Insecticide Treatments Research Articles

The influence of climate and management on transpiration of residential trees during a bark beetle infestation

AbstractTrees in residential environments are affected by a unique combination of environmental and anthropogenic factors, including occasional insect outbreaks that are increasing in frequency and severity due to climate change. We studied loblolly pine trees infested by bark beetles in a residential backyard in a southeastern US city. We investigated the responses of tree and stand‐level transpiration to environmental factors (solar radiation, atmospheric vapor pressure deficit, and soil moisture), severe weather events (strong winds and heavy storms), bark beetle infestation, and human actions (insecticide treatments and tree removals). We used constant heat dissipation probes to make continuous sap flux measurements (J0) in tree boles. Over 22 months of the study, J0 of trees with confirmed infestation decreased from ~90 to ~60 g cm−2 day−1 and J0 of the rest of the trees increased from ~60 to ~80 g cm−2 day−1. One infested tree died, as its J0 steadily declined from 110 g cm−2 day−1 to zero over the course of 2 months, followed by a loss of foliage and visible signs of severe infestation 6 months later. J0 was sensitive to variations in incoming solar radiation and atmospheric vapor pressure deficit. In most trees, J0 linearly responded to soil water content during drought periods. Yet despite complex dynamics of J0 variations, plot‐level transpiration at the end of the study was the same as at the beginning due to compensatory increases in tree transpiration rates. This study highlights the intrinsic interplay of environmental, biotic, and anthropogenic factors in residential environments where human actions may directly mediate ecosystem responses to climate.

Efficacy of Insecticidal Seed Treatment and Foliar Spray against Fall Armyworm, Spodoptera frugiperda1 , on Maize

Efficacy of Insecticidal Seed Treatment and Foliar Spray against Fall Armyworm, Spodoptera frugiperda1 , on Maize

Impact of Seed Protectants on Seed Quality and Pest Infestation in Pigeon Pea (Cajanus cajan L.) Seeds during Storage

This study investigates the efficacy of diverse seed protectants on key parameters affecting seed quality and pest infestation in pigeon pea seeds during storage. Over 3, 6, and 9-month storage periods, the impact of seed protectants on germination percentage, moisture content, vigor index, insect infestation by pulse beetles, and seed weight loss was assessed. Notably, Emamectin benzoate and Deltamethrin consistently maintained high seed quality, with germination percentages ranging from 88.33% to 84.33% and 87.33% to 83.00%, respectively. These insecticidal treatments also exhibited minimal insect infestation, ranging from 0.33% to 1.00%. In contrast, botanical protectants showed varying effectiveness, with Lantana camara and Vitex negundo displaying germination percentages ranging from 86.67% to 80.67% and 87.00% to 82.67%, and insect infestation levels ranging from 0.33% to 1.33%. These findings highlight the importance of seed protectants in preserving seed viability and minimizing pest damage during storage, thereby enhancing crop yield and reducing post-harvest losses in pigeon pea cultivation.

Cereal leaf beetle-associated bacteria enhance the survival of their host upon insecticide treatments and respond differently to insecticides with different modes of action.

The cereal leaf beetle (CLB, Oulema melanopus) is one of the major cereal pests. The effect of insecticides belonging to different chemical classes, with different mechanisms of action and the active substances' concentrations on the CLB bacterial microbiome, was investigated. Targeted metagenomic analysis of the V3-V4 regions of the 16S ribosomal gene was used to determine the composition of the CLB bacterial microbiome. Each of the insecticides caused a decrease in the abundance of bacteria of the genus Pantoea, and an increase in the abundance of bacteria of the genus Stenotrophomonas, Acinetobacter, compared to untreated insects. After cypermethrin application, a decrease in the relative abundance of bacteria of the genus Pseudomonas was noted. The dominant bacterial genera in cypermethrin-treated larvae were Lactococcus, Pantoea, while in insects exposed to chlorpyrifos or flonicamid it was Pseudomonas. Insecticide-treated larvae were characterized, on average, by higher biodiversity and richness of bacterial genera, compared to untreated insects. The depletion of CLB-associated bacteria resulted in a decrease in larval survival, especially after cypermethrin and chlorpyrifos treatments. The use of a metagenome-based functional prediction approach revealed a higher predicted function of bacterial acetyl-CoA C-acetyltransferase in flonicamid and chlorpyrifos-treated larvae and tRNA dimethyltransferase in cypermethrin-treated insects than in untreated insects.

Bio-Efficacy of Newer Insecticides on Major Insect Pests of Rice (Oryza sativa L.)

Present study was carried out at the Farm of Institute of Agricultural Sciences, Banaras Hindu University, Varanasi during 2022-23. In order to study the bio-efficacy of insecticides; field experiment was laid with six treatments viz., chlorantraniliprole 0.53%G @ 29.81 g a.i/ha,chlorantraniliprole 0.53%G@39.75g a.i/ha, chlorantraniliprole 0.53%G@49.69 g a.i/ha, chlorantraniliprole 0.4G@ 40 g a.i/ha and fipronil 0.3G @75 g a.i/ha including the untreated control. In case of stem borer and leaf folder chlorantraniliprole 0.53%GR @39.75g a.i/haprovided significantly better control followed by chlorantraniliprole 0.53% GR @ 49.69g a.i/ha, Fipronil 0.30% GR@ 75g a.i/hachlorantraniliprole 0.53%G @ 29.81 g a.i/ha and Chlorantraniliprole 0.40% GR@ 49.69g a.i/ha. It was concluded that the Bio-efficacy of insecticidal treatments against major pests of paddy showed that chlorantraniliprole 0.53%G 39.5g a.i/ha was first best insecticidal treatment against both Lepidopteran insect pests of paddy.

Community-Directed Vector Control to Accelerate Onchocerciasis Elimination.

Onchocerciasis, or river blindness, has historically been one of the most important causes of blindness worldwide, and a major cause of socio-economic disruption, particularly in sub-Saharan Africa. Its importance as a cause of morbidity and an impediment to economic development in some of the poorest countries in the world motivated the international community to implement several programs to control or eliminate this scourge. Initially, these involved reducing transmission of the causative agent Onchocerca volvulus through controlling the vector population. When ivermectin was found to be a very effective drug for treating onchocerciasis, the strategy shifted to mass drug administration (MDA) of endemic communities. In some countries, both vector control and ivermectin MDA have been used together. However, traditional vector control methods involve treating rivers in which the black fly vectors breed with insecticides, a process which is expensive, requires trained personnel to administer, and can be ecologically harmful. In this review, we discuss recent research into alternatives to riverine insecticide treatment, which are inexpensive, ecologically less harmful, and can be implemented by the affected communities themselves. These can dramatically reduce vector densities and, when combined with ivermectin MDA, can accelerate the time to elimination when compared to MDA alone.

Foliar- and Seed-Applied Insecticides for Management of Melanaphis sorghi (Hemiptera: Aphididae) in Alabama

Abstract Following the emergence of Melanaphis sorghi (Theobald) (Hemiptera: Aphididae) as a new pest of sorghum in the United States, research was conducted to identify tools and techniques successful at reducing populations and preventing economic losses in grain sorghum, Sorghum bicolor (L.) Moench. The objective of this study was to assess the efficacy of seed- and foliar-applied insecticide treatments for management of M. sorghi. Small plot experiments were replicated at two locations to evaluate residual activity of neonicotinoid seed treatments and foliar insecticides. Natural enemy presence was recorded in each of these trials to determine which predator and parasitoid species were using M. sorghi as prey. All seed treatments suppressed M. sorghi populations below a treatment threshold of 75 aphids per plant for 30% of plants for >6 weeks after planting. Foliar insecticides including flupyradifurone, sulfoxaflor, and thiamethoxam provided 3–4 weeks of population suppression, irrespective of M. sorghi pressure. Fifteen natural enemy species were identified in this study, and community structure varied temporally and geographically. In general, natural enemy species richness was correlated with aphid abundance. We identified the most efficacious insecticides available for management of M. sorghi and determined that they should be compatible with biological control and integrated pest management programs.

Characterization and expression of heat shock protein 70s in Liposcelis bostrychophila: Insights into their roles in insecticidal stress response

Liposcelis bostrychophila is one of the most economically significant and important storage pests in the Psocoptera order. Heat shock proteins (HSPs) act as molecular chaperones and play an important role in insect responses to environmental stress. In this study, the genome-wide identification and characterization of 61 HSP proteins in the L. bostrychophila genome was conducted. These HSPs are classified into five different families, comprising 8 HSP70s, 3 HSP90s, 10 HSP60s, 35 HSP40s, and 5 sHSPs genes. Phylogenetic profiling of the HSP gene families disclosed unique inter-group connections for each HSP family. These families maintained relatively stable motif composition and gene structure. Particularly, the HSP40 family expanded substantially in L. bostrychophila. Furthermore, quantitative polymerase chain reaction (qPCR) revealed distinct expression profiles of the LbHSP genes during development of L. bostrychophila. Most LbHSP70 genes expression are induced by insecticide exposures, and differences in their mRNA abundance profiles may be associated with the type and concentration of the tested insecticides. Specifically, LbHSP70.4 and LbHSP70.5 were most significantly up-regulated after insecticide treatments. Silencing the expression of LbHSP70.4 and LbHSP70.5, respectively, resulted in significantly higher mortality upon both beta-cypermethrin and malathion (LC20) treatments. This study affirms the important roles played by specific LbHSP70 genes in responding to insecticide stresses. The findings of this study not only contribute to the database of insect heat shock protein genes but also enhance our understanding of the mechanism underlying resistance or tolerance formation in stored-product psocids.

Demographic analysis of the biological parameters of Spodoptera frugiperda after sublethal exposure to insecticides

Spodoptera frugiperda (JE Smith) is one of the most destructive pests, causing serious yield losses of corn on all continents except Europe. Low-lethal concentrations of insecticides may affect not only the survival rate but also the demographic parameters of a pest. To understand the effect of low-lethal concentrations of insecticides on S. frugiperda, the developmental parameters after low-lethal concentrations treatment by three different modes of action pesticides tetrachlorantraniliprole, spinetoram, and lufenuron were analyzed. For F0 generation, the pupal length and weight of FAW after insecticide treatment were significantly longer and heavier than that of control. For the F1 generation, the adult longevity and egg hatching rate after spinetoram and lufenuron treated was significantly shorter and lower than that of the control. While no significant effect was observed for the intrinsic rate of increase (r), finite rate of increase (λ), and mean generation time (T) of S. frugiperda, the net reproductive rate (R0) significant decreased after the spinetoram and lufenuron treatment. Results showed tetrachlorantraniliprole, spinetoram, and lufenuron negatively affect larval survival rate, but spinetoram and lufenuron caused early maturity, and all three insecticide treatments increased egg reproduction. The results of this study suggest that low-lethal concentration exposure to insecticides negatively impacts the life table parameters of S. frugiperda, and those three insecticides from different modes of action cannot cause FAW resurgence and can be recommended as insecticides to control FAW. Those results will be helpful for researchers working on S. frugiperda management using chemical pesticides in an integrated pest management program.

Bio-efficacy of certain new insecticides against pod borer complex in pigeonpea (Cajanus cajan L.)

A study on evaluation of certain new insecticides against pod borer complex in pigeonpea was conducted at Regional Agricultural Research Station, Warangal for three consecutive years from Kharif 2019-20 to Kharif 2021 22 in medium maturity pigeonpea cultivar ‘Rudreswara’ (WRG-65). Seven treatments including untreated control were evaluated for their relative efficacy towards suppression of pod borer larval population and reduction of percent pod damage. The insecticide treatments along with untreated control were applied two times during the crop season viz., 50% flowering and pod formation stage. The results revealed that chlorantraniliprole 18.5 SC @ 0.3 ml/L followed by emamectin benzoate 5 SG proved significantly superior against gram pod borer (Helicoverpa armigera) and spotted pod borer (Maruca vitrata) with highest mean percent larval reduction and cumulative least percent pod damage (10.8 and 14.7%, respectively) over control. Further, chlorantraniliprole 18.5 SC followed by emamectin benzoate 5 SG @ 0.4 g/l recorded higher grain yields and best ICBR ratio (1:4.6; 1:4.5). Thus, the effective chemicals observed in the study could be used as basis for selection of label recommended insecticides for successful management of pod borers in pigeonpea.

Comparative Efficacy of Pyrethroid-Based Paints against Turkestan Cockroaches.

The Turkestan cockroach, Periplaneta lateralis (Walker), is an invasive urban pest prevalent in dry areas of the southwestern United States. Treatment with liquid spray formulations containing insecticides is the most conventional method to decrease Turkestan cockroach population abundance around buildings. Intensive application of insecticide treatments near natural environments has prompted concerns regarding the impacts on non-target aquatic and terrestrial ecosystems. Technologies embedding insecticides in a paint matrix have successfully been used for the long-term reduction in disease-vector populations in tropical areas. Here, we evaluated the potential effectiveness of three pyrethroid-based paints against Turkestan cockroach nymphs on common surfaces inhabited by this species. Turkestan cockroaches continuously exposed for 1 h to 1-month aged alphacypermethrin and deltamethrin paints applied to concrete, metal, or PVC caused moderate to high mortality. Evaluations using choice boxes indicated that deltamethrin and transfluthrin paints had combined lethal and repellent effects on cockroaches. Alphacypermethrin also caused repellency and killed cockroaches rapidly. We discuss the implications of these findings on cockroach control practices.

Ecological and economic analysis of insecticidal control of fall armyworm

Fall Armyworm (FAW), Spodoptera frugiperda (Lepidoptera: Noctuidae) , is a significant pest causing substantial economic losses worldwide, particularly in Sub-Saharan Africa. The prevalent strategy for managing FAW involves insecticide applications, ranging from synthetic to botanical and microbial agents. However, the ecological and economic impacts of these interventions often remain unassessed. This study scrutinizes the ecological and economic viability of two insecticidal treatments: one based on emamectin benzoate and another comprising a combination of Pieris rapae granulovirus (PrGV) and Bacillus thuringiensis subsp. kurstaki (Btk) with varied application timings and frequencies. Our findings indicate that both insecticide types were effective in reducing FAW larval populations and the associated crop damage. From an ecological standpoint, the PrGV|Btk treatment enhanced parasitism rates, especially when applied only at the early stage of the crop. However, this approach did not significantly lower crop damage compared to a "targeted" strategy, where insecticide application was contingent upon observed injury levels. Remarkably, the "targeted" strategy led to increased FAW larval parasitism, particularly at the V7 growth stage of the crop. Economically, the "targeted" insecticide application emerged as both effective and efficient, minimizing the need for multiple sprays and thus recommended for managing FAW infestations while considering cost and ecological balance.

Pea leaf weevil, Sitona lineatus (L.) (Coleoptera: Curculionidae), adult feeding preference and larval development on pulse crop varieties in Montana.

Montana accounts for approximately 45% of US dry pea production and the pea leaf weevil (PLW; Sitona lineatus (L.)) is the most common insect pest in this region. After crop emergence adult PLW feed on the foliage to mature and subsequently mate, and the soil-dwelling larvae feed and develop on the nitrogen-fixing root nodules. Producers commonly apply prophylactic insecticide treatments to the seed at planting as well as one or two post-emergent insecticide sprays to control PLW damage. To develop alternative management strategies based on integrated pest management (IPM), this field study evaluated pulse crops grown in Montana for adult feeding preference and larval development. Ten different field pea varieties, along with two faba bean, lentil and chickpea varieties, were evaluated during the 2020 and 2021 field seasons at the Montana State University Arthur H. Post Agronomy Farm. Significant PLW pest pressure was observed within the research plots during both experimental years. Field pea and faba bean were preferred by the foliage feeding adult stage, with all but one variety averaging 39.2 to 86.3 average notches per plant. The pea variety Lifter was significantly preferred over all other comparisons, averaging 142.4 and 95.0 notches per plant in 2020 and 2021, respectively. Adult PLW feeding on lentil and chickpea was minimal, averaging 3.3 to 8.2 and 0.5 to 1.6 notches per plant, respectively. Numbers of larvae were highest on the roots of pea varieties, a known reproductive host, and almost nil on lentil and chickpea roots. Faba bean is also known as reproductive host, but, unexpectedly, larval populations were also low on the two faba bean varieties. The results from this study provide some limited evidence for alternative IPM strategies for field peas based on host plant tolerance or resistance within the range of varieties tested. Adult preference and larval development of PLW varied between the different pulse crops with field peas and faba beans being the most susceptible and lentils and chickpeas being the least susceptible. Host plant resistance against PLW could provide more sustainable IPM approaches in the future. © 2024 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Sublethal Effects of Insecticides on the Parasitism of Acerophagus flavidulus (Hymenoptera: Encyrtidae) Parasitoid of the Obscure Mealybug, Pseudococcus viburni (Hemiptera: Pseudococcidae)

Insecticides used to control agricultural pests can interfere with beneficial arthropods. This study determined the sublethal effects of two insect growth regulators—buprofezin and pyriproxyfen—and the neonicotinoid insecticide acetamiprid on adults of Acerophagus flavidulus (Brethés), a parasitoid of the obscure mealybug, Pseudococcus viburni (Signoret). A. flavidulus was exposed to insecticide residues at the minimum recommended rate of buprofezin and pyriproxyfen (1×) and 0.005× of acetamiprid on apple leaves under laboratory conditions. Each female parasitoid was in contact with the insecticide residues for 24 h and then allowed to parasitize three mealybug densities (two, four, and six nymphs) per parasitoid for 24 h. Parasitism, emergence rate, clutch size, development time, longevity, and secondary sex ratio were evaluated under each insecticide treatment and mealybug density. Application of the growth regulators buprofezin and pyriproxyfen at the labeled rate (1×) induced less sublethal effects than acetamiprid applied at a low rate (0.005×) on A. flavidulus. Pyriproxyfen and acetamiprid reduced parasitism, but they did not affect other aspects of development such as emergence rate, clutch size, development time, longevity, and secondary sex ratio. Our data suggest that buprofezin and pyriproxyfen are more compatible with A. flavidulus than acetamiprid, which could be integrated with parasitoid activity only when low residue levels in the field are attained.

Pine wilt disease: A global threat to forestry

AbstractPines are the most economically important trees in the world and, together with eucalyptus, they dominate commercial forests. But the success of a relatively small number of widely planted species, such as Pinus pinaster, the maritime pine, comes at a price. Pines are attractive to damaging pathogens and insect pests, including the pinewood nematode (PWN), Bursaphelenchus xylophilus, the causal agent of pine wilt disease (PWD). Originally described in Japan, PWD has caused widespread destruction to forests in countries such as China, Taiwan, Portugal, Spain and the United States. PWN causes irreparable damage to the vascular system of its pine hosts, leading to mortality within 3 months. Pine sawyer beetles (Monochamus spp.) are key vectors of PWD, introducing the PWN to healthy trees during feeding. Other organisms contribute to PWD spread and development, including bacteria, fungi and bark beetles. Control measures include tree felling to prevent vector transmission of PWN, insecticide treatments, trapping of Monochamus spp. and tree breeding for plant resistance. The PWN is a quarantine pathogen and subject to regular legislation and phytosanitary measures aimed at restricting movement and preventing introduction to new areas. Current research is investigating the use of biopesticides against PWN and Monochamus spp. This review examines the biology, epidemiology, impact and management of PWD through published research, grey literature and interviews with people directly involved in the management of the disease in Portugal.

Efficacy of Chromafenozide Insecticide to Control Tirathaba rufivena and Its Impacts on Oil Palm Pollinator E. kamerunicus

Newly marketed insecticide known with active ingredient Chromafenozide claimed to be potent against various lepidopterous insects, but at the same time almost non-toxic to non-lepidopterous species, including pollinators, predators and parasitoids. This trial aim to evaluate the effectiveness of Chromafenozide insecticides to control population of Tirathaba rufivena in oil palm planted on peat soil and its impact on pollinator weevil, Elaedobius kamerunicus. The trial was divided into two parts which are field assessment of insecticides efficacy and laboratory assay to know the direct effect of insecticide application on E. kamerunicus. Besides Chromafenozide, insecticides used in this trial Cypermethrin and Bacillus thuringiensis var kurstaky as comparison. The results of efficacy test showed that Tirathaba infestation decreased significantly in the Cypermethrin, B. thuringiensis, and Chromafenozide treatments compared to control. However, among these treatments did not show a significant difference. Nevertheless, each of the tested insecticide caused significantly mortality to E. kamerunicus. E. kamerunicus mortality rate of each insecticide treatment showed that Chromafenozide was less detrimental as compared Cypermethrin, but significantly detrimental to B. thuringiensis. B. thuringiensis was not significantly different compared to control.

Despite structural identity, ace-1 heterogenous duplication resistance alleles are quite diverse in Anopheles mosquitoes

Anopheles gambiae s.l. has been the target of intense insecticide treatment since the mid-20th century to try and control malaria. A substitution in the ace-1 locus has been rapidly selected for, allowing resistance to organophosphate and carbamate insecticides. Since then, two types of duplication of the ace-1 locus have been found in An. gambiae s.l. populations: homogeneous duplications that are composed of several resistance copies, or heterogeneous duplications that contain both resistance and susceptible copies. The substitution induces a trade-off between resistance in the presence of insecticides and disadvantages in their absence: the heterogeneous duplications allow the fixation of the intermediate heterozygote phenotype. So far, a single heterogeneous duplication has been described in An. gambiae s.l. populations (in contrast with the multiple duplicated alleles found in Culex pipiens mosquitoes). We used a new approach, combining long and short-read sequencing with Sanger sequencing to precisely identify and describe at least nine different heterogeneous duplications, in two populations of An. gambiae s.l. We show that these alleles share the same structure as the previously identified heterogeneous and homogeneous duplications, namely 203-kb tandem amplifications with conserved breakpoints. Our study sheds new light on the origin and maintenance of these alleles in An. gambiae s.l. populations, and their role in mosquito adaptation.

Laboratory evaluation of toxicity of selected insecticides against egg and larval stages of cotton pink bollworm, Pectinophora gossypiella (Saunders) (Lepidoptera: Gelechiidae)

BackgroundThe cryptic nature of pink bollworm Pectinophora gossypiella (Saunders) larvae enables its reduced vulnerability to insecticidal control. Further, the development of resistance against Bacillus thuringiensis (Bt) toxins posed a serious threat to transgenic cotton cultivation. This necessitated determining the critical timing of spray applications on the control effectiveness. This study assessed the influence of egg age (freshly laid vs. three-day-old) and the location of larvae (directly exposed to the insecticide residues on the boll rind vs. burrowed inside the bolls) on insecticide control efficacy.ResultsThe results revealed a significant decrease in the ovicidal activity of tested insecticides with an increase in the age of eggs from one day old to three days old (paired t-test, P < 0.05). The larvae directly exposed to the insecticide residues on the boll rind were more susceptible (> 80% mortality) than the larvae exposed after they had burrowed inside the bolls (< 49% mortality). The inhibitory effects of tested insecticides on developmental biology were more pronounced in the experiment on pre-larval release insecticide treatment compared with insecticide treatment given post-larval release and entry inside the bolls.ConclusionEgg age influences the insecticide susceptibility, as does the larval location, directly exposed vs burrowed inside the bolls. Older eggs and the larvae that had burrowed inside the green bolls of cotton were relatively less susceptible to the insecticide treatments. The toxic effects of insecticides on egg and larval stages were primarily ephemeral. These findings are significant for devising a comprehensive strategy for pink bollworm management on a sustainable basis.

Mortality Pattern of Poecilus cupreus Beetles after Repeated Topical Exposure to Insecticide─Stochastic Death or Individual Tolerance?

The mortality of organisms exposed to toxicants has been attributed to either stochastic processes or individual tolerance (IT), leading to the stochastic death (SD) and IT models. While the IT model follows the principles of natural selection, the relevance of the SD model has been debated. To clarify why the idea of stochastic mortality has found its way into ecotoxicology, we investigated the mortality of Poecilus cupreus (Linnaeus, 1758) beetles from pesticide-treated oilseed rape (OSR) fields and unsprayed meadows, subjected to repeated insecticide treatments. We analyzed the mortality with the Kaplan-Meier estimator and general unified threshold model for survival (GUTS), which integrates SD and IT assumptions. The beetles were exposed three times, ca. monthly, to the same dose of Proteus 110 OD insecticide containing thiacloprid and deltamethrin, commonly used in the OSR fields. Kaplan-Meier analysis showed that the mortality of beetles from meadows was much higher after the first treatment than after the next two, indicating the IT model. Beetles from the OSR displayed approximately constant mortality after the first and second treatments, consistent with the SD model. GUTS analysis did not conclusively identify the better model, with the IT being marginally better for beetles from meadows and the SD better for beetles from OSR fields.

Combination Insecticide Treatments with Methoprene and Pyrethrin for Control of Khapra Beetle Larvae on Different Commodities.

Trogoderma granarium Everts, the khapra beetle, is a serious pest of stored products throughout the world. Larvae pose a significant threat to stored products because they feed on >100 different commodities, possess the ability to enter facultative diapause, and are difficult to detect. Control methods for T. granarium include fumigation, contact insecticides, trapping, and insecticide-incorporated packaging. The objective of this study was to determine the residual efficacy of two insecticide formulations (methoprene + deltamethrin + piperonyl butoxide synergist Gravista® and methoprene + deltamethrin, DiaconIGR®Plus). These insecticides were evaluated on three stored product commodities, corn, wheat, and brown rice, by exposing T. granarium larvae during a 12-month testing period. Both formulations significantly reduced adult emergence on corn and wheat for 12 months and on brown rice for up to 6 months. Adult emergence was highest at month 12 for corn (8.41%), and brown rice (85.88%), and month 9 for wheat (39.52%), treated with DiaconIGR®Plus or Gravista®, respectively. A biological index used to measure the development of exposed larvae on the treated grain from the larval stage (low values) to adult emergence (high values) was lower (fewer adults) on corn and wheat compared to controls. Despite differences in formulations, each of these grain protectants could be utilized by stored commodity managers to protect commodities during storage and transportation for T. granarium when and if this pest is detected at USA ports of entry.