Primary Pest Research Articles

Phenology and Monitoring of the Lesser Chestnut Weevil (Curculio sayi).

Simple SummaryThe lesser chestnut weevil (Curcilio sayi) is an emergent pest of chestnuts in the United States. Knowledge of this weevils phenology and the ability to monitor its populations will help us understand how this pest is emerging with expanding chestnut production and provide the means to begin to mitigate its effects on chestnut production. We explored the seasonal emergence of C. sayi in upstate New York through the use of traps and soil microcosms to understand when weevils begin to emerge and when the population peaks. We found that pyramid traps are most effective for monitoring and that populations have one generation that tends to peak late in the season. We also found that generational cohorts may stagger their emergence and delay leaving the soil for more than one year.With the introduction in recent years of high-yield blight-resistant chestnut varieties, the commercial chestnut industry in the United States is expanding. Accompanying this expansion is a resurgence in a primary pest of chestnut: C. sayi, the lesser chestnut weevil. This weevil damages the nut crop and infestations can surge from 0 to close to 100% in as little as two years. Understanding the dynamics of this pest has been challenging. Most work was conducted in the 1900s and only recently has this weevil garnered renewed interest. Recent work on C. sayi phenology has been completed in Missouri but conflicted with anecdotal reports from northern growers. From 2019 to 2020, we used a combination of trapping and microcosm studies to understand both C. sayi phenology and the means of monitoring this pest. C. sayi populations were univoltine and peaked in mid-October. Pyramid traps were the most effective at capturing adult C. sayi. C. sayi larvae, pupae, eclosed adults, and emerging adults were recovered from microcosm experiments. These results suggest that C. sayi emerges later in the northern US with the potential for a single generation to emerge over multiple subsequent years. Understanding C. sayi phenology along with the means of monitoring forms the basis for effective management and control in commercial chestnut orchards.

Resistance in Pink Bollworm Pectinophora gossypiella (Saunders) against Bt Cotton, a Major Threat to Cotton in India: A Brief Review

The pink bollworm, Pectinophora gossypiella (Lepidoptera: Gelechiidae) is a primary pest of cotton in many regions of the world. In many parts of India, pink bollworm (PBW) has become resistant to BG-I (Bollgard I®) that expresses a single Bt gene (Cry1Ac) in 2009 and BG-II (Cry1Ac and cry 2Ab) in 2015. The brief review addresses the possible reasons and solutions to resistance posed by this insect. The review addresses the following points: reasons for resistance in PBW is discussed; the life-history is discussed how it’s distinctness from other bollworms; the introduction of hybrid cotton lead to insecticide treadmill in India; reduced accomplishment of the refugia recommendations also contributed to the problem; poor compliance of the bio-safety laws also led to the problem; unfavorable crop management practices prove to be an add-on to the problem. Furthermore, the possible solutions of the problem are discussed; monitoring and mating disruption; cultivation of High-density short season (HD-SS) pure line varieties; case studies of sterile insect technique (SIT) proved to be supporting in control of PBW; RNA interference technique can overcome the problem of resistance; use of chemical insecticides in different manner can change the perspective; proper cultural or farming practices can make the difference; Bio-control agents can overcome the problem; extension functionaries can help in solving the PBW problem. Therefore the management of resistance in PBW requires a broader vision and development of technology.

Biological Activity of Insecticides Against Bradysia ocellaris Larvae (Diptera: Sciaridae): A New Pest of Strawberry Crops.

Black fungus gnat larvae are one of the primary insect pests in greenhouse and nursery crops, and Bradysia ocellaris (Comstock) (Diptera: Sciaridae) is one common pest species. This pest is difficult to control in Brazil because of the absence of registered insecticides. The aim of this work was to evaluate the effects of some insecticides on B. ocellaris larvae. We also verified that the insect growth regulator novaluron caused the deformation of B. ocellaris. Of the insecticides evaluated, malationa, and thiamethoxam showed high mortality rate (96 and 86 % respectively). Further, bioassays with acetamiprid (78 %) and novaluron (44 %) showed that the lethal concentrations (LC50) were 19.18 mg a.i.L-1 at 48h to acetamiprid and 1.24 mg a.i.L-1 at 120 h to novaluron. When larvae were fed on potato pieces treated with novaluron, independently of the dose, the mortality rate was 100 %, since no larvae could complete the development cycle. Among all evaluated insecticides, only acetamiprid and novaluron were considered effective tools for control of B. ocellaris larvae under laboratory conditions.

Surveillance Strategies of Rodents in Agroecosystems, Forestry and Urban Environments

Rodents belong to the group of occasionally economically significant to very significant pests. Some species, especially synanthropic species, cause material damage in various ways. Successful and sustainable management of rodent control strategies requires different procedures such as prevention and rodent control measures. The present study gives an overview of the most common rodent species and methods for estimating the rodent population to assess the risk of economic damage that may occur due to rodents feeding in field crops, gardens, orchards, and young forest plantations, as well as contamination of stored food. As a prerequisite for effective integrated control of mice and voles, it is necessary to implement an adequate long-term monitoring system of these species, as they are primary pests. The integrated approach improves the treatment efficacy and reduces the treatment costs but also is considered ecologically friendlier compared to conventional measures. An integrated approach should provide an effective strategy for rodent management and control in all types of rodent habitats, from agricultural and forestry production fields to residential and public areas. By combining different preventive measures, it is possible to prevent the presence of pests, which will therefore result in a reduction of pesticide use.

Kerentanan Relatif Beras terhadap Hama Kumbang Bubuk Gabah (Rhyzopertha dominica (F.))

The lesser grain borer, Rhyzopertha dominica (F.) (Coleoptera: Bostrichidae) is a primary pest that causes damage to stored cereals such as corn, grain, rice, wheat, sorghum, tubers, and starch-containing substrates and packaging made from wood. R. dominica not only cause losses in terms of quantity but also affect quality during the storage period through their feeding activities. The study aimed to determine the level of susceptibility to rice during storage to R. dominica. The research was conducted at the Laboratory of Plant Pest and Disease, Faculty of Agriculture, Malikussaleh University, Aceh which began from November 2019 to February 2020. The study was done in the form of laboratory experiments using a Completely Randomized Design (CRD) nonfactorial with a total treatment of 10 rice varieties. The results of variance analysis using the Duncan Multiple Range test showed that the susceptibility level of rice to R. dominica infestation was classified into moderate category. The highest percentage of weight loss was found in Mekongga varieties (1,95%) while the lowest in Inpari 30 (0,73%)

Combined effects of insecticide and IGP on native and invasive ladybeetles in apple orchard

AbstractThe Asian ladybeetle Harmonia axyridis Pallas is an invasive species commonly found in Canadian apple orchards. It threatens native ladybeetles through exploitative competition and intraguild predation (IGP), including the 12 spotted ladybeetle Coleomegilla maculata DeGeer (Gagnon, Heimpel and Brodeur, 2011). Both species are exposed to novaluron, a reduced risk insecticide used against the codling moth Cydia pomonella (L.), the primary pest in apple orchards. Previous research showed that novaluron is highly toxic for the invasive H. axyridis, but it is less toxic for the indigenous C. maculata. Novaluron reduces the adaptive value of IGP for H. axyridis but not for C. maculata. However, there is a lack of knowledge on the combined effect of novaluron and IGP outside laboratory conditions. This study explores under semi‐field conditions the effect of novaluron residues and IGP on the survival of H. axyridis and C. maculata larvae. IGP was assessed considering third instar larvae as predators. Results showed that novaluron was toxic for first instar larvae of both species after 10 days of exposure. When H. axyridis was the intraguild predator, novaluron increased the survival of the intraguild preys. Novaluron did not change the outcome of the IGP when C. maculata was the intraguild predator. These results indicate that novaluron can change the competition outcome between the invasive H. axyridis and a native ladybeetle species. This is the first demonstration that intraguild predation and competition may be greatly altered in the presence of pesticides.

Winter Cover Crops Reduce Spring Emergence and Egg Deposition of Overwintering Navel Orangeworm (Lepidoptera: Pyralidae) in Almonds.

Habitat diversification has been shown to positively influence a variety of ecosystem services to agriculture, including biological control of arthropod pests. The impact of increased biodiversity tends to be species specific though, and practices therefore need to be developed on a case-by-case basis for each cropping system. In perennial systems, numerous studies have demonstrated that cover crops can have positive impacts on soil quality and other ecosystem services, such as pollination and pest management. However, few studies have focused on the use of cover crops to enhance pest control in almond orchards, especially winter cover crops. The primary pest of almonds in North America is navel orangeworm, Amyelois transitella Walker, which overwinter as larva or pupa on remnant nuts, many of which remain on the orchard soil surface. In the spring, first flight adults subsequently use these remnant nuts as reproductive substrate. An experiment was conducted to evaluate the influence of two distinct winter cover crop mixtures on overwintering mortality and spring egg deposition of A. transitella. Remnant nuts placed into cover crop plots produced fewer adult A. transitella in the spring, suggesting increased overwintering mortality. Additionally, spring egg deposition was reduced on remnant nuts in the cover crops, possibly due to the ground covers interfering with host location and access. In this way, winter cover crops appear to contribute to the reduction of A. transitella populations in the orchard by altering abiotic and physical conditions, although studies to document specific mechanisms are still needed.

Effects of multigenerational imidacloprid and thiamethoxam stress on metabolism and physiology of Aphis glycines Matsumura (Hemiptera: Aphididae).

The soybean aphid, Aphis glycines Matsumura (Hemiptera: Aphididae), a primary pest of soybean, poses a severe threat to soybean production. In this study, the 4th instar nymphs were exposed to the LC50 and LC30 of imidacloprid and thiamethoxam from F0 to F4 generations to evaluate the activities of peroxidase, pyruvate kinase, and trehalase using microassay. We found that peroxidase and pyruvate kinase activities in soybean aphids increased rapidly, first to peak and then decreased slowly generation by generation under imidacloprid and thiamethoxam stress. In contrast, the trehalase activity was significantly decreased in F1 to F5 generations when treated with the LC50 and LC30 and imidacloprid and thiamethoxam compared to control. In addition, the Enzyme-Linked Immunosorbent Assay (ELISA) was used to monitor the changes in molting and juvenile hormone expressions of the soybean aphids in each generation (F1-F5). The expression of juvenile hormone in soybean aphids was increased significantly in each generation under continuous stress of imidacloprid and thiamethoxam LC50 imidacloprid and LC50 thiamethoxam inhibited the expression of molting hormones in soybean aphids of each generation. LC30 imidacloprid or LC30 thiamethoxam significantly stimulated the expression of molting hormone in the 1st and 2nd instar nymphs in each generation. In this paper, the differences in antioxidant regulation, energy metabolism intensity, and hormone expression of multi-generation soybean aphids were monitored under continuous stress of imidacloprid and thiamethoxam. Our results revealed the effects of continuous insecticide stress on the main endogenous substances. Further, they clarified the regulation rules of resistance in soybean aphids, providing a reference for efficient control with imidacloprid and thiamethoxam.

Field investigation- and dietary metabarcoding-based screening of arthropods that prey on primary tea pests.

Predatory natural enemies play key functional roles in biological control. Abundant predatory arthropod species have been recorded in tea plantation ecosystems. However, few studies have comprehensively evaluated the control effect of predatory arthropods on tea pests in the field. We performed a 1‐year field investigation and collected predatory arthropods and pests in the tea canopy. A total of 7931 predatory arthropod individuals were collected, and Coleosoma blandum (Araneae, Theridiidae) was the most abundant species in the studied tea plantation. The population dynamics between C. blandum and four main tea pest species (Aleurocanthus spiniferus, Empoasca onukii, Ectropis grisescens, and Scopula subpunctaria) were established using the individual number of predators and pests in each month. The results showed that C. blandum appeared to co‐occur in the tea canopy with A. spiniferus, Em. onukii, and Ec. grisescens in a longer period. The prey spectrum of C. blandum was further analyzed using DNA metabarcoding. Among prey species, A. spiniferus, Em. onukii, and Ec. grisescens were included, and the relative abundance and positive rates of target DNA fragments of A. spiniferus were greater than that of other two pests. Combined with the high dominance index of C. blandum, co‐occurrence between C. blandum and A. spiniferus in time and space and high positive rate and relative abundance of target DNA fragments of A. spiniferus, C. blandum was identified to prey on A. spiniferus, and C. blandum may be an important predator of A. spiniferus. Thus, C. blandum has potential as a biological control agent of A. spiniferus in an integrated pest management strategy.

Microwave Energy in Controlling Warehouse Insects (Sitophilus oryzae L) and Determining the Percentage of Killing on the Unit Weight of Wheat Seeds

Sitophilus oryzae L (Coleoptera) is a primary pest of stored grains in many regions of the world. This research paper aims to use non-traditional methods to control some insects on stored grain. The use of insecticides and their side effects on health and the environment, in general, are proven Pest control should take another direction. Wheat samples were taken with different weights of 10,20,40,60,80,100,200 g for three separate packages, and (30) insects of Sitophilus oryzae L were added to each sample and were mixed randomly., 5, 10,15,20,25 ‘30’ seconds to calculate the time on the amount of weight of treated seeds to give the best results weight 10 g, microwave treatment, time of 20 seconds, the killing rate was 100%, and 15 seconds was 90%. Weight 20g Microwave treatment for 25 seconds (100 percent kill rate) and 20 seconds (92.30 percent kill rate) for optimal results. Weight 40g Microwave treatment for 20 seconds (100 percent kill rate) and 15 seconds (76.10 percent kill rate) for optimal results. Microwave 60g for 25 seconds for a 100% kill rate and 20 seconds for an 88 percent kill rate for optimal outcomes. Microwave 80g for 25 seconds for a 100% kill rate and 20 seconds for an 86.60 percent kill rate for optimal outcomes. For optimal results, microwave 100g for 30 seconds for a 100% kill rate and 25 seconds for a 99.80% kill rate. Microwave 200g for 35 seconds for a 100% kill rate and 30 seconds for a 99.60% kill rate for optimal outcomes. From this, we can deduce that the time needed to kill all insects in the sample preparation for testing must be doubled for every 20 g of wheat seeds added.

Susceptibility and field exposure of Striacosta albicosta (Lepidoptera: Noctuidae) eggs and larvae in Ontario, Canada to four insecticides.

Striacosta albicosta Smith (Lepidoptera: Noctuidae) is a primary pest of corn, Zea mays L., in the Great Lakes region, causing yield loss and exacerbating mycotoxin contamination of grain. Foliar insecticides are currently used to manage S.albicosta; however, the toxicity and residual activity of these insecticides against S.albicosta are unknown. Laboratory and field bioassays were conducted to determine the susceptibility and period of in-field efficacy provided by chlorantraniliprole, lambda-cyhalothrin, spinetoram, and methoxyfenozide against S.albicosta. Bioassay data were used to simulate management scenarios. For all insecticides tested, 1st instars were highly susceptible to the recommended field application rates and were >3-fold more susceptible to insecticides than 3rd instars. Insecticide activity decreased after application for all insecticides, with chlorantraniliprole having the longest residual activity. In simulated management scenarios where an insecticide was applied at or below the recommended 5% egg mass threshold with additional oviposition, methoxyfenozide application resulted in greater larval survival 14 days after application (DAA) than the other insecticides tested. In scenarios where insecticides were applied 7 days before threshold was reached, all insecticides resulted in larval survival. These data demonstrate that chlorantraniliprole, lambda-cyhalothrin and spinetoram, applied in conjunction with monitoring, provide effective control of S.albicosta larvae for 10-14 days, whereas methoxyfenozide provides effective control for less than 7 days. © 2022 Society of Chemical Industry.

Local isolate of Bacillus thuringiensis (Berliner, 1915) (Bacteria: Bacillaceae) from Cydalima perspectalis (Walker, 1859) (Lepidoptera: Crambidae: Spilomelinae) includes cry1, cry3 and cry4 genes and their insecticidal activities

Cydalima perspectalis (Walker, 1859) (Lepidoptera: Crambidae: Spilomelinae) is a primary pest on boxwood. The larvae of this pest cause damage by eating the leaves. They prevent the plant from performing photosynthesis, gnaw the bark of the shoots, damage the cambium layer and thus dry the boxwood shoots and branches. The boxwood moth, which is an exotic species in Türkiye, was first found in gardens and parks in Istanbul in 2011 and subsequently in Artvin and Düzce in 2015, and Bartın in 2016. The aim of this study is to develop a control method for this pest by considering the damage of the species. In this context, bacteria were isolated from the larvae collected from Artvin in May 2021 and bacteria screening was conducted to obtain an effective isolate. At the end of this isolation, Bacillus thuringiensis (Berliner, 1915) (Bacteria: Bacillaceae) was found. When cry gene analysis of this bacterium was performed, it was determined that it contained cry1, cry3 and cry4 genes. The insecticidal activity of this bacterium was tested on C. perspectalis and a mortality rate of 85% was obtained.

Contextualization of Trait Nexus and Gene Action for Quantitative and Qualitative Characteristics in Indian Mustard

After soybean and palm oil, the world’s third largest oil seed crop is rapeseed mustard. Out of the seven consumable oil seed crops grown in India, rapeseed mustard is responsible for one-third of production. Mustard aphid (Lipaphis erysimi Kalt) is considered the primary pest causing mayhem in crop production. Understanding the genetics behind resistance will aid breeders in developing a resistant/tolerant strain. Appropriate parent selection and analyzing gene action contribute to economic benefit maximization. The aims of the current study are to use seven lines and five testers to determine the best-performing parents and crosses based on their general and specific capacity to combine and to examine the level of heterosis for yield and related features like mustard aphid resistance. Due to the self-pollination nature of Indian mustard, Kempthorne’s line X tester method is helpful to judge the combining ability. Therefore, seven lines and five testers of Indian mustard (Brassica juncea L.) were employed in the present study. The findings suggested that there was substantial genetic variation for all traits examined. The mean oil yield of R1 B2-26 × R1 B2-25, JD6 × R1 B2-25, and JD6 × R1 B2-29 hybrids was more significant than that of the ancestors. The results show that R1 B2-26 × R1 B2-25, JD6 × R1 B2-25, and JD6 × R1 B2-29 hybrids produced more oil than their parents. The variance explained by SCA was greater than that explained by GCA, as indicated by the Ϭ2 gca/Ϭ2 sca ratio being less than one for all characters, implying that nonadditive gene actions such as dominance, epistasis, and other interaction effects played an important role in the presence of these attributes. Punjab Local was discovered to be an excellent general merge for reducing crop duration, whereas JD6 was an excellent combiner for seed yield per crop, aphid infestation indicator, seed yield per crop, and oil production per plant. The predictability ratio was found to be less than 0.5 for almost all traits, denoting that the nonadditive gene measure is involved in controlling the nature except days to 50% flowering, aphid infestation index, oil content, and oil yield per plant. Thus, based on these four traits, selection for superior plants may be practiced in later generations.

Insecticidal Activity of Organic Extracts of Solidago graminifolia and Its Main Metabolites (Quercetin and Chlorogenic Acid) against Spodoptera frugiperda: An In Vitro and In Silico Approach

Spodoptera frugiperda (S. frugiperda) remains a global primary pest of maize. Therefore, new options to combat this pest are necessary. In this study, the insecticidal activity of three crude foliar extracts (ethanol, dichloromethane, and hexane) and their main secondary metabolites (quercetin and chlorogenic acid) of the species Solidago graminifolia (S. graminifolia) by ingestion bioassays against S. frugiperda larvae was analyzed. Additionally, the extracts were phytochemically elucidated by ultra-performance liquid chromatography-mass spectrometry (UPLC-MS) analysis. Finally, an in silico study of the potential interaction of quercetin on S. frugiperda acetylcholinesterase was performed. Organic extracts were obtained in the range from 5 to 33%. The ethanolic extract caused higher mortality (81%) with a half-maximal lethal concentration (LC50) of 0.496 mg/mL. Flavonoid secondary metabolites such as hyperoside, quercetin, isoquercetin, kaempferol, and avicularin and some phenolic acids such as chlorogenic acid, solidagoic acid, gallic acid, hexoside, and rosmarinic acid were identified. In particular, quercetin had an LC50 of 0.157 mg/mL, and chlorogenic acid did not have insecticidal activity but showed an antagonistic effect on quercetin. The molecular docking analysis of quercetin on the active site of S. frugiperda acetylcholinesterase showed a −5.4 kcal/mol binding energy value, lower than acetylcholine and chlorpyrifos (−4.45 and −4.46 kcal/mol, respectively). Additionally, the interactions profile showed that quercetin had π–π interactions with amino acids W198, Y235, and H553 on the active site.

The Correlation between Volatile Compounds Emitted from Sitophilus granarius (L.) and Its Electrophysiological and Behavioral Responses.

The granary weevil Sitophilus granarius (L.) is one of the most serious primary insect pests of stored products. When S. granarius present in grains, various volatile organic compounds are released as chemical signals which can be used to detect the insects. In this study, volatile chemical compounds released from S. granarius were analyzed using the headspace solid phase micro-extraction (HS-SPME) coupled with gas chromatography (GC)-mass spectrometry (MS) techniques. Two key compounds, 3-hydroxy-2-butanone and 1-pentadecene, were identified from mixed gender of S. granarius adults at high density. Moreover, both male and female adults showed dose-dependent electroantennography (EAG) responses to 3-hydroxy-2-butanone. In behavioral assays, S. granarius was attracted to 3-hydroxy-2-butanone at 0.001 µg/10 µL but repelled at 10 µg/10 µL or higher. S. granarius was consistently repelled by 1-pentadecene at concentrations at 0.001 and 1000 µg/10 µL. 3-hydroxy-2-butanone and 1-pentadecene have considerable potential to offer in the development of new approaches for the monitoring and management of this destructive stored grain insect pest.

Transgenerational responses to heat and fasting acclimation in the Angoumois grain moth

Transgenerational plasticity (TGP) is a physiological mechanism where environmental experiences of parents affect phenotypes of the offspring, and potentially facilitates organisms' survival in stressful environments. The Angouimois grain moth, Sitotroga cerealella (Olivier), is a dominant primary grain pest in Africa, particularly affecting sorghum and maize staples. Despite its widely known economic significance, little is known on its thermal responses, particularly how acclimation in one generation impacts fitness in successive generations. We tested how heat (acute and dynamic) as well as fasting acclimation in one generation affects physiological tolerance (i.e., critical thermal maxima [CTmax] and heat knock down time [HKDT]) using laboratory-reared S. cerealella populations. Specifically, we assessed whether pre-exposure to heat or fasting stress confers fitness costs or benefits in subsequent generations (i.e., through TGP). Results showed acclimation had significant effects in interaction with temperature ramping rates on CTmax. Moderate acute heat (34 °C) and dynamic temperature (28–38 °C) acclimations reduced F1 CTmax and HKDT, particularly at low ramping rates (for CTmax). We did not find fasting acclimation to significantly affect CTmax, indicating a lack of evidence for cross tolerance and/or susceptibility. For HKDT, all acclimation treatments (including fasting) showed significantly lower HKDT compared to controls, and mostly so, for the 38 °C and dynamic acclimation (28–38 °C) treatments, indicating a transgenerational fitness cost of acclimation. This is the first report of the costs of transgenerational plasticity in a stored product pest of economic significance and has implications in designing heat-based phytosanitary grain treatments.

Impact of the fall armyworm, Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae), invasion on maize and the native Spodoptera litura (Fabricius) in East Java, Indonesia, and evaluation of the virulence of some indigenous entomopathogenic fungus isolates for controlling the pest

BackgroundThe fall armyworm, Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae), is an invasive alien species in Indonesia. This study aimed to assess the impact of its invasion in Indonesia by measuring the damaged area caused by the pest in maize fields located across East Java and simultaneously determine whether S. frugiperda outcompetes the native Asian armyworm Spodoptera litura (Fabricius). Secondly, the virulence of 14 entomopathogenic fungus (EPF) isolates against S. frugiperda larvae was evaluated in an effort to find effective biocontrol agent candidates.ResultsThe damaged area caused by S. frugiperda was generally higher than that caused by S. litura during the survey period from August 2019 to December 2021. It indicated that S. frugiperda may have dominated the native armyworm and become the primary key pest of maize in Indonesia. Based on a single-concentration assay (106 conidia ml−1), the tested EPF isolates displayed varying degrees of virulence against S. frugiperda larvae, causing larval mortality of 3.5 to 71% at 10-day post-treatment, with the highest mortality rates provided by Beauveria bassiana sensu lato and Trichoderma asperellum sensu lato. At a concentration of 108 conidia ml−1, B. bassiana s.l. and T. asperellum s.l. elicited high larval mortality of 76 and 81%, respectively, at 10-day post-treatment. Nevertheless, the probit analysis based on a concentration–response assay revealed that T. asperellum s.l. had lower LC50 and LC90 values than B. bassiana s.l.ConclusionsThe attack and invasion of S. frugiperda seem to be a continual threat to the maize agro-ecosystem in Indonesia. As a consequence, Indonesia should mitigate and be well-prepared for future outbreaks of S. frugiperda. Indigenous EPF isolates used in this study may act as promising biocontrol agents of S. frugiperda, especially T. asperellum s.l. This study also serves as the first report documenting the direct lethality of Trichoderma fungus on S. frugiperda larvae.

First record of <em>Microctonus brassicae</em> in Czechia, a potential biological control agent against a primary oilseed rape pest

After the ban on treating oilseed rape seeds with neonicotinoids in European Union, cabbage stem flea beetles (Psylliodes chrysocephala Linnaeus, 1758) again became one of its main pests. In Czechia, the impact of this pest increases every year, given with the narrowing spectrum of suitable insecticides and growing damage to oilseed rape plants in autumn. Based on this scenario, it is appropriate to look for alternative options to control oilseed rape pests. One option could be supporting beneficial organisms. One of these organisms is the hymenopteran braconid parasitoid Microctonus brassicae (Haeselbarth, 2008), which parasitizes adult cabbage stem flea beetles. Its occurrence has now been confirmed outside Great Britain in Czechia and continental Europe respectively. Five male specimens of M. brassicae emerged from 50 collected adults of cabbage stem flea beetle by sweep netting from two localities in central Bohemia. This parasitoid of adult cabbage stem flea beetles and its larval parasitoids probably play an important role in the life cycle and population dynamics of this pest. Current knowledge about the biology, taxonomic classification and identification of this parasitoid is summarized in this paper.

Field Trapping and Flight Capacity of Eucosma giganteana (Riley) (Lepidoptera: Tortricidae) in Response to Behaviorally Active Congeneric Semiochemicals in Novel Silflower Agroecosystems.

Simple SummaryRosinweed is a novel perennial crop being developed for oilseed and biofuel in the midwestern US. A primary pest is the Giant Eucosma Moth (GEM). Little is known about the chemical ecology or flight behavior of adults, but many attractants have been identified from other closely related species. The goals of this study were to evaluate whether any of these compounds could improve the capture of GEMs on sticky cards in the field and determine whether the most attractive volatiles might affect flight behavior in the laboratory. We found that there was significant attraction to (E)-8-dodecenyl acetate, which may possibly be a component in the pheromone blend for GEM. Exposure to these compounds in the laboratory reduced flight capacity. Our results suggest these two compounds could be included in monitoring or management programs for the Giant Eucosma moth.Silphium integrifolium is a novel perennial crop being developed for oilseed and biofuel in the midwestern US. One of the primary pests in this system is Eucosma giganteana (Lepidoptera: Tortricidae). Little is known about the chemical ecology or flight behavior of E. giganteana, but many semiochemicals have been identified from other closely related Eucosma species. Some of these compounds include: (Z)- and (E)-8-dodecenyl acetate, (E)-9-dodecenyl acetate, (Z)-8-dodecenol, (E,E)-8,10-dodecadienyl acetate, and (Z,E)-9,12-tetradecadienyl acetate. The goals of this study were to evaluate whether any of these compounds could improve capture of E. giganteana on clear sticky cards in the field, and the most attractive volatiles might affect flight behavior on a computer-automated flight mill assay. We found that there was significant attraction to (E)-8-dodecenyl acetate in two years in the field, which may possibly be a component in the pheromone blend for E. giganteana. On flight mills, E. giganteana flew an average of 23 km in a 24 h period. The presence of attractive stimuli (e.g., (E)-8-dodecenyl acetate) had arresting properties and decreasing flight distance on the mill by 78 to 80%. The longest flight distances were registered in the morning (4:00–12:00) and were 1.8-fold greater than flight distances and durations at night (20:00–4:00). (E)-8-dodecenyl acetate may be useful in behaviorally based monitoring and management strategies for E. giganteana. Overall, our research expands the knowledge on the chemical ecology of adult E. giganteana.

Toxicity and Compatibility of Botanical Insecticide From Clove (Syzygium Aromaticum), Lime (Citrus Aurantifolia) and Garlic (Allium Sativum) Essential oil Against Callasobruchus Chinensis L

Cowpea beetle of Callosobruchus chinensis (Coleoptera: Bruchidae) is one of the primary storage pests of green beans that can reduce the beans’ quality and quantity. Plant essential oils are known to have insecticidal activity against insect pests. The study aims to investigate the toxicity, oviposition deterrence, and compatibility of botanical insecticides formulas of Syzygium aromaticum, Citrus aurantifolia, and Allium sativum essential oils to C. chinensis. The essential oils were obtained by distillation method. Contact and fumigant methods were used to test the toxicity of the oils. The toxicity levels (LC50 and LC95) were analyzed. The three essential oils tested were toxic and also had oviposition deterrent to C. chinensis. A. sativum essential oil showed the highest toxic (LC50=0.07%, LC95 = 0.89%), followed with S. aromaticum (LC50 = 0.08%, LC95 = 0.95%), and C. aurantifolia (LC50 = 0.07%, LC95 = 1.21%) after 72 h contact exposure to the adults. The three essential oils also showed an oviposition deterrence. A. sativum and S. aromaticum essential oils mixture at a ratio of 1:1 showed the strongest synergistic interaction to C. chinensis. The study suggests that the essential oil formula could be developed as a potential botanical insecticide.