Beneficial Insect Populations Research Articles

Seminatural areas act as reservoirs of genetic diversity for crop pollinators and natural enemies across Europe

AbstractDespite increasing recognition of the importance of the multiple dimensions of biodiversity, including functional or genetic diversity as well as species diversity, most conservation studies on ecosystem service‐providing insects focus on simple diversity measures such as species richness and abundance. In contrast, relatively little is known about the genetic diversity and resilience of pollinators or natural enemies of crop pests to population fragmentation and local extinction. The genetic diversity and demographic dynamics of remnant populations of beneficial insects in agricultural areas can be a useful indicator proving additional insights into their conservation status, but this is rarely evaluated. Although gene flow between agricultural and seminatural areas is key to maintaining genetic diversity, its extent and directionality remain largely unexplored. Here, we apply a pan‐European sampling protocol to quantify genetic diversity and structure and assess gene flow between agricultural and nearby seminatural landscapes in populations of two key ecosystem service‐providing insect species, the lady beetle Coccinella septempunctata, an important predator of aphids and other crop pests, and the bee pollinator Andrena flavipes. We show that A. flavipes populations are genetically structured at the European level, whereas populations of C. septempunctata experience widespread gene flow across the continent and lack any defined genetic structure. In both species, we found that there is high genetic connectivity between populations established in croplands and nearby seminatural areas and, as a consequence, they harbor similar levels of genetic diversity. Interestingly, demographic models for some regions support asymmetric gene flow from seminatural areas to nearby agricultural landscapes. Collectively, our study demonstrates how seminatural areas can serve as genetic reservoirs of both pollinators and natural enemies for nearby agricultural landscapes, acting as sources for recurrent recolonization and, potentially, contributing to enhancing ecosystem service and crop production resilience in the longer term.

Evaluation of Spring-type and Winter-type Brassica napus Germplasm for Genetic Diversity in Response to Flea Beetle Herbivory in Typical and Atypical Planting Windows

Current practices of flea beetle [Phyllotreta spp.] control in Brassica napus L. rely heavily on seed treatments and due to growing concerns regarding the safety of such treatments on non-target and beneficial insect populations, genetic resistance would be beneficial for a more balanced integrated pest management strategy. However, none of the registered B. napus. canola varieties exhibit measurable resistance to flea beetle injury. To this end, an evaluation of 14 winter-type B. napus breeding lines and 15 spring-type B. napus breeding lines for resistance to flea beetle feedings was conducted, as it was found that at least one line in each family exhibited noticeably reduced flea beetle damage compared to sister lines in a breeding nursery. The study revealed natural genetic variation within B. napus for flea beetle antixenosis which could be used by dedicated breeders to develop canola varieties with higher levels of flea beetle resistance. Data indicated that host plant resistance did not vary between feeding by newly emerged adult flea beetles in the fall and the overwintered adults in the spring in either winter-type or spring-type canola, as well as for adult feeding preferences. This indicates that favourable genes identified in in either habitat-type could be used interchangeably to confer resistance even though the flea beetle life cycle is different for each planting period, while either overwintered adults or newly emerged adults can be used to evaluate feeding damage.

Mycovirus: Biocontrol agent against S. sclerotiorum of Rapeseed

Plant disease control is one of the essential aspects of food production Use of pesticide causes severe damage to our environment and have terrible effects on human health. It has been observed that the abundance use of pesticides also disturbs natural populations of various beneficial insects. Now environmental pollution has become a global problem, and due to the negative effect of chemical control, we must focus on new methods to control plant diseases, and the best of them is to use biological control method; this method includes the use of various beneficial microorganism having the potential to control plant diseases. Viruses that infect fungi are called as mycoviruses, and some of them could confer hypovirulence and thus have the capacity to control fungal diseases. Sclerotinia sclerotiorum, a widespread ascomycete fungus, can attack more than 450 plant species and subspecies. It causes stem rot on rapeseed and leads to substantial economic loss each year. Previously, several hypovirulence-associated mycoviruses have been identified from S. sclerotiorum, suggesting that this fungus could host various mycoviruses. Keywords: Biological control, Hypovirulence, Mycovirus, Sclerotinia sclerotiorum, RNA-seq, virus transmission

Effects of Integrated Pest Management (IPM) Practice on Insects Population and Yield of Cabbage in Cameron Highlands

Plutella xylostella is the main pest of cruciferous plants which are widely planted in Cameron Highlands. This pest attack causes losses of up to 90% to farmers. To overcome this problem, most farmers use synthetic chemical pesticides intensively and exceed the prescribed dose. This situation causes pollution to the environment and endangers the health of consumers due to the effects of toxic residues on harvested vegetables. In addition, excessive use of insecticide will increase the insect's immunity to the insecticide, and this will reduce the effectiveness of the insecticide in the future. If this happens, farmers will incur losses because they have to use insecticides at a higher rate or use insecticides that are much more expensive. This study evaluates the effect of using integrated pest management (IPM) methods in MARDI Cameron Highlands cabbage fields in terms of insect population distribution whether pests or natural enemies and cabbage yield for each season. In this study, there were two treatments which were IPM and conventional grown cabbage. Each treatment has 5 replications and was repeated for three seasons. For IPM treatment, pesticide spraying was determined through evaluation of natural pests and enemies found in cabbage on a weekly basis. IPM treatment also uses yellow and blue sticky traps as well as biological control agents to control pests. Monitoring of pest and beneficial insect populations was carried out once every 2 weeks using the direct count and sweeping net method. The name and number of acquired species of insects were recorded in the scoresheet. The harvested cabbage is weighed, and the yield was recorded. The results of the study show that the use of IPM methods in cabbage fields has a positive effect on the interaction between pest populations and natural enemies, and the quality of the harvest also does not show qualitative and quantitative differences compared to conventional cultivation.

Microclimate Refugia: Comparing Modeled to Empirical Near-Surface Temperatures on Rangeland

Microhabitats can provide thermal niches that affect geographic range shifts of species as the climate changes and provide refuges for pest and beneficial insect populations in agricultural regions. The spatial distribution of microhabitats is influenced by topography that can influence local extinction and recolonization by animal populations. Scaling local temperature-dependent processes to a regional scale of population expansion, and contraction requires the validation of biophysical models of near surface temperatures. We measured temperature at 2.5 cm above and below ground at 25 sites in each of the two regions: southern and northern Utah, USA. Using NichMapR version 3.2.0, we modeled the temperature at these same sites with local slopes and aspects for four years for the former and eight years for the latter region. Empirical and modeled air temperatures differed by 7.4 °C, on average, and soil temperatures differed less (4.4 °C, on average). Site-specific additions of hill shading at 25 m distance or soil parameters did not improve the agreement of the empirical and modeled temperatures. A hybrid model for air temperature that incorporated soil temperature at 0 cm depth when snow depth exceeded 3 cm resulted in an average improvement of 8% that was as great as 31%. Understanding biological processes at the regional scale and in projected future climates will continue to require biophysical modeling. To achieve the widest applications possible, biophysical models such as NichMapR need to be validated with empirical data from as wide a variety of altitudes, latitudes, soil types, and topographies wherein organisms currently inhabit and where their ranges might expand to in the future.

Importance of Biotechnology in Controlling Insect Pests

Agriculture is considered an important source of national income for a lot of countries and most of inhabitants of these countries are dependent on farming for their food. Insects have been one of the most important sources of food production damage, accounting for 20% to 30% of global production losses. Approximately 67,000 insect species are thought to inflict harm to plantations and tropical regions, which are often the poorest in the world and are hit hardest by insect pests. Agriculture spends billions of dollars each year on insect control around the world. Pesticide use has resulted in pesticide-resistant insects, a drop in beneficial insect populations, and a slew of other negative effects for humans and the environment. These concerns have led researchers to consider a different approach in order to produce more environmentally friendly insect control tactics that use both synthetic and natural chemicals. The use of bio-pesticides in pest management has been increasing in recent years. There are three types of the ecofriendly management agents bio-pesticides have been identified as follows: bio-control organisms (pathogenic microorganism, predators and parasites); plant-incorporated protectants (transgenic Bt toxin); and biochemical pesticides (botanical pesticides and other natural compounds. Most of chemical companies such as Monsato, Dupont, and Ciba Geigy, are now promoting biotechnology as a strategy to ensure high productivity, these companies invests millions of dollars in biotechnology research to develop genetically modified crops, animals, and microorganisms to combat pests, produce fertilizer, and improve efficiency. Where they uploaded this businesses and scientific institutions are the slogans that biotechnology is the future of agriculture.

Economic benefits of conservation biocontrol: A spatially explicit bioeconomic model for insect pest management in agricultural landscapes

Spatially explicit population dynamic models have been successfully used to explore management scenarios in terms of pest suppression across a wide range of systems. However, the economic implications of pest management, particularly in the case of biological control and non-crop management strategies, have not been well considered. A bioeconomic spatially explicit simulation model was developed, that integrates models of pest population dynamics, pest movement and economics of management. The utility of the model is demonstrated here usingNysius vinitor, a pest of grain crops in Australia. The model estimates the short- and long-term economic benefits of three pest management strategies: (1) in-field pesticide spray; (2) pest suppression through weed management in non-crop habitat; and (3) bolstering biocontrol through revegetation with, or maintenance of, native vegetation. Across all management types, high yield and low relative management cost resulted in a greater chance of a gross profit. The impacts of the pests themselves were shown to be non-linear, with an intermediate level of pest pressure maximizing the economic gain from management. Pest dispersal capacity influenced the profitability of management of non-crop vegetation, with lower pest dispersal resulting in a greater likelihood of benefit, as benefits from non-crop management are localized (e.g., increased beneficial insect populations). In an intensively cropped landscape, pesticide management was most profitable over the short-term. Once a 10-year horizon was reached, then the profitability of revegetation was greater and continued to increase. While weeding requirements are low, it is likely to always be profitable in the long-term to maintain or restore native vegetation in good condition to control this pest in an intensively cropped landscape. Using pesticide alongside revegetation gave some short-term gain, but the negative impact of pesticide on beneficials outweighed the benefit and in the long-term it is less profitable. These results do not hold in a low production landscape, due to increased pest pressure and costs of managing non-crop habitat. In summary, when quantified over a 10–20 year time horizon, revegetation or conserving native remnants in good (i.e., non-weedy) condition could be economically more beneficial to control an insect pest than ongoing pesticide use, in intensively cropped landscapes.

Signatures of increasing environmental stress in bumblebee wings over the past century: Insights from museum specimens.

Determining when animal populations have experienced stress in the past is fundamental to understanding how risk factors drive contemporary and future species' responses to environmental change. For insects, quantifying stress and associating it with environmental factors has been challenging due to a paucity of time-series data and because detectable population-level responses can show varying lag effects. One solution is to leverage historic entomological specimens to detect morphological proxies of stress experienced at the time stressors emerged, allowing us to more accurately determine population responses. Here we studied specimens of four bumblebee species, an invaluable group of insect pollinators, from five museums collected across Britain over the 20th century. We calculated the degree of fluctuating asymmetry (FA; random deviations from bilateral symmetry) between the right and left forewings as a potential proxy of developmental stress. We: (a) investigated whether baseline FA levels vary between species, and how this compares between the first and second half of the century; (b) determined the extent of FA change over the century in the four bumblebee species, and whether this followed a linear or nonlinear trend; (c) tested which annual climatic conditions correlated with increased FA in bumblebees. Species differed in their baseline FA, with FA being higher in the two species that have recently expanded their ranges in Britain. Overall, FA significantly increased over the century but followed a nonlinear trend, with the increase starting c. 1925. We found relatively warm and wet years were associated with higher FA. Collectively our findings show that FA in bumblebees increased over the 20th century and under weather conditions that will likely increase in frequency with climate change. By plotting FA trends and quantifying the contribution of annual climate conditions on past populations, we provide an important step towards improving our understanding of how environmental factors could impact future populations of wild beneficial insects.

Field margins and botanical insecticides enhance Lablab purpureus yield by reducing aphid pests and supporting natural enemies.

Botanical insecticides offer an environmentally benign insect pest management option for field crops with reduced impacts on natural enemies of pests and pollinators while botanically rich field margins can augment their abundance. Here, we evaluated the non‐target effects on natural enemies and pest control efficacy on bean aphids in Lablab of three neem‐ and pyrethrum‐based botanical insecticides (Pyerin75EC®, Nimbecidine® and Pyeneem 20EC®) and determine the influence of florally rich field margin vegetation on the recovery of beneficial insects after treatment. The botanical insecticides were applied at the early and late vegetative growth stages. Data were collected on aphids (abundance, damage severity and percent incidence) and natural enemy (abundance) both at pre‐spraying and post‐spraying alongside Lablab bean yield. The efficacy of botanical insecticides was similar to a synthetic pesticide control and reduced aphid abundance by 88% compared with the untreated control. However, the number of natural enemies was 34% higher in botanical insecticide‐treated plots than in plots treated with synthetic insecticide indicating that plant‐based treatments were less harmful to beneficial insects. The presence of field margin vegetation increased further the number of parasitic wasps and tachinid flies by 16% and 20%, respectively. This indicated that non‐crop habitats can enhance recovery in beneficial insect populations and that botanical insecticides integrate effectively with conservation biological control strategies. Higher grain yields of 2.55–3.04 and 2.95–3.23 t/ha were recorded for both botanical insecticide and synthetic insecticide in the presence of florally enhanced field margins in consecutive cropping seasons. Overall, these data demonstrated that commercial botanical insecticides together with florally rich field margins offer an integrated, environmentally benign and sustainable alternative to synthetic insecticides for insect pest management and increased productivity of the orphan crop legume, Lablab.

Landscape composition and configuration affect bees in the olive agroecosystem

AbstractOlive groves constitute a landscape that covers a large area in the Mediterranean basin, with essential economic importance, but which can also have environmental importance if an olive grove landscape is designed that favours populations of beneficial insects. Bees are also essential from an economic and environmental viewpoint and are in increasing decline. This work aimed to determine the landscape parameters in the olive agroecosystem that favour bee populations. Fifteen olive groves were sampled in central Spain throughout 2015 and 2016. Bees belonging to 6 families and 24 genera were captured. The most numerous family was Halictidae, and the most numerous genus Lasioglossum. The parameter that mostly affected the abundance and richness of bee genera was the scrubland area (CAMME), with a positive effect. The olive grove area (CAO) had a negative effect in general, although the responses of the different families vary slightly. The configuration of the landscape (MSI) also positively affected bees, which indicates the importance of maintaining linear elements with wild vegetation, to contribute to the maintenance of these important insects. Environmental conditions can affect the importance of olive grove as a supplier of resources for bees, being greater in dry and warm years.

Impact of habitat manipulation on the diversity and abundance of beneficial and pest arthropods in sugarcane ratoon

Abstract. Prabowo H, Rahardjo BT, Mudjiono G, Rizali A. 2021. Impact of habitat manipulation on the diversity and abundance of beneficial and pest arthropods in sugarcane ratoon. Biodiversitas 22: 4002-4010. Sugar production in Indonesia faces several challenges such as infestation of pests and diseases that lead to decline in sugarcane production and productivity. In order to overcome the loss of yields from the presence of pests, alternative new approaches are sought by solving of the problem that can have a sustainable impact by applying habitat manipulation. Habitat manipulation changes the diversity and density of arthropods populations in agro-ecosystem. In the concept of managing agroecosystems with habitat manipulation, it is hoped that the development of agro-ecosystem resilience against pest management will be expected to be suistainable. The results showed that there was an increase in the number of arthropods in the research area for 20 weeks after the management of agro-ecosystems through habitat manipulation. The arthropods in all the traps were dominated by Collembola, Diptera, Coleoptera, Aranea, and Hymenoptera. There were 44 genera that belong to predators and 8 species are belonging to parasitoids. The diversity index of Shannon-Wiener (H '), Simpson Dominance (C) and Species Evenness (E) was not significantly different between treatment and control, but habitat manipulation treatment was able to increase the number of detritivores, predators, parasitoids, and pollinators by 38.81; 43.88; 58.4; and 75.35%. The full role of arthropods in the food chain of the sugarcane ecosystem has been identified and efforts are needed to optimize the role of natural enemies in the agroecosystem to maintain ecosystem stability. Habitat manipulation can increase the number of beneficial insect populations in short run, but it might take time to increase their diversity in agroecosystem.

Comparison of Yellow and Blue Sticky Cards for Detection and Monitoring Parasitoid Wasps of the Invasive Halyomorpha halys (Hemiptera: Pentatomidae).

The invasive Halyomorpha halys (Stål) is a significant agricultural and urban nuisance pest in many parts of the world. In North America, biological control of H. halys by parasitoid wasps in the families Scelionidae and Eupelmidae has shown promise. An effective technique for detection and monitoring native and exotic parasitoids is the deployment of yellow sticky cards; however, yellow cards also attract nontarget arthropods, reducing efficiency and accuracy of parasitoid screening. This study sought to identify an alternative yet effective trapping technique by comparing the number of target parasitoid wasps [Anastatus spp. Motschulsky (Hymenoptera: Eupelmidae), Telenomus spp. Haliday (Hymenoptera: Scelionidae), and Trissolcus spp. Ashmead (Hymenoptera: Scelionidae)] and arthropod bycatch on yellow and blue sticky cards deployed in urban, orchard, and vegetable landscapes in northern Utah from late May to early October in 2019 and 2020. Yellow sticky cards captured 54–72% more target parasitoids than blue cards from June through August in all three landscape types in both years; however, a positive correlation in parasitoid capture indicated blue cards detect target parasitoids, just in fewer numbers. Both card colors detected adventive Trissolcus japonicus (Ashmead) (Hymenoptera: Scelionidae) in initial findings of 2019, and in expanded locations of 2020. Furthermore, blue cards captured 31–48% less Diptera and nontarget Hymenoptera than yellow cards in both years across all three landscapes, translating to reduced card processing time and impacts to beneficial insect populations. Our results suggest that blue vs yellow sticky cards offer an alternative monitoring technique to survey for H. halys parasitoids.

Neonicotinoid Pesticides Cause Mass Fatalities of Native Bumble Bees: A Case Study From Wilsonville, Oregon, United States.

In June of 2013 an application of dinotefuran on an ornamental planting of European linden trees (Tilia cordata Mill. [Malvales: Malvalceae]) in a shopping mall parking lot in Wilsonville, Oregon provoked the largest documented pesticide kill of bumble bees in North America. Based on geographic information systems and population genetic analysis, we estimate that between 45,830 and 107,470 bumble bees originating from between 289 and 596 colonies were killed during this event. Dinotefuran is a neonicotinoid that is highly effective in exterminating and/or harming target pest insects and non-target beneficial insects. Analysis to detect the concentration of pesticides in flowers that received foliar application revealed that the minimum reported dinotefuran concentration of a sampled T. cordata flower was 7.4 ppm, or in excess of 737% above the LC50 of the beneficial pollinator, the honey bee (Apis mellifera Linnaeus, 1758 [Hymenoptera: Apidae]). Furthermore, sampled Vosnesensky bumble bees (Bombus vosnesenskii Radoskowski, 1862 [Hymenoptera: Apidae]) were found to have an average dinotefuran concentration of 0.92 ppm at the time of death, which exceeds the maximum LC50 of A. mellifera (0.884 ppm). Our study underscores the lethal impact of the neonicotinoid pesticide dinotefuran on pollinating insect populations in a suburban environment. To our knowledge, the documentation and impact of pesticide kills on wild populations of beneficial insects has not been widely reported in the scientific literature. It is likely that the vast majority of mass pesticide kills of beneficial insects across other environments go unnoticed and unreported.

Floral Plantings in Large-Scale Commercial Agroecosystems Support Both Pollinators and Arthropod Predators.

Simple SummaryPollinators and insect predators are in decline, largely due to commercial agricultural land use and practices. Planting a mixture of wildflowers in the unused margins of agricultural fields may help to conserve these insects and the important benefits that they provide (pollination and pest suppression). We compared wildflower plantings around commercial potato fields to unmanaged grass and weed margins to determine whether these plantings supported greater numbers of pollinators and predators. We found that wildflower plantings increased the numbers of both pollinators and predators within field margins. Additionally, margins with more flowers blooming led to more pollinators, although, interestingly, more flowers did not lead to more predators. This suggests that predators may benefit from wildflower plantings without needing the flowers they provide, while pollinators benefit from flowers specifically. When we measured pollinators and predators in the nearby potato crops, we found that wildflower plantings did not lead to greater numbers of pollinators or predators. Our results suggest that wildflower plantings can help conserve pollinators and predators in commercial agricultural areas, but that these beneficial insects do not move into adjacent crops, where they would be most likely to provide pollination or pest suppression services. Beneficial insect populations and the services that they provide are in decline, largely due to agricultural land use and practices. Establishing perennial floral plantings in the unused margins of crop fields can help conserve beneficial pollinators and predators in commercial agroecosystems. We assessed the impacts of floral plantings on both pollinators and arthropod predators when established adjacent to conventionally managed commercial potato fields. Floral plantings significantly increased the abundance of pollinators within floral margins compared with unmanaged margins. Increased floral cover within margins led to significantly greater pollinator abundance as well. The overall abundance of arthropod predators was also significantly increased in floral plantings, although it was unrelated to the amount of floral cover. Within adjacent potato crops, the presence of floral plantings in field margins had no effect on the abundance of pollinators or predators, although higher floral cover in margins did marginally increase in-crop pollinator abundance. Establishing floral plantings of this kind on a large scale in commercial agroecosystems can help conserve both pollinators and predators, but may not increase ecosystem services in nearby crops.

Determination of the sampling size for the reliable identification of organic crops by inducing sublethal effects in beneficial insects

Among the main innovations in olive growing, the conversion of cultivation practices towards organic agriculture stands out. Since the organic crops are subject to the granting of economic subsidies by the Spanish Ministry of Agriculture, this has given rise to fraudulent situations, masking the use of conventional pesticides in “fake organic” crops. To investigate alternative methods, complementary to analytical chemists that can provide reliable information to discerning organic crops from those subjects to synthetic pesticides is the aim of this research. A new technique is being developed, based on the induction of sublethal effects on the beneficial insects, through the experimental application of a commercial insecticide on a small scale, in the target crop. The effect triggered by the insecticide can be monitored by means of a yellow sticky trap device, installed for each olive tree, which allows to observe deviations in its capture rate from what occurs in the absence of insecticide (control) and finally verifying if the populations of beneficial insects affected in the olive grove, whether or not they are accustomed to the toxic action of the insecticide. Obviously, in order to maintain environmental integrity in the supposed ecological target olive groves, this induction test should be applied on the smallest scale as possible, thus reducing the application area of the pesticide, which implies adjusting the sample size to a minimum, maintaining an acceptable reliability in the estimates. During the autumn of 2017, six plots of 7x7 configuration were selected in an olive grove in the province of Jaén (southern Spain), three of these were treated with Dimethoate, while the remaining were considered as control. After the treatment application, sticky yellow traps were installed (one in each of the olive trees), thus allowing a maximum of 49 repetitions per plot. Among the identified beneficial insects, the most abundant species was Aeolothrips intermedius. Taking this species as a reference, the results indicate that the differences between treated and control parcel were statistically significant from a minimum sample size of 17 replications onwards. In coincidence with the above, the results have allowed determining that the minimum size of the experimental target plot, to obtain acceptable population estimates (relative error of up to 10%), would require a minimum area of at least 100 m2, representing a minimum number of 17 olive trees. These results provide a reasonable statistical basis for suitably adapting the methodology that allows acceptable estimates, therefore, the application of this methodology of detection of organic crops would require a very small area, equivalent to a practically insignificant number of olive trees, so it would not compromise the ecological quality of the target plantation.

Chemical control of the mealybug Phenacoccus solenopsis (Hemiptera: Pseudococcidae) in Australian cotton: glasshouse assessments of insecticide efficacy

AbstractThe efficacy of commercially available chemical insecticides and biopesticides on the cotton mealybug (CMB), Phenacoccus solenopsis, was evaluated in the glasshouse. Spirotetramat, sulfoxaflor and buprofezin were identified as key insecticides for use in integrated pest management (IPM) strategies aimed at controlling CMB without flaring other co‐occurring pests. When used as a single application, spirotetramat and sulfoxaflor at the rate of 96 g (active ingredient, ha−1) provided variable control of CMB. Spirotetramat used in a double spray tactic (two sequential sprays, 14–15 days apart) without crop oil provided ≥80% control of adult CMB while the addition of oil (5% v/v) increased control to ≥90%. Clothianidin synergised the spirotetramat + oil combination and was identified as a potentially useful tank mix option for use in situations where a quick knockdown of high density and/or large infestation of CMB is required, or to treat high risk infestations in squaring or younger cotton when the abundance of beneficial insects is typically low. Sulfoxaflor used in a double spray tactic provided ≥90% control of adult CMB. The addition of Pulse® penetrant (0.5% v/v) to both options improved overall efficacy. Addition of crop oil to sulfoxaflor did not yield any tangible benefits. Spirotetramat and buprofezin were identified as important tools in managing situations where whitefly (Bemisia tabaci) is the primary pest management target, but CMB is also present in the crop. Buprofezin was effective on early instar mealybugs; this makes it an option for arresting CMB population growth while allowing the beneficial insect populations to increase. Sulfoxaflor was shown to be a useful option in situations where CMB is present along with key pests such as mirids (Creontiades spp.). Mealybugs are typically well controlled by naturally occurring beneficial insects without the need for insecticide use. Chemical insecticides for CMB control should be considered only as a last resort and deployed within the bounds of an IPM strategy.

Neonicotinoids in global agriculture: evidence for a new pesticide treadmill?

Bakker, L., W. Van der Werf, P. Tittonell, K. A. G. Wyckhuys, and F. J. J. A. Bianchi. 2020. Neonicotinoids in global agriculture: evidence for a new pesticide treadmill? Ecology and Society 25(3):26. https://doi.org/10.5751/ES-11814-250326

An assessment of acute insecticide toxicity loading (AITL) of chemical pesticides used on agricultural land in the United States.

We present a method for calculating the Acute Insecticide Toxicity Loading (AITL) on US agricultural lands and surrounding areas and an assessment of the changes in AITL from 1992 through 2014. The AITL method accounts for the total mass of insecticides used in the US, acute toxicity to insects using honey bee contact and oral LD50 as reference values for arthropod toxicity, and the environmental persistence of the pesticides. This screening analysis shows that the types of synthetic insecticides applied to agricultural lands have fundamentally shifted over the last two decades from predominantly organophosphorus and N-methyl carbamate pesticides to a mix dominated by neonicotinoids and pyrethroids. The neonicotinoids are generally applied to US agricultural land at lower application rates per acre; however, they are considerably more toxic to insects and generally persist longer in the environment. We found a 48- and 4-fold increase in AITL from 1992 to 2014 for oral and contact toxicity, respectively. Neonicotinoids are primarily responsible for this increase, representing between 61 to nearly 99 percent of the total toxicity loading in 2014. The crops most responsible for the increase in AITL are corn and soybeans, with particularly large increases in relative soybean contributions to AITL between 2010 and 2014. Oral exposures are of potentially greater concern because of the relatively higher toxicity (low LD50s) and greater likelihood of exposure from residues in pollen, nectar, guttation water, and other environmental media. Using AITL to assess oral toxicity by class of pesticide, the neonicotinoids accounted for nearly 92 percent of total AITL from 1992 to 2014. Chlorpyrifos, the fifth most widely used insecticide during this time contributed just 1.4 percent of total AITL based on oral LD50s. Although we use some simplifying assumptions, our screening analysis demonstrates an increase in pesticide toxicity loading over the past 26 years, which potentially threatens the health of honey bees and other pollinators and may contribute to declines in beneficial insect populations as well as insectivorous birds and other insect consumers.

Local and Landscape Effects to Biological Controls in Urban Agriculture-A Review.

Urban agriculture is widely practiced throughout the world. Urban agriculture practitioners have diverse motivations and circumstances, but one problem is ubiquitous across all regions: insect pests. Many urban farmers and gardeners either choose to, or are required to forego, the use of chemical controls for pest outbreaks because of costs, overspray in populated areas, public health, and environmental concerns. An alternative form of pest control is conservation biological control (CBC)—a form of ecological pest management—that can reduce the severity of pest outbreaks and crop damage. Urban farmers relying on CBC often assume that diversification practices similar to those used in rural farms may reduce insect pest populations and increase populations of beneficial insects, yet these management practices may be inappropriate for applications in fragmented urban environments. In this review, we assess urban CBC research and provide a synthesis for urban agriculture practitioners. Our findings indicate that local and landscape factors differentially affect insect pests and beneficial arthropods across the reviewed studies, and we identify several on-farm practices that can be implemented to increase biological control in urban agriculture.

Quality evaluation of laboratory populations of entomophages by DNA markers

In order to increase the prospects of the use of entomophages for the natural and artificial regulation of the number of pests, it is necessary to study the genetic structure and genetic diversity of the populations of beneficial insects, which is an integral part of the monitoring of useful biota. The use of DNA-markers allows monitoring of both parasites and predators applied in biological plant protection programs. Using samples of the ectoparasite Habrobracon hebetor Say, the predatory beetles Harmonia axyridis Pall. and Adalia bipunctata L., the predatory bugs Perillus bioculatus F. and Podisus maculiventris Say, we carried out a comparative molecular genetic analysis of laboratory and natural populations of these entomophages using RAPD- and ISSR-markers. An original method has been elaborated for the quality evaluation of laboratory parent populations of entomophages, artificially grown for mass release into the agrocenoses, as bioagents in plant protection. This method is based on the evaluation of DNA polymorphism and genetic diversity of insect populations using RAPD- and ISSR-markers and can be used as a quality criterion for commercial lots of bioagents, which can significantly increase the effectiveness of biological protection of agricultural plants against harmful arthropods. The method of molecular genetic diagnostics can be used in the future to control the species composition and quality of the batch of parasitic and predatory entomophags imported from the countries of near and far abroad.