title: Sex pheromone studies on the grass grub (Costelytra Zealandica (White)) and the common army worm

authors: Henzell, Ronald Francis

abstract: This thesis describes the identification of a sex pheromone of the grass grub beetle, Costelytra zealandica, and the attempts to use the sex pheromone directly to control grass grub infestations. The partial identification of a sex pheromone of the common armyworm moth, Pseudaletia separata, is also described.

The larval stages of the grass grub beetle cause extensive damage to pasture during the autumn-winter period and constitute New Zealand’s major insect pest. Since the banning of DDT, the larvae have been treated by spraying pastures with one of a number of organophosphate insecticides but, in general, these materials have not given adequate control.

Attempts have been made, therefore, to develop alternative control procedures and to establish more selective and effective ways of using insecticides. Promising preliminary results have been obtained with other insects in using sex pheromones both as direct and indirect control agents. In the latter respect, a more judicious and effective use of the insecticide has been achieved, by using the properties of specificity and sensitivity of an insect’s sex pheromone to detect, and to estimate, the insect population prior to the application of the insecticide.

The female grass grub beetle was shown to contain a sex pheromone which stimulated mating activity in males in the laboratory. Methods were developed to extract the sex pheromone and its properties in functional group tests were consistent with those of a phenolic compound. The active component was isolated by the means of high vacuum distillation onto dry ice followed by gas chromatography. The isolated material was then examined by high resolution mass spectroscopy and found to be phenol. On average each female beetle at the time of mating contained about 1.5μg phenol. Phenol itself not only stimulated mating activity in males in the laboratory but also attracted large numbers of young males in mating flights in the field. Field tests were also carried out with a number of substituted phenols but none of these was active.

An electroantennogram was developed to measure the antennal response to phenol and a number of closely related phenolic materials. In all the tests, phenol gave the largest response. A comparison at the antennal level between phenol and a crude female extract indicated phenol was the sole pheromone. 

Attempts were made to use phenol for grass grub control. The compound is cheap and readily available. Hence its direct use could provide an economically acceptable control method. Interestingly, this was one of the first opportunities to attempt to control an insect population with an unlimited supply of the sex pheromone. 

There are two ways, in which phenol might be used to prevent effective mating from taking place in the field. Firstly, the attractant properties might be used to out-compete females in the natural population. Secondly, sufficient phenol could be permeated into the atmosphere to possibly confuse the male in its search for the female. Both methods were evaluated in the field with grass grub infestations which ranged from 50 to 220 beetles per m². In the first approach the best attractant sources used were only about ten times more attractive than virgin females and therefore, as they could not compete successfully with the large number of females in the natural population, control was not achieved. In the attempts to use the second approach it was possible to confuse male flight behaviour by releasing 5 grams/hour/hectare (5g/h/ha) of phenol over the trial sites. However, it was not possible to prevent males from locating females even with as much as 110 g/h/ha of phenol released over the trial sites. Presumably, the beetle density of the infestations was such, that males could locate females by sight or simply by chance. 

Larvae of the common armyworm can cause extensive damage to pastures and crops and although conventional insecticide methods give satisfactory control, the main problems are early detection and estimation of infections. In this respect a knowledge of the sex pheromone used by the female moth should allow insecticides to be used more effectively. 

The sex pheromone was extracted from the abdominal tips of female armyworm moths using methylene chloride. Functional group tests indicated that the sex stimulatory component was an unsaturated aliphatic acetate. Comparison of the Rf values and retention times of the active component with those of standard compounds on thin layer and gas chromatography (GC) respectively, suggested that a mono-unsaturated hexadecenyl acetate was involved. Of the mono-unsaturated hexadecenyl acetates tested for EAG activity, only cis-11-hexadecenyl acetate induced an intense antennal response. Furthermore, 0.1, 1.0, and 10.0 ng of this compound on glass rods induced strong sex stimulatory activity in males in laboratory behavioural tests.

The crude female extract was injected onto a number of different GC columns and several active fractions were collected from each column. This indicated that the female moth probably uses a multiple component pheromone system. The behaviour of one of the sex stimulatory components in the female extract, in all the chemical and concentration steps, was consistent with that of cis-11-hexadecenyl acetate.

In an attempt to verify that cis-11-hexadecenyl acetate was a natural pheromone of the common armyworm moth a GC fraction of the crude female extract, eluting at the retention time of cis-11-hexadecenyl acetate, was collected and ozonized. One of the ozonolysis products of cis-11-hexadecenyl acetate is 11-acetoxyundecanal but this was not detected in the ozonized GC fraction, using the technique of mass fragmentography in which a mass spectrometer acts as a specific GC detector. It appears, therefore, that cis-11-hexadecenyl acetate is not present in female armyworm moths. When tested in the field, however, it attracted male moths into traps but was not as effective as virgin females.

text: Sex pheromone studies on the grass grub (Costelytra Zealandica (White)) and the common army worm This thesis describes the identification of a sex pheromone of the grass grub beetle, Costelytra zealandica, and the attempts to use the sex pheromone directly to control grass grub infestations. The partial identification of a sex pheromone of the common armyworm moth, Pseudaletia separata, is also described.

The larval stages of the grass grub beetle cause extensive damage to pasture during the autumn-winter period and constitute New Zealand’s major insect pest. Since the banning of DDT, the larvae have been treated by spraying pastures with one of a number of organophosphate insecticides but, in general, these materials have not given adequate control.

Attempts have been made, therefore, to develop alternative control procedures and to establish more selective and effective ways of using insecticides. Promising preliminary results have been obtained with other insects in using sex pheromones both as direct and indirect control agents. In the latter respect, a more judicious and effective use of the insecticide has been achieved, by using the properties of specificity and sensitivity of an insect’s sex pheromone to detect, and to estimate, the insect population prior to the application of the insecticide.

The female grass grub beetle was shown to contain a sex pheromone which stimulated mating activity in males in the laboratory. Methods were developed to extract the sex pheromone and its properties in functional group tests were consistent with those of a phenolic compound. The active component was isolated by the means of high vacuum distillation onto dry ice followed by gas chromatography. The isolated material was then examined by high resolution mass spectroscopy and found to be phenol. On average each female beetle at the time of mating contained about 1.5μg phenol. Phenol itself not only stimulated mating activity in males in the laboratory but also attracted large numbers of young males in mating flights in the field. Field tests were also carried out with a number of substituted phenols but none of these was active.

An electroantennogram was developed to measure the antennal response to phenol and a number of closely related phenolic materials. In all the tests, phenol gave the largest response. A comparison at the antennal level between phenol and a crude female extract indicated phenol was the sole pheromone. 

Attempts were made to use phenol for grass grub control. The compound is cheap and readily available. Hence its direct use could provide an economically acceptable control method. Interestingly, this was one of the first opportunities to attempt to control an insect population with an unlimited supply of the sex pheromone. 

There are two ways, in which phenol might be used to prevent effective mating from taking place in the field. Firstly, the attractant properties might be used to out-compete females in the natural population. Secondly, sufficient phenol could be permeated into the atmosphere to possibly confuse the male in its search for the female. Both methods were evaluated in the field with grass grub infestations which ranged from 50 to 220 beetles per m². In the first approach the best attractant sources used were only about ten times more attractive than virgin females and therefore, as they could not compete successfully with the large number of females in the natural population, control was not achieved. In the attempts to use the second approach it was possible to confuse male flight behaviour by releasing 5 grams/hour/hectare (5g/h/ha) of phenol over the trial sites. However, it was not possible to prevent males from locating females even with as much as 110 g/h/ha of phenol released over the trial sites. Presumably, the beetle density of the infestations was such, that males could locate females by sight or simply by chance. 

Larvae of the common armyworm can cause extensive damage to pastures and crops and although conventional insecticide methods give satisfactory control, the main problems are early detection and estimation of infections. In this respect a knowledge of the sex pheromone used by the female moth should allow insecticides to be used more effectively. 

The sex pheromone was extracted from the abdominal tips of female armyworm moths using methylene chloride. Functional group tests indicated that the sex stimulatory component was an unsaturated aliphatic acetate. Comparison of the Rf values and retention times of the active component with those of standard compounds on thin layer and gas chromatography (GC) respectively, suggested that a mono-unsaturated hexadecenyl acetate was involved. Of the mono-unsaturated hexadecenyl acetates tested for EAG activity, only cis-11-hexadecenyl acetate induced an intense antennal response. Furthermore, 0.1, 1.0, and 10.0 ng of this compound on glass rods induced strong sex stimulatory activity in males in laboratory behavioural tests.

The crude female extract was injected onto a number of different GC columns and several active fractions were collected from each column. This indicated that the female moth probably uses a multiple component pheromone system. The behaviour of one of the sex stimulatory components in the female extract, in all the chemical and concentration steps, was consistent with that of cis-11-hexadecenyl acetate.

In an attempt to verify that cis-11-hexadecenyl acetate was a natural pheromone of the common armyworm moth a GC fraction of the crude female extract, eluting at the retention time of cis-11-hexadecenyl acetate, was collected and ozonized. One of the ozonolysis products of cis-11-hexadecenyl acetate is 11-acetoxyundecanal but this was not detected in the ozonized GC fraction, using the technique of mass fragmentography in which a mass spectrometer acts as a specific GC detector. It appears, therefore, that cis-11-hexadecenyl acetate is not present in female armyworm moths. When tested in the field, however, it attracted male moths into traps but was not as effective as virgin females.

year: 1973

title: Dispersal patterns and population connectivity of New Zealand stream insects: Integrating landscape and population genetics

authors: de Araujo Barbosa, Vanessa

subjects: Dispersal

abstract: Increasing anthropogenic habitat fragmentation in riverine ecosystems, in particular the loss of natural riparian vegetation, has profound consequences for dispersal and connectivity of aquatic insects. Aquatic insects depend on dispersal to colonise new sites and expand their ranges, but colonisation is only effective if followed by successful reproduction of the colonising individual within the receiving population. Populations that are connected by dispersal are likely to possess and maintain higher levels of genetic diversity through gene flow, which enhances their long-term viability. Conversely, altered and/or restricted movement of individuals in fragmented landscapes may disrupt the connectivity of populations across habitats, reducing gene flow and decreasing genetic diversity of remnant populations. Thus, the ability to successfully disperse through fragmented and disturbed patches can be a key determinant of the long-term viability of populations.
Genetic markers provide an indirect approach to estimate dispersal potential and infer a species’ gene flow, genetic diversity, and population connectivity. A variety of different genetic markers have been used over the past decades, each with advantages and disadvantages. Mitochondrial DNA (mtDNA) is commonly used in aquatic insect research and provides insight into historic dispersal, connectivity and isolation, while nuclear markers identified through next-generation sequencing approaches can reflect changes on a more contemporary time scale. The application of such markers in landscape genetics research further enables quantification of the effects of landscape and environmental features on gene flow, and identification of potential barriers to dispersal. This thesis is a collection of individual research papers that together provide new knowledge of functional connectivity and dispersal patterns of stream insect populations in altered landscapes. The research findings could ultimately assist with conservation and restoration planning.
An overview of the most commonly-used genetic markers, including their main features as applied to studies of aquatic insect dispersal, is provided as a global review in Chapter 2. Traditional markers, such as allozymes and mtDNA, are the most popularly applied and studies assessing the effects of specific landscape features on shaping population connectivity among habitats, especially in fragmented landscapes, are rare. Higher resolution markers (e.g. single nucleotide polymorphisms; SNPs), have recently become available, providing high- throughput genome-wide data at low cost. With their potential to detect finer-scale genetic structure, these markers are expected to become more common in future studies, providing more accurate estimates of contemporary patterns of dispersal. Chapter 3 compares the resolution power of mitochondrial cytochrome c oxidase subunit I (COI) and genome-wide SNP markers in estimating fine-scale genetic differentiation for three endemic New Zealand aquatic insects. Both markers provided comparable results: a general lack of strong population structure within each species, and fine-scale genetic differentiation among some populations. These results indicated substantial connectivity of the three analysed species within and between proximate streams separated up to 11 km. However, findings were considered preliminary as small sample sizes and limited data quality for the SNP datasets may have compromised their power to uncover genetic structuring. Nevertheless, an important overall finding was that either COI or SNP markers can provide suitable initial estimates of fine-scale population genetic differentiation in stream insects. Finally, Chapter 4 provides a detailed analysis of functional connectivity and dispersal patterns for the three stream insect species at multiple spatial scales, increasing the sample size and geographic coverage of sequenced individuals from Chapter 3. For all three species, clear spatial genetic structure marked by Isolation by Distance (IBD) was only observed at larger spatial scales (among mountain regions separated by ~30 and 170 km), whereas most gene flow occurred locally (up to 11 km). At the local spatial scale, landscape genetic analyses revealed that Isolation by Resistance (IBR) - particularly the influence of land cover - generally provided a better prediction of spatial genetic structure. Species-specific findings further highlighted the potential influence of continuous forest in the riparian zone in enhancing population connectivity and dispersal within the stream channel. Meanwhile, dispersal over pastoral land may be more common when insects must search for suitable habitat that cannot be found locally. These key findings are likely to be fundamental for future colonisation and persistence of these populations. Understanding in-stream and overland dispersal, and how these affect the gene flow of species, is important for successful implementation of stream restoration measures. This research collectively elucidated patterns of population connectivity and dispersal potential in a fragmented landscape that will provide valuable knowledge for conservation efforts aimed at enhancing restoration of stream insect biodiversity.

text: Dispersal patterns and population connectivity of New Zealand stream insects: Integrating landscape and population genetics Increasing anthropogenic habitat fragmentation in riverine ecosystems, in particular the loss of natural riparian vegetation, has profound consequences for dispersal and connectivity of aquatic insects. Aquatic insects depend on dispersal to colonise new sites and expand their ranges, but colonisation is only effective if followed by successful reproduction of the colonising individual within the receiving population. Populations that are connected by dispersal are likely to possess and maintain higher levels of genetic diversity through gene flow, which enhances their long-term viability. Conversely, altered and/or restricted movement of individuals in fragmented landscapes may disrupt the connectivity of populations across habitats, reducing gene flow and decreasing genetic diversity of remnant populations. Thus, the ability to successfully disperse through fragmented and disturbed patches can be a key determinant of the long-term viability of populations.
Genetic markers provide an indirect approach to estimate dispersal potential and infer a species’ gene flow, genetic diversity, and population connectivity. A variety of different genetic markers have been used over the past decades, each with advantages and disadvantages. Mitochondrial DNA (mtDNA) is commonly used in aquatic insect research and provides insight into historic dispersal, connectivity and isolation, while nuclear markers identified through next-generation sequencing approaches can reflect changes on a more contemporary time scale. The application of such markers in landscape genetics research further enables quantification of the effects of landscape and environmental features on gene flow, and identification of potential barriers to dispersal. This thesis is a collection of individual research papers that together provide new knowledge of functional connectivity and dispersal patterns of stream insect populations in altered landscapes. The research findings could ultimately assist with conservation and restoration planning.
An overview of the most commonly-used genetic markers, including their main features as applied to studies of aquatic insect dispersal, is provided as a global review in Chapter 2. Traditional markers, such as allozymes and mtDNA, are the most popularly applied and studies assessing the effects of specific landscape features on shaping population connectivity among habitats, especially in fragmented landscapes, are rare. Higher resolution markers (e.g. single nucleotide polymorphisms; SNPs), have recently become available, providing high- throughput genome-wide data at low cost. With their potential to detect finer-scale genetic structure, these markers are expected to become more common in future studies, providing more accurate estimates of contemporary patterns of dispersal. Chapter 3 compares the resolution power of mitochondrial cytochrome c oxidase subunit I (COI) and genome-wide SNP markers in estimating fine-scale genetic differentiation for three endemic New Zealand aquatic insects. Both markers provided comparable results: a general lack of strong population structure within each species, and fine-scale genetic differentiation among some populations. These results indicated substantial connectivity of the three analysed species within and between proximate streams separated up to 11 km. However, findings were considered preliminary as small sample sizes and limited data quality for the SNP datasets may have compromised their power to uncover genetic structuring. Nevertheless, an important overall finding was that either COI or SNP markers can provide suitable initial estimates of fine-scale population genetic differentiation in stream insects. Finally, Chapter 4 provides a detailed analysis of functional connectivity and dispersal patterns for the three stream insect species at multiple spatial scales, increasing the sample size and geographic coverage of sequenced individuals from Chapter 3. For all three species, clear spatial genetic structure marked by Isolation by Distance (IBD) was only observed at larger spatial scales (among mountain regions separated by ~30 and 170 km), whereas most gene flow occurred locally (up to 11 km). At the local spatial scale, landscape genetic analyses revealed that Isolation by Resistance (IBR) - particularly the influence of land cover - generally provided a better prediction of spatial genetic structure. Species-specific findings further highlighted the potential influence of continuous forest in the riparian zone in enhancing population connectivity and dispersal within the stream channel. Meanwhile, dispersal over pastoral land may be more common when insects must search for suitable habitat that cannot be found locally. These key findings are likely to be fundamental for future colonisation and persistence of these populations. Understanding in-stream and overland dispersal, and how these affect the gene flow of species, is important for successful implementation of stream restoration measures. This research collectively elucidated patterns of population connectivity and dispersal potential in a fragmented landscape that will provide valuable knowledge for conservation efforts aimed at enhancing restoration of stream insect biodiversity.

year: 2022

title: Whānau Stories: Creating meaningful engagement and wellbeing for the indigenous culture of Aotearoa New Zealand

authors: Cruse, Diana Caroline Annavale

subjects: Engagement

abstract: This research sees my interests coalesce into a particular focus on how collaborative partnerships with parents/caregivers can provide whānau Māori with opportunities to strengthen wellbeing in their own lives. It is located in Aotearoa New Zealand and within the context of Te Whāriki (Ministry of Education, 1996), Aotearoa New Zealand’s early childhood curriculum.  The Ministry of Education has a target that 98% of all children in Aotearoa New Zealand under 5 will attend an early childhood education setting (Ministry of Education, 2016), with Māori children having lower participation rates than the national participation rate (Ministry of Education, 2013).  The premise for this thesis is that meaningful whānau engagement in early learning contexts within Aotearoa New Zealand can empower whānau Māori, and honour the promises made in Te Tiriti o Waitangi of partnership, participation, and protection.
Therefore, this thesis sets out to examine what constitutes meaningful engagement for whānau Māori in an early childhood setting in Aotearoa New Zealand, and how meaningful engagement can assist whānau to enjoy an increase of wellbeing.
To explore this issue, I conducted research within an early childhood setting in Aotearoa New Zealand, using methodologies of Kaupapa Māori Research and Narrative Inquiry.  I listened to the narratives of whānau Māori indicating how meaningful engagement was created for them, and investigated if links were generated between engagement and wellbeing for their whānau. These links were identified in the literature as significant levers for educational success.
This research discovered three stages of engagement for the whānau Māori who participated in this study: establishing engagement, developing engagement and solidifying engagement.  Once created, meaningful engagement can lead to flourishing, indicating that there is relationship between meaningful engagement and whānau wellbeing.

text: Whānau Stories: Creating meaningful engagement and wellbeing for the indigenous culture of Aotearoa New Zealand This research sees my interests coalesce into a particular focus on how collaborative partnerships with parents/caregivers can provide whānau Māori with opportunities to strengthen wellbeing in their own lives. It is located in Aotearoa New Zealand and within the context of Te Whāriki (Ministry of Education, 1996), Aotearoa New Zealand’s early childhood curriculum.  The Ministry of Education has a target that 98% of all children in Aotearoa New Zealand under 5 will attend an early childhood education setting (Ministry of Education, 2016), with Māori children having lower participation rates than the national participation rate (Ministry of Education, 2013).  The premise for this thesis is that meaningful whānau engagement in early learning contexts within Aotearoa New Zealand can empower whānau Māori, and honour the promises made in Te Tiriti o Waitangi of partnership, participation, and protection.
Therefore, this thesis sets out to examine what constitutes meaningful engagement for whānau Māori in an early childhood setting in Aotearoa New Zealand, and how meaningful engagement can assist whānau to enjoy an increase of wellbeing.
To explore this issue, I conducted research within an early childhood setting in Aotearoa New Zealand, using methodologies of Kaupapa Māori Research and Narrative Inquiry.  I listened to the narratives of whānau Māori indicating how meaningful engagement was created for them, and investigated if links were generated between engagement and wellbeing for their whānau. These links were identified in the literature as significant levers for educational success.
This research discovered three stages of engagement for the whānau Māori who participated in this study: establishing engagement, developing engagement and solidifying engagement.  Once created, meaningful engagement can lead to flourishing, indicating that there is relationship between meaningful engagement and whānau wellbeing.

year: 2017