Long-term suitability of an alternative host for rearing the sugarcane stalk borer parasitoid Tetrastichus howardi.

The continuous utilisation of an alternative host may influence parasitoid performance across successive generations due to conditioning in natal hosts. Tetrastichus howardi (Olliff) has successfully been reared using Tenebrio molitor L. pupae as a feasible alternative host. However, the extended rearing of T. howardi on this alternative host may impact the biological features of the parasitoids. Parasitoids were reared using T. molitor pupae for 30 consecutive generations. Quality criteria were assessed during the generations F5, F15, and F30, offering pupae of the target pest, Diatraea saccharalis (Fabr.), and compared with the F0 generation (parasitoids reared in D. saccharalis pupae). Criteria included assessments of parasitism performance, host selection, and wing form variation in the parasitoid wasps. Additionally, we examined the fecundity of T. howardi females that emerged from both hosts, considering their age, egg loading before and after one oviposition, as well as parasitism of sugarcane stalk borer pupae. Rearing T. howardi using pupae of T. molitor did not affect its biological traits or preference for the target pest for 30 generations. After parasitism, the parasitoid left the host pupa inside the stalk, and one oviposition was enough to kill D. saccharalis pupae and obtain viable parasitoid progeny. Female sexual maturation and egg loading occurred 72 and 96 h after parasitoid emergence. Egg-loading recovery after parasitism did not happen within 24 h. T. howardi can be reared for up to 30 generations using alternative hosts without compromising its parasitism performance or egg loading.

Classification of sugarcane genotypes susceptible and resistant to the initial attack of sugarcane borer Diatraea saccharalis using epicuticular wax composition.

Identifying compounds present in the sugarcane epicuticular wax and using these compounds to classify the genotypes susceptible and resistant to the initial attack of sugarcane borer (Diatraea saccharalis) was the aim of this study. A greenhouse experiment was performed in a factorial scheme with and without borer infestation using genotypes previously characterized as resistant or susceptible in field-based experiments. Sugarcane whorls of six-month-old plants were collected before (BI) and after (AI) 72 h of sugarcane borer infestation. The sugarcane epicuticular wax was extracted in both times, i.e., BI and AI and its chemical composition was assessed by gas chromatography coupled to mass spectrometry (GC-MS). Twenty-five compounds were identified for both BI and AI. Classification models were built using partial least squares for discriminant analysis (PLS-DA) and linear discriminant analysis (LDA). Variable selection methods were used to improve the classification models. Ordered predictors selection for discriminant analysis (OPSDA) selected compounds that correctly classified all the test samples before borer infestation (Error = 0.000), and exhibited the most suitable classification parameters for the test set after borer infestation (Error = 0.111). The C30 pentacyclic triterpene friedelin and a high alcohol/aldehyde ratio were associated with the classification of resistant genotypes. Our findings have applicability in developing a screening methodology for breeding programs interested in identifying genotypes resistant to the initial feeding of sugarcane borer.

Conventional Sampling Plan for Scouting Neoleucinodes elegantalis (Lepidoptera: Crambidae) Eggs on Tomato Fruits.

The small tomato borer, Neoleucinodes elegantalis (Guenée), is an important pest of tomato (Solanum lycopersicum L.) in South and Central America. This pest is a potential threat for many tomato-producing areas and was listed in 2014 as an A1 quarantine pest by the European and Mediterranean Plant Protection Organization. Soon after hatching, the neonate N. elegantalis larvae penetrate the fruits where they feed until pupation. Therefore, effective N. elegantalis management relies on the timely scouting of egg densities to allow decision-making prior to penetration of neonates into fruits. This study aimed to develop a conventional sampling plan for scouting N. elegantalis eggs on tomato plants. The most representative and precise sampling unit was the most basal fruit cluster for plants bearing up to three clusters (S1 plants). For plants with more than three fruit clusters (S2 plants), the most representative and precise sampling unit was the combination of the second and third fruit clusters. Among the four variables evaluated (eggs/fruit, egg masses/fruit, percentage fruit with eggs, and percentage clusters with eggs), the percentage of clusters with eggs was the most economical for N. elegantalis sampling based on the number of samples and cost required. For this variable, the number of samples determined at the 25% error level was 42 and 36 samples for S1 and S2 plants, respectively. The sampling plan developed for scouting N. elegantalis is fast, reflects pest infestation in tomato fields, and costs less than US$1.50 per field scouted.

Tetrastischus howardi density and dispersal toward augmentation biological control of sugarcane borer.

The number of Tetrastischus howardi (Olliff) females to be released and their dispersion should be known, that way, used D. saccharalis pupae as sentinel host to measure parasitism as function of the release density of the parasitoid and its location in the field. Two sets of trials were run aiming first to define the number of parasitoids to be released and the dispersal of the parasitoid using plots in sugarcane commercial fields, respectively. Pieces of sugarcane stalk holding sentinel pupae were taken to the field and exposed to parasitism in both trials. The parasitoid was released at the rate of 20, 40, 80, and 160 females per sentinel pupa, except for the control plot without releasing. The parasitism rate was calculated based on the recovered pupae after 96 h of exposure time from releasing the parasitoids. The models estimated the best parasitism rate by releasing 102 parasitoids per pupa. In the second trial, sentinel pupae were arranged in five subsequent circles corresponding 4, 8, 12, 16, and 20 m around the central parasitoid releasing point at rate of 4, 8, 12, 16, and 18 pupae per circle. The mean estimated dispersal distance was 7.64 m, with a covering area of 80.07 m2. Based on these findings, release of T. howardi is recommended in 125 points per hectare of sugarcane at rate of 102 females per pupa of the pest aiming to achieve homogeneous distribution and parasitism.

Susceptibility of Duponchelia fovealis Zeller (Lepidoptera: Crambidae) to Soil-Borne Entomopathogenic Fungi.

Duponchelia fovealis (Lepidoptera: Crambidae) is an invasive species that has had a large impact on strawberry crops in Brazil. Pesticides have had limited effectiveness and the use of biological control agents to improve its management is the most appropriate approach. The aim of this study was to evaluate the pathogenicity and virulence of entomopathogenic fungi—isolated from soil—against Duponchelia fovealis larvae under laboratory and greenhouse conditions. Pathogenicity screenings were performed for twenty isolates from Beauveria bassiana, Beauveria caledonica, Isaria javanica, Metarhizium anisopliae, and Lecanicillium sp. against third instar larvae of D. fovealis at the concentration of 108 conidia·mL−1. Lethal concentration (LC50) and lethal time (LT50) were determined for the most pathogenic isolates and for one commercial mycoinsecticide. Mortality rates varied from 10 to 89%. The isolates B. bassiana Bea1, Bea110, Bea111 and I. javanica Isa340 were the most pathogenic. The most virulent isolates were B. bassiana Bea111 and I. javanica Isa340 with LC50 values of 2.33 × 106 and 9.69 × 105 conidia·mL−1, respectively. Under greenhouse conditions, the efficacy of LC50 of the isolates I. javanica Isa340 and B. bassiana Bea111 were 45% and 52%, respectively. Our results indicate that these isolates are strong candidates for application in the control of D. fovealis. This study is the first evaluation of soil-borne entomopathogenic fungi against D. fovealis.

The Active Space of Mexican Rice Borer Pheromone Traps.

The Mexican rice borer, Eoreuma loftini (Dyar) (Lepidoptera: Crambidae), is an invasive pest of sugarcane, Saccharum spp., rice, Oryza sativa L., and other graminaceous crops in the United States. Traps baited with the synthetic female sex pheromone of E. loftini are used for monitoring and management of this invasive pest. However, the active space, or radius of attraction, of these traps is not known. Two field experiments examined the effect of intertrap distance on trap captures with hexagonal arrays of traps deployed in rice stubble habitat in Texas (2011) and Louisiana (2013). Trap capture increased with increasing intertrap distance. Trap interference occurred at intertrap distances ≤50 m in the 2011 experiment. Results from the experiment conducted in 2013 indicate that trap interference occurs at intertrap distances of 50 m, but not at distances ≥100 m. These results suggest that under field conditions, E. loftini pheromone traps attract males from distances of 50-100 m. The active space of pheromone traps also was examined under controlled wind conditions by direct observation of male response to detection of the female sex pheromone. Eoreuma loftini males responded to the pheromone blend by becoming active, fanning their wings, and rapidly walking in circles. The mean distance from the pheromone source at which males responded was 47.6 m. This work provides the first documentation of active space for traps baited with female sex pheromone for a crambid species, and these data will improve pheromone trap deployment strategies for E. loftini monitoring and management.

Annotated check list of the Pyraloidea (Lepidoptera) of America North of Mexico.

An annotated check list of Pyraloidea of North America north of Mexico is presented, including 861 Crambidae and 681 Pyralidae with 1542 total species. It includes all new species described, tropical species with new records in the United States, and species introduced from Europe and Asia since 1983. The Notes section provides the seminal citations, data and/or commentary to all changes since 1983 for easy and future reference. In addition, this list proposes seven new generic combinations, the transfer of a phycitine species, Salebria nigricans (Hulst), to Epipaschiinae and its syn. n. with Pococera fuscolotella (Ragonot), and three new records for the United States. Purposefully, no new taxa are described here, but we found a gradual increase of 10% in the number of species described since 1983. Finally, we also include a list of thirteen species not included or removed from the MONA list. Many higher-level changes have occurred since 1983 and the classification is updated to reflect research over the last 30 years, including exclusion of Thyrididae and Hyblaeidae from the superfamily and recognition of Crambidae and Pyralidae as separate families. The list includes multiple changes to subfamilies based on morphology such as the synonymization of the Dichogamini with the Glaphyriinae, but also incorporating recent molecular phylogenetic results such as the synonymization of the Evergestinae with the Glaphyriinae.

A new species of Cordyligaster Macquart, reared from caterpillars in Area de Conservacion Guanacaste, northwestern Costa Rica.

We describe a new species of Cordyligaster Macquart (Diptera: Tachinidae) from Area de Conservacion Guanacaste (ACG) in northwestern Costa Rica. Cordyligastercapellii sp. n., is described and photographed. All specimens of C.capellii were reared from Syngamiaflorella (Stoll, 1781) (Lepidoptera, Crambidae, Spilomelinae), a leaf-rolling caterpillar collected in ACG rain forest. By coupling morphology, photographic documentation, life history and molecular data, we provide a clear and concise description of this new species. In addition the authors provide new distribution and host records for C.fuscipennis (Macquart) reared in ACG.

Herpetogramma bipunctalis (Lepidoptera: Crambidae) biology and techniques for rearing on leaves of the blackberry (Rubus spp., Rosaceae) / Biologia e técnica de criação de Herpetogramma bipunctalis (Lepidoptera: Crambidae) em folhas de amoreira-preta (Rubus spp., Rosaceae)

The larvae of the southern beet webworm Herpetogramma bipunctalis (Fabricius, 1794) damage the leaves of species in the plant genus Rubus. The present study investigated the biology of H. bipunctalis and developed a protocol for raising H. bipunctalis under laboratory conditions. On the basis of the biological data, we devised a life table. In order to develop the rearing procedures, we determined which oviposition substrate and blackberry cultivar were the most appropriate for larval development. The mean durations of the egg, larval, and pupal stages were 5.59 days, 26.37 days, and 13.37 days, respectively, and the corresponding survival rates were 80.83%, 49.07%, and 83.23%. The mean pupal weight was 0.0491 g for males and 0.0536 g for females. The mean life cycle (egg-to-adult) period was 45.33 days, and overall survival to adulthood was 33.01%. H. bipunctalis females laid a mean of 252.63 eggs over a mean of 13.60 days of oviposition; the mean pre-oviposition period was 2.67 days. Mean female and male life spans were 17.51 and 19.25 days, respectively, and the sex ratio was 0.51. The life-table data indicated that H. bipunctalis can reproduce 57.9 times per generation. Each cage contained one blackberry leaf placed on a paper towel. This method allowed us to obtain the greatest number of eggs. The larval stage was shorter for insects reared on leaves of the Guarani cultivar than for those reared on leaves of the Xavante cultivar (22.63 vs. 26.37 days). These basic data can aid in establishing strategies for the management of H. bipunctalis on blackberry farms.(AU)

Lagartas de Herpetogramma bipunctalis (Fabricius, 1794) causam danos nas folhas da amoreira-preta (Rubus spp.). O objetivo deste trabalho foi estudar sua biologia e desenvolver uma técnica de criação, em condições de laboratório. Com os dados de biologia, foi elaborada uma tabela de vida de fertilidade. Para o estudo da técnica de criação, foram determinados o substrato para obtenção de ovos e a cultivar de amoreira-preta mais adequada para o desenvolvimento larval. A duração dos estágios de ovo, lagarta e pupa foram de 5,59, 26,37 e 13,37 dias, com sobrevivência de 80,83, 49,07 e 83,23%, respectivamente. O peso das pupas foi 0,0491 g para machos e 0,0536 g para fêmeas. O ciclo biológico (ovo-adulto) foi de 45,33 dias, com sobrevivência total de 33,01%. As fêmeas colocaram, em média, 252,63 ovos durante 13,60 dias, com um período de pré-oviposição de 2,67 dias. A longevidade média de fêmeas e machos foi de 17,51 e 19,25 dias, respectivamente, e a razão sexual, de 0,51. Por meio da tabela de vida de fertilidade, determinou-se uma capacidade de aumento de 57,9 vezes a cada geração. Gaiolas revestidas com papel toalha e com a presença de folhas de amoreira-preta propiciaram a obtenção de uma maior quantidade de ovos. A duração do estágio larval para os insetos alimentados com folhas de amoreira-preta cv. Guarani (22,63 dias) foi menor do que aqueles alimentados com folhas da cv. Xavante (26,37 dias). Estas informações são básicas e auxiliarão em futuros estudos, visando ao estabelecimento de estratégias de manejo de H. bipunctalis em amoreira-preta.(AU)

Herpetogramma bipunctalis (Lepidoptera: Crambidae) biology and techniques for rearing on leaves of the blackberry (Rubus spp., Rosaceae) / Biologia e técnica de criação de Herpetogramma bipunctalis (Lepidoptera: Crambidae) em folhas de amoreira-preta (Rubus spp., Rosaceae)

The larvae of the southern beet webworm Herpetogramma bipunctalis (Fabricius, 1794) damage the leaves of species in the plant genus Rubus. The present study investigated the biology of H. bipunctalis and developed a protocol for raising H. bipunctalis under laboratory conditions. On the basis of the biological data, we devised a life table. In order to develop the rearing procedures, we determined which oviposition substrate and blackberry cultivar were the most appropriate for larval development. The mean durations of the egg, larval, and pupal stages were 5.59 days, 26.37 days, and 13.37 days, respectively, and the corresponding survival rates were 80.83%, 49.07%, and 83.23%. The mean pupal weight was 0.0491 g for males and 0.0536 g for females. The mean life cycle (egg-to-adult) period was 45.33 days, and overall survival to adulthood was 33.01%. H. bipunctalis females laid a mean of 252.63 eggs over a mean of 13.60 days of oviposition; the mean pre-oviposition period was 2.67 days. Mean female and male life spans were 17.51 and 19.25 days, respectively, and the sex ratio was 0.51. The life-table data indicated that H. bipunctalis can reproduce 57.9 times per generation. Each cage contained one blackberry leaf placed on a paper towel. This method allowed us to obtain the greatest number of eggs. The larval stage was shorter for insects reared on leaves of the Guarani cultivar than for those reared on leaves of the Xavante cultivar (22.63 vs. 26.37 days). These basic data can aid in establishing strategies for the management of H. bipunctalis on blackberry farms.

Lagartas de Herpetogramma bipunctalis (Fabricius, 1794) causam danos nas folhas da amoreira-preta (Rubus spp.). O objetivo deste trabalho foi estudar sua biologia e desenvolver uma técnica de criação, em condições de laboratório. Com os dados de biologia, foi elaborada uma tabela de vida de fertilidade. Para o estudo da técnica de criação, foram determinados o substrato para obtenção de ovos e a cultivar de amoreira-preta mais adequada para o desenvolvimento larval. A duração dos estágios de ovo, lagarta e pupa foram de 5,59, 26,37 e 13,37 dias, com sobrevivência de 80,83, 49,07 e 83,23%, respectivamente. O peso das pupas foi 0,0491 g para machos e 0,0536 g para fêmeas. O ciclo biológico (ovo-adulto) foi de 45,33 dias, com sobrevivência total de 33,01%. As fêmeas colocaram, em média, 252,63 ovos durante 13,60 dias, com um período de pré-oviposição de 2,67 dias. A longevidade média de fêmeas e machos foi de 17,51 e 19,25 dias, respectivamente, e a razão sexual, de 0,51. Por meio da tabela de vida de fertilidade, determinou-se uma capacidade de aumento de 57,9 vezes a cada geração. Gaiolas revestidas com papel toalha e com a presença de folhas de amoreira-preta propiciaram a obtenção de uma maior quantidade de ovos. A duração do estágio larval para os insetos alimentados com folhas de amoreira-preta cv. Guarani (22,63 dias) foi menor do que aqueles alimentados com folhas da cv. Xavante (26,37 dias). Estas informações são básicas e auxiliarão em futuros estudos, visando ao estabelecimento de estratégias de manejo de H. bipunctalis em amoreira-preta.

First record of damage by an insect pest in a commercial amaranth crop in Brazil

Insect pests have not been recorded for amaranth (Amaranthus cruentus L.) in Brazil. Generalized plant lodging was observed after the grain-filling period in an irrigated commercial amaranth crop (7 ha), located in Cristalina, state of Goiás (Brazil), which was cultivated between Aug. and Dec. 2009. Almost all sampled plants presented internal galleries bored by lepidopteran larvae. The larvae were reared, and the adults were identified as Herpetogramma bipunctalis (F.) (Crambidae). This is the first report of an insect pest causing significant damage in a commercial amaranth crop in Brazil, which indicates the need to develop pest management strategies in order to support the increased production in Brazil.

First record of damage by an insect pest in a commercial amaranth crop in Brazil

Insect pests have not been recorded for amaranth (Amaranthus cruentus L.) in Brazil. Generalized plant lodging was observed after the grain-filling period in an irrigated commercial amaranth crop (7 ha), located in Cristalina, state of Goiás (Brazil), which was cultivated between Aug. and Dec. 2009. Almost all sampled plants presented internal galleries bored by lepidopteran larvae. The larvae were reared, and the adults were identified as Herpetogramma bipunctalis (F.) (Crambidae). This is the first report of an insect pest causing significant damage in a commercial amaranth crop in Brazil, which indicates the need to develop pest management strategies in order to support the increased production in Brazil.