Insect Population Density Research Articles

The Importance of Integrated Pest Control on Wheat Crops Production, during 2015-2016, at Agricultural Research-Development Station Turda

In the wheat crops of central Transylvania a rich complex of phytophagous insects species is reported. Species of thrips, aphids, leafhoppers, flies, cereal leaf beetle and cereal bugs, affects the level of production and quality indicators of wheat grains. In the period of 2015-2016, various integrated pest control models have been applied, watching their effect on the production and quality indicators of wheat, based on applied insecticide treatments, in the experimental lots at ARDS Turda. The results on the quantified production parameters showed oscillations over previous multiannual values, due to the special climatic conditions of 2015 and 2016, to the density of entomophagous and phytophagous insect populations, influenced by the applied treatment system. It is noted that in the years 2015-2016, characterized as exceptional years, with unfavorable thermal and pluviometric conditions, with much higher values than the multiannual average, the gluten and protein content, zeleny index have lower values than in the previous years, at ARDS Turda. The specific annual climate characteristics have a major influence on the production and quality of wheat. Also, pest control strategies have a major impact on the production parameters and qualitative indicators of wheat.

Population Density of some Insect Pests Infesting Fallen Soft Dates and their Associated Natural Enemies in Giza Governorate, Egypt

This study aimed to determine the population density and survey the insect pests infesting fallen dates fruits of soft cultivars (Zagloul, Samani and Amhat) in Giza Governorate, Egypt and associated natural enemies, parasitoid and predatory species during two successive seasons 2016/2017 & 2017/2018. Ten insect pests belongs to three insect orders (Lepidoptera, Coleoptera, and Homoptera) were recorded. Lepidopterous insects were,Batrachedra amydraula Meyrick (Fam.: Cosmpterigidae), Arenipses sabella Hampson (Fam.: Pyralidae), Ephestia calidella Guenee (Fam. Pyralidae),Ephestia cautella Walker (Fam. Pyralidae), Ectomyelois ceratoniae Zeller (Fam.Pyralidae) and Stathmopoda auriferella (Walker) (Fam. Stathmopodidae). Coleopterous pests were Coccotrypes dactyliperda (Fabricius) Fam. Scolyitldae, Carpophilus spp. (Fam. Nitidulidae) and Oryzaephilus surinamensis Linnaeus (Fam. Silvanidae). The Homopterous insect was Parlatoria blanchardi Targioni (Fam. Diaspididae).one predatory species, Labidura riparia Pallas, (O.:Dermaptera: Fam.: Labiduridae )and one parasitoids species bracon hebetor (Say) (Hymenoptera: Braconidae ) were found. Results showed that there was no significant difference between the numbers of insects in the two years of study or between the three tested cultivars. While there were significant differences between the inspection dates and between the recorded insect's species numbers. In addition, the results showed that the highest average number of the insect species were Carpophilus spp. followed by E. calidella, P. blanchardi and E. cautella respectively. Mean daily temperature &RH had a low and negative effect on insect population density, while there were differences between the insect pests numbers in different date of inspection. In addition, there was a significant difference between the insect pests numbers, which belongs to order Homoptera and each of (Lepidoptera and Coleoptera).Regarding infestation, percentage, there were significant differences between the averages infestation percentage for the three tested cultivars as well as between the two years of study. Bracon hebetor (Say) was the only recorded parasitoid during the period of study. Percentages of parasitism had no significant difference between the two years of the study, while it had a significant difference between the three date palm cultivars.

Influences of Insect-Resistant Genetically Modified Rice (Bt-T) on the Diversity of Non-Target Insects in an LMO Quarantine Field

This study was conducted to develop environmental risk assessments and biosafety guides for insect-resistant genetically modified rice in an LMO (Living Modified Organism) isolation field. In the LMO quarantine area of Kyungpook National University, the species diversities and population densities of non-target insects found on insect-resistant genetically modified rice (Bt-T), rice resistant to Cnaphalocrocis medinalis, and non-GM rice (Dongjin-byeo and Ilmi-byeo) were investigated. The Bt-T plants were, therefore, evaluated under field conditions to detect possible impacts on above ground insects and spiders. In 2016 and 2017, the study compared transgenic rice and two non-GM reference rice, namely Dongjin-byeo and Ilmi-byeo, at Gunwi. A total of 9,552 individuals from 51 families and 11 orders were collected from the LMO isolation field. From the three types of rice fields, a total of 3,042; 3,212; and 3,297 individuals from the Bt-T, Dongjin-byeo, and Ilmi-byeo were collected, respectively. There was no difference between the population densities of the non-target insect pests, natural enemies, and other insects on the Bt-T compared to non-GM rice. The data on insect species population densities were subjected to principal component analysis (PCA) without distinguishing between the three varieties, namely GM, non-GM, and reference cultivar, in all cultivation years. However, the PCA clearly separated the samples based on the cultivation years. These results suggest that insect species diversities and population densities during plant cultivation are determined by environmental factors (growing condition and seasons) rather than by genetic factors.

The application of self-limiting transgenic insects in managing resistance in experimental metapopulations.

The mass release of transgenic insects carrying female lethal self‐limiting genes can reduce pest insect populations. Substantial releases are also a novel resistance management tool, since wild type alleles conferring susceptibility to pesticides can dilute resistance alleles in target populations. However, a potential barrier is the need for large‐scale area‐wide releases. Here, we address whether localized releases of transgenic insects could provide an alternative means of population suppression and resistance management, without serious loss of efficacy.We used experimental mesocosms constituting insect metapopulations to explore the evolution of resistance to the Bacillus thuringiensis toxin Cry1Ac in a high‐dose/refugia landscape in the insect Plutella xylostella. We ran two selection experiments, the first compared the efficacy of “everywhere” releases and negative controls to a spatially density‐dependent or “whack‐a‐mole” strategy that concentrated release of transgenic insects in subpopulations with elevated resistance. The second experiment tested the relative efficacy of whack‐a‐mole and everywhere releases under spatially homogenous and heterogeneous selection pressure.The whack‐a‐mole releases were less effective than everywhere releases in terms of slowing the evolution of resistance, which, in the first experiment, largely prevented the evolution of resistance. In contrast to predictions, heterogeneous whack‐a‐mole releases were no more effective under heterogeneous selection pressure. Heterogeneous selection pressure did, however, reduce total insect population sizes.Whack‐a‐mole releases provided early population suppression, indistinguishable from homogeneous everywhere releases. However, insect population densities tracked the evolution of resistance in this system, as phenotypic resistance provides access to additional diet containing the toxin Cry1Ac. Thus, as resistance levels diverged between treatments, carrying capacities and population sizes increased under the whack‐a‐mole approach. Synthesis and applications. Spatially density‐dependent releases of transgenic insects, particularly those targeting source populations at a landscape level, could suppress pest populations in the absence of blanket area‐wide releases. The benefits of self‐limiting transgenic insects were reduced in spatially localized releases, suggesting that they are not ideal for “spot” treatment of resistance problems. Nevertheless, spatially homogeneous or heterogeneous releases could be used to support other resistance management interventions.

Efficiency of Colored Sticky Traps on the Population of Certain Sap-Sucking Insects on Cucumber Plants in Greenhouses

Experiments were conducted in the experimental Horticulture Research Station at Qaha, Qalubiya governorate under greenhouse conditions during two successive seasons (2016-2017 and 2017-2018). The study aims to evaluate some pest control methods on cucumber, Cucumis sativus L. and their effect on total yield. Population density of Bemisia tabaci (Geen.), Frankliniella occidentalis (Pergande) and Phenacoccus solenopsis Tinsley determined on cucumber plants. Blue and yellow sticky traps were settled in first greenhouse in rate of 13 traps (10 blue and 3 yellow). The second greenhouse was treated in foliar spray by (closer SC24% “Sulfoxaflor” at 10cm3 /20L plus 13 traps (10 blue and 3 yellow). The third greenhouse without treatments (untreated). Results indicated that, the activity period of B. tabaci, F. occidentalis and P. solenopsis on cucumber plants during both seasons was expressed by two and three peaks. The effects of different treatments of pest control methods (traps, pesticides + traps) were high significantly in reducing pests` population and increase yield. Where, in untreated plots, B. tabaci, F. occidentalis and P. solenopsis were responsible for 98% and 99%, reduction in yield respectively. Maximum and minimum temperature were showed that significant negative effect on the population in first season conversely, in the second season cleared significant positive on B. tabaci, F. occidentalis and P. solenopsis population. The relative humidity had significant positive effect on first season however in the second season found insignificant. The combined effect (E.V) of these ecological factors on B. tabaci, F. occidentalis and P. solenopsis showed that these factors were responsible as a group for 94 %, 90 %, 92 during 2016-2017 and 98, 98, 99 during 2017-2018 effects on the population density of insects throughout both seasons, respectively. The obtained results revealed that, the treatment of pesticide with traps (yellow and blue) reduced effectively population of whitefly, thrips and mealy bugs and increase the yield during the two seasons of the study.

Hatay İli Yonca Üretim Alanlarında Bulunan Böcek Faunasının Tespiti ve Bazı Türlerin Popülasyon Yoğunlukları

The current study was conducted to determine insect fauna and population densities of some phytophagous and beneficial insect species at two different alfalfa fields in Narlıca district of Hatay province, Turkey in 2009-2010. In the first year biweekly, and in the second year weekly samplings were carried out by 25 sweep-net samplings taken by walking in diagonal directions. Aphids, thrips and gallery flies were also sampled by counting of 30 alfalfa stalks in every 8-10 steps in each of the sampling fields. As a result, 53 phytophagous species belonging to 14 families of five orders and 30 natural enemy species including 20 predators and 10 parasitoids belonging to nine families of six orders were obtained. With 19 species, Cicadellidae has been the largest number of species-containing family and Asymmetrasca descedens and Empoasca decipiens were the most intensively species in this family. In addition, Lygus rugulipennis was the most dominant species among all phytophagous species obtained. It has been found that populations of all pests species were affected by mowing the alfalfa, and show a decline. Predators were predominant among detected natural enemies, and their populations were persistent in the alfalfa fields despite approximately 7-8 mowing per year.

Control of field insect pests of mung bean (<i>Vigna radiata</i> L. Wilczek) using some plant extracts in Umudike, Nigeria

Field trials were conducted at Umudike, Nigeria, during the 2015 and 2016 cropping seasons to determine the efficacy of plant extracts from seven plant species against field insect pests of mung bean, Vigna radiata L. Wilczek. The extracts tested were obtained from scent leaf (Ocimum gratissimum), neem leaf (Azadirachta indica), bitter leaf (Vernonia amygdalina), garlic (Allium sativum), turmeric (Curcuma longa), plantain (Musa paradisiaca) peel and Negro pepper (Xylopia aethiopica). Karate (Lambda-cyhalothrin EC) at 50 mL was introduced as a check in the trials. The experimental design was a randomised complete block design (RCBD) with three replicates. Data were collected weekly on the insect population densities, yield and yield components. The results indicated that all the treatments were effective against mung bean insect pests (Aphis craccivora [aphid], Bemisia tabaci [whitefly], Amrasca biguttula biguttula [jassid] and Zonocerus variegatus[grasshopper]). There was a significant (p ≤ 0.05) reduction in the population of insects on the plots treated with plant extracts and karate in 2015 and 2016 cropping seasons. The population densities of grasshoppers in 2015 and whitefly in 2016 were significantly lower in the treated plots compared with the control plots. Azadirachta indica and C. longa extracts recorded the highest seed yield of 50.00 kg/ha and 42.33 kg/ha in 2015 and 2016, respectively. No significant differences were observed between the plant extracts and karate, which recorded significantly higher yields when compared with the control (23.30 kg/ha). All the plant extracts used exhibited insecticidal activity against the insect pests of mung bean. It is, therefore, recommended that these plant extracts can be used for the control of mung bean insect pests to achieve sustainable production, food security and quality.

Impact of Biocide, Insecticides, Compost and Mineral Fertilizers Treatments on the Abundance of Parasitoid and Predator Insects in Rice Fields

The present study was designed to investigate the effect of rice straw compost, recommended mineral fertilizers, Organic Insecticides and chemical Insecticides on the abundance pattern of natural enemies in rice ecosystems. To maximize rice productivity, rice growers tend to use chemical fertilizers and pesticides particularly to control different pest species, regardless of damage levels. Accordingly, rice fauna of natural enemies is severely impaired, leading to unbalanced rice ecosystems. The current investigation was carried out at the experimental farm of Rice Research and Training Center (RRTC), Sakha, Kafr El-Sheikh during 2016 and 2017 rice seasons. Using both D–Vac machine and pit–fall traps, parasitoids and predator insects were surveyed. Twelve hymenopterous parasitoid species were surveyed. Most of the parasitoid species were found belonging to Mymaridae, Trichogrammatidae and Braconidae. Twenty insect predator species, related to 13 families and seven orders, were identified, most of which are belonging to Coleoptera and Hymenoptera. Also this study aimed to surveying natural enemies (parasitoids and predator insects) and the effect of compost as an organic fertilizer on population densities of such beneficial insects. Although the application of insecticides successfully controlled insect pests, these chemicals have almost eradicated (more than 90 % reduction) the natural enemies. Biocide applications, especially Achook (Neem) and Tracer, achieved a considerable insect pest control, with population reductions of 33.30-57.32 and 10-46.01%, respectively. Unfortunately, the evaluated biocides induced mortalities to the considered natural enemies, but with too much less levels than did the insecticides. The current results indicate that the biocides could be applied to control rice insects in case of moderate insect infestations, with taking into consideration that they are not completely safe to the beneficial insects.

Comparative assessment of insect pests population densities of three selected cucurbit crops

Comparative assessment of insect pests population densities of three selected cucurbit crops

Effects of strip-tilled cover cropping on the population density of thrips and predatory insects in a cucurbit agroecosystem

Strip-till cover cropping provides a structurally complex habitat (both diverse above ground vegetation and modified soil surface environment) in subsequent crops, which can contribute to suppressing herbivores in the cash crop, through either enhancing conservation biological control or altering herbivore behavior to the complex habitat. Two field trials (spring and autumn) were conducted to examine effects of strip-tilled cover crops (sunn hemp and marigold) on population densities of thrips (primarily, Frankliniella occidentalis and Thrips palmi) and generalist predators (Orius spp. and ground beetles, Aephnidius spp.) in cucurbit plantings. The results showed that strip-tilled cover crop treatments reduced thrips densities on cucurbit crops compared to the conventional monoculture. The strip-tilled treatments suppressed thrips densities more consistently in the autumn than in the spring trial. The reduced densities of thrips in strip-tilled cover crop plots were not attributable to the enhanced activity of predatory insects, but were most likely due to the disruption of host locating ability of thrips. Our study showed that the strip-till cover cropping could be an effective pest management technique for sustainable cucurbit production.

Density-mediated indirect effects from active predators and narrow habitat domain prey.

The hunting-mode-habitat-domain-range framework suggests that the mechanism driving trophic cascades (i.e., trait-mediated indirect interactions [TMIIs] vs. density-mediated indirect interactions [DMIIs]) should depend upon the functional traits of predators and prey. For example, trophic cascades containing active, broad habitat domain range (BHDR) predators interacting with narrow habitat domain range (NHDR) prey are predicted to arise primarily via TMIIs, because these prey should reduce their conspicuous activity in the presence of these predators. Unfortunately, this hypothesis is difficult to test given the strong bias against studies assessing trophic cascades containing NHDR prey. Furthermore, this hypothesis ignores evidence that (1) active predators can have high consumption rates on prey, (2) continuously responding to active predators foraging across broad areas is energetically costly for prey, and (3) cues from active, BHDR predators may not influence prey density. We examined the TMIIs and total indirect interaction (TII) produced during interactions between an active, BHDR ladybeetle predator (Naemia seriata) and its NHDR prey (scale insects). We exposed scale insects to nonlethal and lethal ladybeetle predators in laboratory mesocosms for 15 weeks. We measured the growth of the scale insect's host plant (cordgrass) and the population density of scale insects. Contrary to theory, nonlethal ladybeetles did not induce TMIIs. However, lethal ladybeetles increased cordgrass total and root dry biomass by 36% and 44%, respectively, suggesting the presence of strong DMIIs. Additionally, both lethal and nonlethal ladybeetles reduced scale insect population density. Our findings suggest that DMIIs, rather than TMIIs, can result from interactions between active BHDR predators and NHDR prey.

A study on the feasibility of quantifying the population density of stored product insects in air-tight grain storage using CO2 concentration measurements

This study was aimed at estimating the number of insects per 1 kg of paddy (IPK) in an air-tight mock-up silo by CO2 concentration monitoring. The first experiment was to determine the respiration rates of adult Sitophilus zeamais, Rhyzopertha dominica, and Tribolium castaneum. CO2 concentrations were recorded from groups of 50, 100 and 200 insects with and without 125 g of brown rice. The respiration rate was calculated from the slope of the CO2 concentration curve. A sample size of at least 100 insects was recommended. In 100-insect group, with the presence of food the respiration rates of S. zeamais, R. dominica, and T. castaneum were 9.57–14.13, 1.96–3.93 and 4.59–11.76 μlCO2/insect−h, respectively. In the second experiment, S. zeamais populations at actual IPK = 2, 0.5, 0.25, 0.125 and 0.0625 in a 1.618 m3 silo filled with paddy were quantitatively determined. Similarly, R. dominica and T. castaneum populations at actual IPK = 0.5, 0.25, 0.125 and 0.0625 in 0.064 m3 silos were estimated in the third experiment. In each trial, small containers filled with a known number of adult insects along with brown rice were buried in the silo. Additionally, a control silo containing only disinfested paddy was set up in parallel. The insect population density was calculated from the difference in the slopes of the CO2 curves between the infested and control silos divided by the respiration rate of one insect. On average, for each species and each infestation level the estimated population density was not greater than twice of the actual ones. Although several assumptions (e.g., silos being completely sealed, only one species and one life stage of infesting insects) had to be made, monitoring CO2 concentrations could potentially be an effective tool for determining insect population density during grain storage.

High Triatoma brasiliensis Densities and Trypanosoma cruzi Prevalence in Domestic and Peridomestic Habitats in the State of Rio Grande do Norte, Brazil: The Source for Chagas Disease Outbreaks?

AbstractA total of 2,431 Triatoma brasiliensis were collected from 39 populations of Paraíba (PB) and Rio Grande do Norte (RN) states, Brazil. In PB, Trypanosoma cruzi infection was not detected in either peridomestic or domestic vector populations. In contrast, in RN, T. brasiliensis was detected with high parasite prevalence in these ecotopes (30.7-40.0%). Moreover, peridomicile insect population densities were more than double the average densities of all other settings evaluated (19.17 versus < 8.94 triatomine/man-hour). Genotyped parasites evidenced a mix of T. cruzi lineages circulating in both peridomestic and sylvatic populations. Although vector control efforts have dramatically decreased Chagas disease transmission to humans, recent outbreaks have been detected in four municipalities of RN state. Our results clearly evidence a worrisome proximity between infected vectors and humans in RN. Indeed, finding of infected T. brasiliensis inside homes is routinely recorded by local vector control surveillance staff around the outbreak area, challenging the current and conventional view that vector transmissions are controlled in northeastern Brazil. This scenario calls for strengthening vector control surveillance and interventions to prevent further Chagas transmission, especially in RN State.

Hellbenders (Cryptobranchus alleganiensis) May Exhibit an Ontogenetic Dietary Shift

Abstract Organisms in lotic habitats often experience dietary shifts over their lifetime. The diet of adult Cryptobranchus alleganiensis (Hellbender) is well studied throughout the species' range, but knowledge regarding the natural history of larval Hellbenders, including dietary information, remains scarce. We obtained non-lethal diet samples from 23 larval Hellbenders. Larval Hellbenders consumed primarily invertebrate prey including mayfly (Ephemeroptera) and caddisfly (Trichoptera) nymphs. Since these items do not comprise a large proportion of the adult diet, Hellbenders may undergo an ontogenetic dietary shift. Therefore, future management and conservation decisions regarding the Hellbender should consider the abundance and density of aquatic insect populations.

Effect of size, color and height of pheromone baited sticky traps on captures of Dacus oleae flies

The size of sticky pheromone traps has no effect on Dacus οleae catches when insect population densities are low. At high population densities trap catches increase with surface area. There were no differences in the numbers of D. οleae caught on yellow and white pheromone traps in periods of high pheromone effectiveness, which coincide with periods of high insect reproductive activity. During periods of reduced pheromone effectiveness, due either to low temperatures at the time of pheromone activity (dusk) or reduced insect reproductive activity, traps of yellow hues tend to capture more insects than traps of white color. The height at which pheromone traps are located inside the tree canopy has no effect on catches of D. οleae.

Mortality and movement of Cryptolestes ferrugineus and Rhyzopertha dominica in response to cooling in 300-kg grain bulks

We examined the effect of low temperatures on insect population density and mortality of adult and immature stages of Cryptolestes ferrugineus and Rhyzopertha dominica in three barrels holding 300 kg of wheat each. Barrels were infested with 2 insects/species/kg and left to develop at 30 °C for 5 months. Temperature of the grain mass before cooling was 38 °C in the centre to a low of 28 °C on the periphery. On 11 February the building door was opened to allow for cooling of the grain. During the 3 weeks of cooling, temperatures in the centre reached as low as −5 °C. Segregated (11 segments) grain trier samples were collected from three locations in each barrel, from February until March 2013 (6 dates), sieved, and the number of live and dead adults counted. Sieved grain was held for 5 weeks 30 °C and emerged adults counted to give an estimation of immature stages within the grain at the time of sampling. Rhyzopertha dominica adults were found mainly in the top 40 cm of the barrel, and there was little movement to the centre as the grain mass cooled. The initial distribution of C. ferrugineus adults was more complex; in two barrels adults were mostly in the centre of the grain mass, while in the other barrel, more adults were found on the periphery. When the grain mass cooled, C. ferrugineus adults in all barrels were found mostly in the centre. On day 0, the average number of live adults of C. ferrugineus and R. dominica were 232 ± 56 and 414 ± 48 insects/100 g, respectively. Rhyzopertha dominica adults were more susceptible to low temperatures than C. ferrugineus. The density of immatures of C. ferrugineus and R. dominica were similar at 0 d, there was a decline over the 21 d, but there was some survival at day 21.

English

Wheat flour samples were artificially infested with Corcyra cephalonica, Ephestia kuehniella, Tribolium confusum (separately) and with the three insect populations together. The effect of insects’ infestation on wheat flour quantity and quality loss, fungal contamination and presence of mycotoxins was studied after two months of storage (25±2C and 65%RH). Wheat flour infested with insects was sieved into two portions (sieved and residual flour) after insects populations have been recorded. The results revealed radical changes in weight loss, population density of insects, nutritional composition, interaction between insects and fungal contamination in the flour samples. The maximum residual flour loss was recorded by C. ceplalonica followed by E. kuehniella while the minimum residual loss was induced by T. confusum. The flour consumption by the tested insects may be arranged in descending order as follows: three insects tested together > C. cephalonica > T. confusum > E. kuehniella. There was a significant correlation between the amount of flour consumed and insect population. Also, there was a significant increase in the total protein contents and decrease in the monosaccharaides and disaccharides in all infested sieved and residual flour samples tested. The average log total molds count in control flour samples was 1.28, while the average log of insect infested flour samples ranged from 2.36 to 4.34. Seven to ten fungal species belonging to five genera (Aspergillus, Penicillium, Cladosporium, Eurotium and Emercilla) were isolated from control and infested flour samples. Many fungal species were isolated from infested flour, but most of them belong to Aspergillus and Penicillium. Aflatoxins B1, B2 were detected in all flour samples, but at different levels. Ochratoxin A was not detected in the control samples and C. cephalonica flour samples while it was detected in flour samples infested with the other treatment. © 2016 Friends Science Publishers

The Prediction Research of Population Density Based on Deep Learning in Grain Stored Insects

Precision of pests, in stored grain insect population density, has been a hot and difficult research in pest detection and control system. The accuracy of prediction of pest density will directly affect to warehouse grain temperature and the food quality etc. In order to improve the accuracy, the paper which using the depth study method, established an insects density prediction mode with the depth of the belief network as the core. The model is applied to the algorithm of deep learning predictive control. According to the temperature and humidity of the grain obtained from the actual measurement and the initial density of the pest, we predicted the pest density. Simulation results show that the root mean square error is small between the predictive value and actual value, high prediction accuracy. The deep learning algorithm is applied to the population density of pests is effective.

Population Density of Certain Piercing-Sucking Insects Infesting Wheat and its Associated Coccinellid Predator in Relation to Sampling Methods

Population Density of Certain Piercing-Sucking Insects Infesting Wheat and its Associated Coccinellid Predator in Relation to Sampling Methods

Tratamento de sementes para manejo do percevejo-barriga-verde na cultura de soja e milho em sucessão

Resumo: O objetivo deste trabalho foi avaliar o efeito do tratamento de sementes com inseticidas sobre o manejo de Dichelops melacanthus e a produtividade da soja e do milho, cultivados em sucessão. O estudo foi realizado em campo, nas safras 2012/2013 (I) e 2013/2014 (II). Avaliaram-se os inseticidas imidacloprido, tiametoxam, tiodicarbe, fipronil e abamectina. Determinaram-se: a densidade populacional do percevejo, a produtividade de soja e milho, e a intensidade da injúria em milho. A densidade do percevejo permaneceu abaixo de um inseto por metro quadrado, na maior parte do ciclo da soja. Os picos populacionais foram observados nas primeiras semanas, após a emergência do milho, e atingiram 2,2 (safra I) e 6,7 (safra II) percevejos por metro quadrado. Na cultura da soja, os inseticidas não reduziram a densidade populacional do percevejo. Na cultura do milho, o imidacloprido reduziu a densidade do percevejo em 23,2% (safra I) e 38,8% (safra II), e a injúria em 61,8% (safra I) e 26,4% (safra II). O tiametoxam reduziu a densidade dos insetos em 27,8% (safra II) e a injúria em 42,7% (safra I). O tratamento de sementes com inseticidas não proporciona aumento de produtividade à soja e ao milho, portanto, não se justifica sua utilização nas condições deste estudo.