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Título de Químico Ambiental. / En insectos eusociales, el reconocimiento y la comunicación entre compañeros de nido soportan la estructura social de la colonia. Estas conclusiones se basan más en estudios en himenópteros que en termitas (Blattodea). En las termitas se distinguen tres castas principales: reproductores primarios (reproducción); soldados (defensa); y obreras o pseudo-obreras (alimentación y cuidado de otras castas y jóvenes, mantenimiento y expansión del nido). La comunicación entre compañeros de nido se produce generalmente por señales químicas. Dentro de estas son especialmente relevantes los compuestos cuticulares, particularmente los hidrocarburos. Estos recubren por completo la cutícula de los insectos y cumplen dos funciones: evitar la pérdida de agua y actuar como compuestos semioquímicos para el reconocimiento entre individuos. En este seminario, se estudió las diferencias cualitativas (escalamiento multidimensional) y cuantitativas (análisis de componentes principales- PCA) en los perfiles de hidrocarburos cuticulares entre castas y entre dos sitios de recolección, usando la termita endémica nidificadora de una pieza, Neotermes chilensis, a través de cromatografía de gases acoplada a espectrometría de masas, técnica que permite separar, identificar y cuantificar los componentes de una mezcla. Se identificaron 27 hidrocarburos en la cutícula de N. chilensis, 19 metil-alcanos (70,4%), 7 n-alcanos (25,9%) y un n-alqueno (3,70%). Los análisis estadísticos mostraron diferencias significativas en la composición cualitativa y cuantitativa entre el sitio de recolección y entre las castas. Los principales resultados mostraron que pseudo-obreras y soldados eran distintos entre sí y de otras castas. Además se determinó los principales hidrocarburos responsables de las diferencias entre castas. x En conclusión, en este seminario se demostró las diferencias cualitativas y cuantitativas complementarias de los perfiles de hidrocarburos cuticulares entre distintas castas y entre dos sitios de recolección diferentes de N. chilensis. Los resultados contribuyen con una interpretación química al fenómeno de reconocimiento intraespecífico en una termita nidificadora de una pieza. / In eusocial insects, recognition and communication between nestmates support the social structure of the colony. These conclusions are based mostly in studies concerning hymenopterans rather than termites (Blattodea). In termites, three main castes may be distinguished: primary reproductors (reproduction); soldiers (defense); and workers or pseudo-workers (feeding and taking care of young and of other castes, maintenance and expansion of the nest). During the swarming season, alates of both sex emerge from the parental colony, loose their wings, and eventually mate and found a new colony. Communication among nestmates is usually based on chemical signals. Cuticular compounds, particularly hydrocarbons, have special relevance. They cover the cuticle of the insects and avoid water loss and function as semiochemicals for recognition among individuals. In this seminar, I studied qualitative (multidimensional scaling) and quantitative (principal component analysis- PCA) differences in cuticular hydrocarbon profiles between castes and between two collection sites, using the endemic one piece nesting termite, Neotermes chilensis; I used gas chromatography coupled to mass spectrometry, a technique, which allows the separation, identification and quantitation of the components of a mixture. I identified 27 hydrocarbons in the cuticle of N. chilensis: 19 methyl-alkanes (70.4%), 7 n-alkanes (25.9%) and one n-alkene (3.70%). The statistical analyses showed significant differences in qualitative and quantitative compositions between collection site and between castes. The main results showed differences between pseudo-workers and soldiers, and also differences between them and the other castes. xii Furthermore, I determined the main hydrocarbons responsible for the differences between castes. In conclusion, in this seminary I demonstrated the complementary nature of qualitative and quantitative differences of the cuticular hydrocarbons profile between different castes and between two different collecting sites of N. chilensis. This result contributes with a chemical interpretation of the phenomenon of intraspecific recognition in a one-piece nesting termite.

Genome size or nuclear DNA content is a a trait which varies greatly among living organisms, with no apparent relashionship between genome size and organismal complexity. It is usually described using the C-value as either a number of base pairs or picograms of DNA. Unresolved questions regarding mechanisms influencing genome size and relationships between genome size and other organismal traits are together known as the C-value enigma. Genome size is known to positively correlate with cell size and negatively with developmental and cell division rate. A maximum constraint of 2 pg has also been proposed for haploid genome sizes of holometabolous insects. Despite the fact that there are about one million described insect species, genome sizes are only known in a fraction of them. This thesis thus aims to extend the dataset of known insect genome sizes by as many species of cockroaches (Blattodea) as possible. Another aim is to compare results with known phylogeny and also to compare difference in genome size between sexes. Flow cytometry was used for genome size estimations, which is a rapid, simple and effective method, also suitable for study of ploidy levels and other cellular charasteristics.

Polyneoptera is an assemblage of eleven insect orders comprising the "orthopteroid" insects. It includes familiar insects such as grasshoppers, roaches, termites, earwigs and preying mantises; as well as the more obscure web-spinners, angel insects and ice-crawlers. We present a phylogenetic analysis of the polyneopteran orders based on 18S rDNA, 28S rDNA, Histone 3, and a coded morphology matrix for an extensive sampling of taxa. We investigate the use of congruence between separate datasets as an a priori measure of alignment quality. Our results support the paraphyly of Polyneoptera, the monophyly of Dictyoptera, sister taxon relationships between Embiidina + Phasmatodea and Dermaptera + Zoraptera, and a relatively basal placement of Plecoptera. The analyses also support a sister taxon relationship between the newly described Mantophasmatodea and Grylloblattodea, a small order of cryophilic insects confined to the northwestern Americas and northeastern Asia. This placement coupled with the morphological disparity of the two groups validates the creation of a new order for Mantophasmatodea. Our results also suggest the Direct Optimization (formerly Optimization Alignment) produces alignments that are more predictable across the parameter landscape than alignment via CLUSTAL X, as measured by congruence among independent data partitions. Dense taxon sampling and phylogenetic analysis of six molecular markers (12S, 16S, 18S, 28S, COII, and H3) and morphological data for the order Plecoptera demonstrates that the subordinal groups Arctoperlaria and Antarctoperlaria are monophyletic. Euholognatha and Systellognatha are also monophyletic, with the exception of the genus Megaleuctra which is the basal lineage for the order and deserves recognition as a distinct family (Megaleuctridae). Notonemouridae is strongly supported as a monophyletic clade. Within the Systellognatha Styloperlidae is the basal lineage, followed by Peltoperlidae then Pteronarcyidae, and Perloidea is a strongly supported monophyletic group with Chloroperlidae as sister taxon to Perlidae + Perlodidae. The family Gripopterygidae is strongly supported as paraphyletic. Many Plecoptera (stoneflies) exhibit a pre-mating communication known as "drumming." Species of the genus Isogenoides have complex drumming behavior in which (i) the male calls the female by tapping his abdomen against the substrate, (ii) the female answers with her own distinctive tapping, and (iii) the male responds with a confirmatory series of taps. These drumming patterns are specific to individual species and may vary within a species to form distinct dialects. Phylogenetic analysis for the genus based on six molecular markers (12S, 16S, 18S, 28S, COII, and H3) supports Yugus as its nearest extant relative and I. hansoni as the basal lineage within the genus. Drumming behavioral characters appear to be largely incongruent with the phylogeny.