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Due to ongoing climate change and the spread of invasive pests, understanding and predicting climatic suitability for invasive insect species has shown growing demand from government and industry biosecurity managers. The invasive pest Bactericera cockerelli, (Šulc) (Hemiptera: Triozidae), commonly known as tomato potato psyllid (TPP), is native to North America and has recently invaded Australasia. TPP is also the vector of the bacterial plant pathogen Candidatus Liberibacter solanacearum (CLso), which has caused severe economic losses for potato growers worldwide. We used the niche modelling software CLIMEX to predict the potential geographical distribution of TPP in Australasia and worldwide under current and future climatic scenarios. Our model prediction of the current climate conditions closely agrees with all the known distributions of TPP. In its native range (North America), TPP is predicted to expand its current geographical range in semi‐arid, temperate, and continental climates. Within Australia, along with the known occurrence of TPP in Western Australia, potential expansion into South Australia, Victoria, New South Wales and Queensland is predicted. The predicted distribution closely matches all the known records with higher climatic suitability in New Zealand. Globally, the model projected that the pest‐free countries in Europe and East Asia are climatically more suitable for TPP. Predictions under the future climate change scenarios (A1B, CSIRO Mk 3.0 for 2090) showed a significant reduction of the known geographical range of TPP with a possible expansion towards higher latitudes. Areas in North America and Australia are projected to be less climatically suitable for the survival of TPP in future climates. However, our model suggested that Europe and New Zealand will remain unchanged or will become more favourable in the future. These CLIMEX projections for current and future climatic distribution provide valuable information for existing and future biosecurity preparedness and management programmes, which may prove helpful in risk assessments and identifying potential areas that are likely to be susceptible to a TPP invasion. [ABSTRACT FROM AUTHOR]

In Central and North America, Australia and New Zealand, potato (Solanum tuberosum) crops are attacked by Bactericera cockerelli, the tomato potato psyllid (TPP). ‘Mesh crop covers’ which are used in Europe and Israel to protect crops from insect pests, have been used experimentally in New Zealand for TPP control. While the covers have been effective for TPP management, the green peach aphid (GPA, Myzus persicae) has been found in large numbers under the mesh crop covers. This study investigated the ability of the GPA to penetrate different mesh hole sizes. Experiments using four sizes (0.15 × 0.15, 0.15 × 0.35, 0.3 × 0.3 and 0.6 × 0.6 mm) were carried out under laboratory conditions to investigate: (i) which mesh hole size provided the most effective barrier to GPA; (ii) which morph of adult aphids (apterous or alate) and/or their progeny could breach the mesh crop cover; (iii) would leaves touching the underside of the cover, as opposed to having a gap between leaf and the mesh, increase the number of aphids breaching the mesh; and (iv) could adults feed on leaves touching the cover by putting only their heads and/or stylets through it? No adult aphids, either alate or apterous, penetrated the mesh crop cover; only nymphs did this, the majority being the progeny of alate adults. Nymphs of the smaller alatae aphids penetrated the three coarsest mesh sizes; nymphs of the larger apterae penetrated the two coarsest sizes, but no nymphs penetrated the smallest mesh size. There was no statistical difference in the number of aphids breaching the mesh crop cover when the leaflets touched its underside compared to when there was a gap between leaf and mesh crop cover. Adults did not feed through the mesh crop cover, though they may have been able to sense the potato leaflet using visual and/or olfactory cues and produce nymphs as a result. As these covers are highly effective for managing TPP on field potatoes, modifications of this protocol are required to make it effective against aphids as well as TPP.

Vibrational pest management techniques involve the manipulation of the mating behaviour of the target species. Development of such techniques require a deep understanding of the pair formation process. Two types of bioassays were conducted to determine whether a vibrational disruptive approach could be used for Bactericera cockerelli. First, we conducted trials with either single individuals or pairs of a male and a female to ascertain whether B. cockerelli uses vibrational signals to achieve mating. Second, playback trials were conducted using two different female signals to manipulate the behaviour of males. Signals emitted during the trials were recorded using a laser vibrometer from the surface of a leaf where either single individuals or pairs of B. cockerelli were released. We described the communication phases that led to mating and the associated male and female signals. Pair formation started with a male call followed by a female response, which established a vibrational duet. During the female reply, the male searched for the female without emitting vibrational signals. Mating could be achieved if the male could maintain the female replies and reach her. In the playback trials, two different female playbacks attracted males to the signal source. Furthermore, males stimulated with female playbacks spent more time near the source of the signal than insects in the silent control group. We concluded that the B. cockerelli mating behaviour relies on vibrational signals and is potentially susceptible to vibrational manipulation, thus a future vibrational management technique could be developed to monitor or control this species. [ABSTRACT FROM AUTHOR]

In Central and North America, Australia and New Zealand, potato (Solanum tubero- sum) crops are attacked by Bactericera cockerelli, the tomato potato psyllid (TPP). 'Mesh crop covers' which are used in Europe and Israel to protect crops from insect pests, have been used experimentally in New Zealand for TPP control. While the covers have been effective for TPP management, the green peach aphid (GPA, Myzus persicae) has been found in large numbers under the mesh crop covers. This study investigated the ability of the GPA to penetrate different mesh hole sizes. Experiments using four sizes (0.15 x 0.15, 0.15 x 0.35, 0.3 x 0.3 and 0.6 x 0.6 mm) were carried out under laboratory conditions to investigate: (i) which mesh hole size provided the most effective barrier to GPA; (ii) which morph of adult aphids (apterous or alate) and/or their progeny could breach the mesh crop cover; (iii) would leaves touching the underside of the cover, as opposed to having a gap between leaf and the mesh, increase the number of aphids breaching the mesh; and (iv) could adults feed on leaves touching the cover by putting only their heads and/or stylets through it? No adult aphids, either alate or apterous, penetrated the mesh crop cover; only nymphs did this, the majority being the progeny of alate adults. Nymphs of the smaller alatae aphids penetrated the three coarsest mesh sizes; nymphs of the larger apterae penetrated the two coarsest sizes, but no nymphs penetrated the smallest mesh size. There was no statistical difference in the number of aphids breaching the mesh crop cover when the leaflets touched its underside compared to when there was a gap between leaf and mesh crop cover. Adults did not feed through the mesh crop cover, though they may have been able to sense the potato leaflet using visual and/or olfactory cues and produce nymphs as a result. As these covers are highly effective for managing TPP on field potatoes, modifications of this protocol are required to make it effective against aphids as well as TPP. [ABSTRACT FROM AUTHOR]

"Candidatus Liberibacter solanacearum" (Lso) (="Candidatus Liberibacter psyllarous") is an uncultured, phloem-limited bacterium that is associated with zebra chip disease (ZC) in potato (Solanum tuberosum L.) and transmitted by the potato psyllid (Bactericera cockerelli (Šulc)). Vector density and timing of infection have been shown to affect ZC prevalence at harvest; however, little work has been done on disease development during storage. Here we confirm with field-cage trials that ZC prevalence at harvest was greater with increased time between inoculation and vine kill. Moreover, we show that with Pacific Northwest growing conditions, ZC can develop over time during storage. Plants inoculated 2 to 3 weeks before vine kill showed little or no ZC symptoms in tubers at harvest, but higher prevalence of symptoms after 3 months in storage. For plants inoculated at 4 to 5 weeks before vine kill, tubers exhibited notable symptoms at harvest, but still showed evidence of symptom development after storage. Plants inoculated within 1 week before vine kill exhibited little or no risk of ZC in tubers at harvest or after storage. Higher vector density tended to contribute to ZC prevalence, but was far less important than timing of infection. These results underscore the potential danger of underestimating ZC prevalence at harvest for tubers being stored long term, and suggest that plants at risk of Lso infection should be protected from potato psyllids until at least 2 weeks before vine kill. [ABSTRACT FROM AUTHOR]

The tomato potato psyllid (TPP), Bactericera cockerelli (Sulc) (Hemiptera Psylloidea), is a major pest on potato (Solanum tuberosum) and tomato (Solanum lycopersicum) in North and Central America and, introduced, in New Zealand; it has recently been reported from Western Australia and the Norfolk Island. The TPP causes the plant disorder called "psyllid yellows" in addition to vector the devastating plant pathogen Candidatus Liberibacter solanacearum (LSO), which is the causal agent of the zebra chip (ZC) disease on potato. ZC is detrimental to a number of solanaceous crops in North and Central America as well as in New Zealand. Here we report for the first time the presence of B. cockerelli feeding on potatoes in South America (Ecuador). Molecular tests on a mitochondrial gene confirmed the population from Ecuador as central haplotype. This suggests that the psyllid populations found in Ecuador might come from North or Central America, probably along with agricultural products or other plant material. All Ecuadorian TPPs in our study were tested for LSO and they are free of the pathogen. Nonetheless, there is a risk of introduction of psyllid yellows and ZC into South America. Comprehensive field surveys of solanaceous plants and fine-scaled genomic studies should be considered to locate the source of the psyllid, which could help to prevent the introduction of the pathogen into South America. [ABSTRACT FROM AUTHOR]

Behaviours of insects can be manipulated by transmitting vibrational signals to host plants in order to develop pest management techniques. Bactericera cockerelli is an important pest and uses vibrations for mate-finding. In order to design a future control strategy for B. cockerelli, three different bioassays were performed to assess whether vibrational signals could affect relevant behaviours. Single males or pairs were treated with a female playback in test 1 and 2, respectively. In test 3, mixed sex groups received either different disturbance playbacks. The use of a female playback significantly reduced the mating success of males, since they were attracted towards the source of the stimulus. Moreover, test 2 revealed that B. cockerelli females are competitive, since they used their signals to cover the playback and to duet with males, while in test 3, the disturbance playback, consisting of broadband noises significantly reduced male signalling activity. However, none of the treatments of test 3 negatively affected the mating success of males, which tended to mount the other conspecifics present on the same leaf. The role of vibrations in sexual communication and their potential application as control technique for B. cockerelli are discussed as well.

Fourteen potato lines, including some indicating reduced susceptibility to zebra chip (ZC), were assessed in trials over three seasons at Pukekohe (New Zealand) under three insecticide regimes: FULL (pre-plant plus 14-15 foliar applications through the season), REDUCED (4-5 foliar applications) and NIL (no insecticide). In all three seasons there were consistent reductions in tuber yield, dry matter and tuber size from the FULL to the REDUCED to the NIL insecticide treatment. ZC severity recorded in crisp slices before and after frying tended to be highest in the NIL treatment and lowest in the FULL treatment. All lines had symptoms of ZC in both raw and fried crisp samples but there were clear differences between lines, with some showing significantly fewer symptoms of ZC than current widely grown potato lines in New Zealand. The potential of these ZC-symptom tolerant lines, both as parents in a breeding programme and for possible release, is discussed. CLso titre of individual tubers of three lines was also determined from the 2014 NIL plots using qPCR. There was little relationship between CLso titres and ZC scores in either raw or fried crisp slices both within and between lines. [ABSTRACT FROM AUTHOR]

Tomato potato psyllid (TPP),Bactericera cockerelli(Sülc) (Hemiptera: Triozidae), is a vector forCandidatusLiberibacter solanacearum (Lso), a phloem-limited bacterium that causes severe production problems within the New Zealand potato industry. Field trials were conducted over three consecutive growing seasons between 2013 and 2016 at Pukekohe, New Zealand to determine the efficacy of an isoparaffinic petroleum distilled oil (JMS Stylet Oil®), applied as a foliar treatment within an insecticide programme, to control TPP. The effects of treatments on potato yield, tuber dry matter content and the incidence of zebra chip (ZC) in fried potato crisps were also assessed. This research demonstrated that JMS Stylet Oil, when used in combination with insecticides, achieved fewer insecticide applications, leading to reduced numbers of TPP nymphs and eggs on potato foliage, and lower incidence of ZC in deep-fried tuber crisps than weekly insecticide sprays, without adversely affecting plant growth and crop yields. [ABSTRACT FROM AUTHOR]

Co-innovation can be effective for addressing complex challenges involving multiple stakeholders who hold diverse viewpoints and perceptions. Addressing these challenges requires changes at various scales. However, there is limited systematic research on how co-innovation can work in different projects and what impacts it can have on the outcome. Co-innovation principles were tested for their potential to enhance the impact delivered by a fundamental research project investigating options for managing the tomato potato psyllid/Candidatus Liberibacter solanacearum complex in potato crops. A series of interviews and workshops were undertaken to increase interactions within the programme and with industry stakeholders. Additionally, a member of the research team, trained in co-innovation theory and practice, took a leadership role in planning and delivering technology transfer activities. The effects of bringing co-innovation principles to the programme are described, in particular the challenges encountered when introducing these concepts into a fundamental research programme. [ABSTRACT FROM AUTHOR]

Amblydromalus limonicusconsumed fewer first instarFrankliniella occidentalisthrips thanBactericera cockerellipsyllids per day when on the same (1.7 thrips, 3.7 psyllids) or separate (2.9 thrips, 4.4 psyllids) capsicum leaf discs. Mites ate fewer psyllids per day on tomato (1.9) than on capsicum (3.1). Mite survival was similar on both prey and plants. [ABSTRACT FROM PUBLISHER]

Bactericera cockerelli (tomato potato psyllid, TPP) is a serious pest of potato crops, causing feeding damage and also vectoring Candidatus Liberibacter solanacearum, the causal agent of the Zebra Chip (ZC) disease in potatoes. The results of 6 years of early and main crop potato trials at Pukekohe, New Zealand, are summarised and damage caused by TPP is reported. Results show that spring-sown (early) potato crops do not require insecticides. In main crop summer trials we tested action thresholds based on 10 and 20 TPP nymphs per 100 middle leaves but the incidence of ZC damage was commercially unacceptable, ranging from 4 to 9 %. Subsequently we tested an action threshold of >3 TPP adults per yellow sticky trap per week that led to ZC damage ranging from 0.9 to 1.6 %. We also compared monitoring of TPP using sticky trap catches with a degree day model started in mid winter (1 July) for forecasting generation times of TPP. On the basis of the field trial results, we recommend that from early summer onwards, the timing of the first foliar application of insecticide needs to be applied early enough to protect main crop potatoes from the first generation of TPP that occurs after potato tubers have emerged (at Pukekohe, this is the third TPP generation from 1 July when using degree day modelling). Three years of main crop trials indicate that an action threshold of >3 TPP per trap per week provides effective TPP/ZC management in the Pukekohe region when used in conjunction with natural enemies and an insecticide programme that features the use of selective insecticides. [ABSTRACT FROM AUTHOR]

Visual cues play a key role in host finding in many phytophagous insects, including the tomato potato psyllid ( TPP), Bactericera cockerelli ( Šulc) ( Hemiptera: Triozidae), a serious pest of solanaceous crops. This study evaluated the response of TPP to sticky traps of one of three colours, up to four sizes, and with or without green borders in an organic potato crop in Hawke's Bay, New Zealand. On average, large traps caught a higher density of TPP than small traps (with or without border; 25 and 14 TPP per 100 cm2, respectively). Tomato potato psyllid density on the green border was affected by the colour of the centre trap; a blue centre resulted in substantially fewer TPP on the green border than a yellow centre (9.0 vs. 69.6 TPP per 100 cm2). Trap catches in early summer were male biased, whereas catches of male and female TPP in late summer were approximately equal. [ABSTRACT FROM AUTHOR]

Tomato-Potato Psyllid (TPP) Bactericera cockerelli was first identified in New Zealand in 2006 and has caused major problems for the potato industry, particularly in the North Island. TPP and Zebra chip (ZC) resistance are now major priorities in Plant & Food Research's potato breeding programme. ZC is caused by a liberibacter associated with the TPP. Twelve potato lines, including most of the more widely grown potato cultivars in New Zealand, were assessed in main-crop yield trials at Pukekohe under three insecticide levels: FULL (pre-plant plus 13-15 foliar insecticide applications through the season), REDUCED (4-5 foliar applications) and NIL (no insecticide), over two consecutive seasons' harvest (2010 and 2011). In both years work there was a consistent substantial yield reduction from the FULL to the REDUCED insecticide to the NIL insecticide treatment. In most cases a similar trend was seen in dry matter and tuber size. ZC severity recorded in crisp slices before and after frying tended to be highest in the NIL insecticide treatment and lowest in the FULL insecticide treatment. The fresh market cultivar 'Nadine' had very little ZC in any raw tubers of any of the insecticide treatments in either season. Despite this the marketable yield of Nadine with NIL insecticide was almost half that of the FULL insecticide treatment in 2010 and about 60 % of the intensive insecticide level in 2011. There was no real indication that any of the other cultivars in the trial had any effective resistance to TPP or ZC. [ABSTRACT FROM AUTHOR]

Behaviours of insects can be manipulated by transmitting vibrational signals to host plants in order to develop pest management techniques. Bactericera cockerelli is an important pest and uses vibrations for mate-finding. In order to design a future control strategy for B. cockerelli, three different bioassays were performed to assess whether vibrational signals could affect relevant behaviours. Single males or pairs were treated with a female playback in test 1 and 2, respectively. In test 3, mixed sex groups received either different disturbance playbacks. The use of a female playback significantly reduced the mating success of males, since they were attracted towards the source of the stimulus. Moreover, test 2 revealed that B. cockerelli females are competitive, since they used their signals to cover the playback and to duet with males, while in test 3, the disturbance playback, consisting of broadband noises significantly reduced male signalling activity. However, none of the treatments of test 3 negatively affected the mating success of males, which tended to mount the other conspecifics present on the same leaf. The role of vibrations in sexual communication and their potential application as control technique for B. cockerelli are discussed as well. [ABSTRACT FROM AUTHOR]