Urban Entomology Highlights From 2020—Monitoring and Control of Urban Pests

Pest management professionals aim to answer two primary questions for their customers: 1) ‘Where/What is the pest?’ and 2) ‘How do I kill it?’. These two questions drive at the core of any pest management program. 2020 was an exciting year for entomology research, with much work being done on novel technologies and methods for detecting and controlling pests. The objectives of the current publication were to discuss papers published in 2020 that addressed the key pest management objectives of 1) monitoring and 2) controlling pest populations.

Toxicity of Methyl Benzoate and Analogs to Adult Aedes aegypti

ABSTRACT Methyl benzoate is a natural product (floral volatile organic compound) that is currently used as a food flavoring ingredient. This compound has shown to be insecticidal in laboratory studies against agricultural and urban pests, including spotted wing drosophila Drosophila suzukii, brown marmorated stink bug Hyalomorpha halys, the diamondback moth Plutella xylostella, and the common bed bug Cimex lectularius, to name several insect taxa. In this study we topically treated adult Aedes aegypti females with methyl benzoate and analogs and determined their toxicities. We found that among adult females, 4 analogs—butyl benzoate, n-pentyl benzoate, vinyl benzoate, and methyl 3-methoxybenzoate—were more toxic than the parent compound, methyl benzoate.

Efficacy of several insecticide formulations against Periplaneta americana (L.) (Blattaria: Blattidae) in sewers

Objective: Periplaneta americana (L.) is the most important invasive urban pests in sewers with high significance of public health. The aim of the study was to evaluate the efficacy of several insecticide formulations against American cockroaches in sewers. Methods: The population density of cockroaches was estimated before and after 1 and 5 months of the use of insecticides in sewer manholes. About 10 manholes were allocated for treatment of each insecticide formulation. Twenty manholes were allocated to controls (without the use of insecticides). Insecticides were considered effective achieving more than of 90% mean density reduction of cockroach population per a manhole. Results: The effectiveness of insecticide formulations in sewer manholes were considered effective after 1 month of insecticide treatments while the effectiveness of diazinon EC 5% and 0.05% formulations considered insufficient including 47.% and 19.5%mean density reduction of cockroaches, respectively. The effectiveness of chlorpyrifos EC 5% and Fog, and diazinon EC 5% were observed about 80.5%, 81.5%and 53.5% mean density reduction of cockroaches, respectively after 5 months of treatment while the other formulations did not achieve effectiveness. Conclusions: The insecticide formulations were considered effective and ineffective after 1 and 5 months of the use of insecticides, respectively. It would be more satisfied if insecticide formulations repeated every three months. A reasonable manner is using a combination of integrated pest management strategies recommending for successful P. americana control. Bangladesh Journal of Medical Science Vol.20(3) 2021 p.569-585

Urban Forestry in Sabah, Malaysia

This chapter provides a holistic understanding of the existing conditions of urban green spaces in Sabah by reviewing relevant past studies and publications. Nature serves as the foundation in the establishment of pocket parks, urban parks, and forest protected areas that are made available for public access within and outside of the major urban areas in Sabah. Presently, both native and exotic flora and fauna species are coexisting at the local urban green spaces, although some invasive exotic species have developed into urban pests of Sabah. Moreover, the importance and functions of urban green spaces in maintaining the well-being of mankind and ensuring the survival of indigenous wildlife species are acknowledged by society. Nevertheless, much research is required to fill up the research gaps of urban forestry, and also to provide solutions to the existing problems that happened at the urban green spaces in Sabah.

Biology and Management of the German Cockroach

As a species, the German cockroach is one of the most widespread indoor urban pests worldwide. While numerous products have been developed to control their spread, German cockroaches continue to contaminate food, transmit disease and cause significant, long-term economic expense to homes, restaurants, hospitals and more. Biology and Management of the German Cockroach summarises the many advances in management technology, products, delivery systems, and basic and applied research over the past 25 years. Leading researchers explain why the German cockroach is a medically important pest and how its microbiome can provide new insights on cockroach physiology and potential novel targets for control. The authors also address the research from a practical standpoint, detailing why baits have replaced sprays as the primary method of control and how population genetic studies allow for better understanding of cockroach dispersal and population structure. Leading experts on integrated pest management (IPM) explore how studies on German cockroach control programs demonstrate the value and feasibility of IPM in urban environments. This book provides the reader with a comprehensive understanding of the German cockroach and will be a valuable reference for researchers, graduate students, pest management professionals, health workers and government agencies dealing with urban pests and pesticides.

Insecticidal and Cholinesterase Activity of Dichloromethane Extracts of Tithonia diversifolia on Atta cephalotes Worker Ants (Formicidae: Myrmicinae)

Leaf-cutter ants are agricultural and urban pests that defy chemical control methods. Laboratory and field studies have revealed repellent and insecticidal activity by the extracts of Tithonia diversifolia (Asteraceae), known as Mexican sunflower, as a promising alternative for the control of the leaf-cutter ant Atta cephalotes. This study evaluated the effects of different extracts (non-polar and polar) of T. diversifolia dry leaves on worker ants from laboratory colonies of A. cephalotes through ingestion and contact. In addition, the biological activity of the extracts as inhibitors of acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) was evaluated. A dichloromethane extract at 1000 ppm presented the highest insecticidal activity through ingestion, causing 70% and 90% worker ant mortality after five and seven days of treatment, respectively. The acetylcholinesterase inhibition values showed that the dichloromethane presented the best AChE concentration of inhibition (IC50) at 73.9 ± 11.06 μg/mL, compared to its fractions, which demonstrates that its activity is potentiated when the crude extract is used. Our results can be attributed to the existence of terpenes and sesquiterpene lactones, which are likely inhibitors of AChE, in T. diversifolia.

Effectiveness of Boric Acid by Ingestion, But Not by Contact, Against the Common Bed Bug (Hemiptera: Cimicidae)

Boric acid has been used as an insecticide in the successful control of agricultural, public health and urban pests long before the advent of synthetic organic pesticides. Boric acid products, formulated as dusts, sprays, granular baits, pastes, gels, and liquids, are widely available to consumers and pest management professionals, especially to control pest infestations within homes. Boric acid dust is commonly used against bed bugs (Cimex lectularius L. [Hemiptera: Cimicidae]), but its efficacy has not been demonstrated. We evaluated the efficacy of boric acid as an ingestible and residual contact insecticide on bed bugs, and compared its efficacy on the German cockroach (Blattella germanica L. [Blattodea: Ectobiidae]) which is known to be susceptible to boric acid by both routes. Dose–response studies of 0–5% boric acid in blood demonstrated that ingested boric acid caused rapid mortality at concentrations of ≥2%, and even 0.5% and 1% boric acid caused 100% mortality, albeit at a slower time course. In contrast, bed bugs survived contact with high concentrations of boric acid dust. Smaller boric acid particles did not increase mortality of either unfed or recently fed bed bugs. The same boric acid products were effective at causing mortality of German cockroaches by both contact and ingestion. We thus conclude that although boric acid is an excellent candidate active ingredient for an ingestible bait formulation, residual applications of dust or spray would be ineffective in bed bug interventions.

A “Smart” Trap Device for Detection of Crawling Insects and Other Arthropods in Urban Environments

We introduce a device for the automatic detecting and reporting of crawling insects in urban environments. It is a monitoring device for urban pests that complies with the context of smart homes and smart cities, and is compatible with the emerging discipline of the Internet of Things (IoT). We believe it can find its place in every room of a hotel, hospital, military camp, and residence. This box-shaped device attracts targeted insect pests, senses the entering insect, and takes automatically a picture of the internal space of the box. The e-trap includes strong attractants (pheromone and/or food) to increase capture efficiency and traps the insect on its sticky floor. The device carries the necessary optoelectronic sensors to monitor all entrances of the trap. As the insect enters it interrupts the infrared light source. This triggers a detection event; a picture is taken, and a time-stamp is set before delivering the picture through the Wi-Fi to an authorized person/stakeholder. The device can be integrated seamlessly in urban environments and operates unobtrusively to human activities. We report results on various insect pests and depending on the insect species, can reach a detection accuracy ranging from 96 to 99%.