Control Of Insect Pests Research Articles

Ozonation of Cowpea Grains: Alternative for the Control of Callosobruchus maculatus and Maintenance of Grain Quality

Nowadays, the modified atmosphere with ozone is one of the main alternatives for controlling insect pests in stored grains, as it allows grain quality to be maintained while causing no environmental damage. In light of this, the purpose of this study was to assess the toxicity of ozone to C. maculatus in cowpea grains as well as how it affects the physiological and physical properties of the grains. The toxicity was determined by estimating lethal doses (mg/g) at the top and bottom of the fumigation chamber for 50% and 95% of adult insects (LD50 and LD95). Cowpea grain samples were removed after being exposed to ozone, and the effect of ozonation on the physical and physiological quality of the grains was assessed. The electrical conductivity, water content, and germination were all examined in this manner. The lethal doses LD50 were 65.97 and 45.52 mg/g when the insects were distributed at the top and bottom of the fumigation chamber, respectively. As a result, ozone toxicity was higher at the bottom than at the top. The increase in ozone doses resulted in a decrease in water content. The germination rate exceeded 90% in both locations where ozone was applied. The electrical conductivity remained constant, ranging between 152.01 and 239.59 S cm−1 g −1. The findings indicate that ozone is toxic to C. maculatus but has no effect on grain quality. Ozone may therefore be used to manage C. maculatus in cowpea that has been stored.

RNA interference in insects: the link between antiviral defense and pest control.

RNA interference (RNAi) is a form of gene silencing triggered by double-stranded RNA (dsRNA) that operates in all eukaryotic cells. RNAi has been widely investigated in insects to determine the underlying molecular mechanism, to investigate its role in systemic antiviral defense, and to develop strategies for pest control. When insect cells are infected by viruses, viral dsRNA signatures trigger a local RNAi response to block viral replication and generate virus-derived DNA that confers systemic immunity. RNAi-based insect pest control involves the application of exogenous dsRNA targeting genes essential for insect development or survival, but the efficacy of this approach has limited potency in many pests through a combination of rapid dsRNA degradation, inefficient dsRNA uptake/processing, and ineffective RNAi machinery. This could be addressed by dsRNA screening and evaluation, focusing on dsRNA design and off-target management, as well as dsRNA production and delivery. This review summarizes recent progress to determine the role of RNAi in antiviral defense and as a pest control strategy in insects, addressing gaps between our fundamental understanding of the RNAi mechanism and the exploitation of RNAi-based pest control strategies.

Isolation and Cultivation of Penicillium citrinum for Biological Control of Spodoptera litura and Plutella xylostella

Biological control agents are a promising substitute for chemical pesticides in agricultural pest management. In this study, Penicillium sp. with high pathogenicity to the agricultural pests oriental leafworm moth (Spodoptera litura) and diamondback moth (Plutella xylostella) were isolated from naturally infected insects and grown on different agricultural residues as an inexpensive substrate for their sporulation. Ten strains of Penicillium (P.01~P.10) were identified as P. citrinum based on morphological features and molecular studies, with sequence analysis using an internal transcribed spacer region. Different fungal isolates exhibited a varying degree of pathogenicity against S. litura and Pl. xylostella, and strains P.04 and P.09 showed the highest pathogenicity to S. litura, with a mortality rate of 92.13% after 7 days of treatments, while strain P.06 resulted in the highest mortality of Pl. xylostella (100%) after 6 days of treatment. Moreover, among ten isolates infected with both S. litura and P. xylostella, P.06 showed potential virulence against S. litura and Pl. xylostella, with lethal time for 50% mortality (LT50) values of 4.5 days and 3.0 days, respectively. The ten isolates showed higher virulence to Pl. xylostella than to S. litura. The agro-industrial-based medium showed efficiency for the cultivation of isolates for sporulation on an industrial scale, suggesting that the newly isolated P. citrinum is a potential biological control agent for controlling insect pests and could be further developed for microbial pesticide production.

Fumigant toxicity and behavioral alterations of six plant essential oils against the red fire ant (Solenopsis invicta Buren).

The red imported fire ant (RIFA), Solenopsis invicta Buren (Hymenoptera: Formicidae), is an invasive species that is considered to be among the 100 most dangerous species to human health and the environment. RIFA is currently controlled primarily by chemical insecticides. However, human health concerns and environmental problems require environment friendly, green insect pest control technology. In this study, the HS-SPME-GC/MS method was used to determine the volatile components of six essential oils, namely Illicium verum Burm, Blumea balsamifera (L.) DC., Citrus limon Burm, Acorus tatarinowii Schott, Mosla chinensis Maxim, and Cinnamomum cassia Presl, as well as their fumigation activity against RIFA. D-Limonene was identified as a core volatile in all six essential oils. The effects of volatile substances from essential oils on the fumigation activity and behavior of RIFA workers were studied by closed fumigation method. Except for C. limon essential oil, all other five plant essential oils exhibit excellent fumigation activity under the treatment of a concentration at 10 μL/ cm3 within 24 h. All plant essential oils are capable of causing the death of all red fire ants, while C. limon essential oil exhibited the lowest fumigation activity at 63.25%. Significant reductions in RIFA aggregation, aggressiveness, and gripping abilities were observed with all plant essential oils, and antenna sensilla appeared to bend or break. Moreover, after treating red ant fire ants with essential oil for 24 h, three protective enzyme activities were assessed. All six plant essential oils were shown to have enhanced enzyme activities for superoxide dismutase (SOD), glutathione S-transferase (GST), and catalase (CAT). It has been shown that plant essential oils have the capability of reducing the viability of red fire ants via receptor and behavioral factors, ultimately causing them to die off. As a conclusion, plant oils were demonstrated to be negatively affecting RIFA and providing a green and environmentally sustainable control method in this study.

Insect Pest Diversity of Corn Plants (Zea mays) in Baringeng Village, Soppeng Regency, South Sulawesi Province

Background: Baringeng is a corn-producing village in Soppeng Regency, South Sulawesi. The main problem for corn farmers in the town is insect pests. Insect pests damage the plant, which has an impact on decreasing yields. Control of insect pests must be by the type of insect pests. This study aims to calculate the diversity of insect pests of corn in Baringeng Village and the damage they cause. Methods: Data was collected in Takku Hamlet, Baringeng Hamlet, and Tanjonge Hamlet. with a systematic plot sampling method with the help of light traps, sweep nets, and direct collection of pests. Observations included the number of individuals and types of insect pests. Data were analyzed by the Shannon-Wiener diversity index (H'), evenness index (E), dominance index (C), and similarity index. Results: There were three types of insect pests with a total of 153 individuals that attacked corn in Baringeng Village, namely grasshoppers (Oxya sp.), planthoppers (Peregrinus maidis), and armyworm (Spodoptera frugiperda). The diversity index is included in the low category (H'=0.89), the evenness index (E) is in the high sort (E=0.81), the dominance index is in the low sort (C=0.44), and the lowest similarity index shown between Dusun Baringeng and Dusun Takku (IS=50%). Conclusions: The types of insect pests found in Baringeng Village come from three different orders, namely Orthoptera, Lepidoptera, and Hemiptera. Each problem shows other attack characteristics, but all attack the leaves. So that pest control can use natural materials by spraying on leaves, polyculture, crop rotation, or taking pests directly.

Structural changes upon membrane insertion of the insecticidal pore-forming toxins produced by Bacillus thuringiensis.

Different Bacillus thuringiensis (Bt) strains produce a broad variety of pore-forming toxins (PFTs) that show toxicity against insects and other invertebrates. Some of these insecticidal PFT proteins have been used successfully worldwide to control diverse insect crop pests. There are several studies focused on describing the mechanism of action of these toxins that have helped to improve their performance and to cope with the resistance evolved by different insects against some of these proteins. However, crucial information that is still missing is the structure of pores formed by some of these PFTs, such as the three-domain crystal (Cry) proteins, which are the most commercially used Bt toxins in the biological control of insect pests. In recent years, progress has been made on the identification of the structural changes that certain Bt insecticidal PFT proteins undergo upon membrane insertion. In this review, we describe the models that have been proposed for the membrane insertion of Cry toxins. We also review the recently published structures of the vegetative insecticidal proteins (Vips; e.g. Vip3) and the insecticidal toxin complex (Tc) in the membrane-inserted state. Although different Bt PFTs show different primary sequences, there are some similarities in the three-dimensional structures of Vips and Cry proteins. In addition, all PFTs described here must undergo major structural rearrangements to pass from a soluble form to a membrane-inserted state. It is proposed that, despite their structural differences, all PFTs undergo major structural rearrangements producing an extended α-helix, which plays a fundamental role in perforating their target membrane, resulting in the formation of the membrane pore required for their insecticidal activity.

Refuges of conventional host plants counter dominant resistance of cotton bollworm to transgenic Bt cotton

Transgenic crops have revolutionized insect pest control, but evolution of resistance by pests threatens their continued success. The primary strategy for combating pest resistance to crops producing insecticidal proteins from Bacillus thuringiensis (Bt) uses refuges of non-Bt host plants to allow survival of susceptible insects. The prevailing paradigm is that refuges delay resistance that is rare and recessively inherited. However, we discovered refuges countered resistance to Bt cotton that was neither rare nor recessive. In a 15-year field study of the cotton bollworm, the frequency of a mutation conferring dominant resistance to Bt cotton surged 100-fold from 2006 to 2016 yet did not rise from 2016 to 2020. Computer simulations indicate the increased refuge percentage from 2016 to 2020 is sufficient to explain the observed halt in the evolution of resistance. The results also demonstrate the efficacy of a Bt crop can be sustained by non-Bt refuges of other crops.

Preparation of enzyme-responsive composite nanocapsules with sodium carboxymethyl cellulose to improve the control effect of root-knot nematode disease

Developing an efficient drug delivery system to mitigate the harm caused by root-knot nematodes is crucial. In this study, enzyme-responsive release abamectin nanocapsules (AVB1a NCs) were prepared using 4, 4-diphenylmethane diisocyanate (MDI) and sodium carboxymethyl cellulose as response release factors. The results showed that the average size (D50) of the AVB1a NCs was 352 nm, and the encapsulation efficiency was 92 %. The median lethal concentration (LC50) of AVB1a NCs for Meloidogyne incognita activity was 0.82 mg L−1. Moreover, AVB1a NCs improved the permeability of AVB1a to root-knot nematodes and plant roots and the horizontal and vertical soil mobility. Furthermore, AVB1a NCs greatly reduced the adsorption of AVB1a by the soil compared to AVB1a emulsifiable concentrate (EC), and the effect of the AVB1a NCs on controlling root-knot nematode disease was increased by 36 %. Compared to the AVB1a EC, the pesticide delivery system significantly reduced the acute toxicity to the soil biological earthworms by approximately 16 times that of the AVB1a and had a lower overall impact on the soil microbial communities. This enzyme-responsive pesticide delivery system had a simple preparation method, excellent performance, and high level of safety, and thus has great application potential for plant diseases and insect pests control.

Insect chaperones Hsp70 and Hsp90 cooperatively enhance toxicity of Bacillus thuringiensis Cry1A toxins and counteract insect resistance.

Bacillus thuringiensis (Bt) produces different insecticidal proteins effective for pest control. Among them, Cry insecticidal proteins have been used in transgenic plants for the control of insect pests. However, evolution of resistance by insects endangers this technology. Previous work showed that the lepidopteran insect Plutella xylostella PxHsp90 chaperone enhanced the toxicity of Bt Cry1A protoxins by protecting them from degradation by the larval gut proteases and by enhancing binding of the protoxin to its receptors present in larval midgut cells. In this work, we show that PxHsp70 chaperone also protects Cry1Ab protoxin from gut proteases degradation, enhancing Cry1Ab toxicity. We also show that both PxHsp70 and PxHsp90 chaperones act cooperatively, increasing toxicity and the binding of Cry1Ab439D mutant, affected in binding to midgut receptors, to cadherin receptor. Also, insect chaperones recovered toxicity of Cry1Ac protein to a Cry1Ac-highly resistant P. xylostella population, NO-QAGE, that has a disruptive mutation in an ABCC2 transporter linked to Cry1Ac resistance. These data show that Bt hijacked an important cellular function for enhancing its infection capability, making use of insect cellular chaperones for enhancing Cry toxicity and for lowering the evolution of insect resistance to these toxins.

Wolbachia infection in native populations of Blattella germanica and Periplaneta americana.

Cockroaches are significant pests worldwide, being important in medical, veterinary, and public health fields. Control of cockroaches is difficult because they have robust reproductive ability and high adaptability and are resistant to many insecticides. Wolbachia is an endosymbiont bacterium that infects the reproductive organs of approximately 70% of insect species and has become a promising biological agent for controlling insect pests. However, limited data on the presence or strain typing of Wolbachia in cockroaches are available. PCR amplification and sequencing of the wsp and gltA genes were used to study the presence, prevalence and molecular typing of Wolbachia in two main cockroach species, Blattella germanica (German cockroach) and Periplaneta americana (American cockroach), from different geographical locations of Iran. The Wolbachia endosymbiont was found only in 20.6% of German cockroaches while it was absent in American cockroach samples. Blast search and phylogenetic analysis revealed that the Wolbachia strain found in the German cockroach belongs to Wolbachia supergroup F. Further studies should investigate the symbiotic role of Wolbachia in cockroaches and determine whether lack of Wolbachia infection may increase this insect's ability to tolerate or acquire various pathogens. Results of our study provide a foundation for continued work on interactions between cockroaches, bacterial endosymbionts, and pathogens.

Recent Developments in the Applications of GO/rGO-Based Biosensing Platforms for Pesticide Detection

Pesticides are often used in different applications, including agriculture, forestry, aquaculture, food industry, etc., for the purpose of controlling insect pests and weeds. The indiscriminate usage of pesticides poses a massive threat to food, environmental, and human health safety. Hence, the fabrication of a sensitive and reliable sensor for the detection of pesticide residues in agro products and environmental samples is a critical subject to be considered. Recently, the graphene family including graphene oxide (GO) and reduced graphene oxide (rGO) have been frequently employed in the construction of sensors owing to their biocompatibility, high surface-area-to-volume ratio, and excellent physiochemical, optical, and electrical properties. The integration of biorecognition molecules with GO/rGO nanomaterials offers a promising detection strategy with outstanding repeatability, signal intensity, and low background noise. This review focuses on the latest developments (2018 to 2022) in the different types of GO/rGO-based biosensors, such as surface plasmon resonance (SPR), fluorescence resonance energy transfer (FRET), and electrochemical-based techniques, among other, for pesticide analysis. The critical discussions on the advantages, limitations, and sensing mechanisms of emerging GO/rGO-based biosensors are also highlighted. Additionally, we explore the existing hurdles in GO/rGO-based biosensors, such as handling difficult biological samples, reducing the total cost, and so on. This review also outlines the research gaps and viewpoints for future innovations in GO/rGO-based biosensors for pesticide determination mainly in areas with insufficient resources.

The gut symbiont Sphingomonas mediates imidacloprid resistance in the important agricultural insect pest Aphis gossypii Glover

BackgroundNeonicotinoid insecticides are applied worldwide for the control of agricultural insect pests. The evolution of neonicotinoid resistance has led to the failure of pest control in the field. The enhanced detoxifying enzyme activity and target mutations play important roles in the resistance of insects to neonicotinoid resistance. Emerging evidence indicates a central role of the gut symbiont in insect pest resistance to pesticides. Existing reports suggest that symbiotic microorganisms could mediate pesticide resistance by degrading pesticides in insect pests.ResultsThe 16S rDNA sequencing results showed that the richness and diversity of the gut community between the imidacloprid-resistant (IMI-R) and imidacloprid-susceptible (IMI-S) strains of the cotton aphid Aphis gossypii showed no significant difference, while the abundance of the gut symbiont Sphingomonas was significantly higher in the IMI-R strain. Antibiotic treatment deprived Sphingomonas of the gut, followed by an increase in susceptibility to imidacloprid in the IMI-R strain. The susceptibility of the IMI-S strain to imidacloprid was significantly decreased as expected after supplementation with Sphingomonas. In addition, the imidacloprid susceptibility in nine field populations, which were all infected with Sphingomonas, increased to different degrees after treatment with antibiotics. Then, we demonstrated that Sphingomonas isolated from the gut of the IMI-R strain could subsist only with imidacloprid as a carbon source. The metabolic efficiency of imidacloprid by Sphingomonas reached 56% by HPLC detection. This further proved that Sphingomonas could mediate A. gossypii resistance to imidacloprid by hydroxylation and nitroreduction.ConclusionsOur findings suggest that the gut symbiont Sphingomonas, with detoxification properties, could offer an opportunity for insect pests to metabolize imidacloprid. These findings enriched our knowledge of mechanisms of insecticide resistance and provided new symbiont-based strategies for control of insecticide-resistant insect pests with high Sphingomonas abundance.

The gut bacterium Serratia marcescens mediates detoxification of organophosphate pesticide in Riptortus pedestris by microbial degradation

AbstractOrganophosphate insecticides have been widely used in agriculture to control insect pests and raised growing problems including insecticide resistance. According to recent studies, microbial symbionts play important roles in developing insecticide resistance. The bean bug Riptortus pedestris is a notorious pest of leguminous crops, harbouring diverse microorganisms in their insect midguts. However, the potential biological roles of many gut‐associated bacteria are largely unknown. In this study, we isolated a bacterial strain from the midgut of R. pedestris and identified it as Serratia marcescens based on its morphological characteristics and the phylogenetic analysis of the 16S rRNA gene sequence. A halo of phosphorus‐solubilizing bacteria was observed on a medium containing lecithin and an organophosphorus insecticide dimethoate. Subsequently, the microbial degradation of dimethoate was determined using Gas Chromatography with Mass Spectroscopy (GC–MS). Further analysis indicated that the S. marcescens contained organophosphorus‐degrading MBL‐fold metallo‐hydrolase gene. Additionally, we discovered that the bacterium could colonize the insect midgut stably and enhance the host survivorship when exposed to dimethoate. Our results revealed that an insect gut‐associated bacterium could degrade organophosphorus compounds, thereby reducing related insecticide toxicity to the insect hosts. These findings provided further insights into the host‐microbiota interactions underpinning the development of insecticide resistance.

Diversidad de Insectos en Maíz en la Comarca Lagunera, México

Maize, Zea mays L., is of great economic, social, and cultural importance in Mexico. Its agroecosystem has phytophagous and entomophagous insects. Diversity in the Comarca Lagunera was studied in 2020 and 2021. Thirty-eight species of predators and parasitoids were found, with most common being Bariscapus sp., Orius leavigatus, Tetrastichus sp., Hippodamia convergens, Chrysoperla sp., and Collops vittatus. This complex of entomophagous insects is important for natural biological control of pest insects. Twenty-six species of phytophagous insects were also found, the most common being Chaetocnema ectypa, Diabrotica balteata, Rhopalosiphum maidis, and Dalbulus maidis. This complex of phytophagous insects may be important as a limiting factor of maize productivity or be potential pests. Based on values of the diversity indices of Margalef, Simpson and Shannon-Wiener, diversity of entomophagous insects was more at the beginning of the crop-growing season, while diversity of phytophagous insects was greater mid to late; diversity of entomofauna in maize was intermediate.

Bioinsecticidal efficacy of Eucalyptus camaldulensis (Dehn) and Hyptis suaveolens (L.) Poit. leaf extracts on Callosobruchus maculatus (Cowpea weevil)

The modern method of controlling insect pests, using synthetic insecticides has caused serious problems to human health and the environment. Hence, the need for alternative, cheap, readily available and acceptable insect pest control methods, among which are the use of plant leaf extracts. The aim of this study was to determine the bioinsecticidal efficacy of Eucalyptus camaldulensis and Hyptis suaveolens against cowpea weevils (Callosobruchus maculatus). The bioassay of the powdered methanol extracts of leaves of E. camaldulensis and H. suaveolens was carried varying quantities (3 g, 6 g, 9 g and 12 g) of powdered extracts of the respective plant samples were mixed separately with 50 g of cowpea. Synthetic insecticide, Al2(PO4)3 was used as positive control while the negative control contained no treatment. Proximate compositions of the treated and untreated cowpeas were done using standard procedures while the extracts were characterized using Gas Chromatography-Mass Spectroscopic. Although mortality rates of the C. maculatus in presence of the extracts did not follow any dose-dependant trend, the respective dosages used for treatments inhibited the growth and activities of Callosobruchus maculatus. A high rate of seed damage was observed in the untreated cowpea seeds. Gas Chromatography-Mass Spectroscopy of the extracts identified the presence of seven potential insecticidal compounds (Bargamotene, Globulol, Humulene, Linolein, Prasterone, Terpinen-4-ol and Traumatic acid) in Hyptis suaveolen. In the Eucalyptus camaldulensis extract, 13 potential insecticidal compounds (Barosma camphor, Carvacrol, Carbazon, Irone, Isoborneol, 5-methyl, 1,4-Naphthoquinone, Oleic Acid, Phytol, Piperitone, Pyrazole-3-carboxylic acid, Terpinen-4-ol, Viridiflorol) were identified. The bioinsecticidal activities of these plant extracts could be attributed to the presence of phytochemicals and isolated insecticidal compounds.

Exploration of the DNA Photocleavage Activity of O-Halo-phenyl Carbamoyl Amidoximes: Studies of the UVA-Induced Effects on a Major Crop Pest, the Whitefly Bemisia tabaci

The DNA photocleavage effect of halogenated O-carbamoyl derivatives of 4-MeO-benzamidoxime under UVB and UVA irradiation was studied in order to identify the nature, position, and number of halogens on the carbamoyl moiety that ensure photoactivity. F, Cl, and Br-phenyl carbamate esters (PCME) exhibited activity with the p-Cl-phenyl derivative to show excellent photocleavage against pBR322 plasmid DNA. m-Cl-PCME has diminished activity, whereas the presence of two halogen atoms reduced DNA photocleavage. The substitution on the benzamidoxime scaffold was irrelevant to the activity. The mechanism of action indicated function in the absence of oxygen, probably via radicals derived from the N-O bond homolysis of the carbamates and in air via hydroxyl radicals and partially singlet oxygen. The UVA-vis area of absorption of the nitro-benzamidoxime p-Cl-PCMEs allowed for the investigation of their potential efficacy as photopesticides under UVA irradiation against the whitefly Bemisia tabaci, a major pest of numerous crops. The m-nitro derivative exhibited a moderate specificity against the adult population. Nymphs were not affected. The compound was inactive in the dark. This result may allow for the development of lead compounds for the control of agricultural insect pests that can cause significant economic damage in crop production.

The cumulative use of compost teas and rhizobia against Megalurothrips jostetti for yield improvement in field grown cowpea at Ngaoundere (Cameroon)

Cowpea (Vigna unguiculata) is a food crop legume, considered as one of the cheapest sources of protein. However, its culture is subject to attack by many pests that drastically reduce yield. An alternative for better pest control and increased yield is the simultaneous use of biopesticides and biofertilizers. The objective of this study was to control the pests, while optimizing yields of this legume in a sustainable manner. To achieve this, compost teas and rhizobia were first produced and characterized. Then a pot experiment was set up in a triplicated randomized block design comprising 11 treatments, in order to determine the ability of compost teas and rhizobia to control insect pests and optimize the yield of this Fabaceae. The characterization of the compost teas revealed that the pH varied around the neutrality with an abundance of alkaloids and terpenoids and the absence of tannins. The three isolates obtained were all Gram negative bacteria and did not absorb the dye Congo red. Compost teas reduced and stabilized thrips (Megalurothrips jostetti) population development. Non-aerated compost teas from Tithonia diversifolia (PNA) alone, and its association with rhizobia (Rh + TNA) resulted in a reduction of the number of flower buds attacks. Their effects appeared to be limited outside the pods as they did not positively affect the number of seeds attacked. Both PNA and Rh+TNA treatments increased pod number, and seed biomass. Rhizobia and rhizobia + non-aerated compost tea from Tithonia diversifolia (Rh+TNA) significantly increased the yield of this plant species.

Coloring with Spiders: Our Favorites from Florida

Florida has a rich diversity of spiders that vary greatly in body shape, size, color, hunting strategy, and habitat. While spiders are often feared, they are generally non-aggressive and provide essential ecosystem services, such as controlling pest insects in homes, gardens, and agricultural crops. This downloadable educational coloring book focused on spiders provides a creative way for people of all ages to appreciate the beauty and intrigue of spiders. It accompanies An introduction to Some Common and Charismatic Florida Spiders, a facts sheet highlighting some of the most commonly encountered spiders in Florida and some less common, but particularly charismatic, groups. The fact sheet, available at https://edis.ifas.ufl.edu/publication/IN1366, provides information on species biology along with images and descriptions for spiders across 15 families.

An Introduction to Some Common and Charismatic Florida Spiders

Florida has a rich diversity of spiders that vary greatly in body shape, size, color, hunting strategy, and habitat. While spiders are often feared, they are generally non-aggressive and provide essential ecosystem services, such as controlling pest insects in homes, gardens, and agricultural crops. This publication highlights some of the most commonly encountered spiders in Florida and some less common, but particularly charismatic, groups. The publication provides information on species biology along with images and descriptions for spiders across 15 families. Accompanying the publication is a downloadable educational coloring book focused on spiders, providing a creative way for people of all ages to appreciate the beauty and intrigue of spiders.

Susceptibility Comparison of Bumblebee and Honeybee to Acetamiprid and Imidacloprid

midacloprid and acetamiprid are neonicotinoid insecticides introduced in the market for the control of insect pests of agricultural crops, but unfortunately these insecticides are causing harmful effect on non-target organisms including honeybees and bumblebees. Insecticides of this group effect acetylcholine nicotinic receptors. Apis mellifera, the European honeybee and Bombus haemorrhoidalis are important pollinators for wild and managed crops in Pakistan, but unfortunately their population is declining day by day at alarming rate. This study was design to find out the susceptibility level and insecticidal toxicity comparison on A. mellifera and B. haemorrhoidalis to acetamiprid and imidacloprid under controlled laboratory conditions by using contact and oral exposure methods. The results of oral method by using sugar solution showed that honeybee is more susceptible as compared to bumblebee on both insecticides. Maximum mortality i.e. 20%, 35%, 66%, in honeybee and 16%, 29%, 45% in bumblebee workers at acetamiprid and at imidacloprid 46%, 67%, 83% in honeybee and 34%, 56%, 72% in bumblebee were observed respectively after the exposure of 3hrs. 6hrs. and 24hrs. Similar susceptibly results were found on pollen and contact method. Overall results demonstrate that these both neonicotinoid insecticides are toxic for bumblebees and honeybees, and honeybee workers are more susceptible as compared to bumblebee workers at company recommended field realistic dose.