<p> Experiments were conducted to determine the impact of combining multiple best management practices to manage the tarnished plant bug, Lygus lineolaris (Palisot de Beauvois), on cotton. The implementation of this program reduced the amount of insecticide applications needed, significantly increased both square retention during the three weeks of squaring, and yield in the Delta region. Another study was conducted to explore behavioral responses of tarnished plant bug nymphs to several classes of insecticides. There appeared to be both avoidance and attraction depending on insecticide class. The presence of an insecticide did not affect the fruiting structure tarnished plant bugs were found on in the field, there were significantly more tarnished plant bugs found in the middle of the plant than the top or bottom at 3 DAT. At 7 DAT there were significantly more tarnished plant bugs found on the top of the plant followed by the middle then bottom.</p>

<p> Efforts to document current wild bee faunas are imperative as evidence of changes in local abundance, geographical range, and species diversity among many taxa accumulates. These changes and declines have led to an intensified effort to survey wild bees in representative habitats throughout North America. The objective of this study was to characterize the wild bee fauna of one such coastal habitat in Connecticut, USA, specifically to examine marsh, dune, and coastal scrub bee communities.</p><p> Biweekly surveys were conducted at Grass Island Preserve (Guilford, CT) over a two-year period (2011-2012) using pan traps and effort-based (timed) net collecting. A total of 3929 individual bees were collected, representing five families, 18 genera and 80 species. The total number of species collected represents approximately 23% of the known Connecticut bee fauna. Three species -<i>Hylaeus illinoisensis</i> (Robertson); <i>Hylaeus</i> aff. <i>nelumbonis</i> (undescribed); <i>Lasioglossum michiganense </i> (Mitchell) - are newly recorded for Connecticut. Species accumulation curves constructed for all sub-habitats indicated that bee diversity was steadily increasing over the sample period. No asymptote in accumulation curves were observed at any site.</p>

Thesis (PhD)--Stellenbosch University, 2012. / ENGLISH ABSTRACT: Widespread, human-induced ecosystem degradation and the associated biodiversity loss pose a direct threat to human wellbeing. While there is no substitute for healthy, self-sustaining ecosystems, ecological restoration offers an attractive, and indeed inevitable, supplement where conservation alone is not sufficient to support ecosystem integrity. Restoration is undergoing a revolution, where evidence-based (EB) practice is emerging as a new approach to increase the chances of successfully achieving restoration goals. EB practice is based on the notion that implementation decisions need to be based on the appraisal and use of evidence of effectiveness of alternative options. The point of departure of this thesis is the contention that EB practice need not be dependent only on research evidence. The work presented herein thus addresses the production and use of evidence of effectiveness in restoration practice. Using ten restoration programs in South Africa, the quality of evidence produced in practice was assessed. Three components of evidence production that were evaluated were (i) baseline condition measurement; (ii) goal setting and (iii) monitoring. Results showed poor definition of goals; a bias towards the use of socio-economic goals and indicators; more monitoring of inputs than impact; and inconsistent and short-term monitoring of biophysical indicators. Practitioners regarded the evidence base as adequate, but cited a few challenges associated with planning and resource availability as attributing factors to the gaps observed. I propose that practitioners’ perception of the current evidence base poses an additional threat to the generation of a strong evidence base. In addition to the production of evidence, access to said evidence is a vital component of EB practice. In an exploration of how evidence is made available by practitioners, it became evident in that a considerable amount of the information that was not easily accessible in documented form was known by the practitioners. This highlights the need for a shift in practice culture towards the valuing and rewarding of the dissemination of information. An assessment of EB restoration would have been incomplete without a deliberate consideration of social factors. I thus conducted a case study of an invasive alien plant clearing program, to determine what drives the use of scientific evidence in decision making. I observed that organizational structure, policies, priorities and capacity influence, and even limit, the use of scientific evidence to inform decisions. The challenges to making restoration evidence-based are diverse in nature, ranging from poor planning of restoration work, which points to limited appreciation of the need to produce a strong evidence base, to a lack of instruments and incentives to drive the generation, dissemination and use of evidence that spans both the biophysical and social aspects of restoration. These challenges are largely rooted in the conventional way of approaching restoration from individual disciplinary perspectives, thus artificially simplifying and compartmentalizing a naturally complex problem like degradation. I end by proposing transdisciplinarity, which focuses on a holistic world view and the production of knowledge that embraces complexity, as a possible vehicle to help move the practice of restoration towards being evidence-based. / AFRIKAANSE OPSOMMING: Wydverspreide, mens-veroorsaakte agteruitgang van ekostelsels en die gepaardgaande verlies aan biodiversiteit hou 'n direkte bedreiging vir menslike welsyn in. Alhoewel daar geen plaasvervanger is vir 'n gesonde, selfonderhoudende ekostelsel is nie, bied ekologiese restourasie 'n aantreklike en inderdaad onvermydelik, vul waar bewaring alleen nie voldoende ekosisteem integriteit kan ondersteun nie. Restourasie ondergaan tans ‘n revolusie, waar bewys gebaseerde (BG) praktyk 'n opkomende nuwe benadering om die kanse van die suksesvolle bereiking van herstel doelwitte te verhoog. BG praktyk is gebaseer op die idee dat die uitvoering van besluite gebaseer moet word op die evaluering en die gebruik van bewyse van die effektiwiteit van alternatiewe opsies. Die punt van vertrek van hierdie proefskrif is die bewering dat BG praktyk nie noodwendig afhanklik van navorsings bewys hoef te wees nie. Die werk wat hier aangebied word spreek tot die produksie en gebruik van bewyse van effektiwiteit in die restourasie praktyk. Deur die gebruik van tien restourasie programme in Suid-Afrika is die kwaliteit van die bewyse in die praktyk geassesseer. Die drie komponente van bewyse produksie wat geëvalueer is sluit in (i) basislyn toestand meting, (ii) doelwitstelling en (iii) monitering. Resultate toon 'n swak definisie van doelwitte; 'n vooroordeel ten gunste van die gebruik van sosio-ekonomiese doelwitte en aanwysers; meer monitering van insette as die impak; en teenstrydige en kort-termyn monitering van biofisiese aanwysers. Beofenaars het die gebruik van bewys gebaseerde inligting as voldoende beskou, maar 'n paar uitdagings wat verband hou met die beplanning en die beskikbaarheid van bronne is aangehaal as kenmerkende faktore in die gapings wat tans waargeneem word. Ek stel voor dat beoefenaars se persepsie van die huidige bewysbasis praktyk 'n bykomende bedreiging vir die generasie van 'n sterk bewybasis praktyk inhou. Benewens die produksie van bewyse, is die toegang tot bewyse 'n belangrike komponent van die BG praktyk. In die verkenning van hoe bewyse beskikbaar gestel word deur beoefenaars, is dit duidelik dat 'n aansienlike aantal inligting wel bekend is aan beofenaars maar nie maklik toeganklik in gedokumenteerde vorm is nie. Dit beklemtoon die behoefte vir 'n verskuiwing in die praktyk kultuur tot die waardering en beloning van die verspreiding van inligting. 'n Beoordeling van die BG herstel sou onvolledig wees sonder 'n doelbewuste oorweging van sosiale faktore. Ek het dus 'n gevallestudie van 'n indringerplant verwyderings program uitgevoer om vas te stel wat die gebruik van wetenskaplike bewyse in besluitneming aandryf. Ek het opgemerk dat die organisatoriese struktuur, beleid, prioriteite en kapasiteit die gebruik van wetenskaplike bewyse kan beinvloed, en selfs beperk. Die uitdagings om herstelwerk bewys-gebaseerd te maak is uiteenlopend van aard, dit wissel van swak beplanning van herstel werk, wat dui op beperkte waardering van die behoefte om 'n sterk bewyse basis te produseer, 'n gebrek aan instrumente en aansporings vir die generasie van besyse, verspreiding en gebruik van bewyse wat strek oor beide die biofisiese en maatskaplike aspekte van die restaurasie. Hierdie uitdagings is grootliks gegrond op die konvensionele manier van restaurasie wat gebaseer is op individuele dissiplinêre perspektiewe,wat lei tot die kunsmatige simplifiseering van ‘n uiteraand komplekse problem soos agteruitgang. Ek eindig af deur die gebruik van transdissiplinariteit, wat fokus op 'n holistiese wêreldbeskouing en die produksie en kennis van kompleksiteit insluit voor te stel, as 'n moontlike voertuig om die skuif in praktyk van restourasie na n bewys-basis te vergemaklik.

<p>Symbiotic relationships between insects and beneficial microbes are very common in nature, especially within the Hemiptera. The brown marmorated stink bug, <i>Halyomorpha halys</i> St&aring;l, harbors a symbiont, <i> Pantoea carbekii</i>, within the fourth region of the midgut in specialized crypts. In this dissertation, I explored this insect-microbe relationship. I determined that the brown marmorated stink bug is heavily reliant on its symbiont, and that experimental removal of the symbiont from the egg mass surface prior to nymphal acquisition led to lower survival, longer development, lower fecundity, and aberrant nymphal behavior. Additionally, I determined that even when the symbiont is acquired and housed in the midgut crypts, it is susceptible to stressors. Stink bugs reared at a higher temperature showed lower survival, longer development, and a cease in egg mass production, and when bugs were screened for their symbiont, fewer had successfully retained it while under heat stress. Finally, with the knowledge that the stink bug suffers decreases in fitness when its symbiont is missing or stressed, I wanted to determine if targeting the symbiont was a possible management technique for the stink bug. I tested the efficacy of a number of different insecticidal and antimicrobial products to determine whether prevention of symbiont acquisition from the egg mass was possible, and results indicated that transmission of the symbiont from the egg mass to the newly hatched nymph was negatively impacted when certain products were applied (namely surfactants or products containing surfactants). Additionally, direct effects on hatch rate and survival were reported for certain products, namely the insect growth regulator azadirachtin, which suggests that nymphs can pick up residues from the egg mass surface while probing for the symbiont. I conclude that <i>P. carbekii</i> plays a critically important role in the survival of its host, the brown marmorated stink bug, and its presence on the egg mass surface before nymphal hatch makes it targetable as a potential management technique. </p>

No description available.

A yellow-colored protein (YCP) has been isolated from the hemolymph of fifth instar, wandering stage larvae of Manduca sexta. The molecular mass of reduced and denatured YCP was 31 kDa. Gel filtration chromatography suggested that native YCP was a monomer. The absorbance spectrum of YCP contained maxima at 278 nm and 405 nm. The amino acid composition and the N-terminal sequence of YCP were determined. Circular dichroism indicated that YCP consisted of 68% $\beta$-pleated sheet and 32% random coil. The YCP polypeptide chain was found to be glycosylated. Carbohydrate analysis suggested that mannose and N-acetylglucosamine were present in a 3:1 ratio. Chromophore was released from YCP through treatment with methanol and chloroform. In neutral solution and in acid, the released chromophore showed the absorbance characteristics of the ommochrome, onmmatin D. In addition, the chromophore was sensitive to treatment with arylsulfatase as would be expected for ommatin D. The polypeptide chain of YCP was synthesized by the larval fat body and was detectable in hemolymph throughout the life cycle. However, only during the fifth instar did YCP polypeptide levels in the hemolymph increase significantly. The highest hemolymph concentration was observed on the first day of pupation, whereafter it gradually decreased. The association of chromophore with the YCP polypeptide was transient. In fifth instar wandering stage larvae and in female moths, YCP polypeptide and chromophore were detectable in the hemolymph. During the wandering stage, increasing amounts of chromophore became associated with the YCP polypeptide. However, in feeding fifth instar larvae and in male moths, the YCP polypeptide but not the chromophore was detectable. No representatives of seven other insect orders contained hemolymph proteins that cross-reacted with anti-YCP antiserum. However, each of four other lepidopteran examined had on immunologically-related hemolymph protein of approximately 31 kDa. Ommochromes arise in insects as end products of the metabolism of tryptophan. As such, ommochromes occur in both the tissues and the excreta of insects. We propose that in M. sexta, one such tryptophan metabolite is found in the hemolymph associated with a specific 31 kDa protein.

The sex-specific effects of reproductives and of soldiers on the reproductivity (i.e., tendency to develop into replacement reproductives) of pseudergates of Zootermopsis nevadensis were studied. Reproductives inhibit reproductivity in pseudergates of their own sex only. Reproductives neither inhibit nor stimulate reproductivity in pseudergates of the opposite sex. Reproductives do not require the presence of a reproductive of the opposite sex to stimulate them to inhibit reproductivity in pseudergates. Soldiers had no effect on the reproductivity of pseudergates. The effects of group size and of the presence or absence of reproductives on the development of last-stage nymphs of Z. nevadensis were studied. The size of experimental groups had no effect on the rates of stationary molts or alate molts, suggesting that the correlation between colony size and the onset of alate production in nature may be spurious. The presence or absence of reproductives had no effect on the rate of stationary molts or alate molts, suggesting that in Z. nevadensis neither group size nor the presence of reproductives has any direct effect on alate determination. It is suggested that in Z. nevadensis a form of nutritional castration can delay the onset of alate development; that is to say, that the onset of alate development is determined by the ratio of nutrient-gathering castes to nutrient-receiving castes in the colony. I have found what I believe to be an extraordinary example of deception in Z. nevadensis and Zootermopsis angusticollis. This is the first reported example of caste mimicry in a social insect, and may explain why supernumerary replacement reproductives are common in Z. nevadensis and Z. angusticollis but not in Zootermopsis laticeps. The compositions of 41 field-collected colonies of Zootermopsis were given and the data were analyzed for trends. Most notably, supernumerary replacement reproductives were common in Z. nevadensis and in Z. angusticollis but have never been found in Z. laticeps, by us or by anybody else. These findings are in accordance with our hypothesis of "caste mimicry" in Z. nevadensis and Z. angusticollis.

Relationships between patterns of food (nectar and pollen) harvest and honey bee colony growth and reproduction are poorly understood. Research was conducted on the relationships between food harvest and colony growth in the Sonoran desert of Arizona. Annual patterns of resources (pollen harvest rates, pollen protein content, protein influx rates, and nectar harvest) and colony growth and reproduction (brood area, adult population, and reproductive swarm occurrence) for the Tucson area were obtained. Annual patterns were analyzed for periodicity and stability using autocorrelation time series analysis. Each resource pattern was compared to each colony growth pattern using cross-correlation analysis which revealed time lag interval of correlation between the two data sets. The foraging activity of the honey bee colonies was dominated by pollen foraging, with pollen harvested on a year-round basis. Nectar collection was limited to only a few weeks each year. The colony growth patterns all reached their maxima in spring or early summer. The autocorrelation analysis revealed that all data sets exhibited periodic and stable behaviors based on an annual (52 week) cycle. The colony growth data sets were also predictable in magnitude. The cross-correlation analysis revealed that the areas of sealed brood, number of adult bees, and swarm occurrence were more correlated to protein influx than any other food resource parameter. The timing of the greatest nectar harvest occurred just after the peak of swarm occurrence. Colonies fed supplementary pollen diets containing 24.8% or 17.2% protein were compared to non-fed controls. The number, timing, and survival of swarms was monitored. The initiation of queen-cell construction was directly related to protein influx rates exceeding 20 g colony⁻¹ day⁻¹. The 24.8% protein treatment swarmed earlier than the other two treatments. Swarm survival was highest in swarms that issued just prior to the nectar flow. Honey bee colony growth and reproductive swarming patterns in Tucson are directly related to protein influx rates. This response results in swarm production at a time of year when nectar is most abundant, thus aiding long-term swarm survival. Similar relationships between patterns of food harvest and swarming should occur for all temperate honey bee colonies.

The hypothesis that Manduca sexta arylphorin is a storage protein that provide amino acids for adult protein synthesis was proposed based on its development profile. This study provided experimental evidence supporting this hypothesis. First, preparation of radiolabeled arylphorin of Manduca sexta was compared by in vivo and in vitro biosynthesis from ¹⁴C-phenylalanine. The latter procedure proved to be optimal for obtaining high specific activity. Then turnover of amino acid during adult development was analyzed for phenylalanine and alanine, which represent general patterns of amino acid utilization because of their different metabolic pathways. The pool size and turnover rate of phenylalanine and alanine differed but a similar pattern of changes occurred in rate, being maximum in early and late adult development while at a minimum during middle stage. The pool size was fairly constant with a slight decrease toward the end of development. The absolute values for alanine were consistently higher, varying between 2- to 3-fold higher for pool sizes and 4- to 8-fold for turnover rates. Finally the fate of labeled phenylalanine from free amino acid pool and from arylphorin was compared by injecting ¹⁴C-phenylalanine or ¹⁴C-phe-arylphorin into pupae. The proportion of radioactivity distributed into most tissues or organs of pupae injected with the different labels during either middle or late adult development appeared to have no significant difference. It is suggested that arylphorin is hydrolyzed to free amino acids that mix with the free amino acid pool and are then used for adult development. A small difference in percentage of radioactivity occurred in some organs (i.e., thorax, and leg and wing) indicating that a small amount of arylphorin may be used as intact protein for cuticle formation. The hypothesis that Manduca sexta arylphorin is a storage form for replenishing the free amino acid pool is now confirmed by experimental evidence.

Little is known of the genetics of multipurpose trees in the genus Prosopis. These studies, which examined mating systems and pollination biology of P. velutina Wooten, improved our understanding of genetic structure and gene flow in natural and artificial populations. There was no evidence for either male or female sterility, but early and later flowering trees could be functionally male and female, respectively. Pollen loads on stigmas of mature flowers were adequate for pod production, so low fruit:flower ratios in P. velutina were not attributed to inadequate pollination. Flowers were receptive to pollen prior to complete anthesis when only stigmas were exserted, a trait that will facilitate controlled pollination. Hand pollinations demonstrated that P. velutina was self-fertile. Lower pod production in selfs compared to outcrosses was attributed to genetic load. Multilocus estimates of mating systems parameters derived from data for 3 isozyme systems of 30 open-pollinated families revealed 20.7% selfing and 7.1% biparental inbreeding in mating in three natural populations. Implications of self-fertility and inbreeding were discussed in relation to breeding programs, and natural and artificial populations. Genetic subdivision was found within these populations, but not among them. This genetic structure was attributed to initial long-distance seed dispersal into grasslands by livestock, followed by short-distance seed dispersal from "nucleus" trees by livestock and wildlife. Twenty-six genera of insects foraged on the flowers. Small insects were effective pollinators of P. velutina, but nocturnal insects were not. The most efficient pollinators, based on pod production after single visits to inflorescences, were native leafcutter bees (Megachilidae), followed by Perdita spp., Apis mellifera, and Volucella spp. Insect behavior can affect plant mating systems by altering the relative amounts of selfing and outcrossing, and as pollinator guilds change through the flowering season. It was also found that individual trees can bear up to three cohorts of flowers during a growing season. These factors combine to make the mating systems of P. velutina more complicated than previously thought. Approaches for using insects in breeding and seed orchards were discussed.