Nasonia vitripennis, which is a parasitoid of several flies. Among them, only C. floridanus harbors an endosymbiont, Blochmania floridanus. From the Diptera: (i) two members of the family Culicidae, the yellow fever mosquito Aedes aegypti and Anopheles gambiae, which during their larval stage feed on bacteria, algae, and other microorganisms and during their adult stage feed on nectar, while females also feed on blood to allow the development of their eggs; (ii) the vinegar fly Drosophila melanogaster, which feeds on decomposing plant matter; and (iii) the tsetse fly Glossina morsitans, which feeds exclusively on blood. Only the tsetse fly harbors an obligate endosymbiont Wigglesworthia glossinidia. From the Lepidoptera: the silkworm Bombyx mori, the tobacco hornworm Manduca sexta, the monarch butterfly Danaus plexippus, and the diamondback moth Plutella xylostella. All of them feed on the leaves of different plants during their larval stage and on nectar when they are adults. None of them have associated endosymbionts. Finally, from the order Coleoptera: (i) the emerald ash borer Agrilus planipennis, the Asian longhorned beetle Anoplophora glabripennis, and the mountain pine beetle Dendroctonus ponderosae, which feed on the inner bark and phloem of various tree species; (ii) the small hive beetle Aethina tumida, which feeds on honey and pollen; (iii) the rice weevil S. oryzae and the red flour beetle Tribolium castaneum, which feed on stored grains; and (iv) Nicrophorus vespilloides, a beetle that feeds on the carcasses of other animals. The only beetle with an endosymbiont from the group we selected is S. oryzae. Objectives The main objective of this thesis is to compare the innate immune system and the amino acid biosynthesis pathways between insects that harbor endosymbionts. Both signaling pathways were chosen because it is through them that the insect interacts with its endosymbionts. The organisms chosen were the rice weevil Sitophilus oryzae and the cedar aphid Cinara cedri. These organisms were chosen because we are interested in identifying the differences in the genetic repertoire of insects with endosymbiotic relationships of different ages. While the relationship between C. cedri and Buchnera is quite ancient (established at least 150 million years ago), that of S. oryzae and Sodalis pierantonius is much younger, established around 30,000 years ago. Additionally, we have the sequence of the endosymbionts of both systems, which have been studied in depth by the groups of Abdelaziz Heddi and Amparo Latorre. 1. The first objective is to obtain the genome sequence of S. oryzae and annotate it to identify the genes involved in both the immune system and amino acid metabolism. This group of genes will be compared with the repertoire of T. castaneum and Drosophila melanogaster, the model for beetles and insects, respectively. This comparison will allow us to identify differences between a beetle that harbors an endosymbiont and one that does not have endosymbionts. It is important to remember that S. oryzae and T. castaneum belong to the same order and share an ecological niche. Additionally, the relationship between S. oryzae and S. pierantonius was established very recently, so it would not be surprising to find few differences between both systems. The comparison with D. melanogaster will allow us to identify characteristics that are specific to the order Coleoptera. 2. Obtain the list of genes involved in the innate immune system and amino acid biosynthesis in C. cedri using the assembled and annotated genome sequence. This list of genes will be compared with the orthologs obtained in Acyrthosiphon pisum and D. melanogaster. In this case, A. pisum also harbors an endosymbiont, and the comparison between both aphids will allow us to identify the unique characteristics of C. cedri despite its similarity to A. pisum. By comparing with D. melanogaster, we will be able to identify the unique characteristics of insects with ancestral symbiotic relationships that are not found in the insect model. 3. Compare the genes involved in the immune system or amino acid biosynthesis between S. oryzae and C. cedri. This will allow us to achieve the main objective of this project. However, there are multiple differences between both models in addition to the date of establishment of their endosymbiotic relationships. To take this into account and identify the differences between both caused by other factors, other insects will be included in the comparison. Methodology and Results Chapter 1. The Rice Weevil Sitophilus oryzae The genome of S. oryzae was sequenced with 101X coverage using 20 adults. The obtained genome size was 652 Mb in 17,786 scaffolds. The amount of transposable elements (48.6% of the genome) is among the highest described in insects, including the tiger mosquito Aedes albopictus with 50% and the housefly Musca domestica with 52%. Incorporating RNA-seq information from 12 libraries generated under different conditions and proteins annotated in other beetles, the genome of S. oryzae was annotated. 17,026 gene models were identified with automatic prediction, and 1,675 genes were manually curated, focusing on metabolism, immunity, development, epigenetics, olfactory system, and horizontally transferred genes. The final number of annotated genes in S. oryzae was 17,159. More than 85% of them have an ortholog in at least one of the arthropod species included in our study. Additionally, we determined that S. oryzae has the highest number of lineage-specific genes within beetles. This is possibly associated with the high rate of gene family expansion we calculated in this species. Using a phylogeny of the beetles used in our analysis, we identified families with accelerated evolution in each of the species, and with 174 families, S. oryzae was the beetle with the highest expansion rate (0.409 genes per million years). This process could be linked to the high number of transposable elements, as described in termites. Regarding amino acid metabolism, we determined that alanine and proline are provided by the insect, while threonine, lysine, phenylalanine, and arginine are provided by the endosymbiont. Since the ancestral endosymbiont was only capable of producing tyrosine, this could have given S. pierantonius an advantage over Nardonella. Finally, valine, leucine, isoleucine, tryptophan, methionine, and histidine must be obtained from the diet. We determined that the immune system of S. oryzae is very similar to that of T. castaneum and even D. melanogaster. The genes involved in signaling cascades are conserved, and the main differences are at the level of receptors and effectors. One of the most significant differences is that S. oryzae lacks the PGRP-LE receptor, which could affect its ability to recognize intracellular bacteria, including its own endosymbionts. Another gene not identified in S. oryzae is the kinase Gprk2, which is involved in signal amplification in the Toll pathway and is therefore possibly not essential. The proteases involved in the initiation of the signaling cascade leading to the activation of the Toll receptor could not be identified due to the large number of proteases and the difficulty in establishing orthology relationships among them. Finally, antimicrobial peptides were identified, both those previously described and some new ones. Chapter 2. The Cedar Aphid Cinara cedri The genome of C. cedri was sequenced, assembled, and annotated at the National Genomics Analysis Center. The size of the assembled genome was 396 Mb distributed in 1,740 scaffolds. Although there are no significant differences between the genome sizes of aphids whose genomes are available, there are differences in the number of genes identified in each species. While A. pisum and M. persicae have a similar number of predicted genes, 1,500 fewer genes were found in C. cedri. Given the high quality of the assembly, it seems that these are not technical errors and that C. cedri indeed has a lower number of genes, suggesting specific losses in its lineage or expansions in the Aphididae family to which A. pisum and M. persicae belong. Approximately 62% of the genes in C. cedri have orthologs in at least one other arthropod. Comparing the number of lineage-specific genes of each species, we observe that although C. cedri has the lowest number of genes among the aphids we included in our study, it also has the highest number of lineage-specific genes (6,449, approximately 38% of its genes). Regarding amino acid metabolism in the C. cedri holobiont, Buchnera provides histidine, phenylalanine, lysine, and threonine, while serine, alanine, glutamate, glutamine, proline, aspartate, asparagine, and tyrosine can be synthesized by the insect. Cysteine can be produced by both the insect and Serratia, and glycine by all three members of the consortium. Valine, leucine, arginine, and isoleucine are produced by a collaboration between C. cedri and Buchnera. Tryptophan is produced by a collaboration between Buchnera and Serratia, being one of the main reasons why both are co-primary endosymbionts. Finally, it has been suggested that methionine can be produced through a collaboration between C. cedri and Buchnera; however, this would require an enzyme of C. cedri to function in the opposite direction to which it normally does, and this has never been observed in nature. The alternative is that methionine is obtained from the diet. The immune system of C. cedri is very similar to that of A. pisum, with small differences in the number of copies of some genes. Among the characteristics they share is the absence of most of the genes involved in the signaling of the IMD pathway. This implies that aphids are unable to recognize Gram-negative bacteria, at least by the main described pathway. This possibly allowed not only the acquisition of Buchnera, the primary endosymbiont of aphids, but also of multiple secondary or co-primary endosymbionts, such as Serratia in C. cedri, as it is also a Gram-negative bacterium, it would not have too many problems colonizing the insect. In the case of C. cedri, it was also not possible to establish a clear orthology relationship between the proteases involved in the activation of the aphid's Toll pathway and those defined in D. melanogaster. However, it is known that the pathway is active, either using the orthologs of the proteases in the vinegar fly or other proteases. Finally, one of the most striking differences between aphids and other insects is the absence of antimicrobial peptides, except for thaumatin. However, given the challenge of identifying antimicrobial peptides, it is possible that aphids have other molecules of this type that have not yet been identified in their arsenal. Another interesting factor in C. cedri is that all individuals sampled to date have Wolbachia as an endosymbiont, suggesting that it plays some role in the biology of the insect. Since the sequence of its genome was obtained by sequencing the insect, it was also analyzed, and no pathways for the biosynthesis of amino acids absent in the holobiont or metabolic pathways that could be of interest to C. cedri were identified. The fact that the vast majority of its strain-specific genes are involved in transposition or are hypothetical proteins makes it difficult to hypothesize about their role. Chapter 3. Comparison Between Both Models To contextualize the comparison between C. cedri and S. oryzae, we incorporated the other 26 previously mentioned arthropods. We identified 1,327 conserved genes with one-to-one orthology among all arthropods. Additionally, 1,478 had orthologs in all arthropods without being strictly one-to-one, leading to a total of 2,805 genes that would form the core genome of arthropods. If we consider only insects, we would include an additional group of 2,578 genes found in all of them but not in the two non-insect arthropods. Specifically analyzing beetles, we identified a group of 1,356 genes present only in them, and we observe a more or less homogeneous distribution; however, in A. planipennis, we observe only 784 in this category. This is especially interesting because it is the oldest lineage among the beetles included in the study, suggesting that there could have been a series of duplications in the ancestor of the other beetles. Of special interest is also the group of lepidopterans, as we found 3,106 order-specific genes, the largest number among the analyzed holometabolans and also the most homogeneous. In the case of hemimetabolans, N. lugens seems to represent an anomaly. This insect has a gene repertoire well above any other included in the analysis. The insects we chose for this analysis live in very different environments and must face different types of stress, including obtaining all the nutrients necessary for their correct development. We focused solely on amino acids; however, obtaining other factors such as vitamins is also crucial, and it is known that endosymbionts participate in this task. Regarding the synthesis of glutamate and aspartate, all evaluated arthropods, as well as several endosymbionts, are capable of producing them. This is no surprise since these amino acids are essential for the synthesis of other amino acids. Glutamine, serine, glycine, and cysteine can also be produced by all arthropods and some endosymbionts. The synthesis of proline and alanine is also conserved among all eukaryotes, including the endosymbiont of N. lugens. However, it is not found in any bacterial endosymbiont, suggesting that these pathways have greater relevance in eukaryotes and are dispensable in bacterial endosymbionts. Asparagine can be produced by all arthropods, and the symbionts of insects that feed on phloem are unable to produce it; this may be related to the high content of this amino acid in the phloem. Arginine cannot be fully produced by any arthropod, but all can produce it from citrulline. Some endosymbionts can produce it from ornithine, and interestingly, it seems that lepidopterans also have the ability to catalyze this reaction. Lysine, methionine, valine, leucine, isoleucine, and threonine cannot be produced by any arthropod; however, some endosymbionts are capable of producing them. In the case of lysine, those that cannot produce it are the endosymbionts of insects that feed on blood, suggesting that the content of this amino acid in the diet is sufficient to meet the requirements. Regarding aromatic amino acids, no arthropod is capable of producing them; however, some endosymbionts are capable of producing them. This is the case for the C. floridanus holobiont as well as aphids that can produce all three, or S. oryzae that can produce phenylalanine and tyrosine. Lastly, regarding histidine, Buchnera, B. floridanus, the endosymbiont of N. lugens, and possibly C. Carsonella ruddii DC are capable of producing it. Comparing the immune systems of the arthropods we selected for our study, we observe that antimicrobial peptides are highly specific to each order and even to each lineage. Although we know that most of the diversity of these peptides has not been explored due to the difficulties in identifying them, we can conclude that while aphids only have one family of antimicrobial peptides, holometabolans have a great diversity of these effectors. Regarding the antiviral RNAi response, all arthropods have mostly complete pathways, and only small losses are observed, such as the losses of HPS4 and Nbr that are involved in the loading of miRNA into the Ago1 protein; however, it is known that these are not essential. The JAK/STAT pathway is also highly conserved; however, an important aspect of this pathway is that the main ligand, dome, has not been identified in any other species besides the vinegar fly. The Toll signaling pathway is conserved in most arthropods, but there are difficulties in correctly identifying the proteases involved in the processing of the main ligand. This is mainly because it is a very large family of enzymes, and establishing orthology relationships among them is not trivial. A similar aspect between aphids and beetles is the absence of ref(2)P. Among all the species studied in both groups, it was only identified in A. planipennis, the sister group of all other beetles, suggesting that this gene was lost after the divergence of these lineages. Possibly the most relevant aspect of this study is the large differences in the IMD signaling pathway. Aphids are the only group in which CYLD is not found, and additionally, in no species of the suborder Sternorrhyncha are ird5, imd, relish, or tab2 found. Dredd, Fadd, key, and pirk are not found in any members of the order Hemiptera, suggesting that this group of organisms is unable to identify and possibly respond to infections by Gram-negative bacteria. Since most hemipterans feed on mostly sterile diets, this may not represent too big a problem, also saving the resources necessary to maintain this immune system pathway. Additionally, the lack of the IMD pathway allows these insects to be more easily colonized by potential endosymbionts. General Conclusions The amount of repetitions in the genome of S. oryzae is among the highest observed in other insects and the highest in any studied beetle. The number of mobile elements has possibly led to it being the beetle with the highest rate of gene family expansion among those we included in our study. There is a clear dependence between the metabolism of S. oryzae and its endosymbiont. Regarding essential amino acids, some are produced by the host, others by the endosymbiont, and others must be obtained from the diet. The fact that S. pierantonius is capable of producing more amino acids than Nardonella is a possible reason to explain the replacement given the low abundance of lysine and threonine in cereals. The immune system of S. oryzae is very similar to that of T. castaneum and even D. melanogaster. One of the few differences is the absence of the PGRP-LE receptor, which is a possible explanation for why S. oryzae is capable of tolerating its endosymbiont. Several antimicrobial peptides were also identified. The fact that its immune system is so similar to that of other insects suggests that small changes are sufficient to allow harboring an obligate endosymbiont. We did not find horizontal transfer events in the genome of S. oryzae that seem to come from S. pierantonius. This suggests that there are mechanisms to prevent this phenomenon or perhaps there has not been enough time to observe this transfer. The metabolism of amino acids is shared between C. cedri, Buchnera, and Serratia. Cysteine can be produced by both the host and Serratia. Valine, leucine, arginine, and isoleucine are produced by a collaboration between C. cedri and Buchnera. Finally, it is still unclear whether methionine is obtained from the diet or through a collaboration between C. cedri and Buchnera. The immune system of C. cedri is very similar to that of A. pisum, with small differences in the number of copies of some genes. In comparison with other insects, there are large differences in the IMD signaling pathway. Additionally, no other antimicrobial peptides were identified besides thaumatin. While Wolbachia has been found in all individuals of the species C. cedri, its role, if any, has not been defined. It does not seem to collaborate in the biosynthesis of amino acids, nor were other metabolic pathways that could be of importance to the holobiont identified. The majority of the strain-specific genes are involved in transposition or are hypothetical proteins. Regarding the metabolism of amino acids, all arthropods have a similar repertoire of genes, supporting the idea of a large loss of genes at the origin of metazoans. However, (i) arginine cannot be produced by arthropods, but some endosymbionts can provide this amino acid to their hosts; additionally, lepidopterans have an enzyme that allows them to produce it from ornithine; (ii) lysine can be produced by all endosymbionts except those that inhabit insects that feed on blood; (iii) alanine can be produced by all arthropods; however, it has been lost in all bacterial endosymbionts, suggesting that there is selective pressure for eukaryotes to conserve it; (iv) S. pierantonius can produce phenylalanine and tyrosine, while Buchnera can only produce phenylalanine alone and requires Serratia to produce tryptophan. Antimicrobial peptides are order- or even lineage-specific. In the case of hemimetabolous insects, only defensin and thaumatin were identified. Regarding the antiviral response, all arthropods have intact signaling pathways, which speaks to their importance. This also occurs in the case of the JAK/STAT signaling pathway, which is conserved in all arthropods despite the ligand only being identified in D. melanogaster. Regarding the Toll pathway, there may be differences in the proteases involved in the processing of the Toll receptor ligand; however, it is difficult to affirm due to the difficulty in assigning orthology among the proteases. Aphids lack a large number of elements of the IMD signaling pathway; however, all hemipterans lack certain elements of this pathway. This implies that hemipterans have a reduced capacity to recognize and possibly respond to Gram-negative pathogens. We consider that these are losses in the group of hemimetabolans and not a late acquisition since this signaling pathway is found with all its elements in some hemimetabolous insects such as the American[...]

A 6-year-old mixed-breed male Papillon dog, castrated at the age of 7 months, presented for work-up of a difficulty walking associated with constipation and urinary incontinence. Ultrasonography and radiography were consistent with a tumor of the prostate and lymph node metastases. An irregular osteoproliferation of the ventral edges of L5–L6–L7 suggested tumor invasion. Periosteal proliferative lesions of the pelvis, the femur, the humerus, the tibia and the calcaneus were consistent with hypertrophic osteopathy. Necropsy and histological examination confirmed the diagnosis of prostatic adenocarcinoma with lymph node, pulmonary, liver and bone metastases, associated with hypertrophic osteopathy.

The influence of gut and gonad bacterial communities on insect physiology, behaviour, and ecology is increasingly recognised. Parasitism by parasitoid wasps alters many physiological processes in their hosts, including gut bacterial communities. However, it remains unclear whether these changes are restricted to the gut or also occur in other tissues and fluids, and the mechanisms underlying such changes are unknown. We hypothesise that host microbiome changes result from the injection of calyx fluid (that contain symbiotic viruses known as polydnaviruses) and venom during parasitoid oviposition and that these effects vary by host tissue. To test this, we microinjected Pieris brassicae caterpillars with calyx fluid and venom from Cotesia glomerata, using saline solution and natural parasitism by C. glomerata as controls. We analysed changes in the bacterial community composition in the gut, regurgitate, haemolymph, and labial salivary glands of the host insects. Multivariate analysis revealed distinct bacterial communities across tissues and fluids, with high diversity in the salivary glands and haemolymph. Parasitism and injection of calyx fluid and venom significantly altered bacterial communities in the salivary glands. Differential abundance analysis showed that parasitism affected bacterial relative abundance in the haemolymph, and that Wolbachia was only found in the haemolymph of parasitized caterpillars. Altogether, our findings reveal that parasitism influences the host haemolymph microbiome, and both parasitism and injection of calyx fluid and venom drive changes in the bacterial community composition within the host salivary glands. Given that the composition of salivary glands can influence plant response to herbivory, we discuss these results in the broader context of plant-parasitoid interactions.

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The prickly pear cactus, Opuntia ficus-indica (L.) Miller, is the most economically important Cactaceae species worldwide. It thrives in arid and semiarid agricultural lands with minimal inputs, providing benefits such as livestock fodder, fruit, and vegetable production. The South American cactus moth, Cactoblastis cactorum (Berg), represents the most important insect pest of prickly pear crops. This study aimed to evaluate the impact of C. cactorum feeding on O. ficus-indica plants in a plantation in northwestern Argentina. Fruit production, fruit attributes, and plant size were evaluated under increasing C. cactorum pest densities in a manipulative 3-yr-long experiment (2018 to 2020). In the 2019 harvest, the increase in the pest density significantly reduced the number of fruits produced/plant. Plants with the highest pest density produced 60% fewer fruits than pest-free plants. In the 2020 harvest, the reduction was marginal. Fruit and pulp weights significantly declined with increasing C. cactorum densities in both years. No effect occurred on plant size or fruit sweetness. This was the first effort to measure the magnitude of the impact of C. cactorum on a cactus crop species and provides crucial information for prickly pear fruit producers. This information is helpful to implement more effective preventive and control measures to protect producers’ investment and ensure a profitable harvest. Further studies in younger plantations and other areas will help develop an economic damage threshold level to support Integrated Pest Management decisions to limit C. cactorum’s impact.

1. Describing the genetic structure and diversity of invasive insect pest populations is essential to better understand a species' invasion history and success throughout its distribution range. Tuta absoluta (Meyrick) (Lepidoptera, Gelechiidae) is a destructive pest of tomato and many other solanaceous crops, with very high economic impacts. Its invasion threatens food security in a large part of the globe, in areas such as sub-Saharan Africa where the agricultural resilience has already been weakened by rapid human-induced changes due in particular to population growth, increased trade and global change. 2. This work aimed to investigate the diversity and genetic structure of 60 populations of T. absoluta using microsatellite markers, with a particular focus on sub-Saharan Africa. 3. Our results revealed distinct differentiation and diversity patterns between T. absoluta native versus invaded areas, and high genetic homogeneity among the African populations sampled. However, for the first time, two weakly differentiated but distinct genetic clusters in Africa were identified. 4. The results suggest few introduction events of the species in Africa or multiple introductions from genetically close areas, significant gene flow between outbreaks and seem to indicate the existence of two distinct clusters in Africa. This new data enable us to formulate hypotheses on the species' invasion patterns and the dynamics of its invasive populations. 5. These hypotheses must be verified with more extensive sampling over the whole range of T. absoluta, especially in its presumed native area.

The cotton leafworm, Spodoptera littoralis (Lepidoptera: Noctuidae), is a major agricultural pest affecting crops like cotton, maize, tomatoes, and wheat across southern Europe, Africa, the Middle East, and western Asia. Whole genome analyses have revealed adaptive evolution in chemosensation and detoxification genes in S. littoralis. However, the extent of intraspecific diversity influenced by recent adaptive evolutionary forces remains unclear. In this study, we conducted a population genomics analysis using 31 S. littoralis individuals from sub-Saharan Africa, northern Africa, and southern Europe to assess the existence of intraspecific population divergence and identify the underlying evolutionary forces. We show whole genome differentiation between populations based on geographic origin from the analyzed samples. Phylogenetic analyses indicate that sub-Saharan and southern European populations share a common ancestor, distinct from several northern African populations. FST and dXY statistics along the chromosomes reveal loci with restricted gene flow among populations. These loci are associated with population-specific selective sweeps, indicating the role of divergent natural selection in limiting gene flow. Notably, these loci are enriched with detoxification genes, including cytochrome P450, multidrug resistance, and xanthine dehydrogenase genes, all of which are potentially associated with detoxification. These results demonstrate that divergent selection limits gene flow among geographically distinct populations with the possibility of the involvement of detoxification as a key trait. We argue that this genetic heterogeneity can be considered in pest monitoring and management, as strategies tailored to specific populations may not be relevant for others.

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La dénomination de "veau rosé" est diversement définie et peu étudiée en France. Cette production est bien adaptée aux races locales, comme dans le cas de la Maraîchine. Les performances d’abattage des veaux rosés extraites d’une base de données de 119 veaux obtenue entre 2009 à 2023 sur l’unité expérimentale INRAE de Saint-Laurent-de-la-Prée sont décrites. Les caractéristiques biochimiques et métaboliques ainsi que les qualités sensorielles et nutritionnelles des viandes ont été analysées sur échantillon de 30 veaux rosés (15 élevés au pis et à l’herbe (pâture et/ou foin) (régime H) et 15 veaux élevés au pis et complémentés aux concentrés (régime C)) issus de 8 élevages différents. Les veaux ont un poids vif moyen de 219 kg, un poids carcasse de 128 kg et un poids de viande de 90 kg. Les rendements carcasse sont en moyenne de 59 % et les rendements viande de 70 %. La viande de veau rosée est pauvre en lipides (1,3g/100g de tissu). Elle présente une proportion d’AGPI élevée proche de 20% et un rapport AGPI n-6/n-3 proche de 2. Le régime alimentaire des veaux a des impacts significatifs sur la qualité de la viande. Le régime H impacte la conformation des carcasses, la couleur de la viande, la teneur en fer (+ 24%) et la tendreté. Il augmente de 53% la proportion de fibres lentes et oxydo-glycolytiques. Certaines teneurs en acides gras d’intérêt, en vitamine B2 et des indicateurs santé sont également augmentées. Enfin le régime H entraine également un double enrichissement en antioxydants endogènes ou exogènes et une diminution des teneurs en vitamines B3 et B6.