<p>  </p> <p>Environmental conditions, like light quality and herbivory, can induce changes in plant physiology. Light quality can be manipulated using LEDs (light emitting diodes) to improve crop quality and yield in horticultural production. The manipulation of light quality has also been utilized in the management of agricultural insect pests. Previous research has provided evidence that changes in light quality can have effects on the growth and chemistry of cannabis crops (<em>Cannabis spp.</em>). Varieties of cannabis are grown for the production of the valued cannabinoids CBD and THC. Pest of cannabis include herbivorous arthropods that reduce hemp yield and quality. Arthropod herbivory can induce chemical and physical changes in plants. This thesis further investigates the role of light quality on both cannabis biology and the crop-pest interaction between cannabis and the cannabis aphid (<em>Phorodon cannabis</em>). In the experiments described herein, the effects of light quality and <em>P. cannabis </em>herbivory on cannabis were assessed by measuring impact on biomass accumulation, yield, and the production of CBD and THC. The effects of light quality on the life history traits of <em>P. cannabis </em>were also measured. Cannabis grown under red-blue light quality saw a reduction in vegetative growth but no reduction in yield. Light treatments had no measured effect on the concentrations of CBD and THC in the cannabis buds. Aphid herbivory decreased bud yield but increased vegetative growth. Aphid herbivory reduced the concentration of both CBD and THC in cannabis bud tissue. Under blue-rich light quality, <em>P. cannabis </em>experienced higher reproductive rates when compared to red-blue and full-spectrum lighting. </p>

<p>Across the tree of life, novel genes are thought to be a source of much of the unique behaviors and adaptions between the different taxa. This is especially true in the social insects where novel genes are proposed to contribute to novel social behaviors. In the honey bee (Apis mellifera L.), a group of novel genes called the major royal jelly proteins (MRJPs) are proposed to be important to the expression of novel social behaviors, particularly those related to nursing versus foraging tasks. Unfortunately, identifying the functional role of novel genes is often not possible due to a lack of functional genomic tools in non-model species such as the honey bee. Here I have developed a novel ectopic expression system in Drosophila melanogaster and used it to elucidate how the MRJPs contribute to behavioral and transcriptional changes in the insect brain. I found that the MRJPs regulated the expression of hundreds of genes in Drosophila, and these overlap with genes regulated differentially between nursing and foraging honey bees. Furthermore, I found that MRJP expression impairs or negatively regulated phototaxis. My results demonstrate the MRJPs play a role in behavioral plasticity and highlight that the MRJPs may have a much larger role in the nurse-forager transition than previously thought.</p>

<p dir="ltr">Given the relatively poor visual acuity of compound eyes, many insects have developed alternative means for navigating their environment. For example, insects often rely on chemosensation to find food, mates, and inter- and intraspecific communication. Eusocial insects in particular have developed complex systems of pheromone communication to organize their colonies, enabling them to partition labor for foraging, brood care, and colony defense tasks to different portions of the colony. A variety of genes coding for proteins are involved in detecting these chemicals, including gustatory receptors, ionotropic receptors, and odorant receptors (ORs). Eusocial insects, and especially ants, have evolved an expanded clade of ORs in their genome, likely due to an increased reliance on pheromones compared to other insects. The ability to recognize nestmates from non-nestmates is one of the vital functions performed by these ORs, which detect hydrocarbons present on the cuticle to distinguish friend from foe. However, research into the details of nestmate recognition has been stymied due to difficulties in manipulating OR genes. Despite advances in genetic sequencing and manipulation technologies, strict reproductive divisions within most ant lineages make generating transgenic ants nearly impossible, and so we have been left with limited options to further investigate these receptors. To narrow down the ORs that could be involved in nestmate recognition in the Argentine ant (Mayr, 1868), I took a multi-pronged approach of generating tissue transcriptomes to identify ORs that are selectively upregulated in the antennae, as well as conducting a phylostratigraphic analysis to identify which OR genes arose more recently in the Argentine ant genome. While conducting these analyses, it became necessary to reannotate the set of Argentine ant OR genes, due to current published annotations not containing the full breadth of <i>L. humile</i> ORs. Finally, I orally administered fluorescently-labelled dsRNA to workers, and tracked the extent to which ingested dsRNA is capable of traversing the tissues of ant workers, to investigate whether RNAi is a viable method for investigating gene function for genes showing tissue-selective expression. I discovered a subset of OR genes that are highly expressed in the antennae and confirmed that dsRNA is able to reach the antennae and knock down OR gene expression through ingestion, meaning that RNA interference is a viable method for the practical study of ant OR genes and can be used to further explore how individual ORs regulate nestmate recognition.</p>

<p> Chapter 1 is the first revision of the New World species of the genus <em>Rhipidandrus</em> LeConte, 1862 (Coleoptera: Tenebrionidae). All previously described species except <em>R. fungicola</em> Friedenreich, 1883 are redescribed, including a diagnosis and distribution information. <em>Rhipidandrus punctatus</em> <strong>n. sp.</strong> is described from Peru, Panama, and Chiapas, Mexico. New synonymies (junior synonyms first) include: <em>R. mexicanus</em> Sharp, 1905 = <em>R. paradoxus</em> (Palisot de Beauvois, 1818); <em>R. cornutus</em> (Arrow, 1904) = <em>R. panamaensis </em>(Barber, 1914) = <em>R. peruvianus</em> (Laporte, 1840); <em>R. peninsularis</em> Horn, 1894 = <em>R. micrographus</em> (Lacordiare, 1865). <em>Eledona peruviana </em>Laporte, 1840 is recognized as <em>nomen nudum</em> according to ICZN 1999: Article 12. A revised species checklist, a dichotomous key, an interactive key, and distribution maps are also presented.  </p> <p>Chapter 2 represents the first phylogenetic insight into the relationships within Bolitophagini in relation to Toxicini with more than three taxa sampled. For analyses, 34 taxa were sampled, with representatives from nine bolitophagine genera and seven toxicine genera with 3 outgroup taxa. Six gene regions from nuclear, ribosomal, and mitochondrial DNA were amplified using polymerase chain reactions and sequenced. Bayesian and maximum likelihood analyses were run on the 4049 bp concatenated dataset via the CIPRES Science Gateway. In both resulting trees, the monophyly of Bolitophagini is recovered with high support (BS = 100, PP = 100). The monophyly of Toxicini was recovered, but with poor support (BS = 60, PP = 70). The monophyletic clade containing both Bolitophagini and Toxicini was also recovered with high support (BS = 100, PP = 100).  </p> <p><br></p>