Olfaction Response and Fertility Life Table Parameters of Tetrastichus howardi (Hymenoptera: Eulophidae) Parasitizing Plutella xylostella (Lepidoptera: Plutellidae) and the factitious host Tenebrio molitor (Coleoptera: Tenebrionidae).

Tetrastichus howardi (Olliff) (Hymenoptera: Eulophidae) parasitizes the diamond back moth Plutella xylostella (L.) (Lepidoptera: Plutellidae), but not much is known about its potential as a biocontrol agent. A rearing protocol has been established for this parasitoid on pupae of the factitious host Tenebrio molitor (L.) (Coleoptera: Tenebrionidae), with the aim of releasing it in the field to manage several lepidopteran species. The potential population growth of a parasitoid can be measured through fertility life tables and provide supporting information for using T. howardi in the management of P. xylostella. Also, the fitness and behavior of T. howardi reared on a factitious host can be indicators of its potential to control P. xylostella. Thus, in this study, the fertility life table parameters of T. howardi parasitizing P. xylostella were determined, as well as the effects of the natal host on the behavior of T. howardi towards host volatiles and parasitism rate. The results showed that net reproduction rate (Ro) and the intrinsic rate of population growth (rm) of T. howardi parasitizing P. xylostella were 13.6 (♀/♀) and 0.124 (♀/♀*day), respectively, whereas the mean generation time was 20.9 days. Moreover, the natal host (T. molitor or P. xylostella) did not affect the fitness, parasitism rate, or olfactory response of T. howardi. In general, regardless of the natal host, parasitoid females responded to volatiles of both host species and exhibited the same rate of parasitism on P. xylostella. Therefore, T. howardi reared on the factitious host maintains its attraction and potential to parasitize P. xylostella, and can contribute to the biological control of this pest.

Biology of Trichogramma marandobai and T. manicobai (Hymenoptera: Trichogrammatidae) in eggs of Erinnyis ello (Lepidoptera: Sphingidae)

ABSTRACT Parasitoids of the genus Trichogramma are promising for the biological control of insect pests in several crops, including cassava, which is severely attacked by Erinnyis ello L., 1758 (Lepidoptera: Sphingidae). Evaluating the biological aspects of these parasitoids to understand their dynamics is an important step towards the implementation of this control strategy in the field. Thus, our objective was to evaluate the biology of Trichogramma manicobai Brun, Moraes & Soares, 1984, and T. marandobai Brun, Moraes & Soares, 1986 in E. ello eggs. The parasitoids were obtained by collecting E. ello eggs from a commercial production of cassava, and the host's eggs were obtained from laboratory and greenhouse rearings. The average duration of a generation (T), net reproduction rate (R0), intrinsic rate of increase (rm), and the finite rate of increase (λ) were estimated, and from these, the fertility life table was calculated. The results indicated that T. marandobai has both higher net reproduction rate and a higher intrinsic rate of increase as well as requires less time to double its population than T. manicobai. Thus, T. marandobai has potential for natural and conservative biological control of E. ello. In addition, its potential in applied biological control should be evaluated through studies on the viability of its mass rearing in alternative hosts and its dispersion behavior in the field.

Sublethal effects of spirodiclofen on biological and demographic parameters of the citrus leprosis mite Brevipalpus yothersi (Acari: Tenuipalpidae).

BACKGROUND: Brevipalpus yothersi Baker is one of the main vectors of citrus leprosis. Knowing the biology of this mite species when under chemical control is extremely important to understand its population dynamics, and then to solve problems of management of this pest. Therefore, we assessed the effects of one sublethal dose of spirodiclofen (0.48 ppm) on biological and demographic parameters of B. yothersi under laboratory and greenhouse conditions, comparing them with non-exposed mite population. RESULTS: Under laboratory conditions, where citrus fruits were used as a substrate, the duration of developmental stages (pre-egg-laying and egg-laying) and mite longevity showed no differences between treatments. However, the number of laid eggs increased in acaricide-treated fruits. In the greenhouse experiment, where citrus plants were used as a substrate, the instantaneous growth rate (ri) of mites was positive in all untreated plots. In contrast, in treated plants, ri was negative in 12 experimental units, and mite populations were suppressed in five of them. Moreover, mite population dynamics had a positive ri in three treated plants. CONCLUSIONS: Spirodiclofen sublethal dose had no negative effect on the offspring of B. yothersi females. However, it is not safe for citrus leprosis mite since it may increase egg number per female in some conditions. Biological and demographic differences could influence mite population dynamics in the field, requiring appropriate management strategies to improve citrus leprosis control. © 2019 Society of Chemical Industry.

Resistance of cassava genotypes to Vatiga manihotae (Drake 1922) (Hemiptera: Tingidae)

ABSTRACT Vatiga manihotae (Drake 1922) (Hemiptera: Tingidae) is an important cassava pest due to the great potential damage and the increasing population in recent years. However, few studies about bioecology and control of the cassava lace bug have been conducted and their results don't provide adequate control strategies. An alternative to maintain the population below economic injury levels is through the adoption of host plant resistance. To improve the understanding about the bioecology and find new sources of resistance in cassava, the biological parameters and demographics of V. manihotae on five cassava genotypes (Santa Helena, MEcu 72, Col 22, Clone 02 and Clone 03) under controlled conditions (25±2°C, 14L/10D) were evaluated. Duration and viability of the stages, the period egg-adult, sex ratio, the pre-oviposition period, fecundity and longevity of male and female was determined, and a fertility life table was prepared. Insects fed on MEcu 72 showed increased nymphal, egg-adult, and pre-oviposition periods and reduced female fecundity and longevity in comparison to the other genotypes. Demographic parameters (Ro, rm, T, DT) showed a significant impact on the growth potential of V. manihotae fed on MEcu 72 indicating that the populations would diminish over time. The combined effect of these parameters indicated that MEcu 72 has resistance on V. manihotae specimens hindering their development.

Artificial Corn-Based Diet for Rearing Spodoptera frugiperda (Lepidoptera: Noctuidae).

Spodoptera frugiperda (J.E. Smith, 1797) is considered a key pest of maize. However, the artificial diets used for rearing this insect in the laboratory do not contain corn. The aim of this study was to evaluate the biology and to compare the food consumption by S. frugiperda, as well as the food preference of the larvae in the standard diet and the corn-based diet. Three of the following diets were evaluated: a standard diet based on beans (D1), a diet with corn flour as substitute for wheat germ (D2), and a diet replacing beans with green corn (D3). The biological parameters evaluated were period and survival of larvae and pupae; weight of male and female pupae; sex ratio; fecundity; egg incubation period; and adult longevity. The nutritional indices were determined and the biological data obtained were used to determine the parameters of fertility life tables; we also performed a multiple-choice test (feeding test). Larval development of S. frugiperda occurred in all three diets, although without oviposition by females developed from larval fed on D2. There was no difference among the diets in relation to the fertility life table parameters. The diet D2 resulted in better ingestion, digestion, assimilation, and conversion of food, but was associated with a metabolic cost to assimilate the food. Using a multiple-choice test, we observed that the larvae preferred diet D2. Based on our results, the most adequate diets for rearing S. frugiperda in the laboratory are D1 and D3.

Reproductive parameters of Phytoseiulus macropilis (Banks) fed with Tetranychus urticae Koch (Acari: Phytoseiidae, Tetranychidae) in laboratory / Parâmetros reprodutivos de Phytoseiulus macropilis (Banks) predando Tetranychus urticae Koch (Acari: Phytoseiidae, Tetranychidae) em laboratório

Abstract Predatory mites that belong to the Phytoseiidae family are one of the main natural enemies of phytophagous mites, thus allowing for their use as a biological control. Phytoseiulus macropilis (Banks, 1904) (Acari: Phytoseiidae) is among the main species of predatory mites used for this purpose. Tetranychus urticae Koch, 1836 (Acari: Tetranychidae) is considered to be one of the most important species of mite pests and has been described as attacking over 1,100 species of plants in 140 families with economic value. The objective of the present study was to investigate, in the laboratory, the reproductive parameters of the predatory mite P. macropilis when fed T. urticae. Experiments were conducted under laboratory conditions at 25 ± 2 °C of temperature, 70 ± 10% RH and 14 hours of photophase. In addition, biological aspects were evaluated and a fertility life table was established. The results of these experiments demonstrated that the longevity of adult female was 27.5 days and adult male was 29.0 days. The population was estimated to increase approximately 27 times (Ro) in mean generation time (T), which was 17.7 days. Lastly, the mite population grew 1.2 times/day (λ) and doubled every 3.7 days (TD).

Resumo Os ácaros predadores pertencentes à família Phytoseiidae constituem um dos principais inimigos naturais de ácaros fitófagos, o que possibilita o seu uso em controle biológico. Entre as principais espécies destaca-se Phytoseiulus macropilis (Banks, 1904) (Acari: Phytoseiidae). O ácaro Tetranychus urticae Koch, 1836 (Acari: Tetranychidae) é considerado uma das espécies de ácaros-praga mais importantes, atacando mais de 1.100 espécies de plantas em 140 famílias de valor econômico. Este trabalho foi realizado com o objetivo de estudar, em laboratório, os parâmetros reprodutivos do ácaro predador P. macropilis, quando alimentado com T. urticae. Os estudos foram conduzidos em laboratório à temperatura de 25 ± 2 °C, 70 ± 10% de UR e 14 horas de fotofase e foram avaliados os aspectos biológicos e confeccionada a tabela de vida de fertilidade. Foi constatada uma longevidade de 27,5 dias para fêmeas adultas e 29,0 dias para machos. A população foi estimada em aumentar aproximadamente 27 vezes (Ro) no período médio de duração de geração (T) que foi de 17,7 dias. A população do ácaro cresceu 1,2vezes/dia (λ) e dobrou a cada 3,7 dias (TD).

Biological parameters and fertility life table of Aphis forbesi Weed, 1889 (Hemiptera: Aphididae) on strawberry / Parâmetros biológicos e tabela de vida de fertilidade de Aphis forbesi Weed, 1889 (Hemiptera: Aphididae) em morangueiro

Abstract This study provides the first contribution of the biology and life table of Aphis forbesi Weed, 1889 (Hemiptera: Aphididae), an important strawberry pest throughout the world. This species lives in the crown and leaf petioles of the plant. It is difficulty to rear this species in laboratory due to protocooperation with ants observed only in the field. We studied the life cycle of A. forbesi on the leaves of the Albion strawberry cultivar at 25 ± 2 °C, 60 ± 10% relative humidity, and a 12-h photophase. The experiment was randomised with 100 replicates. The parameters of the fertility life table were calculated using TabVida. In the population studied, 25% and 46% had four and three instars, respectively. A mean of 1.43 nymphs per female per day was generated. The mean reproductive period was seven days and the mean longevity was 10 days. In every 11 days there is a generation of A. forbesi, where each female has the potential to generate between 6 to 9 individuals daily, increasing its population by 1.2 times. The average life cycle was 16.8 days. High viability observed in all instars and the resulting values of R0, rm and λ suggest that A. forbesi has the capacity to increase their numbers in a short period of time, while generating high populations in strawberry crops, requiring differential management.

Resumo Este trabalho apresenta a primeira contribuição ao estudo de biologia e tabela de vida de fertilidade de Aphis forbesi, Weed, 1889 (Hemiptera: Aphididae), uma importante praga de morangueiro no mundo. Esta espécie se desenvolve na coroa e pecíolo do morangueiro. O desenvolvimento desta espécie em laboratório apresentou dificuldades, possivelmente devido à protocooperação com formigas, observada em campo durante coletas. O ciclo de vida de A. forbesi foi estudado em folhas de morangueiro cultivar ‘Albion’ a 25 ± 2 °C, 60 ± 10% umidade relativa, e fotofase de 12 horas. O experimento foi inteiramente casualizado com 100 repetições. Os parâmetros da tabela de vida de fertilidade foram calculados usando o software TabVida. Na população estudada observou-se que as ninfas apresentaram três e quatro instares, sendo 46 e 25% respectivamente, dos indivíduos que completaram o ciclo de vida. Foi gerada uma média de 1,43 ninfas/ fêmea/ dia. O período reprodutivo médio foi de 7 dias e a longevidade média 10 dias. A cada 11 dias ocorre uma geração de A. forbesi onde cada fêmea tem capacidade de gerar de 6 a 9 indivíduos aumentando em 1,2 vezes a população. O ciclo de vida de A. forbesi durou em média 16,8 dias. A alta viabilidade observada em todos os estádios, e os valores de R0, rm e λ sugerem que A. forbesi tem a capacidade de aumentar seu número em um curto período de tempo, gerando altas populações no cultivo do morangueiro, exigindo manejo diferenciado.

Life history of Neoseiulus californicus (McGregor, 1954) (Acari: Phytoseiidae) fed with castor bean (Ricinus communis L.) pollen in laboratory conditions / História de vida de Neoseiulus californicus (McGregor, 1954) (Acari: Phytoseiidae), alimentado com pólen de mamoneira (Ricinus communis L.) em condição de laboratório

The predatory mite, Neoseiulus californicus (McGregor, 1954) (Acari: Phytoseiidae) is one of the principal natural enemies of tetranychid mites in several countries, promoting efficient control of those mites in several food and ornamental crops. Pest attacks such as that of the spider mite, Tetranychus urticae Koch, 1836 (Acari: Tetranychidae), is one of the problems faced by farmers, especially in the greenhouse, due to the difficulty of its control with the use of chemicals because of the development of fast resistance making it hard to control it. The objective of this work was to study the life history of the predatory mite N. californicus as a contribution to its mass laboratory rearing, having castor bean plant [Ricinus communis L. (Euphorbiaceae)] pollen as food, for its subsequent use as a natural enemy of T. urticae on a cultivation of greenhouse rosebushes. The studies were carried out in the laboratory, at 25 ± 2°C of temperature, 70 ± 10% RH and a 14 hour photophase. The biological aspects and the fertility life table were appraised. Longevity of 32.9 days was verified for adult females and 40.4 days for males. The intrinsic rate of increase (rm) was 0.2 and the mean generation time (T) was 17.2 days. The population doubled every 4.1 days. The results obtained were similar to those in which the predatory mite N. californicus fed on T. urticae.

O ácaro predador, Neoseiulus californicus (McGregor, 1954) (Acari: Phytoseiidae) é um dos principais inimigos naturais de ácaros tetraniquídeos em vários países, promovendo um eficiente controle em várias culturas alimentícias e ornamentais. O ataque de pragas como o ácaro-rajado, Tetranychus urticae Koch, 1836 (Acari: Tetranychidae), é um dos problemas enfrentados pelos produtores, principalmente em casa de vegetação, pela dificuldade de seu controle com o uso de agroquímicos devido ao rápido desenvolvimento de resistência o que dificulta seu controle. Foi objetivo deste trabalho estudar a história de vida do ácaro predador N. californicus como contribuição à sua criação massal em laboratório tendo como alimento pólen de mamoneira [Ricinus communis L. (Euphorbiaceae)] para posterior uso como inimigo natural de T. urticae em cultivo de roseiras (Rosa spp.) em casa de vegetação. Os estudos foram conduzidos em laboratório à temperatura de 25 ± 2°C, 70 ± 10% de UR e 14 horas de fotofase. Foram avaliados os aspectos biológicos e confeccionada a tabela de vida de fertilidade. Foi constatada uma longevidade de 32,9 dias para fêmeas adultas e 40,4 dias para machos. A estimativa da capacidade inata de crescimento da população (rm) foi 0,2 dias e a duração média de geração (T) foi 17,2 dias. A população dobrou a cada 4,1 dias. Os resultados obtidos foram semelhantes àqueles nos quais o predador N. californicus foi alimentado com T. urticae.

Técnica de Criação e Aspectos Biológicos de Atheloca subrufella (Hulst) (Lepidoptera: Phycitidae) em Frutos de Coqueiro / Rearing Technique and Biological Traits of Atheloca subrufella (Hulst) (Lepidoptera: Phyci.. dae) in Coconut Fruits

Rearing Technique and Biological Traits of Atheloca subrufella (Hulst) (Lepidoptera: Phycitidae) in Coconut Fruits. Larvae of the coconut moth Atheloca subrufella (Hulst) develop in flowers and fruits of coconut, Cocos nucifera, causing precocious abscission of these structures and, hence, yield decrease. This work studied a feasible and suitable rearing technique for A. subrufella using fruits of coconut. We first determined the appropriate density of larvae to be reared per coconut fruit (among two, three, four or five larvae) and later tested the suitability of this rearing technique for three successive generations. The storage of egg and pupal stages during 0, 5, 10 and 20 days was also studied at 12ºC. Based on the fertility life table parameters, the best results were achieved by rearing two or three larvae per fruit as they yielded the best net reproductive rate and intrinsic rate of population increase. In addition, eggs and pupae of A. subrufella can be stored at 12ºC up to five days with viability higher than 90 percent. Adult moths emerged from pupae stored for five days at 12ºC produced an average of 219.4 eggs and lived 18.8 days. Storage periods for eggs and pupae over 10 days significantly reduced egg viability and adult fecundity, respectively. Thus, the technique in here described was shown to be suitable for the continuous rearing of A. subrufella in laboratory conditions.

Oviposição, desenvolvimento e reprodução de Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) em diferentes hospedeiros de importância econômica / Oviposition, development, and reproduction of Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) fed on different hosts of economic importance

The host selection for oviposition by Spodoptera frugiperda (J.E. Smith) among corn, millet, cotton and soybean, and its relationship with the biological characteristics were investigated. Free and non-choice tests for oviposition using plots containing five plants each, from each host in plastic greenhouse, resulted in similar oviposition preference among the host plants. In addition, selected biological characteristics of S. frugiperda were determined in the laboratory with larvae feeding on host leaves, and the combination of leaf and cotton boll. Neonate larvae exhibited low success of colonization on cotton boll compared to the leaves of all other hosts. Spodoptera frugiperda fed only on cotton bolls exhibited longer larval and pupal development, and longer adult life span; however with similar egg production. Larvae fed cotton leaves during six days and then transferred to cotton bolls, however, exhibited development and reproduction similar to those reared on corn or only on cotton leaves. Therefore, the variations on immature stages of S. frugiperda were not related with host selection for oviposition which was similar among the studied hosts. Based on our data, the millet as a winter, rotational, and cover crop is a potential host for S. frugiperda, while leaves and cotton bolls were diets of intermediate suitability as compared to corn and soybean leaves.

Biological cycle of Tenuipalpus heveae Baker (Acari, Tenuipalpidae) on leaflets of three rubber tree clones / Ciclo de vida de Tenuipalpus heveae Baker (Acari, Tenuipalpidae) em folíolos de três clones de seringueira

Life cycle of Tenuipalpus heveae Baker (Acari, Tenuipalpidae) on leaflets from three rubber tree clones. The biological cycle of Tenuipalpus heveae Baker, 1945 (Tenuipalpidae), a potential rubber tree pest mite, was studied by the observation of individuals reared on leaflets of the clones GT 1, PB 235 and RRIM 600, in controlled environmental conditions. Three daily observations were done of 60 eggs on leaflets from each clone in order to verify the development of immature stages and the female oviposition. The fertility life table was constructed based in the collected data. Mites reared on PB 235 had faster rate of development, requiring less time in days, to double its population in number (TD), and had the highest values for egg production, female longevity, net reproductive rate (Ro), intrinsic rate of natural increase (r m) and finite rate of increase (λ). Lower reproductive values and the longest time necessary to reach adult stage were recorded for the mites on GT 1. In all studied clones, the deutonymphal phase had the highest viability, while the larval phase had the lowest, highlighted by the survivorship curve that indicated high mortality during this life stage. The clone PB 235 allowed the most suitable conditions for the development of T. heveae, followed by RRIM 600, while GT 1 was the less suitable substratum to rear this mite species.

O ciclo de vida de Tenuipalpus heveae Baker, 1945 (Tenuipalpidae), um potencial ácaro-praga da seringueira, foi estudado a partir de indivíduos criados sobre folíolos destacados dos clones GT 1, PB 235 e RRIM 600, em condições controladas. Três observações diárias foram realizadas, acompanhando-se o desenvolvimento de 60 ovos e de sua prole em folíolos de cada um dos clones, para verificação da oviposição das fêmeas e dos estágios de desenvolvimento. A partir dos dados obtidos, foi elaborada uma tabela de vida de fertilidade. Os ácaros criados sobre folíolos de PB 235 apresentaram rápido ciclo biológico, com menor tempo gasto, em dias, para duplicar sua população (TD) e os maiores valores para a produção de ovos, longevidade de fêmeas, taxa líquida de reprodução (Ro), taxa intrínseca de crescimento populacional (r m) e taxa finita de crescimento populacional (λ). Em GT 1 foram observados valores inferiores e o maior tempo de desenvolvimento necessαrio para atingir a fase adulta. Em todos os clones estudados a fase de maior viabilidade foi a deutoninfal, enquanto a menor, a larval, como evidenciado tambιm pelas curvas de sobrevivência, que indicaram maior mortalidade nesse estágio juvenil. O clone PB 235 possibilitou melhor desenvolvimento para T. heveae, seguido por RRIM 600, enquanto que GT 1 foi o menos favorável ao desenvolvimento dessa espécie.

Tetranychus urticae (Acari: Tetranychidae) on Gerbera jamesonii Bolus and Hook (Asteraceae) / Biologia de Tetranychus urticae (Acari: Tetranychidae) em Gerbera jamesonii Bolus and Hook (Asteraceae)

Gerbera (Gerbera jamesonii Bolus and Hook,) is an ornamental Asteraceae of great commercial value, and pests can affect adversely its cultivation. More than 20 species of arthropods cause economic damage on gerbera, among them the two spotted mite, Tetranychus urticae Koch, 1836 (Acari: Tetranychidae), considered a key pest for this and other ornamental plants. In this work, some life-cycle aspects of T. urticae on gerbera, considered important for the knowledge of its population dynamics and for pest management programs, were studied. Mites were reared on 3-cm diameter arenas of gerbera leaf discs maintained on distilled water in Petri dishes, under laboratory conditions of 25 ºC, 70 ± 10 percent RU and 14-hour photophase, with only one egg left per arena, in a total of 262 arenas. Egg viability was 96.5 percent and 97.1 percent for unmated and mated females, respectively. Unmated females originated larvae which lived for 3.2 days and the stages of protonymph and deutonymph, 1.9 and 1.6 days, respectively; those from mated females lived 3.5 days and for protonymphs and deutonymphs, 2.0 and 1.6 days, respectively. Except for the duration of one generation (T), with similar values, 18.6 and 19.7 days, respectively for unmated and mated females, the net reproductive rate of increase (Rº), the innate capacity to increase in number (r m) and the finite rate of growth (λ) were different for mated and unmated females, respectively 11.5 and 24.6 for R0; 0.12 and 0.17 for r m and 1.13 and 1.19 for λ.

A gérbera, Gerbera jamesonii Bolus and Hook, é uma planta ornamental pertencente à família Asteraceae de grande valor comercial. Dentre os vários fatores que podem afetar adversamente o seu cultivo se encontram as pragas. Mais de 20 espécies de artrópodes causam danos econômicos em gérbera, entre elas encontra-se o ácaro-rajado, Tetranychus urticae Koch, 1836 (Acari: Tetranychidae), considerado praga-chave dessa e de outras plantas ornamentais. O presente trabalho teve por objetivo estudar alguns aspectos do ciclo biológico de T. urticae em gérbera considerados importantes para o conhecimento da dinâmica populacional da espécie e para os programas de manejo de pragas. Os ácaros foram criados em arenas constituídas de discos de folhas de gérbera de 3 cm de diâmetro, sobre água destilada, colocados em placas de Petri, em condições de laboratório, a 25 ºC, 70 ± 10 por cento de U.R. e 14 horas de fotofase, deixando-se um ovo por arena, perfazendo um total de 262 arenas. A viabilidade dos ovos foi de 96,5 e 97,1 por cento para fêmeas não acasaladas e acasaladas, respectivamente. As larvas provenientes de fêmeas não acasaladas tiveram duração de 3,2 dias e os estágios de protoninfa e deutoninfa foram de 1,9 e 1,6 dias, respectivamente. Já para fêmeas acasaladas a fase de larva teve uma duração de 3,5 dias, a de protoninfa e deutoninfa 2,0 e 1,6 dias, respectivamente. À exceção da duração de uma geração (T) que tiveram valores próximos, 18,6 e 19,7, respectivamente para fêmeas não acasaladas e acasaladas, a taxa líquida de reprodução (Rº), capacidade inata de aumentar em número (r m) e razão finita de crescimento (λ) foram diferentes para fêmeas acasaladas e não, sendo respectivamente 11,5 e 24,6 para R0; 0,12 e 0,17 para r m e 1,13 e 1,19 para λ.