Ecological factors affecting the establishment of the biological control agent Gargaphia decoris Drake (Hemiptera: Tingidae) : a thesis submitted in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Plant Science at Massey University, Manawatu, New Zealand

The Brazilian lace bug (Gargaphia decoris Drake (Hemiptera:Tingidae)) was released in New Zealand in 2010 for the biological control of the invasive weed woolly nightshade (Solanum mauritianum Scopoli (Solanaceae)). Currently there is scarce information about the potential effect of ecological factors on the establishment of this biological control agent. This study investigated: 1) the effect of maternal care and aggregation on nymphal survival and development; 2) the effect of temperature, photoperiod and humidity on G. decoris performance; and 3) the effect of light intensity on S. mauritianum and G. decoris performance. Maternal care and aggregation are characteristic behaviours of G. decoris. These behaviours have an adaptive significance for the offspring and are key determinants for the survival of the species under natural conditions. Maternal care is reported to increase the survival and development of offspring under field conditions, and higher aggregations to increase the survival of the offspring. However, in this study, maternal care negatively affected the survival and development of the offspring, and higher aggregations had no significant impact on offspring survival. The availability of host plants under laboratory conditions may have influenced the expression of these behaviours. Climate is a factor that constrains insect development and therefore establishment. In this study, temperature affected the survival, nymphal development, life cycle, adult longevity, female reproductive success (i.e. total number of eggs, number of eggs laid per female, number of egg batches, number of eggs per batch, pre-oviposition period, percent females that oviposited successfully, number of eggs in the first batch and percentage of eggs that hatched from the first batch) and population growth parameters (i.e. life table). Temperatures between 20 – 25 °C were the optimal temperatures for G. decoris establishment. Photoperiod affected the mean percentage of egg hatch (i.e. emergence of nymphs in egg batch collected from colony) and total nymphal survival (i.e. egg to adult emergence), adult longevity and population growth parameters. The photoperiod 16L:8D was the optimal photoperiod for insect establishment. Humidity affected the mean percentage of egg hatch, adult longevity and population growth parameters. G. decoris population growth was highest at 70 ± 10% RH but the population growth was faster at 50 ± 10%. The CLIMEX model predicted that G. decoris could occupy broader regions not only on its native range (i.e. Brazil and Argentina) but also other regions where S. mauritianum is considered invasive (i.e. New Zealand and South Africa). G. decoris is predicted to be able to establish optimally in most of New Zealand North Island, except in regions with altitudes higher than 1300 meters above sea level. Most of the South Island is considered unsuitable for G. decoris establishment, except parts of the West Coast, Nelson and the Tasman region, which are predicted to be moderately to marginally suitable. Light intensity and plant age (i.e. day of harvest) affected host plant quality and had an indirect impact on insect establishment. Light intensity and plant age affected key physiological, morphological and defensive traits of S. mauritianum. Three compounds appeared to be involved, and were positively identified as glycoalkaloids: α-solamargine/β- solamarine, solauricine/solasonine, and unknown-954. The reproductive performance of G. decoris was affected because females avoided ovipositing on unshaded plants. The presence of trichomes and an increase in concentration of glycoalkaloids in the second harvest affected the nymphal performance and was reflected in adults, which had smaller bodies and wings. The results of my study have implications for using the Brazilian lace bug G. decoris in biological control programmes. The ecological factors included in this study work synergistically rather than independently and are important to consider when deciding the best locations in which the insect could be liberated

Characteristic Numbers and invariant subvarieties for Projective Webs

We define the characteristic numbers of a holomorphic k-distribution of any dimension on $mathbb P^n$ and obtain relations between these numbers and the characteristic numbers of an invariant subvariety. As an application we bound the degree of a smooth invariant hypersurface

Projective structures and neighborhoods of rational curves

We investigate the duality between local (complex analytic) projective structures on surfaces and two dimensional (complex analytic) neighborhoods of rational curves having self-intersection +1. We study the analytic classification, existence of normal forms, pencil/fibration decomposition, infinitesimal symmetries

Flat 3-webs of degree one on the projective plane

The aim of this work is to study global $3$-webs with vanishing curvature. We wish to investigate degree $3$ foliations for which their dual web is flat. The main ingredient is the Legendre transform, which is an avatar of classical projective duality in the realm of differential equations. We find a characterization of degree $3$ foliations whose Legendre transform are webs with zero curvature.Comment: 14 page

Foliations and webs inducing Galois coverings

We introduce the notion of Galois holomorphic foliation on the complex projective space as that of foliations whose Gauss map is a Galois covering when restricted to an appropriate Zariski open subset. First, we establish general criteria assuring that a rational map between projective manifolds of the same dimension defines a Galois covering. Then, these criteria are used to give a geometric characterization of Galois foliations in terms of their inflection divisor and their singularities. We also characterize Galois foliations on $\mathbb P^2$ admitting continuous symmetries, obtaining a complete classification of Galois homogeneous foliations

Beyond the Politics of Climate Change: How Education and Income Level Affect Environmental Values

Human-caused climate change has been acknowledged for decades, but public opinion on its validity and severity has been consistently questioned in the United States. Despite the overwhelming evidence pointing towards fossil fuel emissions and unsustainable practices as the leading causes of global climate change, its politicization during the beginning of the century has seriously slowed down America’s path towards a green future. Because this has become a partisan issue for many voters, considerable research has been done on the affiliation between party identification and public opinion on climate change. Although party identification has been studied as a major factor, other variables also come into effect. This paper aims to explore the relationship between how Americans view federal spending on the environment with their income and educational background. We will be obtaining and analyzing data from the 2016 American National Election Survey to see if these variables have statistical significance on how important federal climate change action is to the public. We expect that education will have a larger effect on public opinion than income and that people who want to increase the federal environmental budget will have lower incomes but higher education