Toxicity of several insecticide formulations against adult German cockroaches (Dictyoptera: Blattellidae)

Toxicity of bendiocarb, chlorpyrifos, cyfluthrin, cypermethrin, fenvalerate, hydramethylnon, malathion, propetamphos, propoxur, and pyrethrins against the adult German cockroaches, Blattella germanica (L.), was investigated. At LD50, cyfluthrin was the most toxic insecticide to adult males (0.53 microgram/g), adult females (1.2 micrograms/g), and gravid females (0.85 microgram/g). Malathion was the least toxic insecticide to adult males (464.83 micrograms/g), adult females (335.83 micrograms/g), and gravid females (275.90 micrograms/g). Males and gravid females were generally more sensitive than nongravid females to the insecticides that we tested. In tests with malathion, however, males were more tolerant. The order of toxicity of the insecticide classes varied among the stages of adult German cockroaches. The order of toxicity for males and nongravid females was pyrethroids greater than pyrethrins = organophosphates (except malathion) greater than carbamates = amidinohydrazone. The order of toxicity for gravid females was pyrethroids greater than pyrethrins = organophosphates (except malathion) greater than carbamates greater than amidinohydrazone. These differences in toxicity suggest that sex differences should be considered when determining insecticide toxicity for German cockroaches.     

Sublethal effects of insecticides on adult longevity and fecundity of German cockroaches (Dictyoptera: Blattellidae).

The effects of sublethal concentrations of chlorpyrifos, cyfluthrin, and hydramethylnon on adult longevity and fecundity of German cockroaches, Blattella germanica (L.), were investigated. Longevity of males declined linearly with increasing doses of insecticide. An LD50 of cyfluthrin decreased male longevity by 52%, whereas an LD50 of hydramethylnon reduced male longevity by 81%. Longevity of females increased linearly with increasing sublethal doses of chlorpyrifos, whereas all doses of both cyfluthrin and hydramethylnon decreased longevity of females. Fecundity increased linearly with increasing sublethal doses of chlorpyrifos. Number of oothecae formed, oothecae hatched, and number of offspring produced in each ootheca increased with increasing sublethal concentrations of chlorpyrifos. In contrast, fecundity declined with increasing sublethal concentrations of cyfluthrin and hydramethylnon. Formation of the first ootheca occurred approximately 8 d after mating for untreated females but generally longer with sublethal concentrations of all insecticides. The period between oothecae hatch and the formation of subsequent oothecae increased with successive oothecae in all treatments.     

Toxicity, sublethal effects, and performance of sulfluramid against the German cockroach (Dictyoptera: Blattellidae)

Topical and oral toxicity of sulfluramid (N-ethyl perfluorooctane sulfonamide) were determined for the German cockroach, Blattella germanica (L.). The topical LD50 of sulfluramid was 175.6 micrograms/g for adult males, 117.8 micrograms/g for adult females, and 122.3 micrograms/g for gravid adult females. Ingestion increased toxicity approximately 1.4 times for adult male B. germanica. Twenty-four hours after topical treatment with 20 micrograms/insect sulfluramid, the percentage of female cockroaches that dropped their oothecae increased approximately 50% compared with controls treated with acetone. Sulfluramid also decreased oothecal hatch of both dropped and retained oothecae. Approximately 90% of oothecae from untreated females hatches, whereas less than 20% hatched from females treated with 20 micrograms/insect. Mean time for oothecal hatch increased linearly with increasing sulfluramid concentration. In arena studies in Ebeling choice boxes, LT50's ranged between approximately 2.3 and 3.9 d for a 0.331 mg/cm2 deposit and a 1.5% bait, respectively. Higher concentrations of sulfluramid were more repellent in both bait and residual formulations. Performance index values indicated excellent potential field efficacy. Field trials with 1.0 and 1.5% (AI) baits showed up to a 71.3% reduction in cockroach numbers. Baits controlled cockroaches throughout the 12-wk test.     

Monitoring for insecticide resistance in field-collected strains of the German cockroach (Dictyoptera: Blattellidae)

Forty-five field-collected strains of German cockroaches, Blattella germanica were tested for resistance to 12 different insecticides by the time-mortality response method in comparison with a known susceptible strain. Only low to moderate resistance to diazinon, chlorpyrifos, and acephate was detected. Resistance to malathion was widespread; about half of the strains tested showed high resistance. High resistance to the carbamates propoxur and bendiocarb also occurred. High resistance was uncommon with propoxur, but about 35 strains were highly resistant to bendiocarb. High resistance to pyrethrins was observed in about of the strains tested. Resistance to the pyrethroids allethrin, permethrin, phenothrin, fenvalerate, and cyfluthrin was detected in some of the strains examined. All of the strains tested were susceptible to one or more of the insecticides used. These results indicate that, although resistance is a serious problem in this species, satisfactory control should be possible by selection of an appropriate insecticide.     

Inter- and intra- species differences in plants as hosts to shape Tyria jacobaeae

The effects of sublethal doses of deltamethrin and propoxur, applied topically at LD10, LD30 and LD50 on German cockroaches, were studied by reciprocal crossing. Male and female longevities decreased curvilinearly with increasing sublethal doses of deltamethrin, and decreased linearly with increasing sublethal doses of propoxur. Fecundity of females treated with deltamethrin and propoxur was reduced with increasing sublethal doses of both insecticides. Oothecal production, oothecal hatchability and nymphal production also declined with increasing doses of deltamethrin and propoxur. Preoviposition and incubation periods were not affected by sublethal doses of deltamethrin and propoxur, although some significant differences were observed at certain oothecal numbers. Two-way analysis of variance indicated that only treated females showed an effect on oothecal production while oothecal hatch and nymphal production were governed by both treated females and males. Insecticide susceptibility tests on the progeny of parents treated with sublethal doses demonstrated that these doses did not increase insecticidal tolerance in the F1 generation.     

Determination of the resistance to organophosphate, carbamate, and pyrethroid insecticides in Panamanian Anopheles albimanus (Diptera: Culicidae) mosquitoes

Introduction. The susceptibility of Anopheles albimanus to organophosphates, carbamates and pyrethroid insecticides was unknown in the Panama communities of Aguas Claras, Pintupo and Puente Bayano, located in the Amerindian Reservation of Madungandi. This region is considered a malaria transmission area, where An. albimanus is the main vector. Objective. The resistance to organophosphate insecticides, carbamates and pyrethroids was evaluated in field populations of the Anopheles albimanus in Panama. Materials and methods. Progeny of An. albimanus collected in three localities in the indigenous Madugandi region were exposed to bioassays of susceptibility to organophosphate insecticides (fenitrothion, malathion and chlorpyrifos), the carbamate (propoxur) and pyrethroids (deltamethrin, lambdacyhalothrin, cyfluthrin and cypermethrin). The protocols were in accordance with those established for adult mosquitoes by World Health Organization. Results. The three strains of the An. albimanus were resistant to the pyrethroid insecticides deltamethrin, lambdacyhalothrin, cyfluthrin and cypermethrin. Susceptibility remained for the organophosphate insecticides fenitrothion, malathion, chlorpyrifos, and the carbamate insecticide propoxur. Conclusion. The results provided important information to the vector control program, contributing to the application of new strategies on the use of insecticides, and thereby lengthening the life of the insecticide in use.     

In vivo study on combined toxicity of Metarhizium anisopliae (Deuteromycotina: Hyphomycetes) strain ESC-1 with sublethal doses of chlorpyrifos, propetamphos, and cyfluthrin against German cockroach (Dictyoptera: Blattellidae)

The effect of Metarhizium anisopliae (Metschnikoff) Sorokin strain ESC-1 alone and in combination with sublethal doses of commercial formulations of chlorpyrifos, propetamphos and cyfluthrin on mortality of CSMA strain of German cockroach, Blattella germanica (L.), was determined by conducting in vivo studies that included 3 bioassays. Spores of M. anisopliae cultured on SDAY media had germination of >90%. Based on bioassay 1, doses ranging from 0.5 to 300 ppm of chlorpyrifos and propetamphos, and 0.05 to 40 ppm of cyfluthrin were selected for bioassays 2 and 3. Cockroach mortality ranged from 5 to 20% for insecticides alone and 48 to 70% for insecticides + M. anisopliae in bioassay 2. In bioassay 3, mortality ranged from 15 to 60% for insecticides and 57.5 to 92.5% for insecticides + M. anisopliae. Percentage of cockroach mortality resulting from insecticide + M. anisopliae combinations was significantly higher than insecticide alone. Mortality was also significantly higher in certain insecticide + M. anisopliae combinations than M. anisopliae alone. There was no significant interaction between M. anisopliae and insecticides with their concentrations in bioassay 2, indicating an additive effect. But in bioassay 3, a significant interaction was observed when M. anisopliae was combined with multiple insecticide concentrations. The interaction indicated an additive effect for chlorpyrifos and cyfluthrin, and a synergistic effect for propetamphos. There were significant differences in LT50 among various treatment combinations. M. anisopliae alone or insecticide + M. anisopliae combinations did not affect body weight in treated German cockroaches.     

Virulence, horizontal transmission, and sublethal reproductive effects of Metarhizium anisopliae (Anamorphic fungi) on the German cockroach (Blattodea: Blattellidae)

Virulence of Metarhizium anisopliae (Metschnikoff) Sorokin strain EAMa 01/121-Su against the German Cockroach, Blatella germanica (L.), was determined using four concentrations ranging from 4.2 x 10(6) to 4.2 x 10(9) spores per milliliter. The LD50 value was 1.4 x 10(7) spores per milliliter (56,000 spores per cockroach) and LT50 values were 14.8 days and 5.3 days for 4.2 x 10(8) and 4.2 x 10(9) spores per milliliter, respectively. An experiment was conducted to evaluate whether a fungal transmission could exist among infected and healthy cockroaches. Percentage mortality at a ratio of 1:10 of infected to unexposed cockroaches was 87.5% and LT50 was 12.2 days, which indicated the potential of this strain to be horizontally transmitted and to rapidly spread the infection in the insect population. The effect of a sublethal dose (ca. LD60) of M. anisopliae EAMa 01/121-Su strain, applied topically on German cockroaches, was studied by reciprocal crossing. Othecal production, oothecal hatchability, and nymphal production declined upon exposure to M. anisopliae EAMa 01/121-Su strain. The mean number of oothecae laid by female was progressively and significantly reduced by fungal treatment from second oviposition period onwards. Oothecal hatch of fungally challenged females was reduced by 46-49%, oothecal viability by 48-85%, and nymphal production by 22-35%. Only treated females showed an effect on oothecal production, oothecal hatch, and nymphal production, although oothecal hatch was also governed by treated males at a higher significance level. Our results on virulence and horizontal transmission of fungal conidia of M. anisopliae EAMa 01/121-Su strain and its sublethal reproductive effects on German cockroach females are discussed in terms of its potential to decrease the pest status of B. germanica in the short and long terms.     

Resistance and synergistic effects of insecticides in Bactrocera dorsalis (Diptera: Tephritidae) in Taiwan

Oriental fruit flies, Bactrocera dorsalis (Hendel), were treated with 10 insecticides, including six organophosphates (naled, trichlorfon, fenitrothion, fenthion, formothion, and malathion), one carbamate (methomyl), and three pyrethroids (cyfluthrin, cypermethrin, and fenvalerate), by a topical application assay under laboratory conditions. Subparental lines of each generation treated with the same insecticide were selected for 30 generations and were designated as x-r lines (x, insecticide; r, resistant). The parent colony was maintained as the susceptible colony. The line treated with naled exhibited the lowest increase in resistance (4.7-fold), whereas the line treated with formothion exhibited the highest increase in resistance (up to 594-fold) compared with the susceptible colony. Synergism bioassays also were carried out. Based on this, S,S,S-tributyl phosphorotrithioate displayed a synergistic effect for naled, trichlorfon, and malathion resistance, whereas piperonyl butoxide displayed a synergistic effect for pyrethroid resistance. All 10 resistant lines also exhibited some cross-resistance to other insecticides, not only to the same chemical class of insecticides but also to other classes. However, none of the organophosphate-resistant or the methomyl-resistant lines exhibited cross-resistance to two of the pyrethroids (cypermethrin and fenvalerate). Overall, the laboratory resistance and cross-resistance data developed here should provide useful tools and information for designing an insecticide management strategy for controlling this fruit fly in the field.     

Development of resistance to spinosad in oriental fruit fly (Diptera: Tephritidae) in laboratory selection and cross-resistance

In this study, we assessed the potential for the development of resistance to the insecticide spinosad in a laboratory colony of the oriental fruit fly, Bactrocera dorsalis (Hendel) (Diptera: Tephritidae). Resistance was selected by using topical applications of spinosad. After eight generations of selection, the LD50 of the selected line was 408 times greater compared with that of the untreated parental colony. This spinosad-resistant line did not exhibit cross-resistance to 10 other insecticides tested, including six organophosphates (naled, trichlorfon, fenitrothion. fenthion, formothion, and malathion) one carbamate (methomyl), and three pyrethroids (cyfluthrin, cypermethrin, and fenvalerate). However, using lines previously selected for resistance to these same insecticides, two of the 10 lines tested (naled- and malathion-resistant) did show some cross-resistance to spinosad. Also, oriental fruit flies from different field collections where naled and malathion have been used for control purposes displayed some resistance to spinosad. In addition, the effects of direct ingestion of spinosad through dietary supplementation also were tested. Overall, the laboratory resistance and cross-resistance data developed in this study provide new information that will be useful for managing the development of resistance when spinosad is used to control B. dorsalis in the field.     

Extended selections for pyrethroid resistance in the German cockroach (Dictyoptera: Blattellidae).

Selection experiments with a pyrethrins-susceptible and a pyrethrins-resistant strain of German cockroaches, Blattella germanica (L.), were conducted for 17 generations with either permethrin or fenvalerate as the selecting agent. Large nymphs were left on treated glass surfaces for extended periods of time each generation. Mortality was assessed at 24 h. The level of resistance was determined periodically by time-mortality testing. The VPI-susceptible strain served as the basis for comparison. The pyrethrins-susceptible strain developed resistance to pyrethrins early in the selection process; this strain ultimately became resistant to allethrin, phenothrin, permethrin, fenvalerate, cyfluthrin, and cypermethrin. Fenvalerate caused faster development of resistance than did permethrin. The pyrethrins-resistant strain, selected with fenvalerate, quickly became resistant to allethrin, permethrin, phenothrin, and fenvalerate. Ultimately, it developed resistance to all nine pyrethroids tested.     

Sublethal effects of chlorpyrifos-methyl on reproduction in female German cockroaches (Dictyoptera: Blattellidae).

Longevity and lifetime fecundity were significantly reduced after topical application of LC10, LC20, and LC60's of chlorpyrifos-methyl to 2-d-old female German cockroaches, Blattella germanica (L.). Low concentrations (LC10 and LC20) often resulted in failure of the first ootheca to hatch. This effect is temporary, and greater than or equal to 90% of subsequent oothecae hatched normally. Application of an LC60 also resulted in a high percentage of abortions of first oothecae, but also caused greater than 15% inviability in subsequent oothecae.     

Current Perspectives on Plague Vector Control in Madagascar: Susceptibility Status of Xenopsylla cheopis to 12 Insecticides

Plague is a rodent disease transmissible to humans by infected flea bites, and Madagascar is one of the countries with the highest plague incidence in the world. This study reports the susceptibility of the main plague vector Xenopsylla cheopis to 12 different insecticides belonging to 4 insecticide families (carbamates, organophosphates, pyrethroids and organochlorines). Eight populations from different geographical regions of Madagascar previously resistant to deltamethrin were tested with a World Health Organization standard bioassay. Insecticide susceptibility varied amongst populations, but all of them were resistant to six insecticides belonging to pyrethroid and carbamate insecticides (alphacypermethrin, lambdacyhalothrin, etofenprox, deltamethrin, bendiocarb and propoxur). Only one insecticide (dieldrin) was an efficient pulicide for all flea populations. Cross resistances were suspected. This study proposes at least three alternative insecticides (malathion, fenitrothion and cyfluthrin) to replace deltamethrin during plague epidemic responses, but the most efficient insecticide may be different for each population studied. We highlight the importance of continuous insecticide susceptibility surveillance in the areas of high plague risk in Madagascar.     

Stimulus frequency dependence of the central and peripheral somatosensory evoked activity in rats treated with various pesticides

Rats were treated with a combination of insecticide agents in different timing schemes. In acute administration, 1/5 LD50 of the three insecticides: dimethoate, propoxur and cypermethrin, or their combination, was given once by gavage. In the developmental model, female rats received oral doses of 1/25 LD50 of the above insecticides in combination in three timing schemes including pregnancy and lactation. Responses in the somatosensory cortex and in the tail nerve, evoked by peripheral electric stimulation, were recorded in acute preparation under urethane anesthesia. It was tested whether the parameters of the cortical and peripheral evoked response are dependent on the frequency and whether this dependence is different in control and treated animals. The latency increase of the cortical responses with increasing stimulation frequency was significantly stronger in rats treated acutely with cypermethrin and the combination, and in rats receiving the combination during both intra- and extrauterine development. On the duration, the effects were less clear. Frequency dependent increase of the tail nerve action potential latency was significantly intensified by cypermethrin, and the amplitude decrease, by cypermethrin and dimethoate. Fatigue of this response during a stimulation series was also altered by the insecticides. Frequency dependence and fatigue possibly reflect the actual state of the nervous system and may have the potency to be developed to functional biomarkers.     

亚洲小车蝗痘病毒与化学杀虫剂混用的杀虫效果及对寄主主要解毒酶活性的影响

亚洲小车蝗痘病毒（Oedaleus asiaticus entomopoxvirus, OaEPV）作为一种增效剂,分别与马拉硫磷、毒死蜱、高效氯氰菊酯、氟氯氰菊酯 、溴氰菊酯化学杀虫剂混合饲喂亚洲小车蝗若虫,统计致死中浓度 LC₅₀ 和其混合使用后的增效比;测定虫体内与抗性有关的两种重要酶——羧酸酯酶（CarE）和谷胱甘肽 S-转移酶（GSTs）的比活力。结果表明：OaEPV 与化学杀虫剂混合饲喂亚洲小车蝗,OaEPV 与毒死蜱 、高效氯氰菊酯、氟氯氰菊酯、溴氰菊酯混用对亚洲小车蝗无明显的增效作用,OaEPV 与马拉硫磷混用,具有一定的增效作用,增效比为 1.42 倍。混剂感染亚洲小车蝗,除与溴氰菊酯混用外,虫体的中肠部位 CarE 的比活力都受到了明显的抑制作用,其中 OaEPV 与马拉硫磷混用下降了 4.21 倍,抑制作用最大。当 OaEPV 与氟氯氰菊酯、溴氰菊酯化学杀虫剂混用后,中肠部位 GSTs 受到了明显的抑制作用,而其脂肪体部位 CarE 和 GSTs 的变化无一定的规律性。结果提示痘病毒与农药混合处理时,病毒主要通过抑制中肠部位 CarE 比活力而增加了农药的杀虫效果。     

Seasonal changes of resistance to fenvalerate and cypermethrin in the larval parasitoid Cotesia plutellae （Hymenoptera： Braconidae）

The seasonal changes of insecticide resistance and stability in hymenopteran Cotesia plutellae, collected from Jianxin, Fuzhou-City, and Shangjie, Minhou-County, Fujian, China, were assessed by using a dry residual film method. The resistance to two insecticides in the field populations of C. plutellae was not stable under insecticide-free conditions in the insectarium. Compared with susceptible F11 progeny of C. plutellae in the insectarium, the resistance ratios （RR） in F0 parents were 18.4 for fenvalerate and 11.4 for cypermethrin based on LC50 at 9 hours, and 32.8 for fenvalerate and 28.5 for cypermethrin based on LC50 at 24 hours when the parasitoids were left in contact with the insecticides for 1 hour and mortalities were recorded at 9 and 24 hours, respectively. However, the RR in a field population of C. plutellae were 9.2 for fenvalerate and 12.7 for cypermethrin, if the parasitoids were left in contact with the insecticides for 24 hours. The resistances to the two pyrethroids in other field populations collected from Jianxin and Shangjie from November 2000 and July 2004 were also determined. Significant seasonal variations of resistance to the two insecticides in the field populations of C. plutellae were found. The RR were 3.0-18.4 for fenvalerate and 4.8-20.6 for cypermethrin in Jianxin populations from November 2000 to April 2002 based on LC50 at 9 h, and 2.3-13.6 for fenvalerate and 3.6-16.0 for cypermethrin in Shangjie populations from May 2002 to July 2004 based on LC50 at 24 hours. The resistance levels were high in spring and autumn and decreased sharply in summer. In addition, significant recovery from the knocked-down caused by the insecticides was found in the F0 and field populations of C. plutellae which were resistant to fenvalerate and cypermethrin if the parasitoids were left in contact with the pyrethroids for 1 hour. However, no recovery was found in susceptible F11 progeny.     

Detection of insecticide resistance in the German cockroach (Dictyoptera: Blattellidae) with glue-toxin traps.

Glue that contained an insecticide was evaluated for its ability to yield useful toxicological data for German cockroaches, Blattella germanica (L.). Toxicities of three classes of insecticides were evaluated by topical applications (LD50) and exposure to insecticide-impregnated glue (LC50). Cockroaches that were resistant to topical insecticide applications were also resistant to the glue formulation. Reliability was greatest when mortality was scored 40 to 48 h after the cockroaches were placed on the glue. This method should be adaptable for insecticide resistance monitoring of German cockroaches.     

Effect of temperature on the toxicities of ten pyrethroids to German cockroach (Dictyoptera: Blattellidae).

Of 10 pyrethroids tested by topical application of male German cockroaches, Blattella germanica (L.), d-phenothrin was the least toxic at 19, 26, or 31 degrees C. lambda-cyhalothrin was most toxic. Pyrethroids with the alpha-cyano moiety (fluvalinate, fenvalerate, cypermethrin, esfenvalerate, tralomethrin, cyfluthrin, and lambda-cyhalothrin) were more toxic than those without this functional group (d-phenothrin, resmethrin, and permethrin). At LC50, toxicity was negatively related to temperature. Temperature-toxicity responses of five of seven alpha-cyano pyrethroids were parallel, possibly indicating qualitatively identical but quantitatively different levels of detoxification enzymes.     

Insecticide susceptibility status in two medically important mosquito vectors,Anopheles gambiae,and Culex quinquefasciatus to three insecticides commonly used in Niger State,Nigeria

High resistance ability on insecticides among major mosquito vectors of diseases in Nigeria is of growing concern for severe control strategies. The objective of this study was to assess the susceptibility status of females Anopheles gambiae and Culex quinquefasciatus complexes mosquitoes to permethrin (21.5 μg/bottle-pyrethroids), propoxur(12.5 μg/bottle-carbamate) and malathion (50 μg/bottle organophosphate), in Niger State, North-Central, Nigeria. Anopheline and Culecine larvae were collected from the larval habitats of the studied sites (Bosso, Katcha, Lapai, and Shiroro) larvae and pupae were identified guided by standard keys and reared to adults in troughs. Insecticide susceptibility bioassays were performed according to the CDC bottle bioassay standard operating procedures on 3 days old, sugar-fed female Anopheles and Culex mosquitoes. Post-exposure mortality after 24hr and knockdown values for KDT₅₀ were calculated. Knock-down at 1-hour insecticide exposure ranged (84–96 %) permethrin, (94–100 %) propoxur and (100 %) malathion for An. gambiae and (86–97 %) permethrin, (92–100 %) propoxur and (96–100 %) malathion for Cx. quinquefasciatus. Mortality, after 24hr post-exposure was 100 % in malathion, indicating the high effect of the insecticide. Tested samples were found potentially resistant to permethrin recorded against mosquitoes collected from all study sites, in two locations of the study sites to propoxur and one location site to malathion. All the tested mosquitoes were found to be potentially resistant to permethrin, however, mosquitoes tested in Katcha and Shiroro resist potentially to propoxur. Except, Culex quinqufasciatus from Lapai that partially resist malathion, all the tested mosquitoes were found to be susceptible to malathion, across the study sites.     

Toxicity of insecticides in a glass-vial bioassay to adult brown, green, and southern green stink bugs (Heteroptera: Pentatomidae)

Adult brown, Euschistus servus (Say); green, Acrosternum hilare (Say); and southern green, Nezara viridula (L.), stink bugs were collected from soybean, Glycine max (L.) Merr., in fall 2001 and 2002 near Stoneville, MS, and Eudora, AR. A glass-vial bioassay was used to determine LC50 values for the three species of stink bugs for the pyrethroids bifenthrin, cypermethrin, cyfluthrin, lambda-cyhalothrin, and permethrin, and the organophosphates acephate, dicrotophos, malathion, and methyl parathion. Results confirmed findings of other researchers that the brown stink bug was less susceptible to pyrethroid and organophosphate insecticides than were green and southern green stink bugs. The susceptibility of all three stink bug species to the insecticides tested was very similar at both test locations. The study established baseline insecticide mortality data from two locations in the mid-South for three stink bug species that are pests of soybean and cotton, Gossypium spp. Data from the tests are valuable for future use in studies on resistance and in resistance monitoring programs.