Doctor of Philosophy / Entomology / David C. Margolies / Yoonseong Park / Insect metamorphosis is driven by two major hormones, juvenile hormone (JH) and ecdysone (Ec). The presence of JH with an Ec peak in each stadium results in larval-larval molting whereas in the last larval instar a decline of JH to undetectable level combined with pulses of Ec leads to larval-pupal metamorphosis. Larval-pupal metamorphosis normally occurs after a certain number of larval instar and upon reaching a certain size (critical weight). However, in the flour beetle, Tribolium freemani, under crowded conditions larva continue larval-larval molting (LLC) without pupation for longer than 14 instars (6 months). Previous studies have implicated high JH titer as preventing the metamorphosis leading to supernumerary molts. My investigation of JH roles in LLC started by asking whether suppression of JH would rescue the LLC phenotype and allow pupal metamorphosis. Using RNA interference (RNAi), I found that under crowded conditions RNAi of T. freemani methyltransferase3 (TfMT3), which encodes a crucial enzyme for the final methylation step in the JH biosynthesis, or RNAi of T. freemani Krüppel homolog1 (TfKr-h1), the JH downstream gene, did not rescue the larvae but resulted in prepupal lethality. Surprisingly, under crowded conditions prepupal lethality was rescued by RNAi of both TfMT3 and TfKr-h1 administered together, although developmental arrest occurred at the pharate adult stage; this is also the phenotype of TfKr-h1 RNAi-treated larvae under isolated conditions. In investigations of the role of Ec titer in LLC, lethality of the larvae with RNAi of TfMT3 under crowded conditions was associated with the loss of the major ecdysteroid peak, while TfKr-h1 RNAi-treated larvae under crowded conditions showed a delayed, but normal, Ec peak occurring at prepupal arrest. The pattern of Ec peak in RNAi of both TfMT3 and TfKr-h1 together was similar to that with TfKr-h1 RNAi alone. I suggest that a hormonal imbalance, high JH and high Ec in the prepupal arrest of TfKr-h1 RNAi, was rescued by RNAi of both TfMT3 and TfKr-h1 for low JH and high Ec. These results demonstrate that the signaling pathways for LLC are through at least two independent pathways; JH biosynthesis and TfKr-h1-mediated JH response.

Field studies, interviews and participative observations have been the main methods in this master thesis where the author has studied, and partially participated, in the development process of a booking system called FRI. Idavall is the small company that develops this suc-cessful software despite small resources. Characteristic for Idavall is in the way they manage to involve their about 1300 users in the development process. The development process is highly flexible which is required when rapidly changes are common. The overall question in this thesis is: How do Idavall manage to develop this software in a flexible way and successfully involve their users in the development process? Idavall arranges FRI-meetings, courses and demonstrations where users meet each other and a representative from Idavall. All participants discuss FRI and have the opportunity to propose changes, improvements and report bugs. One of the most important parts of the busi-ness idea of Idavall is to offer a proper, friendly and professional support. The support is one of the most important possibilities to be informed about the users? needs, wishes and propos-als. This, what I called, user driven development has a lot of common with Participatory De-sign (PD) where users participate in the design of new software. PD implies that users of software should take part in decisions that affect the system and the way it is used and de-signed. Idavall make use of a kind of Customer Relationship Management (CRM), which is a concept used in the marketing arena. The objective of CRM is to create a strong, mutual and trustful relationship between supplier and customer. By using CRM in combination with PD it is possible to enhance the user participation and enable user driven development. The company has a flexible development process, which is built on an informal way of driving the process. Informal meetings are common where decisions about changes and im-provements are taken quickly. New versions are delivered about 20 times a year. The employ-ees meet several times a day in the central located coffee room and discuss problems. The development process has a lot of common with Extreme Programming (XP), which is a software development methodology that aims to make software development more flexi-ble and focus on highly flexible environments with quickly changing requirements. XP is de-scribed briefly and comparisons are made to the development process of FRI as well as short-comings of XP in the context of PD.