Journal of Biological Control

Entomopathogens and their role in insect pest management

Thu, 11 Apr 2024 00:00:00 +0530

Agricultural production faces significant challenges due to the loss of crop yields, highlighting the need for improvements in pest management methods to enhance productivity. Crop growers are increasingly pressured to minimize the use of chemical pesticides without compromising yields. However, managing pests has become more challenging due to pesticide resistance and limited product availability. Consequently, there is an urgent requirement for alternative approaches. Entomopathogens such as fungi, bacteria, viruses, and nematodes emerge as promising alternatives to broad-spectrum chemical insecticides. They have been widely employed to control insect pests in cultivated crops, employing successful strategies such as augmentation and classical biological control. These methods involve applying or introducing bacteria, baculoviruses, fungi, and nematodes. Utilizing entomopathogens offers numerous benefits beyond their effectiveness. These advantages encompass the capacity to treat expansive areas with a sole application, ensuring safety for both humans and non-target organisms. Additionally, their use leads to decreased pesticide residues in food, the conservation of natural enemies, and a boost in biodiversity within managed ecosystems. Entomopathogens present a viable solution by offering effective pest control while addressing environmental, human health, and ecosystem sustainability concerns. The primary emphasis of this review is on the present condition of bio-formulations, the pathogenicity associated with entomopathogens, their mode of action, and the possible implementation of diverse microbial formulations aimed at achieving sustainable pest management.

Apivectoring: Harnessing pollinators for sustainable crop protection and pollination

AARUSHI SHARMA, DEVIKA SHARMA (Author) — Thu, 11 Apr 2024 00:00:00 +0530

Apivectoring, or Pollinator Biocontrol Vector Technology, employs bees to distribute biological control agents, offering a sustainable solution for managing plant diseases and insect pests while enhancing crop yield and quality. The most commonly used vectors in apivectoring are honey bees and bumble bees, though there’s potential to explore other pollinator species. Commercial dispensers like BeeTreat Dispenser^®, BVT Inoculum Dispenser^® and Flying Doctors^® have been developed in countries like Finland, Belgium, and Canada, respectively. Though initially pioneered in North America, Australia, and Europe, this method is now being evaluated in India. The technology is a promising alternative to chemical pest control, reducing pesticide usage and ensuring crop pollination, although challenges remain in regions deprived of local rearing and/or research facilities.

Evaluating the efficiency of silver nanoparticles prepared using Pseudomonas fluorescens and Bacillus thuringiensis subsp. tenebrionis in controlling eggs and adults of Callosobruchus maculatus (F.) (Coleoptera: Bruchidae)

ISTABRAQ F. ALI, RAGHAD K. I. AL-JOBOORY, HAZIM I. AL-SHAMMARI (Author) — Thu, 11 Apr 2024 00:00:00 +0530

This study aimed to evaluate the efficiency of silver nanoparticles (AgNPs) which are prepared biologically by two bacterial species, Bacillus thuringiensis tenebrionis (Btt) and Pseudomonas fluorescens (P.f) to control southern cowpea beetle insect, Callosobruchus maculatus. Many features of the prepared nanoparticles were examined, and the results obtained showed that the highest absorption value of AgNPs was at 262 nm. Whereas the results of FTIR analysis showed that several compounds played a role in the silver ions reduction process, which included alcohol, alkane, primary amine, and amine group. The scanning electronic microscopic images showed that the average diameter of nanoparticles which was created by P.f was 48.52 nm, while it was 56.08 nm for the nanoparticles prepared by Btt. The study showed no significant differences between the activity of both AgNP types against C. maculatus eggs, while a significant preference was recorded for the activity of Btt AgNPs against the C. maculatus adults. The highest percentage of unhitched eggs was 53.8% recorded at 3000 ppm concentration, while Btt AgNPs gave 59.6% at 3000 ppm. The highest mortality rate of the adults who were treated by Btt AgNPs was 58.8 % at 3000 ppm concentration, while it was recorded 50% at 3000 ppm with P.f AgNPs treatment. The current study demonstrates the efficiency of biologically prepared AgNPs in controlling C. maculatus insect life stages, which encourages using of these nanoparticles as a modern strategy in management of insect pests.

In vitro evaluation of microencapsulated Bacillus thuringiensis (Berliner) formulation against Helicoverpa armigera (Hubner)

Thu, 11 Apr 2024 00:00:00 +0530

An experiment was conducted to evaluate microencapsulated formulation of lyophilized spore crystal aggregate of native isolate BGC-1 and reference isolate HD-1 against second instar larvae of Helicoverpa armigera. The results revealed that the microcapsule diameter was ranged from 3.2 to 8.3 µm. Median lethal concentrations of the BGC-1 and Bt-HD1 were 0.66 g/l and 0.50 g/l respectively. UV protectants viz., melanin and para-amino benzoic acid were evaluated by exposing microencapsulated Bacillus thuringiensis to UV A light at 365nm. Among four microencapsulated formulations, BGC-1 with melanin recorded significantly highest mortality of 95.00 per cent at 0h exposure, as time increased, the mortality decreased and HD-1 was on par with BGC-1.

Diversity of phytophagous and predatory mites in vegetable crops in Himachal Pradesh, India

VIJAY SINGH, USHA CHAUHAN, V. K. RANA (Author) — Thu, 11 Apr 2024 00:00:00 +0530

The surveys carried out in different vegetable growing areas of Himachal Pradesh yielded 25 species of mites belonging to 9 genera under 5 families. Among all, 5 species were phytophagous, 19 were predatory mites and 1 species was of saprophagous mite. On capsicum, a predatory mite of the family Anystidae was recorded for the first time from the state. During the study, majority of predatory mites were recorded on cucumber and brinjal than other vegetables. Four species are the new reports from Himachal Pradesh.

Population dynamics and diversity of Odonata (insecta) at Mini and Mahi rivers of Gujarat, India

DARSHANA M. RATHOD, SANJAY DHOLU, BHAVBHUTI M. PARASHARYA (Author) — Thu, 11 Apr 2024 00:00:00 +0530

Population dynamics, diversity and community structure of Odonata were studied on three adjacent riparian microecosystems in Vadodara district, Gujarat, India. Population dynamics was studied by observing their population by point count method on three microhabitats (Mini River at Sankarda, Sindhrot and Mahi River at Fazalpur). In the course of a twenty-eight-week study, a total of 4783 Odonata were encountered on three microecosystems. Odonata density 9% throughout September 2014 (39^th Meteorological Week) and gained its peak during October 2014 (44^th Meteorological Week). A definite drop in the density was observed during November 2014 (48^th Meteorological Week) and it achieved precisely 1% throughout December 2014 (51^st Meteorological Week). Amongst the three microecosystems, at Fazalpur, species richness began rising from the 4^th week of September (6%) and made it to its highest (11%) throughout the 4^th week of October. At Sankarda, maximum absolute richness (12.61%) was recorded in 3^rd week of October. At Sindhrot, the relative abundance of odonates started increasing in 3^rd week of September (7%) and achieved its highest (13%) during 4^th week of October. A total of twenty-five species were encountered in the terrain. The diversity index was maximum for Sankarda (2.35) followed by Fazalpur (2.27) and Sindhrot (2.01). A total of four species (Ditch Jewel (26.6%), Pigmy Dartlet (19.5%), Green Marsh Hawk (10.3%) and Senegal Golden Dartlet (8.3%) were dominant in all three microhabitats.

Ultrastructure and morphometric characteristics of Oecophylla smaragdina (Fabricius, 1775) (Hymenoptera: Formicidae)

Thu, 11 Apr 2024 00:00:00 +0530

In this study, we explored various aspects of Oecophylla smaragdina, a potential biocontrol agent, evolution by examining its morphometric characteristics. We employed an intensive All-out search method (AOSM) to gather specimens from multiple locations in Vadakku Karaseri, Tamil Nadu. Our analysis involved measuring 16 morphological traits and indices, including Total Length, Head Width, Head Length, Eye Length and more, using specimens from five colonies in each locality. By calculating various morphometric indices, we assessed specific features and conducted a Principal Component Analysis (PCA) to determine the significance of head-related variables, antennae, and body size in shaping morphometric variation. Our study also revealed positive and negative associations between different morphometric variables, as highlighted by Pearson correlation coefficients. Furthermore, we used a Scanning Electron Microscope to examine the ultrastructure of the abdomen, revealing distinct features such as a one-jointed pedicel and modifications of the poison gland and stings. This comprehensive research provides valuable insights into O. smaragdina morphometric characteristics, enhancing our understanding of its variability and potential adaptations in various habitats.

Novel records of parasitoids targeting fall armyworm, Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae), in rice-corn-based cropping systems in the Philippines

Thu, 11 Apr 2024 00:00:00 +0530

In the Philippines, the Fall Armyworm (FAW) was initially documented infesting corn in June 2019 and rice in May 2021. Relying on commercially available insecticides as the primary, if not exclusive, management strategy raises concerns about potential issues arising from FAW developing resistance to these chemicals, and the associated risks these insecticides pose to non-target organisms and the environment. To address these challenges, it is imperative to explore potential naturally occurring indigenous biological control agents and entomopathogens of the FAW. Regular field samplings and monitoring of FAW and its natural enemies were systematically conducted in selected municipalities of Central and Northern Luzon, as well as the Cagayan Valley regions of the Philippines. FAW larvae suspected of parasitization were collected from the field and subsequently reared in the laboratory for parasitoid emergence and other natural enemies. The parasitoids that emerged were sent to the Centre for Agriculture and Biosciences International United Kingdom (CABI UK) Diagnostic and Advisory Service for identification. Two hymenopteran parasitoids, Brachymeria lasus Walker (Family: Chalcididae) and Copidosoma floridanum (Ashmead) (Family: Encyrtidae), were identified from the lab-reared FAW larval samples. These two FAW parasitoids are new records in the Philippines and elsewhere.

Comparing various bio-intensive pest management modules in rice

N. VEERAMANIKANTA REDDY, CHITRA SHANKER, G. ANITHA, D. K. RANA (Author) — Thu, 11 Apr 2024 00:00:00 +0530

Rice is the key cereal crop in the tropics, supporting diverse pests and natural enemy populations. Recurrent pest outbreaks and yield losses led farmers to rely on extensive insecticide application, disturbing the stability of rice ecosystems and increasing residues in the harvestable products. A study has been conducted to assess the impact of various modules of Bio-Intensive Pest Management (BIPM) on its conservational potential and sustainability in comparison with Farmers’ Practices (FP) in Nalgonda district of Telangana state during kharif-2020. The BIPM practices included application of farm yard manure; rice husk ash; clipping of seedlings; alleyways and weekly release of Trichogramma japonicum in the main field; wet seed treatment and foliar application with Pseudomonas fluorescens (BIPM 1), Trichoderma asperellum strain TAIK1 (BIPM 2) and Bacillus cabrialesii strain BIK3 (BIPM 3). Whereas, FP 1 with need-based insecticide spraying and FP 2 with schedule-based insecticide spraying and Untreated control with (UC) with no intervention. The observations were taken by visual counts at 15-day intervals. The incidence of Cnaphalocrocis medinalis was highest in UC (9.50), followed by BIPM 1 (7.25) and least in FP 2 (2.50) whereas the highest mean population of Apanteles sp. was found in the untreated control (13.75), followed by BIPM 3 (9.50) and least in FP 2 (4.25). The Benefit Cost Ratios (BCR) of BIPM 3 (1.68) were highest followed by BIPM 1 (1.64) and least in FP 2 (1.40) elucidating that BIPM practices can be more economically feasible. The Shannon-Wiener Index for species diversity and species evenness was higher in BIPM treatments as compared to farmers’ practices indicating the potential of these BIPM treatments in natural pest control and maintaining crop ecosystem stability.

Mouthparts of ladybird beetles (Coccinellidae: Coleoptera): A comparative analysis

D. NEETHU ROY, T. UMA MAHESWARI, B. RAGHAVENDER (Author) — Thu, 11 Apr 2024 00:00:00 +0530

This study delves into the mouthpart morphology of ladybird beetles belonging to the Coccinellidae family, Coleoptera, with a focus on three representative species: Henosepilachna vigintioctopunctata (phytophagous), Harmonia octomaculata (predatory) and Illeis cincta (mycophagous). The research reveals distinct variations in mouthpart structures among these species, illuminating the connection between mouthpart morphology and host preferences. Predatory beetles, exemplified by Harmonia octomaculata, showcase specialized features such as bifid mandibular apices and larger mandibles (0.80 mm in length, 0.34 mm in width). In contrast, phytophagous ladybird beetles like Henosepilachna vigintioctopunctata exhibit multidentate mandibles with smaller dimensions. Additionally, the outer galea (0.30 mm) and inner lacinia (0.43 mm) of maxillae are significantly more substantial in phytophagous beetles compared to their predatory and mycophagous counterparts. These findings underscore the intricate relationship between mouthpart morphology and feeding habits in ladybird beetles, shedding light on their ecological roles, evolutionary adaptations and potential implications for pest management and entomological research.