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1 Accurate assessment of the impact of natural enemies on pest populations is fundamental to the design of robust integrated pest management programmes. In most situations, diseases, predators and parasitoids act contemporaneously on insect pest populations and the impact of individual natural enemies, or specific groups of natural enemies, is difficult to interpret. These problems are exacerbated in agro-ecosystems that are frequently disrupted by the application of insecticides.2 A combination of life-table and natural enemy exclusion techniques was utilized to develop a method for the assessment of the impact of endemic natural enemies onPlutella xylostellapopulations on commercialBrassicafarms.3 At two of the experimental sites, natural enemies had no impact onP. xylostellasurvival, at two other sites, natural enemy impact was low but, at a fifth site, natural enemies drastically reduced theP. xylostellapopulation.4 The calculation of marginal death rates and associatedk-values allowed the comparison of mortality factors between experimental sites, and indicated that larval disappearance was consistently the most important mortality factor, followed by egg disappearance, larval parasitism and pupal parasitism. The appropriateness of the methods and assumptions made to calculate the marginal death rates are discussed.5 The technique represents a robust and easily repeatable method for the analysis of the activity of natural enemies ofP. xylostella, which could be adapted for the study of other phytophagous pests. [ABSTRACT FROM AUTHOR]

We evaluated the role of the larval parasitoid, Diadegma semiclausum Hellén (Hymenoptera: Ichneumonidae), in controlling Plutella xylostella (L.) (Lepidoptera: Plutellidae) by cage exclusion experiments and direct field observation during the winter season in southern Queensland, Australia. The cage exclusion experiment involved uncaged, open cage and closed cage treatments. A higher percentage (54-83%) of P. xylostella larvae on sentinel plants were lost in the uncaged treatment than the closed (4-9%) or open cage treatments (11-29%). Of the larvae that remained in the uncaged treatment, 72-94% were parasitized by D. semiclausum , much higher than that in the open cage treatment (8-37% in first trial, and 38-63% in second trial). Direct observations showed a significant aggregation response of the field D. semiclausum populations to high host density plants in an experimental plot and to high host density plots that were artificially set-up near to the parasitoid source fields. The degree of aggregation varied in response to habitat quality of the parasitoid source field and scales of the manipulated host patches. As a result, density-dependence in the pattern of parasitism may depend on the relative degree of aggregation of the parasitoid population at a particular scale. A high degree of aggregation seems to be necessary to generate density-dependent parasitism by D. semiclausum . Integration of the cage exclusion experiment and direct observation demonstrated the active and dominant role of this parasitoid in controlling P. xylostella in the winter season. A biologically based IPM strategy, which incorporates the use of D. semiclausum with Bt, is suggested for the management of P. xylostella in seasons or regions with a mild temperature. [ABSTRACT FROM AUTHOR]

Field surveys of egg parasitoids of the diamondback moth, Plutella xylostella, were conducted at Redlands and Gatton, south-east Queensland. Eggs of P. xylostella were present all year round in both localities, and parasitized eggs were consistently found between late spring and early winter. Percent parasitism in the range 30–75% was recorded on many occasions, although rates less than 10% were more common. The major parasitoids included Trichogrammatoidea bactrae Nagaraja and Trichogramma pretiosum Riley. Laboratory evaluation showed that the T. pretiosum from Gatton has a high capacity to parasitize P. xylostella eggs under suitable conditions. This study represents the first record of egg parasitoids of P. xylostella from Australia. [ABSTRACT FROM AUTHOR]

Elevated jasmonic acid (JA) concentrations in response to herbivory can induce wounded plants to produce defences against herbivores. In laboratory and field experiments we compared the effects of exogenous JA treatment to two closely related cabbage species on the host-searching and oviposition preference of the diamondback moth (DBM), Plutella xylostella. JA-treated Chinese cabbage ( Brassica campestris) was less attractive than untreated Chinese cabbage to ovipositing DBM, while JA-treatment of common cabbage ( B. oleracea) made plants more attractive than untreated controls for oviposition by this insect. Similar effects were observed when plants of the two species were damaged by DBM larvae. In the absence of insect-feeding, or JA application, Chinese cabbage is much more attractive to DBM than common cabbage. Inducible resistance therefore appears to occur in a more susceptible plant and induced susceptibility appears to occur in a more resistant plant, suggesting a possible balance mechanism between constitutive and inducible defences to a specialist herbivore. [ABSTRACT FROM AUTHOR]

Field trials and laboratory bioassays were undertaken to compare the performance and efficacy (mortality of diamondback moth larvae) of insecticides applied to cabbages with three high volume hydraulic knapsack sprayers (NS-16, PB-20 and Selecta 12V) and a controlled droplet application (CDA) sprayer. In field experiments, the high volume knapsack sprayers (application rate 500 - 600 L ha  - 1 ) provided better spray coverage on the upper and lower surfaces of inner leaves, the upper surfaces of middle and outer leaves, and greater biological efficacy than the CDA sprayer (application rate 20∼40 L ha  - 1 ). The PB-20 provided better spray coverage on the upper surface of middle leaves and both surfaces of outer leaves when compared with the Selecta 12V. However, its biological efficacy in the field was not significantly different from that of the other high volume sprayers. Increasing the application rate from 20 to 40 L ha  - 1 for the CDA sprayer significantly increased droplet density but had no impact on test insect mortality. Laboratory evaluations of biological efficacy yielded higher estimates than field evaluations and there was no significant difference between the performance of the PB-20 and the CDA sprayer. Significant positive relationships were detected between insect mortality and droplet density deposited for both the PB-20 and the CDA sprayers. [ABSTRACT FROM AUTHOR]

Spiders are among the most abundant predators recorded in grain crops in Australia. They are voracious predators, and combined with their high abundance, may play an important role in the reduction of pest populations. The significance of spider assemblages as biological control agents of key pests such as Helicoverpa spp. in Australian agroecosystems is largely unknown. A thorough inventory was made of the spider fauna inhabiting unsprayed soybean fields at Gatton, south-east Queensland. One-hundred-and-two morphospecies from 28 families were collected using vacuum sampling and pitfall traps across two summer seasons (2000–01, 2001–02). No-choice feeding tests in the laboratory, using eggs and larvae of Helicoverpa armigera (Hübner) as prey, were used to ascertain the predatory potential of each spider group. The field-collected spider assemblage ate on average 2.4 (±0.7 standard error) to 5.0 (±0.8) eggs per 24 h per spider (10–25% of those available), depending on level of starvation. Clubionidae were the only spiders to readily consume eggs in the laboratory (mean of 18.4 ± 1.5 eggs per starved spider and 8.2 ± 3.9 per non-starved spider after 24 h). Starved spiders consumed 9.4 (± 0.1) first-instar larvae per 24 h per spider (90% of those available). This information was combined with field observations and literature from Australian and overseas studies to assess the potential of spider groups as predators of Helicoverpa spp. Lycosidae, Clubionidae, Oxyopidae, Salticidae and Thomisidae have the capacity to contribute to control of Helicoverpa spp. [ABSTRACT FROM AUTHOR]

Simple Summary: Insect pest resistance to synthetic insecticides is a major problem that limits efficient management and thus decreases productivity for farmers and increases the use of harmful materials that pollute the environment and endanger humans and beneficial organisms. A major approach for resistance management is understanding how insect pest field populations develop resistance at molecular levels. To provide a comprehensive insight into the resistance mechanisms of Spodoptera frugiperda larvae to lambda-cyhalothrin 5%, we investigated the molecular basis of resistance mechanism in field collected population of fall armyworm (Spodoptera frugiperda) to lambda-cyhalothrin 5% insecticide, a pyrethroid insecticide by using de novo transcriptomics analysis. We found that resistance to lambda-cyhalothrin 5% can be metabolic by increasing the levels of detoxifying enzymes such as P450, GST and UGT and related genes to insecticide resistance in the field population. The obtained transcriptome information provides large gene resources available for further studying the resistance development of Spodoptera frugiperda to pesticides. The DGE data provide comprehensive insights into the gene expression profiles of fall armyworm (Spodoptera frugiperda) to lambda-cyhalothrin 5% and will facilitate the study of the role of each gene in lambda-cyhalothrin resistance development. The fall armyworm, Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae), is a polyphagous, invasive insect pest which causes significant losses in important crops wherever it has spread. The use of pesticides in agriculture is a key tool in the management of many important crop pests, including S. frugiperda, but continued use of insecticides has selected for various types of resistance, including enzyme systems that provide enhanced mechanisms of detoxification. In the present study, we analyzed the de novo transcriptome of S. frugiperda larvae exposed to Noposion Yihaogong® 5% emulsifiable concentrate (EC) insecticide focusing on detoxification genes and related pathways. Results showed that a total of 1819 differentially expressed genes (DEGs) were identified in larvae after being treated with Noposion Yihaogong® 5% EC insecticide, of which 863 were up- and 956 down-regulated. Majority of these differentially expressed genes were identified in numerous Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways, including metabolism of xenobiotics and drug metabolism. Furthermore, many of S. frugiperda genes involved in detoxification pathways influenced by lambda-cyhalothrin stress support their predicted role by further co-expression network analysis. Our RT-qPCR results were consistent with the DEG's data of transcriptome analysis. The comprehensive transcriptome sequence resource attained through this study enriches the genomic platform of S. frugiperda, and the identified DEGs may enable greater molecular underpinnings behind the insecticide-resistance mechanism caused by lambda-cyhalothrin. [ABSTRACT FROM AUTHOR]

Simple Summary: Walnut aphids are major pests of walnut orchards with few commercially available natural enemies except parasitoids. The predatory bug (Orius sauteri) was assessed as a potential biological control agent against two walnut aphid species. This bug has a strong capacity for consuming both aphid species. Biocontrol efficacy of O. sauteri for each species was high (more than 70%), but declined about 20% when both aphid species present on the same leaf together. This might be due to the competition among two species of aphids tested. Three statistical approaches were employed to show that O. sauteri is a promising biocontrol agent. The commercial release of O. sauteri should be considered for the coexisting aphids in walnut orchards to promote economic and environmental benefits. Walnut aphids are major pests of walnut production with few commercially available natural enemies. We conducted laboratory and field experiments to evaluate the potential of Orius sauteri Poppius (Anthocoridae), a predatory bug, as a biological control agent against two walnut aphid species: the dusky-veined aphid (Panaphis juglandis Goeze) and the walnut aphid (Chromaphis juglandicola Kaltenbach). Both species co-occur on walnut trees; P. juglandis is distributed on the upper surface (adaxial) of leaves while C. juglandicola is found on the lower surface (abaxial) of leaves. Based on functional response experiments, O sauteri had a strong capacity for consuming both aphid species. Biocontrol efficacy of O. sauteri for each species in the laboratory and field experiments was high, 77% for P. juglandis and 80% for C. juglandicola, regardless if one or two predators being present. However, biocontrol efficacy declined 15–25% for C. juglandicola and 20–50% for P. juglandis when both aphid species were present on the same leaf. The efficacy of O. sauteri under (semi)-field conditions gave similar findings based on the percentage reduction of aphids and change in population growth rates of aphids. The reduced biocontrol efficacy of the predatory bug against mixed species populations of aphids can be explained by competition between the aphid species and differences in their preferred location on leaves. Our experiments showed that O. sauteri is a promising biocontrol agent, but biocontrol efficacy may decline when both aphid species are present on walnut trees. This should be considered in the commercial release of O. sauteri in walnut orchards to promote economic and environmental benefits of walnuts production. [ABSTRACT FROM AUTHOR]

Presents a study which looked at the influence of experience on both pre- and post-alighting host selection in adult female Helicoverpa armigera. Detailed information on the methodology used to conduct the study; Discussion based on the results of the study.

• Ophryocystis elektroscirrha was detected in Lepidoptera other than the genus Danaus. • O. elektroscirrha showed a higher host specificity in D. plexippus and lower host specificity in Helicoverpa armigera. • Geographic variation was found in susceptibility of H. armigera populations to O. elektroscirrha. Many parasites are constrained to only one or a few hosts, showing host specificity. It remains unclear why some parasites are specialists and other parasites are generalists. The parasite Ophryocystis elektroscirrha (OE) is a neogregarine protozoan thought to be restricted to monarch butterflies, Danaus plexippus (Nymphaliae) and D. gilippus. Recently, we found OE-like spores in other Lepidoptera, specifically in three noctuid moths: Helicoverpa armigera , H. assulta and H. punctigera , as well as another nymphalid, Parthenos sylvia. To our knowledge, this is the first report of OE-like parasite infections in species other than the genus Danaus. In sequencing 558 bp of 18S rRNA, we found the genetic similarity between OE from D. plexippus and OE-like parasite from the moths H. armigera and H. punctigera to be 95.2%. When we conducted cross-species infection experiments, we could not infect the moths with OE from D. plexippus , but OE-like parasite from H. armigera did infect D. plexippus and a closely related moth species Heliothis virescens. Interestingly, we did not find the OE-like parasite in the H. armigera population from Spain. Inter-population infection experiments with H. armigera demonstrated a higher sensitivity to OE-like infection in the population from Spain compared to the populations from Australia and China. These results suggest geographic variation in OE-like susceptibility and coevolution between parasite and host. Our findings give important new insights into the prevalence and host specificity of OE and OE-like parasites, and provide opportunities to study parasite transmission over spatial and temporal scales. [ABSTRACT FROM AUTHOR]

True setae borne on the abdominal tergites of Ochrogaster lunifer Herrich-Schӓffer caterpillars are the agents of an irritating contact dermatitis, osteomyelitis, ophthalmia, and severe allergic reactions in humans, and are the cause of Equine Amnionitis and Fetal Loss in Australia. The setae are detached and readily dislodge from the integument whereby they disperse throughout the environment. To better understand the true setae of O. lunifer as agents of medical and veterinary concern, we studied their characteristics and distance dispersed. Whereas members of the European Thaumetopoeinae have been widely studied, their southern-hemisphere counterparts such as O. lunifer are not well known despite their harmfulness and known medical and veterinary importance. The caterpillar's investment in true setae increased with age and size, and two distinct size classes co-occurred in setae fields. A previously undescribed morphological type of true seta was found on the first abdominal segment. All true setae were calculated to travel long distances in the air even under light breeze conditions. Our results show there is a high risk of exposure to airborne urticating setae within 100 m of elevated caterpillar activity, and a likely risk of exposure for some kilometers in the direction of the prevailing breeze. This information should be used to inform management strategies in areas where urticating processionary caterpillars are active, and especially during periods of an outbreak. [ABSTRACT FROM AUTHOR]

• P. persimilis showed fine life history traits on the susceptible cucumber cultivar. • The resistant cultivar supported more P. persimilis to have higher predation. • Combination of resistant cucumber cultivar and P. persimilis is offered against TSSM. Tritrophic interactions can provide important insights for improving the efficacy of pest control programs. We studied three cucumber, Cucumis sativus , cultivars for their effects on the life table and predation parameters of the predatory mite, Phytoseiulus persimilis Athias–Henriot, when feeding on eggs and nymphs of the two-spotted spider mite (TSSM), Tetranychus urticae Koch. These cultivars were TSSM-susceptible (cv. Vida), semi-resistant (cv. Sultan), and resistant (cv. Caspian). Under laboratory conditions, the intrinsic rate of increase (r) and net reproductive rate (R 0) of P. persimilis was significantly higher on the susceptible cultivar than on the resistant ones. In contrast, the age-stage-specific predation rate (c xj), net predation rate (c 0) and finite predation rate on the resistant cultivar were all higher than on the semi-resistant or susceptible ones. Although the susceptible cultivar produced the most favorable life table parameters for P. persimilis , the resistant cultivar supported more P. persimilis individuals and had higher levels of predation on TSSM. Resistant cultivars in combination with P. persimilis can improve control of TSSM on cucumber, despite some negative life history impacts on the predator. [ABSTRACT FROM AUTHOR]

Insect herbivores can modify their foraging behavior to obtain a balanced food intake, and they tend to move between food sources with different nutrient values. We investigated this movement in early instar larvae of Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) using a putative optimal artificial diet (OP) and high protein (HP) and high carbohydrate (HC) artificial diets based on protein (p) and carbohydrate (c) ratios. Larvae were allowed to choose between the same kind of diet cubes (effectively no-choice), or diet cubes with different p: c ratios. In no-choice tests, we found that first instar larvae remained longest on OP diet and spent the least time on HC diet, while third instar larvae remained longest on HC diet and spent least time on OP diet. First instar larvae moved the most when provided with HC diet, while third instar larvae moved most when provided with OP diet. However, both stages moved the least when allowed to choose between diet cubes with different p: c ratios. The relative growth rate decreased when larvae increased their movement, but this influence was not evident when larvae fed on HC diet. Larvae that fed only on HC diet had the highest relative growth rate, followed by larvae with access to all diets simultaneously, indicating a behavior to mix nutrient intake. We relate these findings to behavior of this major pest species under field conditions. [ABSTRACT FROM AUTHOR]

The article "Making people buy and eat differently": lessons from the modernization of small independent grocery stores in the early twentieth century written by Frank Cochoy, was originally published electronically on the publisher's internet portal (currently SpringerLink) on 29 June 2017. [ABSTRACT FROM AUTHOR]

Diamondback moth (Plutella xylostella) is a globally significant pest of Brassicaceae crops that has attracted enormous research investment. It is typical of many agricultural pests, with insecticides remaining the most common method of control, despite frequent cases of resistance in pest populations and the potential for other management options such as natural enemies to provide suppression. Here we review scope to make better use of neglected natural enemy taxa and integrate recent work on landscape ecology to identify opportunities for more effective pest suppression. Our main findings are as follows: (1) relatively neglected taxa of natural enemies, especially predators and entomopathogens, are now attracting growing levels of research interest, although parasitoids remain most frequently used and researched; (2) knowledge of the spatio-temporal dynamics of populations at the landscape scale have advanced rapidly in the last decade; (3) ecological insights open new possibilities for exploiting spatial heterogeneity at scales larger than individual fields and even farms that influence pests and their natural enemies; (4) there is evidence for landscapes that selectively favor particular guilds and this knowledge could be developed to favor targeted natural enemies over pests in focal crops; and (5) landscape-scale effects can even over-ride field-scale management practices. The significance of these advances is that future management of diamondback moth and similar pests will benefit from a move away from reliance on the use of particular species of biological control agents, especially exotic parasitoids, and strategies that depend on use of broad-spectrum insecticides. Together with this move, we call for greater use of area-wide management that exploits the potential of landscapes to promote diverse assemblages of natural enemy species. [ABSTRACT FROM AUTHOR]

Plants are sessile, so have evolved sensitive ways to detect attacking herbivores and sophisticated strategies to effectively defend themselves. Insect herbivory induces synthesis of the phytohormone jasmonic acid which activates downstream metabolic pathways for various chemical defences such as toxins and digestion inhibitors. Insects are also sophisticated animals, and many have coevolved physiological adaptations that negate this induced plant defence. Insect behaviour has rarely been studied in the context of induced plant defence, although behavioural adaptation to induced plant chemistry may allow insects to bypass the host's defence system. By visualizing jasmonate-responsive gene expression within whole plants, we uncovered spatial and temporal limits to the systemic spread of plant chemical defence following herbivory. By carefully tracking insect movement, we found induced changes in plant chemistry were detected by generalist Helicoverpa armigera insects which then modified their behaviour in response, moving away from induced parts and staying longer on uninduced parts of the same plant. This study reveals that there are plant-wide signals rapidly generated following herbivory that allow insects to detect the heterogeneity of plant chemical defences. Some insects use these signals to move around the plant, avoiding localized sites of induction and staying ahead of induced toxic metabolites. [ABSTRACT FROM AUTHOR]