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Drought events are expected to limit crop productivity in the context of current climate change. Drought is also likely to affect multitrophic interactions such as those involving plants, phytophagous insects and their natural enemies. We designed a two-phase experiment to test the effect of water availability and fertilizer treatment on the interaction between maize, the fall armyworm and its nucleopolyhedrovirus pathogen. Low irrigation of maize plants reduced virus efficiency in armyworm control. In addition, the insects did not feed on plants with high water availability and without fertilization. We conclude that water stress and plant nutrition can affect virus performance and thereby affect the efficiency of biological control and pest management, especially as water and nutrient limitation will likely increase under climate change.

In the present study, the influence of three sex ratios (1:1, 1:2, and 1:3; female:male) of the miridEngytatus varians(Distant) (Hemiptera) on different biological parameters and on its offspring was evaluated. The prey preference of different developmental stages of this predator for different nymphal instars (N) ofBactericera cockerelli(Sulcer) (Hemiptera: Triozidae) was also evaluated. The fertility was significantly higher (24 nymphs/female) in the 1:3 sex ratio than in the 1:1 and 1:2 sex ratios (14 and 16 nymphs/female, respectively). The females in the 1:1 and 1:2 sex ratios lived 1.14 and 1.43 days more (27 and 28 days, respectively) than those in the 1:3 sex ratio (26 days). The nymphs derived from the females of the three sex ratios (first filial generation, F1) had five instars and a duration of 17 or 18 days. The ratio of the F1generation females was not affected by the sex ratio of their parents. In choice tests, independent of whether the preys were placed on a single or multiple tomato (Solanum lycopersicumL.) leaflets, the consumption of females and males and N3, N4, and N5nymphs ofE. variansonB. cockerelli, generally showed the order of N2>N3>N4>N5. In conclusion, the findings revealed in this study can help to improve the rearing methodology for increasing populations ofE. varians. In addition, they can serve as a guideline for releasing this predator in times when there is an abundance of early instar nymphs ofB. cockerelli.

Este estudio estimó la diversidad de avispas del género Blacus Nees (Braconidae, Blacinae) en dos ecosistemas forestales del noreste de Michoacán, en el Eje Neovolcánico Transversal: Parque Nacional Cerro de Garnica (PN C-Garnica) y Zona Protectora Forestal Los Azufres (ZPF Los Azufres). Se elaboró un mapa de cobertura vegetal con imágenes satelitales de estos ecosistemas forestales. La captura de especímenes se realizó mensualmente desde marzo 2008 hasta febrero 2010 con la ayuda de platos-trampa de color amarillo. Se capturó un total de 172 especímenes de 17 especies del género Blacus, de los cuales 84.3% provinieron del PN C-Garnica (13 especies) y 15.7% de la ZPF Los Azufres (10 especies). El porcentaje de similitud indicó una composición de especies diferente entre las dos áreas estudiadas (índice de Jaccard = 0.35). En el PN C-Garnica se capturaron significativamente más especímenes por mes que en la ZPF Los Azufres (12.1 ± 4.0 vs 2.3 ± 1.20). De acuerdo con el índice de Shannon-Wiener, la diversidad fue similar en ambas áreas estudiadas (2.1 vs 1.9). Los estimadores de riqueza Chao 2 y Jackknife 2 indicaron que en ambas áreas se capturó ~60% de las especies esperadas. Se concluye que el PN C-Garnica y la ZPF Los Azufres mantienen una alta diversidad de especies de Blacus. Las mayores abundancias, así como la mayor riqueza de especies se encontraron en el PN C-Garnica, la cual es una zona con mayor grado de perturbación.

BACKGROUND The multiple nucleopolyhedrovirus of Spodoptera frugiperda (SfMNPV) plays an important role in regulating its natural host and has high potential for use as a bioinsecticide. However, information about how agricultural practices such as fertilization and plant biotic interactions affect the biocontrol efficacy of SfMNPV is limited. In this study, we examined how multitrophic maize-mycorrhiza-insect herbivore interactions affect the biocontrol efficacy of SfMNPV against S. frugiperda under full and reduced mineral nitrogen fertilization. Two fully factorial greenhouse pot experiments with three factors were performed: (i) arbuscular mycorrhizal fungi (AMF) (with and without AMF), (ii) nitrogen fertilization (50% and 100% N), and (iii) insect (with and without of S. frugiperda). The biocontrol efficacy of SfMNPV against S. frugiperda was examined using detached leaves under controlled environmental conditions. RESULTS Associating maize with AMF resulted in multitrophic cascade effects. Plants with AMF showed suppression of plant growth and increased leaf N and P content, which coincided with increased foliar herbivory and larval biomass that finally reduced the susceptibility of S. frugiperda to SfMNPV. Reduced levels of N fertilization mitigated these observed cascade effects on the biocontrol efficacy of SfMNPV with maize mycorrhizas. CONCLUSION Our results show that AMF can modulate S. frugiperda-SfMNPV interactions via plant-mediated phenotypic responses to the mycorrhizal association and are most likely linked with increased leaf food quality for S. frugiperda. These results call for further studies to address the mode of interaction and possible implications for pest management in maize agroecosystems. © 2021 Society of Chemical Industry.

The ectoparasitoid Tamarixia triozae is a promising biological control agent of the tomato psyllid, Bactericera cockerelli, based on its high parasitism rates on different crops. The parasitism, host feeding, and transgenerational effects (in terms of sex ratio) of T. triozae females exposed to three insecticides (soybean oil, imidacloprid, and abamectin) as eggs, larvae, and pupae were evaluated when a mixture of second, third, fourth, and fifth instars of the host B. cockerelli was offered. The concentrations bioassayed of each insecticide corresponded to the minimum field-registered concentration [MiFRC] and one-half the MiFRC. No parasitism of B. cockerelli second instars was recorded when parasitoid's females were exposed in any of the three immature stages to any of the insecticides. In contrast, in some cases, parasitism of T. triozae females treated as eggs, larvae, or pupae with soybean oil and imidacloprid was reduced in third, fourth, or fifth instar. In most cases, the host feeding was reduced in second and third instar of the host B. cockerelli when T. triozae females were treated as eggs, larvae, or pupae. Any insecticide modified the sex ratio in the F2 generation. In conclusion, both parasitism and host feeding were affected by the insecticides depending on the concentration and on the nymphal instar of the host B. cockerelli offered.

A greenhouse study was conducted to investigate the degradation kinetics of spinosad, flufenoxuron, dimethoate and imidacloprid in tomato (Solanum lycopersicum L.) foliage and their residual toxicity on Engytatus varians (Distant) (Hemiptera: Miridae), a predator of the tomato psyllid Bactericera cockerelli (Sulcer) (Hemiptera: Triozidae). Insecticides were sprayed at 100% and 50% of their maximum field-registered concentrations (MFRC). Starting 6 h after spraying, leaf samples were taken every 10 d for 40 d and analyzed while E. varians adults were exposed to treated leaves to evaluate residual toxicity. Immediately after application at 100% MFRC, the residue concentrations were 73.34 μg g−1 spinosyn A and 59.2 μg g−1 spinosyn D, 9.21 μg g−1 flufenoxuron, 71.49 μg g−1 dimethoate and 31.74 μg g−1 imidacloprid. At 50% MFRC, initial residue concentrations were between 75% and 90% those at 100% MFRC. The estimated half-life (DT50) of spinosyns A and D, flufenoxuron, and dimethoate was between 34 and 40 d, while that of imidacloprid was 112 d. Flufenoxuron caused no mortality, while mortality due to spinosad was less than 10%, and only during the first 10 d. Mortality caused by either imidacloprid or dimethoate was around 100% up to 10 d after application, then decreased to around 30% after 40 d. Dimethoate toxicity was approximately proportional to residue concentration, while for imidacloprid there was an apparent threshold around 15 μg g−1. These results can be used to establish periods harmless for release of E. varians in the control of B. cockerelli on tomato crops under greenhouse conditions.

Acalitus orthomera (Keifer) es registrado por primera vez en el Municipio de Ziracuaretiro, Michoacán, México, asociado a brotes vegetativos en cultivos de zarzamora; se proporciona información sobre su daño y su importancia en este cultivo es discutida.

Predation byEngytatus varians(Distant) adults on different development stages of the prey speciesBactericera cockerelli(Sulcer) (egg, second, and third nymphal instars),Spodoptera exigua(Hübner) andSpodoptera frugiperda(J. E. Smith) (egg, first, and second larval instars) was evaluated using tomato (Solanum lycopersicumL.) leaflets or plants. These insects are the primary pest of several agriculturally important crops. The influence ofE. variansage on the predation capacity was also analysed.Engytatus variansfemales consumed significantly moreB. cockerellieggs and nymphs than males. Additionally, female predators consumed significantly more second than third instar prey at two predator ages, while males consumed significantly more the second instar than third instar prey at all predator ages. In most of the cases, females also consumed significantly moreS. exiguaandS. frugiperdaeggs than males; however, in terms of larvae consumption, this difference was observed only in some predator ages. Females consumed more the first than second instarS. exiguathan males, whereas this behaviour was only observed in males when the predators were 15 and 17 days old. No significant differences were observed in the consumption of first and second instar ofS. frugiperdafor both sexes of the predators. Predator age did not cause any systematic effects on the predation rates of any prey species. Based on these results, we confirmed thatE. varianshas potential as a biological control agent forB. cockerelliand also for theSpodopteraspecies bioassayed.

Engytatus varians (Distant) (Hemiptera: Miridae) was observed to prey on eggs and nymphs of the tomato psyllid Bactericera cockerelli (Sulc.) (Hemiptera: Triozidae) on tomato plants, Solanu...

Engytatus varians (Distant) (Hemiptera: Miridae), a polyphagous predator that is widely distributed, has recently been documented for the first time in Mexico, feeding on nymphs of the very detrimental pest of several solanaceous crops Bactericera cockerelli (Sulc.) (Hemiptera: Triozidae). The predation of this mirid was evaluated in a greenhouse in 7 m2 cages containing tomato (Solanum lycopersicum Miller) plants for 12 weeks. Two release rates, 1 and 4 adults of E. varians (Ev)/plant, were studied and compared to the control (0 Ev/plant). An 80 to 90% reduction in both nymphs and adults of B. cockerelli occurred when 1 or 4 adults of Ev/plant were released irrespective of the pest life stage. The cumulative number of E. varians nymphs and adults per day was significantly higher in the treatments than in the control (30 and 3, respectively). On the other hand, due to its zoophytophagous habits, E. varians can feed on tomato plants and cause necrotic rings on the leaves; therefore, this type of injury was also recorded. The number of necrotic rings/leaf was inversely proportional to prey presence, but no significant differences were observed between the treatments. Our results point to E. varians being able to establish and control B. cockerelli populations under greenhouse conditions, without causing significant damage to tomato plants. The potential use of this predator as a biological control agent of B. cockerelli is discussed.

In the present study, the influence of three sex ratios (1:1, 1:2, and 1:3; female:male) of the mirid Engytatus varians (Distant) (Hemiptera) on different biological parameters and on its offspring was evaluated. The prey preference of different developmental stages of this predator for different nymphal instars (N) of Bactericera cockerelli (Sulcer) (Hemiptera: Triozidae) was also evaluated. The fertility was significantly higher (24 nymphs/female) in the 1:3 sex ratio than in the 1:1 and 1:2 sex ratios (14 and 16 nymphs/female, respectively). The females in the 1:1 and 1:2 sex ratios lived 1.14 and 1.43 days more (27 and 28 days, respectively) than those in the 1:3 sex ratio (26 days). The nymphs derived from the females of the three sex ratios (first filial generation, F1) had five instars and a duration of 17 or 18 days. The ratio of the F1 generation females was not affected by the sex ratio of their parents. In choice tests, independent of whether the preys were placed on a single or multiple tomato (Solanum lycopersicum L.) leaflets, the consumption of females and males and N3, N4, and N5 nymphs of E. varians on B. cockerelli, generally showed the order of N2N3N4N5. In conclusion, the findings revealed in this study can help to improve the rearing methodology for increasing populations of E. varians. In addition, they can serve as a guideline for releasing this predator in times when there is an abundance of early instar nymphs of B. cockerelli.

Little information is available about the distribution and biology of Falconia poetica Distant, 1884 (Hemiptera: Miridae). A new distribution and the number of nymphal instars of the species are reported. On September 2018, nymphs and adults of an unknown species in the family Miridae were collected on castor bean (Ricinus communis L.) at Morelia, Michoacan, Mexico. The specimens were identified as F. poetica. Using lengths of the forefemora and foretibiae and Discriminant Analysis, F. poetica was determined to have five nymphal instars. The study is the second record of F. poetica in Mexico and the first to report the mirid feeding on castor bean.

Larvae of fall armyworm, Spodoptera frugiperda (J.E. Smith), were collected from 190 fields of maize (Zea mays L.) in northern Sinaloa, Mexico, during 2016 and 2017. Larvae also were collected from naturally re-growing maize plants after the rainy season. The aim of this study was to determine the natural occurrence of parasitoids and entomopathogens of S. frugiperda in this agricultural area. Taxonomic keys were used to identify parasitoids. Larvae with signs of infection by viruses, bacteria or fungi were analyzed by one-step PCR. In 2016 and 2017, the average percentages of parasitized S. frugiperda larvae in cultured maize fields were 7 and 9.3%, respectively. In contrast, in re-grown maize, 12.5 and 16.5% of larvae were parasitized, respectively. In both years, significant differences were observed in abundance of parasitism among some months. The most common parasitoids were Meteorus laphygmae Viereck (n = 862), Chelonus insularis Cresson (n = 640), and Cotesia marginiventris Cresson (n = 303), with 9.5% of total parasitism. Idiopathic mortality (2.6%) was determined throughout the study, but no entomopathogens were found in any larva collected. Parasitoids associated with S. frugiperda are well established in northern Sinaloa. But, additional studies are needed to determine their potential as biological control agents and to evaluate the possible influence of maize type on their abundance.

The mirid Engytatus varians (Distant) is a promising biological control agent of the tomato borer, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae), one of the most destructive pests of tomato (Solanum lycopersicum L.). The effects of five insecticides commonly used on tomato crops in Brazil were evaluated on E. varians in laboratory and semifield conditions. Glass Petri dish with residues of chlorfenapyr, thiamethoxam, and abamectin caused ˃90% mortality in both stages of the predator 72 h post-treatment, except imidacloprid that caused 78% of nymphs mortality. Teflubenzuron caused 24 and 66% mortality on adults and nymphs, respectively. The offspring of females derived from treated nymphs with teflubenzuron was significantly lower than the control but not when females were treated as adults. Longevity of males derived from nymphs treated with teflubenzuron was significantly reduced, but no effects were observed on females. When males and females were treated as adults with teflubenzuron there were no effects on their longevity. In the greenhouse-aged tomato plants, the 2 h-old residues of thiamethoxam, chlorfenapyr, and abamectin caused more than 70% of mortality of third instar of E. varians at 72 h post-treatment, 12 day-old residues of all three compounds caused a mortality lower than 30%. These data suggest that teflubenzuron can be associated with releases of E. varians adults, while the use of other evaluated pesticides should be avoided in this situation. Although, the low persistence of these products indicate that their spraying and later releases of E. varians adults on tomato crops are a possible strategy to control T. absoluta.

The biological activity of 4 Mexican isolates (SeSIN6, SeSIN8, SeSLP6, and SeSLP8) of the homologous multiple nucleopolyhedrovirus SeMNPV and their effects on the development of the beet armyworm, Spodoptera exigua (Hubner) (Lepidoptera: Noctuidae), were studied. An exotic isolate of SeMNPV from the United States (SeUS2) was used as a reference. Early third-instar larvae were inoculated with 5 × 106 occlusion bodies per mL, resulting in 78% mortality for SeUS2 and approximately 90% mortality for each of the 4 Mexican isolates at 144 h post-inoculation. At 168 h postinoculation, 100% mortality was obtained in all cases. All of the isolates, including SeUS2, significantly reduced the body weights of S. exigua larvae compared with the control larvae; however, at 120 h post-inoculation, the differences among isolates were not significant. All of the isolates reduced the development time of third-instar S. exigua larvae (range: 1.2– to 1.6–fold) compared with the control larvae. An independent experiment was performed to determine production of occlusion bodies and mean time to death. Third-instar S. exigua larvae (15 h after molting) were inoculated with each isolate using the same concentration mentioned above. The occlusion body production rate was similar among all isolates. The isolates SeUS2, SeSLP6, and SeSLP8 yielded the fastest mortality (range: 187–191 h). Thus, the biological activities of the Mexican SeMNPV isolates were similar to the activity of the exotic isolate, indicating that these indigenous viruses are promising for the biological control of S. exigua in Mexico. Resumen Se estudio la actividad biologica y los efectos sobre el desarrollo del gusano soldado Spodoptera exigua (Hubner) (Lepidoptera: Noctuidae) de 4 aislados mexicanos (SeSIN6, SeSIN8, SeSLP6 y SeSLP8) de su nucleopoliedrovirus multiple homologo (SeMNPV). Se uso como referencia un aislado exotico, originario de Estados Unidos (SeUS2). La inoculacion de larvas recien mudadas de tercer estadio con 1 × 106 cuerpos de inclusion per mL resulto en 78% de mortalidad para SeUS2 y aproximadamente 90% para 4 aislados mexicanos a las 144 h post inoculacion. A las 168 h post inoculacion se observo una mortalidad del 100% en todos los casos. Todos los aislamientos, incluyendo el SeUS2, provocaron un efecto significativo en la reduccion del peso corporal promedio de las larvas de S. exigua en comparacion con el control; sin embargo, a 120 h post inoculacion las diferencias entre aislados no fueron significativas. Todos los aislados redujeron el tiempo de desarrollo de las larvas de tercer instar (rango: 1.2–1.6 veces) en comparacion con el control. Se realizo un experimento independiente para determinar la produccion de cuerpos de inclusion y el tiempo medio de muerte. Para ello, las larvas de tercer estadio de S. exigua (15 h despues de la muda) se inocularon con cada aislado utilizado la misma concentracion descrita arriba. La tasa de produccion de cuerpos de inclusion fue similar entre todos los aislados probados. Los aislados SeUS2, SeSLP6, y SeSLP8 causaron una mortalidad mas rapida (rango: 187–191 h). Se concluyo que la actividad biologica de los aislados mexicanos del SeMNPV fue similar a la observada en el aislado exotico, indicando que estos virus son prometedores para el control de S. exigua en Mexico. View this article in BioOne

The incorporation of baculovirus into semi-synthetic diets has been used for the inoculation of large batches of insect larvae reared under gregarious conditions. The preparation of most artificial diets involves heating to dissolve the agar gelling agent followed by cooling to ∼55–60°C whereupon virus occlusion bodies (OBs) are incorporated into the diet. To avoid exposure of thermolabile OBs to high temperatures, a cool-textured diet using soy fiber was evaluated as a simple method to inoculate batches of larvae with the baculovirus OBs. Spodoptera exigua larvae that fed on a diet with 120, 140 or 160 g/l of soy fiber, as a substitute for agar, had a similar weight gain over a 24 h period than larvae that consumed a standard agar diet. The larval weight gain with cool-textured diets with 140 g/l of soy fiber was not improved by the addition of chlorophyll, green food dye colour, or by the removal of ascorbic acid, sodium benzoate and potassium sorbate. Preliminary tests performed to determine th...

BACKGROUND Control of the Asian citrus psyllid Diaphorina citri Kuwayama, the most important pest of citrus worldwide, is based on the use of insecticides, though unsatisfactory results have recently been reported. In this study, insecticide resistance of D. citri to three insecticides (bifenthrin, malathion, and chlorpyrifos) was examined. RESULTS Three populations (designated Dci-CParacuaro, Dci-El Junco, and Dci-Antunez) of both adults and fourth-instar D. citri individuals were collected in 2014 at two different times and on one occasion, respectively, from three locations (Crucero de Paracuaro, El Junco, and Antunez). These locations represent the major commercial Mexican lemon production areas in the Apatzingan Valley in the state of Michoacan, Mexico. The three populations of D. citri adults and fourth-instar nymphs at the different collection times showed low levels of resistance (≤7-fold) to bifenthrin, but were very resistant to malathion (≤345- and ≤432-fold for adults and fourth instars, respectively) and chlorpyrifos (≤2435- and ≤1424-fold for adults and fourth instars, respectively). CONCLUSION Resistance levels to the tested insecticides were highly variable but homogeneous among seasons and localities. Resistance management programmes that include crop sanitation, use of biological and cultural control practices, and rotation of insecticide classes should be established, particularly in areas where D. citri has developed resistance to malathion and chlorpyrifos. © 2017 Society of Chemical Industry

The effects of 2 concentrations (15 and 30%) of ethanolic Argemone ochroleuca Sweet (Papaveraceae) extracts were determined on the feeding behavior and development of 3rd instar larvae of the fall armyworm, Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae) through their continuous ingestion of treated maize leaves for 48 h. The extracts were obtained from dried whole plants including stems, leaves, and flowers. Armyworm food consumption was slightly reduced (by 13 to 14%) at both concentrations compared with the controls. Larval growth was significantly affected only at the highest concentration, with a 23% reduction in larval weight after 48 h of feeding on the treated leaves and a 38% reduction after another 48 h of feeding on an untreated artificial diet. By contrast, the duration of the larval and pupal stages was prolonged by 43% (from 13.5 to 19.4 d) and by 8% (from 2.1 to 2.2 d), respectively. Total larval mortality was also higher at the highest concentration (31%) than in controls (10%). During the pupal stage, neither the number of pupae that formed nor their mortality or weight was significantly affected by the treatments. However, both of the bioassay concentrations significantly lengthened the duration of the pupal stage in males, whereas in females, only the higher concentration did. In addition, no effect was observed on the adult emergence, sex ratio, and fecundity. In summary, the primary effect of ethanolic A. ochroleuca extracts appears to be a reduction in feeding, which simultaneously slows larval growth and increases mortality.

Damage caused by phytophagous mites is one of the main phytosanitary problems on blackberry crop. The mite species identification is a very significant activity to implement a program of integrated pest management. The aim of this study was to identify the species of phytophagous mites, predators, and other mites associated with blackberry crop in two locations of Michoacan, Mexico. The research was performed in two blackberry orchards located at Ziracuaretiro and Tacambaro municipalities, which had different type of management: conventional and non-conventional, respectively. In each orchard, 18 samples were collected at 15 d-intervals during an annual cycle, from June 2015 to May 2016. The collected mites were mounted in permanent slide for their taxonomic determination with specific keys with specific keys. Seventeen mite species belonging to ten families were identified, which six were phytophagous species, six were predatory, and five had varied habits. Six of the 17 taxa identified are new records of mites associated with blackberry crop. Most of the mites were collected in the conventional crop (65.4 %), while the abundance of predator mites was highest in the no-conventional crop.

Two new species, Coelinius carmenae Figueroa, Sánchez, and Kula, n. sp. and Coelinius danielae Figueroa, Sánchez, and Kula, n. sp., from Mexico are described and illustrated. These are the first records of Coelinius sensu Wharton (1994) reported from Mexico. Four Nearctic species, Coelinius mahackemoi (Viereck), stat. rev., Coelinius meromyzae Forbes, stat. rev., Coelinius nigripes Ashmead, stat. rev., and Coelinius occom (Viereck), stat. rev. are returned to Coelinius Nees from Coelinidea Viereck. Coelinius longulus Ashmead, stat. rev. is returned from Lepton Zetterstedt, 1838 nec Turton, 1822 to Coelinius. Coelinius linearis (Provancher), n. comb. is transferred from Coelinidea to Coelinius.

The life cycle and several life parameters of the zoophytophagous predator Engytatus varians (Distant) (Heteroptera: Miridae), including nymphal growth according to Dyar’s rule, were examined in the laboratory. The egg, nymph (five instars), and adult stages were 9.20, 17.36, and 19.02 d in length, respectively. The growth ratio for nymphs was consistent with Dyar’s rule based on the lengths of the femora of the forelegs, the tibiae and femora of the middle legs, and the antennae. Some biological characteristics of E. varians were also evaluated when the mirid was fed three different diets (B. cockerelli third instars, Sitotroga cerealella Olivier [Lepidoptera: Gelechiidae] eggs, and a mixture of both instars and eggs). The length of the nymphal stage was three days longer on a diet of only S. cerealella eggs than when the mirids were fed the third instars of B. cockerelli only or a mixture of both. The sex ratio was not affected by the type of diet. Nymphs of E. varians consumed B. cockerelli nym...

The leafroller Argyrotaenia montezumae (Walsingham) (Lepidoptera: Tortricidae) was found feeding on blackberry leaves ( Rubus sp.) in three localities of Michoacan, Mexico, for the first time in 2008. Several biological parameters of this insect were assessed under laboratory conditions (25 ± 2°C, 75 ± 5% relative humidity, and a photoperiod of 16:8 [L:D] h). The egg, larval (five instars), prepupal, pupal, and adult stages lasted 7.28, 21.62, 3.89, 8.37, and 17.64 d, respectively. Larval growth of A. montezumae followed Dyar's rule, and the growth ratios for the widths between the genae and the distance between the frontal setae of the head were 1.43 and 1.54, respectively. Female and male pupae weighed 33 and 21 ± 0.56 mg, respectively. The adult sex ratio (percentage of females) was 48%. When females oviposited on the inner walls of a transparent plastic container, the cumulative number of eggs per female over a lifetime was 391, with preoviposition and oviposition periods of 3.5 and 8.1 d, respectively. Peak oviposition activity was recorded when female age ranged from 4 to 8 d (47.35 and 52.12 eggs per female, respectively). The egg hatching percentage was 92.24%. The influence of the oviposition substrate color on the fecundity of A. montezumae was assessed using high-density polyethylene of different colors. The overall number of eggs per female was higher on green (352.5), blue (327.86), and yellow (250.60) substrates than on transparent (192.22) and pink (197.00) substrates.

To determine the natural parasitism in fruit fly populations in disturbed areas adjacent to commercial mango orchards in the states of Chiapas and Veracruz, Mexico, we recorded over one year the fruit fly-host associations, fly infestation, and parasitism rates in backyard orchards and patches of native vegetation. We also investigated the relationship between fruit size, level of larval infestation, and percent of parasitism, and attempted to determine the presence of superparasitism. The most recurrent species in trap catches was Anastrepha obliqua (Macquart), followed by Anastrepha ludens (Loew), in both study zones. The fruit infestation rates were higher in Chiapas than in Veracruz, with A. obliqua again being the most conspicuous species emerging from collected fruits. The diversity of parasitoids species attacking fruit fly larvae was greater in Chiapas, with a predominance of Doryctobracon areolatus (Szépligeti) in both sites, although the exotic Diachasmimorpha longicaudata (Ashmead) was well established in Chiapas. Fruit size was positively correlated with the number of larvae per fruit, but this relationship was not observed in the level of parasitism. The number of oviposition scars was not related to the number of immature parasitoids inside the pupa of D. areolatus emerging from plum fruits. Mass releases of Di. longicaudata seem not to affect the presence or prevalence of the native species. Our findings open new research scenarios on the role and impact of native parasitoid species attacking Anastrepha flies that can contribute to the development of sound strategies for using these species in projects for augmentative biological control.

This study describes the biological activity of two Spodoptera frugiperda multiple nucleocapsid nucleopolyhedrovirus (SfMNPV) isolates recovered from the soil of maize crops in the states of Yucatan and Chiapas, Mexico (Sf-YUC and Sf-CHI). The biological activity was determined for four Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae) field populations: Sf-Motozintla, Sf-Erongaricuaro, Sf-Abasolo, and Sf-Culiacancito. As a reference, a laboratory colony (Sf-Lab) was used. Biological characterization was compared with that for a characterized SfMNPV isolate from Nicaragua (Sf-NIC). The LC50 values for both the Sf-NIC and Sf-CHI isolates did not differ in any of the insect populations tested. In contrast, the Sf-YUC isolate was less active than the Sf-NIC isolate in the Sf-Motozintla population, but this isolate was more active in the Sf-Erongaricuaro and Sf-Abasolo populations. The killing speed and OB productivity were variable among isolates in each insect population. A small-scale field trial was performed to evaluate the degree of pest control achieved by the Sf-YUC isolate, applied at a rate of 3 × 1012 OBs/ha, in maize grown in central Mexico. The larval mortality caused by the virus was 58%, 78%, and 84% at 2, 5, and 7 d post application, respectively. At 7 d post application, the incidence of insect parasitoids in the virus treatment was significantly lower than in the control. In conclusion, the insecticidal characteristics of both Mexican isolates (Sf-CHI and Sf-YUC) varied according to their insect population. In addition, the Sf-YUC isolate may be suitable as the basis for a biopesticide for the control of S. frugiperda in Mexico.

Lethal and sublethal effects of refined soybean oil, imidacloprid, and abamectin on Tamarixia triozae (Burks; Hymenoptera: Eulophidae) were assessed after exposure of the eggs, larvae, and pupae of this parasitoid to three concentrations of these active substances: the LC50 for fourth-instar Bactericera cockerelli (Sulc.; Hemiptera: Triozidae)and 50% and 100% of the minimum field-registered concentration (MiFRC). Soybean oil caused 26-61% mortality in T. triozae eggs and 6-19% in larvae; mortality in both eggs and larvae was ≤19% for imidacloprid and 4-100% for abamectin. All three compounds caused T. triozae pupae, with the exception of the abamectin 50% (47%) and 100% (72%) MiFRC. The mortality of larvae and pupae derived from treated eggs was ≤39% for all three insecticides, and that of pupae derived from treated larvae was ≤10%. In general, emergence of adults developed from treated eggs, larvae, and pupae was affected more by abamectin than by the other treatments. The proportion of females derived from all three development stages was not affected by treatment with the compounds, except when the parasitoid was treated as larvae with the soybean oil 100 and 50% MiFRC (66 and 68%, respectively) or when treated as pupae with the imidacloprid LC50 and 100% MiFRC (~60%). Female longevity was generally higher than that of males. The use of imidacloprid, soybean oil, and abamectin in combination with T. triozae for pest control may be effective when the parasitoid is in the pupal stage because this stage is less susceptible than other immature stages., Centro de Estudios Parasitológicos y de Vectores

A new species of Apanteles from Mexico is described and illustrated. Apanteles montezumae Sanchez, Figueroa and Whitfield, new species, attacks Argyrotaenia montezumae Walsingham and Amorbia cuneana (Walsingham) (Lepidoptera: Tortricidae) on Rubus sp. in Michoacan state, Mexico.

Tamarixia radiata (Waterson) (Hymenoptera: Eulophidae) is an idiobiont ectoparasitoid of the Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Psyllidae). This study evaluated natural parasitism of the different nymphal instars of D. citri by T. radiata on three different dates in 2015 at four sites with Mexican lemon (Citrus aurantifolia Swingle) groves and at one site with orange jasmine (Murraya paniculata [L.] Jacq.) plants in the Apatzingan Valley, Michoacan state. Different patterns of parasitism by T. radiata were observed among the different nymphal instars of D. citri, sites, and collection dates. No parasitism of first and second instars was observed, and it only reached up to 5.0% in third instars. In fourth and fifth instars, parasitism was highly variable (2-69 and 1-38%, respectively). In terms of the accumulated parasitism across host instars, the highest percentages were observed in the collections conducted in May in Crucero de Paracuaro (86%) and Antunez (91%), and they were approximately 45% in the collections conducted on 23 March in Antunez and on 10 April in Nueva Italia-2. In the remaining collections, parasitism was between 2 and 15%. Our results suggest that T. radiata is an important mortality factor for populations of D. citri; this could have potentially important implications for the biological control of D. citri and for the management of huanglongbing, a disease transmitted by D. citri, in citrus groves.

Engytatus varians (Distant) (Hemiptera: Miridae) es una especie zoofitófaga debido a que se alimenta de las plantas hospederas y de los insectos que viven en ellas como áfidos, moscas blancas, pseudocóccidos y lepidópteros. Actualmente, esta especie presenta una amplia pero imprecisa distribución. En este trabajo se reporta por primera vez la presencia de E. varians en México depredando ninfas del psílido del tomate, Bactericera cockerelli (Šulc) (Hemiptera: Triozidae) bajo condiciones de invernadero. En promedio, una ninfa de cuarto estadio de E. varians se alimentó de 46% de las ninfas de tercer estadio de B. cockerelli en un periodo de 24 h. Este resultado muestra que este depredador podría representar un candidato potencial para el manejo del psílido del tomate. También se incluye información de su distribución, plantas hospederas y presas.

The blackberry, Rubus sp., crop in the state of Michoacan, Mexico is the second-most important crop after avocado, Persea americana Mill., in relation to value of production and employment. In this study was identified a blackberry leafroller, its parasitoids, and population dynamics in two commercial orchards at Michoacan, Mexico, during the growing seasons of 2007 and 2008. Collected rolled leaves containing larvae and pupae where maintained in a laboratory until leafroller adults and their parasitoids emerged. Population dynamics of moths were determined using wing traps containing the sex pheromone of Argyrotaenia citrana (Fernald) (Lepidoptera: Tortricidae). Numbers of males caught peaked in September and November 2007 at the two locations. After these months, numbers gradually decreased to almost zero during the dry season in 2008. Moths that emerged were identified as Argyrotaenia montezumae (Walsingham) (Lepidoptera: Tortricidae). Of the A. montezumae larvae collected in the field, 38% w...

Superparasitism refers to the action of parasitoids ovipositing eggs in hosts that are already parasitized; this inevitably results in the elimination of supernumerary larvae in solitary parasitoids. Here, we investigated superparasitism performed by two species of solitary parasitoids on the larvae of Anastrepha ludens (Loew; Diptera: Tephritidae): a native species, Doryctobracon crawfordi (Viereck; Hymenoptera: Braconidae), and an exotic species, Diachasmimorpha tryoni (Cameron; Hymenoptera: Braconidae). Tests were conducted under laboratory conditions evaluating the behaviour of females acting alone (self-superparasitism) or in groups (conspecific superparasitism). Parasitism strategies were different between these two species. In D. crawfordi, the number of first instar larvae found in each dissected host pupa was never greater than two, regardless of the number of oviposition scars observed per pupa. In contrast, there was a positive correlation between the number of oviposition scars and the number ...

The combined and alone effects of azadirachtin (AZA) and Spodoptera frugiperda multicapsid nucleopolyhedrovirus (SfMNPV) on the mortality and food consumption of third instar S. frugiperda (J. E. Smith) (Lepidoptera: Noctuidae) were evaluated under laboratory conditions using maize leaf bioassays. The LC50 values for SfMNPV and AZA were determined to be 1.30x106 viral occlusion bodies (OBs)/ml and 6.54 mg l-1 at 192 h and 144 h after treatment, respectively. These LC50 values were estimated for 4 days of continuous exposure. Although the interaction of SfMNPV with AZA increased the percentage of mortality observed in most of the cases, only one mixture (1x106 OBs/ml + 5 mg l-1) resulted in a synergistic effect on mortality of S. frugiperda. Application of SfMNPV (1x106 OBs/ml), AZA (0.5, 0.1 or 0.25 mg l-1) or SfMNPV–AZA mixtures resulted in a significant reduction in the maize-leaf piece consumption of larvae treated in the third instar across the experiment, by onefold, 2–5-fold, and 2–3-fold, respectively, compared with the control. However, the interaction of two SfMNPV–AZA mixtures (1x106 OBs/ml + 5 mg l-1 and 1x106 OBs/ml + 10 mg l-1) did not reduce the food consumption compared with AZA alone. It was concluded that SfMNPV–AZA mixtures require validation to determine whether this mixture may offer a valuable means of improving the efficacy of the SfMNPV.

Summary The combined and individual effects of spinosad and Spodoptera frugiperda multiple nucleopolyhedrovirus (SfMNPV) (Baculoviridae) on the mortality and food consumption of 3rd instars of S. frugiperda were evaluated using maize-leaf bioassays. The mortality data from spinosad (0.001 mg/L)-SfMNPV (106 OBs/mL) mixtures showed a low synergistic effect at 144 h after treatment. The consumption rate was significantly reduced by 2- to 12-fold in the spinosad—SfMNPV mixture treatment compared with the control, but no difference in consumption rate was observed between this treatment and the treatment with spinosad alone. Laboratory observations on the efficiency of spinosad—SfMNPV mixtures require validation in field studies under commercial growing conditions.

The leafroller, Amorbia cuneana (Walsingham) (Lepidoptera: Tortricidae), is recorded for the first time in blackberry (Rubus sp. cultivar Tupi) in Rancho Huatarillo, Municipality of Peribán, in the state of Michoacán, Mexico. It is important to assess the damage that this insect may cause to the plants, in order to avoid the possibility that it reach the pest status in the later crop.

Lepidopteran erebid Zale phaeograpta (Hampson) has recently been found feeding on blackberry leaves (Rubus sp., cultivar “Tupi”) in two sites of Michoacan, Mexico. The life cycle and several life parameters of this insect, including parasitism, were examined in the laboratory. The egg, larva (seven instars), prepupa, pupa, and adult stages lasted 4.1, 35.9, 3.1, 14.5, and 29.1 d, respectively. Eggs are turquoise blue. The prolegs of first-instar larvae have an enlarged dark area that runs laterally. From second instar onwards, a whitish longitudinal dorsal band is observed along the entire body. Third-instar larvae wear a pair of dorsal protuberances in abdominal segment VIII. The fourth- and fifth-instar larvae are cream-colored, whereas sixth instars are entirely creamy. Pupa is covered with a waxy bloom. The apical margin of the forewings in males has two silvery bands, whereas in females, a dark band is present. Female and male pupae had the same weight (0.5 g) and measured 2.21 and 2.25 cm, respectively. The adult sex ratio of females to males was 1.1:1. The cumulative number of eggs laid by female during her lifetime was 281, with preoviposition and oviposition periods of 9.9 and 7.3 d, respectively. Maximum oviposition occurred 3.9 d after the start of oviposition (87.7 eggs per female). Larvae of Z. phaeograpta were parasitized by Microplitis sp. (Braconidae) (33%) and a currently unidentified Ichneumonidae species (9%), and pupae were parasitized by Brachymeria comitator (Walker) and another unidentified Brachymeria sp. (Chalcididae).

The combined and alone effects of azadirachtin (AZA) and Spodoptera frugiperda multicapsid nucleopolyhedrovirus (SfMNPV) on the mortality of S. frugiperda (J. E. Smith) (Lepidoptera: Noctuidae) were evaluated in the laboratory. For this, diet surface contamination bioassays were performed on S. frugiperda in the third instar. LC50 values for SfMNPV alone were determined to be 430 and 373 viral occlusion bodies (OBs)/mm2 at 192 and 216 h after treatment, respectively. LC50 values for AZA alone were estimated for two periods of continuous exposure (4 or 5 days). In this case, LC50 values were 45.5 and 16.8 mg L−1 at 216 h after treatment (4 or 5 days of larval exposition to insecticide, respectively). We observed that although the interaction of AZA with SfMNPV increased viral pathogenicity, such improvements were of greater magnitude and more consistent at the lower OB concentration used (177 OBs/mm2). Application of SfMNPV (430 OBs/mm2), AZA (26.4 mg L−1) or SfMNPV–AZA mixtures resulted in a sign...

E. dolichocerus Figueroa and Sanchez, new species of Eurytenes from Mexico is described and illustrated. A key to identify the described species of Eurytenes s. str. of the New World is included.

A greenhouse study was conducted to investigate the persistence of methoxyfenozide in pepper (Capsicum annuum L.) foliage. An aqueous suspension of methoxyfenozide was sprayed on pepper plants at concentrations of 72 and 144 mg of active ingredient (a.i.)/L. Foliage was collected at different intervals of time (0, 3, 5, 10, 20, 30, 40, and 50 days) after the treatment, and the methoxyfenozide residue was measured by high-performance liquid chromatography. The foliage was also used in bioas- says to determine the residual toxicity on and the consumption rate of the third-instar larvae of the beet armyworm, Spodoptera exigua (H¨ ubner) (Lepidoptera: Noctuidae). The methoxyfenozide concentrations observed after 50 days had decreased to 19 and 69 µg/g per sample, corresponding to a loss of 61% and 28% from the application concentra- tions of 72 and 144 mg a.i./L, respectively. When fitting a first-order kinetics degradation model, the half-life (DT50) of this compound was 76 days. Both application concentrations of methoxyfenozide caused a high mortality rate (≥97%) when the larvae were fed the pepper foliage collected at all of the time intervals. Lastly, at all of the time points, the consumption rate by the larvae was reduced to between 57% and 92% for both concentra- tions that were bioassayed. Our results indicate that, under the present greenhouse condi- tions, the degradation of methoxyfenozide was slower than that reported by other authors and that its residues were highly toxic to S. exigua larvae. The implications of these results for the management programs of this pest are discussed.

This study describes four multiple nucleocapsid nucleopolyhedrovirus isolates recovered from infected larvae of beet armyworm, Spodoptera exigua (Hübner) (Lepidoptera: Noctuidae), on crops in two different geographical regions of Mexico. Molecular and biological characterization was compared with characterized S. exigua multiple nucleopolyhedrovirus (SeMNPV) isolates from the United States (SeUS1 and SeUS2) and Spain (SeSP2). Restriction endonuclease analysis of viral DNA confirmed that all Mexican isolates were SeMNPV isolates, but molecular differences between the Mexican and the reference isolates were detected using PCR combined with restriction fragment length polymorphism (RFLP). Amplification of the variable region V01 combined with RFLP distinguished the two Mexican isolates, SeSLP6 and SeSIN6. BglII digestions showed that the majority of the isolates contained submolar bands, indicating the presence of genetic heterogeneity. Amplification of the variable regions V04 and V05 distinguished between American and the Spanish isolates. Biological characterization was performed against two laboratory colonies of S. exigua, one from Mexico, and another from Switzerland. Insects from the Mexican colony were less susceptible to infection than insects from Se-Swiss colony. In the Se-Mex colony, SeSP2 was the most pathogenic isolate followed by SeSIN6, although their virulence was similar to most of the isolates tested. In Se-Swiss colony, similar LD50 values were observed for the five isolates, although the virulence was higher for the SeSLP6 isolate, which also had the highest OB (occlusion body) yield. We conclude that the Mexican isolates SeSIN6 and SeSLP6 possess insecticidal traits of value for the development of biopesticides for the control of populations of S. exigua.

Arthropod abundance was monitored in maize (Zea mays L.) crops on two farms located in western central Mexico during a single growing season. At the first farm (El Calvario, Michoacan), a no-tillage system was used in maize plots, while in the second farm (Singuio, Michoacan), a conventional tillage system was established. At these sites, sampling was conducted on nine occasions at seven day-intervals. Soil arthropods were captured using pitfall traps. At each sample point, maize plants were randomly selected and the number of arthropods observed on each plant was recorded. Poecilus mexicanus Chaudoir (Coleoptera: Carabidae) was the most abundant insect captured and comprised 75% (n = 2530) of the total capture of arthropods. Other carabid species together represented 18% of the total capture of arthropods at these sites and was significantly greater in the no-tillage farm compared to the conventional tillage farm. Staphylinids were the second most common group and were more abundant in the no-...

A species of Diospilus from Mexico is described and illustrated. Diospilus sisyphus Sanchez, Figueroa and Sharkey new species attacks Anthonomus sisyphus Clark (Coleoptera: Curculionidae) on the fruit of red nanche, Malpighia mexicana A. Juss. A key is included to identify the described species of Diospilus of the New World.

BACKGROUND: The immediate lethality caused by spinosad has been widely studied onSpodopteraexigua(H¨ ubner). However, long-term effects can also provide valuable information on insecticide toxic action. Here, the persistence of spinosad on Capsicum annuum L. foliage and the lethal and sublethal effects of greenhouse-aged foliar residues of this insecticide on third instars of S.exigua are reported. RESULTS: Foliage was collected at 0, 3, 5, 10, 20, 30, 40 and 50 days after application, and spinosad residues were measured. Residues decreased over time according to first-order kinetics. The average rate constant and half-life of disappearance were 4.44×10 −3 and156 daysand5.80×10 −3 and120 daysfor60and120 mg L −1 respectively.Larvalmortalitygraduallydecreased, corresponding to the residues, but was still appreciable (35 and 65% for 60 and 120 mg L −1 respectively) when the larvae were fed with foliage collected 50 days after treatment. Subsequently, pupal development was reduced and varied between 20 and 60% and between 21 and 41% for 60 and 120 mg L −1 , respectively, in all ages of leaf residues that were bioassayed. At all time points, the consumption rate by the larvae was reduced between 62 and 84% for both concentrations that were bioassayed. CONCLUSION:Itisconcludedthat,underthepresentgreenhouseconditions,thedegradationofspinosadwasslowerthanthat reported by other authors in the field, and, because of that, its residues could cause lethal and sublethal effects to S. exigua larvae. c � 2012 Society of Chemical Industry

A key to species and descriptions are presented for 14 species of the New World genus Crassomicrodus Ashmead. Seven new species, Crassomicrodus azteca, Crassomicrodus clypealis, Crassomicrodus costaricensis, Crassomicrodus jalisciensis, Crassomicrodus mariae, Crassomicrodus oaxaquensis,and Crassomicrodus olgae are described. Crassomicrodus fenestratus (Viereck) is synonymized with Crassomicrodus nigriceps (Cresson). Crassomicrodus melanopleurus (Ashmead) is recognized as a valid species.

Entomopathogenic fungi represent excellent candidates for biological insecticides. Among the many entomopathogenic fungi, Beauveria bassiana (Balsamo) Vuillemin (Hypocreales: Clavicipitaceae) is one of the most promising species. Here, we report the results of infection studies performed using four B. bassiana native isolates (Bb37, Bb38, Bb40, and Bb45) compared with the commercial product Mycotrol® (strain GHA) on adult Mexican bean beetle Epilachna varivestis Mulsant (Coleoptera: Coccinellidae), one of the most important pests of bean production in Mexico. First, single concentration (1 × 108 conidia mL−1) assays were carried out using all isolates applied using an immersion method. Examinations at 10 days after inoculation indicated that isolates Bb37, Bb38, and Bb40 significantly reduced adult survival, causing 60–75% mortality compared to the commercial strain GHA (33%) and control (29%). Second, using two selected isolates (Bb37 and Bb40), the mean lethal concentration values (LC50) were estimated for third instar larvae and adult E. varivestis. The LC50 values for Bb37 and Bb40 isolates decreased 5.26-fold and 3.19-fold, respectively, in third instars compared with adults. However, such difference for Bb40 isolate was not significant. Finally, an experiment, to compare the median survival time (MST) values between third instar and adult E. varivestis, was conducted using Bb37 and Bb40 at 1 × 109 conidia mL−1. MST values were significantly reduced against larvae (87 and 100 h) compared with adults (130 and 134 h) by Bb37 and Bb40, respectively. We conclude that native isolates of B. bassiana represent an important alternative for the control of E. varivestis. However, to demonstrate its effectiveness under field conditions, detailed studies are needed.

The toxicity and sublethal effects of methoxyfenozide were evaluated in third instars of the beet armyworm, Spodoptera exigua (Hubner) (Lepidoptera: Noctuidae), that fed on contaminated semisynthetic diet. The LC50 value was estimated at 0.23 mg of active ingredient (AI)/kg diet (range, 95% CI: 0.17–0.37) at 264 h after treatment. The effects on development, survival, and reproduction were observed in third instars of this pest that survived exposure to an LC25 concentration of methoxyfenozide. The larvae from the insecticide treatment exhibited lower pupal weights, an increase in both larval and pupal developmental times and a higher frequency of malformations of the wings in adults than untreated larvae. Adults from the methoxyfenozide treatment did not show reduced fecundity (mean cumulative number of eggs laid per female), but fertility as measured by the percentage of eggs hatched (fertility) was significantly reduced compared with untreated control insects. No significant effects were observed on pupal sex ratio. We concluded that the lethal and sublethal effects of methoxyfenozide are likely to have a significant impact on S. exigua populations on treated crops.

A detailed description of the adult of Crassomicrodus fulvescens (Cresson) is provided along with illustrations. New distributional data in the USA and Mexico are presented, and the first records from Canada are reported. Microdus medius Cresson is found to be a junior subjective synonym of M. fulvescens. Autographa californica (Speyer) is reported as a possible host for C. fulvescens based exclusively on label data.

BACKGROUND: Resistance to spinosad and methoxyfenozide has been studied in several insect pests, but there is a lack of information on Spodoptera exigua (Hubner) in Mexico. Therefore, evidence for the development of resistance in this pest to both compounds was examined. The effects of methoxyfenozide on reproductive parameters of S. exigua adults were also determined. RESULTS: Third instars from a field population were exposed for 24 h to the LC50 of spinosad or methoxyfenozide for over six generations (G2–G7). No significant reduction in susceptibility to either compound was detected for up to five generations. In G7, LC50 values for insects exposed to spinosad and methoxyfenozide were respectively 2.75-fold and 1.25-fold greater than for G1 larvae. Oral treatment with methoxyfenozide reduced the fecundity and fertility of G7 adults, confirming sublethal effects on reproduction. Finally, five populations (Se-La Floriza, Se-Lazareto, Se-Bachigualato, Se-Los Agustinos and Se-Villa de Arista) of S. exigua were collected from fields in three states of Mexico for resistance monitoring to spinosad and methoxyfenozide. With the exception of Se-Villa de Arista, the other populations showed significant resistance to spinosad, with resistance ratios between 16- and 37-fold, compared with a susceptible laboratory colony. In contrast, only one population (Se-Lazareto) showed significant resistance to methoxyfenozide (13-fold). CONCLUSION: Resistance management programmes should be established, particularly in areas where S. exigua has developed resistance to spinosad. Copyright © 2008 Society of Chemical Industry