Journal of Applied Entomology最新文献

Pest attack is an important biotic threat to sorghum productivity, and one of the main insect pests of grain sorghum is sugarcane borer (SCB) Diatraea saccharalis. Despite the importance of this insect species, little is known about the relationship between SCB infestation and reduction in sorghum grain yield, as well as on the gain threshold and economic injury level for decision making of pest control. This study evaluated the influence of SCB infestation on plant performance and grain production in three commercial grain sorghum hybrids. Hybrids AG1090, BRS 373, and DKB 590 were planted in three crop seasons in Sete Lagoas, Brazil, and six treatments were assessed in the experiments, consisting of three grain sorghum hybrids with and without the insecticide chlorantraniliprole at 52.5 g a.i. ha⁻¹ under SCB natural infestation. The parameters evaluated on sorghum plants were the length of tunnels, plant height, length and weight of panicles, stem borer injury, and grain yield. The infestation of SCB was higher when sorghum plants were not treated with insecticide, resulting in lower productivity. The use of insecticide increased plant height, reduced tunnel length, and increased panicle length and weight. Hybrids only affected panicle weight. The hybrid that presented the highest panicle weight when using the insecticide was AG 1090. Hybrids AG 1090 and DKB 590 showed reduced grain production with increasing gallery length, whereas BRS 373 did not show a significant correlation, which may suggest a certain level of tolerance to SCB attack. This is the first study that determines the gain threshold and economic injury level and that effectively shows how much grain yield is lost by SCB attack in grain sorghum hybrids.

The control of pests and diseases is one of the main challenges of sustainable agriculture. Plantains, with an annual production of nearly 12 million tons, are a significant staple food crop in West and Central Africa, as well as in Central America. Cosmopolites sordidus is the major pests for plantains and is present in all production areas. This study assessed how the traits and associated agricultural practices of 12 crops, usually associated with plantains in Cameroun, affected the arthropods trophic network and C. sordidus abundance. The abundance and the diversity of arthropods in experimental plots associating plantains with each of the 12 tested crops were measured. Each associated crop was described by a unique profile of traits and agricultural practices. This ‘trait’ approach allowed linking the plant characteristics to the abundance of arthropods from different trophic groups. Structural equation modelling was used to analyse the interactions between associated crops traits, their associated agricultural practices and the abundance of main trophic groups. The highest abundance of C. sordidus was observed in plots with Ananas comosus and Xanthosoma sagittifolium as associated crops. These plots also had the lowest abundance of omnivores and predators. In contrast, plots with the lowest abundance of C. sordidus were those with weeds and Vigna unguiculata, where more omnivores and predators were observed. Grouping associated crops by their traits and agricultural practices allowed for drawing conclusions on a wider range than the set of plants tested. For instance, this study showed that plants from the higher strata tend to decrease ground-dwelling predators. The ideal crop traits and agricultural practices to maximize the regulation of C. sordidus should not be obtained by a single species of crop but rather by a community of associated crops.

An online survey was conducted from June 2018 to March 2021 to elicit information from commercial farmers and growers on the economic impact of the Brown Marmorated Stink Bug (BMSB) (Halyomorpha halys (Stål)) on agriculture and their attitudes towards adopting various alternative management practices, including use of Trissolcus japonicus as a biocontrol agent. Most respondents reported that BMSB reduced the profitability of their operation, with the largest impacts coming from reduced quality and increased spray cost. Improved monitoring techniques and natural enemies have the greatest probability to be used to manage BMSB, while tactics like attract and kill, border sprays, repellents, trap crops and netting were less likely to be adopted. Further analysis using ordered logistic and tobit regression models shows that the factors that influence potential adoption vary significantly for each management practice. This suggests that adoption efforts for alternate management practices should focus on the attributes of specific commodity groups and targeted educational programmes may be required to overcome the resistance of growers using conventional growing practices. Several variables have a consistent impact on the respondent's willingness to pay for a T. japonicus-based biocontrol including being a commercial producer (positive impact), use of conventional growing practices (negative) and increased concern about the impact of BMSB (positive).

Small hive beetles (SHB), Aethina tumida, are free-flying parasites, which actively seek and invade honeybee host colonies. Previous research suggests that SHB prefer colonies in the shade. Further, it has been stated that SHB invade any colony with equal impunity. Though, the impact of colony aggressiveness on SHB infestation levels has never been quantified. Here, we confirm significantly higher SHB infestation levels in shaded colonies and further suggest that host colony aggression is of minor importance only. In the state of Rio de Janeiro, Brazil, local Africanized honeybee colonies at a sunny (N = 10) and at a shaded apiary (N = 11) were tested for aggression and visually screened for SHB infestations using standard methods. Both colony aggression and infestation levels were variable, but not significantly correlated. The results confirm that infestation levels are significantly higher in the shaded apiary than in the sun-exposed one. However, host colony aggression is unlikely to interfere with SHB infestation levels of colonies. Instead, SHB seem to remain even in aggressive colonies. The underlying mechanisms for the significant differences in colony infestation levels due to sun exposure remain unknown. Beekeepers are advised to prefer sun-exposed apiary locations in regions, where SHB are a pest of concern.

Larvae of chironomids are benthic organisms, having the extreme capability to adapt to the changing physicochemical parameters of the aquatic body and the potentiality to accommodate that adverse situation. In spite of the demand for chironomid larvae as fish food, no proper technique of chironomid farming has been reported till today. This instance encourages the research on farming these larvae, in both open and captive settings. The present research shows a good result all over the year, with seasonal variance along with changing physicochemical parameters. This farming is based on minimal space requirements, reuse of condensate water, and the application of a low-cost diet, resulting in enormous production of this insect. Thus, it can be placed as a small-scale industry to uplift the economic status of rural people. A nutritious diet for both carnivorous and omnivorous fish and low-cost farming with a huge production of these larvae is good for the fish industry as well.

Larvae of Hydrotaea are facultative predators of larvae of flies commonly found in poultry farms, chicken and pig waste, and decaying carcasses. One species, the black dump fly, Hydrotaea aenescens (Wiedemann, 1830), coexists with the housefly Musca domestica (Linnaeus, 1758) in these environments and has been employed in the biological control of the housefly in the USA and Germany. To assess the predatory efficacy of H. aenescens larvae on M. domestica larvae, we conducted controlled laboratory experiments in which we selected larvae of different sizes of the larvae and the densities of both predator and prey. We set up the experiment using adult flies from a poultry farm and reared the larvae they produced in our laboratory. Our findings indicate that second- and third-instar H. aenescens larvae effectively suppressed populations of housefly larvae under laboratory conditions, especially when the latter was smaller or the same size as the former. Under these ideal experimental conditions, a single H. aenescens larva consumed up to 29 larvae of M. domestica, potentially leading to a complete eradication of the housefly population at predator–prey density levels of 1:1 and 1:4, but only when considering both the natural mortality rate of M. domestica larvae and the additional mortality caused by H. aenescens larvae. These results corroborate a pattern previously observed in other predatory larvae and have important implications for biological control and integrated pest management programs targeting M. domestica in poultry and swine farms across South America.

To understand the role of Apis cerana cerana in olive tree (Olea europaea L.) pollination, pollinators and pollen carried by bees were collected from 11 experimental plots during the flowering period. The abundance and diversity of pollen plant species were investigated using DNA metabarcoding. A total of 583 pollinators were collected and A. cerana cerana accounts for 46.83%. Further analysis revealed a total of 56 families, 136 genera and 195 plant species in bee pollens. O. europaea is the dominant species accounting for 42.02 ± 34.89% and then followed by Sedum japonicum (8.70 ± 16.42%). Diversity index showed that the abundance and diversity of pollen plant species were the highest in Wanzhou (WZ) and lowest in Hechuan (HC). This suggests that Wanzhou sample plot has a greater abundance of plant species to supplement the bee diet. Excessive presence of miscellaneous flowering plants in olive plantations can distract bees from collecting olive tree pollens. Therefore, their abundances can be reduced appropriately while ensuring food diversity for the bees. Based on the abundance of plants in pollens, we recommend that appropriately planting of S. japonicum, Youngia japonica and Vicia villosa in olive plantations with fewer flowering plants could be an effective supplement of bee food. Our results not only contribute to future studies on olive tree pollination but also provide new ideas for enriching flowering plants in or around olive plantations.

The oriental fruit fly (Bactrocera dorsalis) is an exceptionally hazardous pest that can cause up to 100% loss. Male annihilation using male attractant methyl eugenol (ME) is the most adopted control measure of this insect. The molecular process underlying this perception of insects remains unexplored. In this study, we focus on gene functionality of odorant-binding protein 13 (OBP13) in ME perception by knockout using CRISPR/Cas9 mediated embryonic editing through microinjection. The electrophysiological study of mutant flies through electroantennogram has shown highly depressed ME perception and further the genetic-level mutational confirmation stating that OBP13 is a major OBP involved in ME perception. The molecular docking of OBP13 with ME revealed the predicted key interactions involved, thus providing more scope in targeting gene editing and in engineering ME substitutes.

The tomato potato psyllid, Bactericera cockerelli Šulc, originating from North and Central America, poses a serious threat to Solanaceae crops in Australia. This study investigates the potential of the Australian native and commercially available green lacewing, Mallada signatus Schneider, as a biological control agent for B. cockerelli. The effect of feeding on B. cockerelli on the development rate and survival, of M. signatus were evaluated. Further, a greenhouse cage study was conducted to determine the optimal density of M. signatus larvae needed to effectively control an established B. cockerelli population. In our study, the third instar larvae of M. signatus consumed over 75 B. cockerelli nymphs in 24 h. Following the introduction of M. signatus larvae to caged tomato plants, eight M. signatus larvae per caged tomato plant decreased B. cockerelli population by 64% at the end of the sampling. These results indicated M. signatus, particularly at the larval stage, is an effective biological control option for B. cockerelli, especially in greenhouse tomato cultivation. This research offers valuable insights for the Australian horticultural industry, presenting a viable, eco-friendly alternative to traditional, chemical pesticide-reliant pest management strategies.

Honeydew, a sugary excretion produced by sap-feeding insects, plays a pivotal role in shaping intricate interactions between insects and plants. This review explains the multifaceted aspects of honeydew, beginning with an overview of its production mechanisms and factors influencing its variability across insect species and plant hosts. Exploring its composition, we examine the chemical components and nutritional aspects, highlighting variations based on insect species and plant sources. The impact of honeydew on microbial communities is explored, shedding light on its role in influencing the diversity and abundance of microorganisms. Furthermore, the review investigates how honeydew affects pest behaviour and population dynamics, elucidating plant responses to honeydew deposition. In the realm of biocontrol, we examine the intricate relationships between honeydew and natural enemies, considering potential implications for integrated pest management. Beyond these individual components, the paper discusses the broader ecological consequences of honeydew in ecosystems, emphasizing the interconnected relationships between insects, plants and microorganisms. The review concludes by identifying research gaps and suggesting future directions, recognizing the need for further investigation into areas with potential applications for agriculture and ecology. This review provides a comprehensive synthesis of the current understanding of honeydew's significance in insect–plant interactions, offering insights for both researchers and practitioners in the field.