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Mosquitoes, as hematophagous ectoparasites, are significant pests and vectors of numerous pathogens, causing diseases such as dengue, lymphatic filariasis, malaria, chikungunya, and Japanese encephalitis in India. This study investigates the potential of natural insecticides derived from plants to combat mosquito populations, focusing on botanical extract from the leave of Sphaeranthus indicus. Specifically, the hexane extract of S. indicus exhibited notable efficacy against Aedes aegypti and Culex quinquefasciatus mosquitoes. The research entailed the extraction, fractionation, and structural identification of active compounds through spectroscopic analysis. Among ten fractions isolated, fraction 4 demonstrated the highest mosquitocidal activity, leading to the identification of β-isocostic acid as the primary active compound. The study's biological assays included ovicidal, larvicidal, and pupicidal tests, revealing that β-isocostic acid exhibited significant efficacy, with ovicidal activity rates of 75.2% and 78.2% at 2 ppm against Ae. aegypti and Cx. quinquefasciatus , respectively. Larvicidal and pupicidal assays further confirmed the potent activity of β-isocostic acid, with LC 50 values of 1.02 ppm and 0.96 ppm against Ae. aegypti and Cx. quinquefasciatus larvae, and 1.20 ppm and 1.14 ppm against Ae. aegypti and Cx. quinquefasciatus pupae respectively. The isolated compound demonstrated comparable efficacy to azadirachtin and temephos, indicating its potential as a natural mosquitocidal agent. This research underscores the importance of exploring botanical sources for developing effective and environmentally sustainable mosquito control strategies, particularly in light of increasing resistance to synthetic insecticides. The findings suggest that β-isocostic acid could serve as a viable alternative to chemical mosquitocides, contributing to integrated vector management programs. [Display omitted] • First report on larvicidal, pupicidal, and ovicidal effects of β-isocostic acid. • β-isocostic acid was isolated from the leaves of Spharanthus indicus. • Characterized using IR, NMR, and GC-MS techniques. • The compound exhibited promising ovicidal, larvicidal and pupicidal efficacy. • Supports natural products as promising alternatives to synthetic insecticides. [ABSTRACT FROM AUTHOR]

[Display omitted] • Nanoemulsified Citronella EO 15% is lethal for eggs of C. hominivorax. • Nanoemulsified Citronella EO 15% is lethal for larvae of C. hominivorax. • Nanoemulsified Citronella EO 15% reduces the oviposition of C. hominivorax. • Adult of C. hominivorax are sensitive to nanoemulsified Citronella EO 15%. Cochliomyia hominivorax is the dipteran that causes the worst and most serious types of myiasis in animals and humans in the Americas. They are parasitic affections caused by the massive infestation of larvae of this species on the tissues of living mammals. The routine treatment uses chemosynthetic products that have high toxicity and can cause several injuries to animal and human health, besides environmental contamination. The development of more friendly alternatives to the treatment of this disease is an important knowledge gap nowadays. Citronella (Cymbopogon winterianus) is the most widely cultivated medicinal plant in tropical and subtropical regions. Essential oils have a recognised repellent and larvicidal activity against a wide variety of insects. This work aimed to evaluate the repellent, ovicidal and larvicidal efficacy of a topical commercial formulation composed of 15% (w/v) nanoemulsified Citronella essencial oil (Nano Citronela Plus®) in in vitro trials on specimens of C. hominivorax created under laboratory conditions. Nano Citronela Plus® is an oil-in-water nanoemulsion obtained by high-pressure homogenization method. The composition of tested nanoemulsion was Cymbopogon winterianus essential oil, vanillin, caprylic/capric triglyceride, polysorbate 80, sorbitan oleate, tocopheryl acetate, sodium benzoate and water. Nano Citronela Plus® demonstrated 100% lethality on eggs and first and second stage larvae of C. hominivorax. Mortality in the larvae of third stage was 69.33% and inhibited the oviposition of C. hominivorax females. Nano Citronela Plus® proved to be a possible herbal alternative for the control and treatment of myiasis caused by C. hominivorax. In vivo studies may test this hypothesis. [ABSTRACT FROM AUTHOR]

Natural pyrethrin insecticides produced by Dalmatian pyrethrum (Tanacetum cinerariifolium) have low mammalian toxicity and short environmental persistence, providing an alternative to widely used synthetic agricultural insecticides that pose a threat to human health and the environment. A recent surge of interest in the use of pyrethrins as agricultural insecticides coincides with the discovery of several new genes in the pyrethrin biosynthetic pathway. Elucidation of this pathway facilitates efforts to breed improved pyrethrum varieties and to engineer plants with improved endogenous defenses or hosts for heterologous pyrethrin production. We describe the current state of knowledge related to global pyrethrum production, the pyrethrin biosynthetic pathway and its regulation, and recent efforts to engineer the pyrethrin pathway in diverse plant hosts. Pyrethrin insecticides produced by Tanacetum cinerariifolium provide a human-safe and ecologically sound alternative to widely used synthetic insecticides. The development of transcriptomic and genomic resources for T. cinerariifolium facilitated the elucidation of numerous steps in the pyrethrin biosynthetic pathway. Pyrethrin biosynthetic genes have been engineered into diverse plant hosts; these efforts demonstrate the promise of engineering plants with improved endogenous defenses or of the development of an alternative source to pyrethrins for use as insecticides. [ABSTRACT FROM AUTHOR]

• Insecticidal effect of Tithonia diversifolia was evaluated against the fall armyworm. • Fraction A reduced the pupal weight. • Fractions B and C increased the duration of the larval phase. • Sesquiterpene lactones reduced the larval period and pupal weight. Plant extracts can be used as an alternative to synthetic insecticides for the control of insect pests. This work aimed to evaluate the insecticidal effect of the ethyl acetate fractions and sesquiterpene lactones from Tithonia diversifolia (Asteraceae) leaf extract against the fall armyworm, Spodoptera frugiperda (Lepidoptera: Noctuidae). As a result, we found that the fraction A (20% methanol (MeOH)) at 100 ppm reduced pupal weight by 12.2% compared to the control. Fractions B (40% MeOH) and C (60% MeOH) at 100 ppm increased the duration of the larval period by 1.87 and 2.03 days, respectively. The sesquiterpene lactones tagitinin A (1), tagitinin C (2) and 1 β -methoxydiversifolin (3) at 100, 50 and 10 ppm affected the larval development with reduction of the larval period and pupal weight. Neither the fractions nor the pure compounds interfered with the duration of the pupal phase, nor did they cause larval or pupal mortality. [ABSTRACT FROM AUTHOR]

[Display omitted] • InertPMS, DiaHerb, DEBBM, and DEA were the most effective DEs. • InertPMS killed all T. castaneum parental individuals at 125 ppm after 3 days. • InertPMS, DiaHerb, DEBBM, and DEA suppressed progeny at 125 ppm. • DiaFil 610 was the least effective DE for adult mortality and progeny. The utilization of diatomaceous earths (DEs) has been considered as a potential alternative to traditional insecticides for controlling grain storage insect pests. In this study, 19 different commercial DEs obtained from various regions of the world were evaluated for their effectiveness to manage Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae), in vitro. Two different series of bioassays were carried out, with the first screening all 19 DEs and the second evaluating the eight most effective ones at different doses and exposure intervals for mortality assessment and progeny production. Four enhanced DEs, namely InertPMS, DEA, DiaHerb, and DEBBM were highly effective compared to other DEs tested. InertPMS exhibited complete adult mortality at 50 mg/kg, followed by DEA at 75 mg/kg, DiaHerb at 100 mg/kg, and DEBBM at 125 mg/kg, while GrainGuard exhibited 94.52 % at 125 mg/kg, 14 days post-exposure. Protect-It, SilicoSec, and DiaFil 610 were less effective at 400 mg/kg, causing 87.3 %, 84.4 %, and 79.2 % mortality after 14 days, respectively. The offspring was suppressed in wheat treated with InertPMS at 75 mg/kg, while DEA, DiaHerb, and DEBBM revealed no progeny emergence at 125 mg/kg. GrainGuard, Protect-It, SilicoSec, and DiaFil 610 were not successful at progeny suspension after 62 days. These findings suggest that the use of specific DEs at low doses could be a viable option to mitigate the use of conventional insecticides and diminish the residues of insecticides on stored grains, making them the most feasible components for integrated pest management (IPM) in stored grain systems. [ABSTRACT FROM AUTHOR]

Extracts and compounds from the Chilean plants canelo, Drimys winteri J.R. Forst. & G. Forst. (Winteraceae), tabaco del diablo, Lobelia tupa L. (Campanulaceae), huevil, Vestia foetida Hoffmans. (Solanaceae) and violeta, Viola portalesia Gay (Violaceae) were evaluated against Sitophilus granarius L. (Coleoptera: Curculionidae), one of the most widespread and destructive primary pests of stored cereals. Total extracts at concentrations of 2.5% w / w in diets, over 6-days, display insecticidal effects against S. granarius . D. winteri caused the mortality of 87.5% of insects; L. tupa 80%, V. foetida 5 6% whereas V. portalesia killed 45% of insects under the same conditions. In an effort to determine the active compounds, the extracts of Lobelia tupa and Drimys winteri were purified by preparative chromatography. The piperidine alkaloid lobelanidine was isolated from L. tupa and the drimane sesquiterpenes drimenin, drimenol and polygodial were isolated as the major components in the extract from D. winteri . The purified compounds compounds displayed insecticidal activity against S. granarius in a concentration/dependent-time manner (% mortality at 0.5% w / w over 6-days): polygodial 80%, drimenol 60%, lobelanidine 47%, and drimenin 20%. In agreement with these results, grains treated with polygodial showed greater protection against the feeding attack by the granary weevil. These results provide evidence of the importance of elements of the native Chilean flora as new potential sources of botanical pesticides for the insect pest control. [ABSTRACT FROM AUTHOR]

The effects of kaolin and diatomaceous earth applied alone and in combinations with sweet orange [ Citrus sinensis (L.) Osbeck] peel essential oil against Rhyzopertha dominica (F.) (Coleoptera: Bostrichidae) and wheat microbial populations were evaluated. Adult beetles reared on durum wheat (cv Simeto) were used to carry out the tests. Five formulations at five application rates were tested. Both insect mortality and progeny production were affected by the treatment, the application rate and the exposure time. C. sinensis essential oil showed a synergistic effect on the mortality of R. dominica , if combined with kaolin, and antagonistic effect when admixed with diatomaceous earth. Yeasts and moulds as well as total mesophilic aerobic bacteria growths were reduced by C. sinensis essential oil applied alone more than the other dusts and dust-essential oil-based treatments. Kaolin admixed with C. sinensis peel essential oil might be a viable alternative to the chemical pesticides commonly used in wheat pest management. [ABSTRACT FROM AUTHOR]

Abstract: Carbaryl is currently one of the most commonly used insecticides for the control of the pineapple fruit borer, Strymon megarus (Godart), in commercial pineapple production. To evaluate more sustainable biological alternatives to conventional insecticides, three microbial and one botanical insecticide were studied. Beauveria bassiana, Metarhizium anisopliae, Bacillus thuringiensis (Bt) and a plant extract from Quassia amara were compared with carbaryl in replicated field trials in Costa Rica during 2005 and 2006. In both years of testing, the untreated control received over 50% fruit damage from S. megarus. Bt and carbaryl provided the highest level of control and the lowest level of fruit damage compared to all other treatments. Based on the results of this study, Bt appears to be an acceptable biological alternative to the conventional insecticide (carbaryl) for control of S. megarus on pineapple. In addition, Bt was the least expensive treatment used in this study. [Copyright &y& Elsevier]

The insecticidal efficacy of the diatomaceous earth (DE) formulation SilicoSec (Biofa GmbH) against adults and larvae of the confused flour beetle, Tribolium confusum DuVal (Coleoptera: Tenebrionidae) was evaluated in laboratory tests. These tests were conducted at five temperatures, 22°C, 25°C, 27°C, 30°C and 32°C, and two relative humidity levels, 55% and 65%. SilicoSec was applied to three types of product, hard wheat, soft wheat and wheat flour, at four dose rates, 0.25, 0.5, 1 and 1.5 g/kg of each product. In order to assess the influence of larval instar on the efficacy of SilicoSec, the larvae were divided into two groups, young and old larvae, corresponding to 1–3 and 4–7 instar larvae, respectively. Similarly, adults were divided into three different groups, 1, 2 and 7-d old adults, respectively. For both adults and larvae, mortality on wheat or flour treated with SilicoSec increased with the exposure interval and the dose rate. Larvae were more sensitive to DE than adults, given that adults could survive exposure intervals and application rates that were lethal to larvae. The mortality of larvae and adults exposed to SilicoSec increased with increasing temperature. In contrast, the efficacy of SilicoSec notably decreased with the increase of relative humidity from 55% to 65%. Significantly, more adults and larvae were dead in SilicoSec-treated wheat than in treated flour. The efficacy of SilicoSec was substantially affected by the age of the exposed individuals. Young larvae were significantly more sensitive than old ones. Adults became significantly less susceptible to SilicoSec as their age increased from 1 to 2 and to 7 d. [Copyright &y& Elsevier]

The insecticidal efficacy of the diatomaceous earth formulation SilicoSec® (Agrinova GmbH, Germany) against the rice weevil, Sitophilus oryzae (L.) (Coleoptera: Curculionidae) was evaluated on peeled rice, paddy rice, maize and barley in laboratory tests. SilicoSec was applied at five dose rates: 0.125, 0.25, 0.5, 1 and 1.5 g/kg of grain. The treated grains were infested with S. oryzae adults, and the weevil mortality was estimated after 24, 48 h, 7 and 14 d of exposure on treated grain. After the 14 d counts, all the exposed adults were removed and progeny production on treated grains was assessed 45 and 90 d later. Insecticidal efficacy of SilicoSec against the rice weevil was highly affected by grain type, exposure interval and dose rate. In all grains tested, longer exposure intervals increased weevil mortality. The efficacy of SilicoSec on maize was not satisfactory, given that after a 14 d exposure at the highest dose rate the mortality did not exceed 65%. Moreover, progeny production on treated maize was high, regardless of the dose rate. On the other hand, 100% of weevils were dead on barley treated with the two highest dose rates of SilicoSec, after a 7 d exposure. However, a complete suppression of progeny production on treated barley was not achieved, even at the highest dose rate. A satisfactory level of protection was recorded on paddy rice treated with 1 and 1.5 g of SilicoSec/kg. At these two rates, all adults were dead after a 7 d exposure, and no progeny were produced during the 90 d incubation period. In contrast, the mortality on peeled rice treated with 1.5 g of SilicoSec/kg did not reach 100%, even after 14 d of exposure, and a high number of progeny were recorded. [Copyright &y& Elsevier]

The insecticidal effect of Trichoderma harzianum (TH), diatomaceous earth (DE), kaolin (KA) and their combinations against Callosobruchus maculatus (F.) and Callosobruchus chinensis L. (Coleoptera: Chrysomelidae: Bruchinae) was evaluated. The fungus T. harzianum was applied at 1 × 105, 1 × 106 and 1 × 107 spores/kg of cowpea seeds individually and mixed with 100, 500 and 1000 mg/kg of DE or KA. The effect of individual and binary treatments on adult mortality after 3 and 7 days of exposure was determined. The progeny production of both insects and weight loss in cowpea seeds were assessed after 45 days of exposure. Complete adult mortality of both insect species was achieved by using the highest application rate of DE/TH mixture (1000 mg/kg of DE+1.0 × 107 spores/kg of TH) after 7 days. A mixture of KA/TH (1000 mg/kg of KA+1.0 × 107 spores/kg of TH) caused 100.0 and 97.9% mortality of C. maculatus and C. chinensis , respectively, after 7 days of exposure. Progeny production of both insect species was significantly decreased for all individual and combination treatments compared to the control. No progeny of C. chinensis was detected in cowpea seeds treated with the mixture 1000 mg/kg of KA+‏ 1.0 × 107 spores/kg of TH after 45 days. Also, the combination treatments protected cowpea seeds from damage caused by C. maculatus and C. chinensis for 45 days. These results indicate that the combinations of TH fungus with DE or KA could be successfully used for the management of C. maculatus and C. chinensis in stored cowpea seeds. • The use of natural products is acceptable approach worldwide to overcome problems associated with synthetic insecticides. • Combination of T. harzianum with DE or KA gave satisfactory management of C. maculatus and C. chinensis on stored cowpea. • Complete adult mortality and progeny suppression were achieved by using high application rates of fungus with inert dusts. • The combinations of inert dusts and fungus were more toxic to C. chinensis than C. maculatus. [ABSTRACT FROM AUTHOR]

• The major constituent of Syzygium aromaticum essential oil is eugenol. • Syzygium aromaticum essential oil and eugenol are effective for control of C. felis. • Positive results point to the development of natural insecticides for flea control. The aim of this study was to evaluate the in vitro activity of Syzygium aromaticum essential oil (SAEO) and its main constituent eugenol (EG) against adult fleas and their action in the maturation of eggs into adults of Ctenocephalides felis felis. In order to evaluate the pulicidal activity, 10 adult fleas were exposed to a filter paper impregnated with SAEO and EG at increasing concentrations of 0.047; 0.094; 0.188; 0.375; 0.750; 1.50; 3.00; 6.00; 12.00 and 24.00 μg cm−2. Flea mortality was evaluated 24 and 48 h after exposure. In order to evaluate the inhibition of the maturation of eggs into adults, 10 eggs were exposed to filter paper impregnated with SAEO and EG at the same concentrations used in the pulicidal test, and the evaluation was performed 30 days after incubation. Untreated repetitions were maintained in both studies (control group). The lethal concentration 50 (LC 50) of pulicidal activity to SAEO was 5.70 μg cm−2 in 24 h and 3.91 μg cm−2 in 48 h. The LC 90 was 16.10 μg cm−2 and 15.80 μg cm−2 in 24 and 48 h, respectively. The LC 50 of inhibition of the maturation of eggs into adults was 0.30 μg cm−2 and the LC 90 3.44 μg cm−2. The LC 50 of pulicidal activity to EG was 2.40 μg cm−2 in 24 h and 1.40 μg cm−2 in 48 h; the LC 90 was 8.10 μg cm−2 and 3.70 μg cm−2 in 24 h and 48 h, respectively. The LC 50 of inhibition of the maturation of eggs into adults was 0.10 μg cm−2 and the LC 90 0.68 μg cm−2. Based on the results obtained, it is possible to conclude that the both SAEO and EG have in vitro pulicidal activity as well as acting as inhibitors of the maturation of eggs into adults of the flea C. felis felis. [ABSTRACT FROM AUTHOR]

• The essential oil of E. caryophyllus was more toxic than I. verum against Callosobruchus maculatus in contact test. • Both oils reduced the number of eggs and insects emerged in both contact and repellency tests. • The LC 95 concentration for both oils was repellent to C. maculatus. • Both oils presented fumigant effect on C. maculatus. The cowpea weevil Callossobruchus maculatus Fabr. (Coleoptera: Chrysomelidae: Bruchinae) is the major pest in stored cowpea, especially in subtropical countries. Thus, the present study aimed to evaluate the insecticidal potential of the essential oils of Illicium verum Hook. F. and Eugenia caryophyllus Spreng on adults of C. maculatus. The components of the essential oils were obtained and identified, the contact toxicity and the repellent and fumigant effect were determined. In the contact and fumigation test the lethal concentrations LC 50 and LC 95 were determined, the lethal concentrations determined in the contact test were used in the repellency test. For contact and repellency tests, the number of eggs and adults emerged were counted. According to the chemical analysis of the oils, E-anethole (88.85 %) and eugenol (74.31 %) for I. verum and E. caryophyllus , respectively, were the compounds in greater quantity. The values of lethal concentrations LC 50 and LC 95 in the contact test were estimated at 9.62 and 32.78, 1.27 and 11.95 μL/20 g, respectively, for the oils of I. verum and E. caryophyllus. The essential oil of E. caryophyllus presented higher toxicity for both lethal concentrations, being 5.44 and 2.74 times more toxic than I. verum for LC 50 and LC 95 , respectively. In contact and repellency tests both oils reduced the number of eggs and insects emerged. The LC 95 concentration for both oils was repellent to C. maculatus. The essential oils of E. caryophyllus and I. verum presented a potential fumigant effect on C. maculatus with relatively low lethal concentration (LC 50) (22.36 and 20.27 μL/L of air for I. verum and E. caryophyllus , respectively), thus being an alternative to synthetic chemical insecticides for the control of stored grain pests. [ABSTRACT FROM AUTHOR]