No description available.

No description available.

This research project consisted of three primary objectives: (1) Improve rearing methods for L. lineolaris, (2) Determine if selected behaviors displaying photoperiodicity are under circadian control, and (3) Estimate phase angle shifts of selected circadian rhythms, in an effort to contribute toward the future improvement of current integrated pest management techniques. Improving rearing methods was accomplished in three areas: (1) Estimating the optimal stocking rate to maximize production while maintaining acceptable insect quality as a function of photoperiodic regime, (2) Estimating fecundity at the optimal stocking rate and photoperiodic regime, and (3) Determining the timing of oviposition, mating, feeding and egg hatch, under the optimal stocking rate and photoperiodic regime. The stocking rate maximizing production of females was 8.93 (SE = 2.54) egg packets/rearing container. It was also determined that average female weight significantly declined as stocking rate increased. Therefore, a lower stocking rate of six oviposition packets is recommended as a compromise between productivity and product quality appropriate for many rearing purposes. Fecundity under the optimal stocking rate was also determined. Females produced an average of zero to seven eggs per day over the course of their lifetime, and an average of 83.49 eggs over the course of a single female’s lifespan (SE = 9.4). This is unusually low compared to other studies due to an infection of Nosema spp. in the laboratory colony. Oviposition peaked nine to 12 days after eclosion. Fecundity data can be used by rearers as a measure of fitness, allowing them to gauge the overall vigor of their colony. Oviposition and mating behaviors were determined to be periodic with respect to photoperiod, while feeding and egg hatch were not. Oviposition and mating were also determined to be under circadian control, because they met the four criteria stated by Saunders (2001). No significant phase angle shift occurred between 16:8 and 12:12 LD photoperiods for either behavior. Therefore the calculation of a phase angle shift was not possible. Additionally, the investigation of light intensity effect on peak oviposition showed that L. lineolaris did not respond differently to on/off light signals compared to simulated “dawn/dusk” signals.

No description available.

Toxoneuron nigriceps is a koinobiont larval endoparasitoid of the tobacco budworm, Heliothis virescens. No koinobiont parasitoid (which develop in active, growing hosts) has been reared completely in vitro. However, T. nigriceps has been partially reared in vitro, from egg stage through 2nd larval instar and from 2nd to 3rd larval instar. Despite reaching its final larval instar, T. nigriceps failed to develop past the larval stage. In the following study, two aspects of T. nigriceps development, post-egression tissue feeding and cocoon formation through pupation, were examined to determine why T. nigriceps failed to develop in vitro beyond the larval stage and how in vitro rearing might be improved to rear T. nigriceps to adulthood. The importance of post-egression feeding and the possibility of developing an artificial post-egression diet were examined by manipulating the post-egression feeding behavior of T. nigriceps. The tissues of pre- and post-tissue feeding T. nigriceps larvae were analyzed to investigate the macronutritional benefit of post-egression feeding. A preliminary artificial post-egression diet was tested, and the putative quality of T. nigriceps reared to adulthood using this diet was examined. The formation of subterranean pupation chambers by healthy and parasitized H. virescens larvae was examined to investigate potential behavioral manipulation by T. nigriceps during this process. Finally, the potential use of artificial pupation chambers by T. nigriceps was investigated. Post-egression feeding was determined to be a vital part of T. nigriceps development, contributing to both parasitoid size and survival to adulthood. A preliminary artificial post-egression diet was developed, which facilitated rearing of T. nigriceps from 3rd larval instar to adulthood. The dimensions and burial depth of chambers formed by parasitized H. virescens were significantly different from those of chambers formed by healthy H. virescens, suggesting that T. nigriceps manipulated host behavior during excavation. Toxoneuron nigriceps was able to use a number of common laboratory items as substitute pupation chambers during cocoon formation, and the merits of several artificial chambers were discussed. With provision of an adequate post-egression and artificial pupation chamber, in vitro rearing of T. nigriceps from the larval stage to adulthood may be possible.

The conversion of natural forests to production land uses has led to huge losses of biodiversity and continues to threaten remaining terrestrial flora and fauna throughout the world. The global demand for wood products and energy, which was partly responsible for the loss of primary native habitat, is now one of the leading drivers of afforestation with significant new areas of plantation replacing former agricultural lands. While plantations do not support the same biodiversity values as natural forests they do provide significant habitat for a range of species. Saproxylic invertebrates (species that are dependent on deadwood) are strongly affected by the temporal and spatial availability of different deadwood resources. Previous research on saproxylic invertebrates has largely been restricted to natural or managed natural forests predominantly in the Northern Hemisphere, where forest management practices have been modified to conserve these species This thesis fills a distinct research gap in New Zealand and is the first large scale study to quantify the effects of deadwood age, wood species, and landscape composition on saproxylic invertebrates in our plantation forests by direct rearing. In this thesis I show that thinning residues, which are currently retained in many plantation forests, provide significant habitat for a range of native invertebrate taxonomic groups, including diverse assemblages of Coleoptera and Hymenoptera. Deadwood age is an important attribute determining taxonomic richness of saproxylic invertebrates. Richness of invertebrate orders/classes and Coleoptera species all increased in older deadwood material, and a stepwise multidimensional analysis procedure indicated that the age of deadwood was the most important factor structuring saproxylic invertebrate community composition in Pinus radiata thinning residues. Deadwood age was a stronger predictor of community composition in thinning residue than measures of landscape composition, such as the proportion of remnant native forest cover. The change in saproxylic invertebrate composition that occurs with deadwood age was related to changes in the feeding guilds, with a transition from primary wood feeding species to predators/parasitoids and fungal feeders with increasing dead wood age. Because thinning’s are carried out at prescribed times throughout the stand rotation, stand age could be adopted as a proxy for deadwood age in these systems allowing forest managers a simple method for monitoring saproxylic beetle habitat availability . My research provides strong empirical evidence that supports the existing conservation paradigm that forest managers should seek to create a mosaic of habitats at the landscape scale to enhance biodiversity opportunities in plantations. In addition to the habitat opportunities provided by P. radiata deadwood that is derived from silvicultural practices there are several sources of native wood in plantations. Native woody resources are found in either the embedded remnant areas of native forest or in the understory of stands as many native woody species colonise this habitat. As yet the importance of native understory deadwood resources for saproxylic species is unknown. In addition it is unclear how the importance of such understory resources is influenced by proximity to remnant native forest patches. I used experimental wood billets of four tree species (3 native and the exotic P. radiata) placed along replicated transects spanning native habitat and adjacent early stage regenerating plantation stands to assess the saproxylic invertebrate assemblages associated with different deadwood species as a function of proximity to native forest. I found that an interaction between wood host specificity (local scale) and proximity to interior native forest (landscape scale) was the most important factor regulating saproxylic invertebrate community structure. Deadwood of the native subcanopy trees Schefflera digitata, Melicytus ramiflorus, Aristotelia serrata and the exotic conifer P. radiata provided habitat for different subsets of the saproxylic fauna. The most pronounced differences in saproxylic community structure were between the native sub-canopy broadleaf species and the exotic P. radiata. Surprisingly the P. radiata supported a greater species richness and abundance of saproxylic Coleoptera in native remnants than the native wood species in the same habitat. In general, species richness was higher in native forest habitats and declined with increasing distance from native habitat. These results suggest that both the diversity of deadwood resources that are available and their proximity to native remnants are important for maintaining saproxylic communities in plantations. However, two of the native wood species (M. ramiflorus and A. serrata) exhibited steep declines in species richness at the plantation native forest boundary, suggesting that the contrasting stand types (native remnant and young regenerating plantation stands) with their different microclimate may have had a significant influence. Future research needs to compare the saproxylic fauna of dead wood in mature plantation stands with adjacent native remnants to ascertain if the effect of native habitat proximity is due to landscape composition or a reflection of microclimatic differences. The large diversity of saproxylic species observed during this study highlights the importance of plantations as habitat for saproxylic species, particularly in heavily fragmented landscapes that retain little original native forest. My research findings provide forest managers with options for improving forest management to enhance opportunities for the conservation of saproxylic invertebrates. In addition my thesis provides one of the most comprehensive multi-taxon data sets of saproxylic species associated with a variety of deadwood resources. This information will be invaluable to future researchers that continue to work on New Zealand’s saproxylic fauna.

Thesis (Ph. D.)--Illinois State University, 2007. / Title from title page screen, viewed on February 11, 2008. Dissertation Committee: Steven A. Juliano (chair), Diane L. Byers, L. Philip Lounibos, Charles F. Thompson, William L. Perry. Includes bibliographical references (leaves 152-163) and abstract. Also available in print.

Esta pesquisa teve por objetivos avaliar os aspectos biológicos de Metallactus sp. em Eucalyptus urophylla e desenvolver uma técnica de criação do inseto em laboratório. As condições ambientais foram: temperatura 25±1°C, umidade relativa de 90±5% e fotofase de 14 horas. Os parâmetros biológicos avaliados foram: duração, viabilidade da fase larval e número de ínstares larvais; duração, viabilidade da fase pupal e peso da escatoteca; longevidade de machos e fêmeas, razão sexual, dimorfismo sexual, período de pré-oviposição, período de oviposição, número de ovos por fêmea; período de incubação e viabilidade dos ovos; duração e viabilidade do ciclo (ovo-adulto) e tabela de vida de fertilidade. / This paper deals with the biological aspects of Metallactus sp. on Eucalyptus urophylla and the development of a technique to rear this insect in laboratory (25±1º C; 90±5% RH; 14-hour photophase). The following parameters were evaluated: duration, viability and number of instars of the larval stage; duration and viability of the pupal stage; case weight; longevity of male and female adults; sex ratio; sexual dimorphism; preoviposition period; oviposition period; number of eggs per female; egg period and egg viability; duration and viability of the life cycle (egg-adult period); and fertility life table.

Esta pesquisa teve por objetivos avaliar os aspectos biológicos de Metallactus sp. em Eucalyptus urophylla e desenvolver uma técnica de criação do inseto em laboratório. As condições ambientais foram: temperatura 25±1°C, umidade relativa de 90±5% e fotofase de 14 horas. Os parâmetros biológicos avaliados foram: duração, viabilidade da fase larval e número de ínstares larvais; duração, viabilidade da fase pupal e peso da escatoteca; longevidade de machos e fêmeas, razão sexual, dimorfismo sexual, período de pré-oviposição, período de oviposição, número de ovos por fêmea; período de incubação e viabilidade dos ovos; duração e viabilidade do ciclo (ovo-adulto) e tabela de vida de fertilidade. / This paper deals with the biological aspects of Metallactus sp. on Eucalyptus urophylla and the development of a technique to rear this insect in laboratory (25±1º C; 90±5% RH; 14-hour photophase). The following parameters were evaluated: duration, viability and number of instars of the larval stage; duration and viability of the pupal stage; case weight; longevity of male and female adults; sex ratio; sexual dimorphism; preoviposition period; oviposition period; number of eggs per female; egg period and egg viability; duration and viability of the life cycle (egg-adult period); and fertility life table.

This diploma thesis is focused on the silk production of invertebrates. The aim of the work is to systematically introduce important species and describe the purpose of their silk production. The ability to produce silk is widespread in many insect families. The production of proteinaceous fibers also occurs in arachnids and (in the form of byssus threads) also in mollusks. The Domestic Silk Moth (Bombyx mori) is an economically important insect, being a primary producer of silk. Hence, an integral part of the thesis focuses on Domestic Silk Moth. In this thesis all developmental stages of Silk Moth (from an egg to an adult) are described. In the past, efforts to breed silkworms also appeared in the Czech lands. Therefore, a short chapter of the thesis is devoted to the history of sericulture. Furthermore, this thesis describes methods of rearing silkworm larvae. For students of Natural Sciences and Biology, it is crucial to be in touch with live objects. Because the silkworm rearing is quite simple, it is possible to incorporate this topic to the school projects about holometabolous insects. The practical part of this thesis contains schedule of practical exercise about silk moths. And in final section of practical part, worksheets for lower-secondary students are presented. Keywords: silkworm...