Effect of Carbon dioxide (CO₂) on mortality and reproduction of <italic>Anagasta kuehniella</italic> (Zeller 1879), in mass rearing, aiming at the production of <italic>Trichogramma</italic> spp.

<p id="para1">Eggs of <italic>Anagasta kuehniella</italic> (Zeller 1879) are widely used for mass rearing of <italic>Trichogramma</italic> spp. and other parasitoids and predators, largely commercialized in many countries. The aim of this study is to evaluate the effect of carbon dioxide (CO₂) originated from larval metabolism on the biological parameters of <italic>A. kuehniella</italic>. For that purpose, we assess the production of carbon dioxide (CO₂) per rearing tray of <italic>A. kuehniella</italic> and the effect of CO₂ on the viability of egg-to-adult period and oviposition of <italic>A. kuehniella</italic>. Results allow to estimate that a rearing tray, containing 10,000 larvae between the 4^th and 5^th instars, produces an average of 30.67 mL of CO₂ per hour. The highest egg production of <italic>A. kuehniella</italic> was obtained when the larvae were kept in rooms with lower concentration of CO₂ (1,200 parts per million - ppm), producing 23% more eggs than in rooms with higher CO₂ concentrations. In rooms with high density of trays (70 trays/room), CO₂ concentration exceeded 4,400 ppm. The viability of the egg-to-adult period was not influenced by carbon dioxide.</p><br><p id="para2">Ovos de <italic>Anagasta kuehniella</italic> (Zeller, 1879) s&#227;o muito utilizados para a cria&#231;&#227;o massal de <italic>Trichogramma</italic> spp. e de outros parasit&#243;ides e predadores, sendo comercializados em muitos pa&#237;ses. O objetivo deste trabalho foi avaliar o efeito do di&#243;xido de carbono (CO₂), proveniente do metabolismo larval, em par&#226;metros biol&#243;gicos de <italic>A. kuehniella</italic>, principalmente na postura. Para que este objetivo fosse atingido, foram avaliados a produ&#231;&#227;o de di&#243;xido de carbono (CO₂) por bandeja de cria&#231;&#227;o de <italic>A. kuehniella</italic> e o efeito do CO₂ na viabilidade do per&#237;odo ovo-adulto e na postura de <italic>A. kuehniella</italic>. Por meio dos resultados obtidos p&#244;de-se estimar que uma bandeja de cria&#231;&#227;o, com lagartas entre o 4&#176; e 5&#176; &#237;nstares, inoculada com 10.000 lagartas produz, em m&#233;dia, 30,67 ml de CO₂ por hora. A maior produ&#231;&#227;o de ovos de <italic>A. kuehniella</italic> foi obtida quando as lagartas foram mantidas em salas com concentra&#231;&#227;o de CO₂ inferior a 1.200 ppm, produzindo 23% mais ovos nesta condi&#231;&#227;o em rela&#231;&#227;o a de insetos provenientes de salas com concentra&#231;&#245;es maiores. Em salas com alta densidade de bandejas (70 bandejas/sala), a concentra&#231;&#227;o de CO₂ ultrapassou 4400 ppm. A viabilidade do per&#237;odo ovo-adulto n&#227;o foi influenciada pelo di&#243;xido de carbono.</p

A new concept for insect damage evaluation based on plant physiological variables

The objective of this study was to determine the damage levels caused by Orthezia praelonga Douglas, 1891 and Leucoptera coffeella (Guérin-Mèneville 1842), on rangpur lime and Obatã coffee leaves, respectively. Measurements were based on a new concept for the evaluation of the following plant physiological parameters: photosynthesis, stomatal conductance, leaf temperature and transpiration, and internal concentration of CO2 (by infrared analyzer). A negative correlation between infestation level and photosynthesis was found, where the negative inflexion point of the curve was considered as a reference for damage levels. The control level for O. praelonga is below the 7-13% limit for damaged leaf area (40 to 70 scales per leaf), while for L. coffeella it is below the 26-36% limit for the same variable. Photosynthesis provided the best correlation for this type of analysis

Temperature effects on the mating frequency of Anticarsia gemmatalis Hüebner and Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae)

Este trabalho estudou a influência da temperatura na freqüência de cópula de Anticarsia gemmatalis Hübner e Spodoptera frugiperda J. E. Smith, que empregam diferentes estratégias de alocação, e a utilização de nutrientes para suas atividades reprodutivas. Os insetos foram criados em dieta artificial a 25ºC, sendo a influência da temperatura na freqüência de cópula, fecundidade, fertilidade e longevidade de adultos avaliada em cinco temperaturas (15, 20, 25, 30 e 35ºC). A temperatura afetou a freqüência de cópula de ambas as espécies, sendo o seu efeito mais evidente nas temperaturas extremas estudadas (15ºC e 35ºC), principalmente, para A. gemmatalis, que apresentou redução drástica em sua atividade de cópula. Temperaturas intermediárias (20ºC a 30ºC) permitiram o maior número de cópulas, com S. frugiperda apresentando (até oito cópulas) atividade de cópula muito superior à de A. gemmatalis (até duas cópulas). Mesmo com a variação encontrada na atividade de cópula nas diferentes temperaturas, não foi verificada correlação entre o número de cópulas e os demais parâmetros biológicos observados (fecundidade, fertilidade e longevidade), com exceção da fecundidade de S. frugiperda a 25ºC, que apresentou correlação positiva com a atividade de cópula nessa temperatura (r = 0,589; P = 0,003), indicando que as alterações na atividade reprodutiva desse inseto foram decorrentes, basicamente, de sua resposta à temperatura. Fêmeas de S. frugiperda foram mais fecundas nas temperaturas entre 20ºC e 30ºC e as de A. gemmatalis a 25ºC. A longevidade de ambos os sexos decresceu com o aumento da temperatura para as duas espécies estudadas.This paper deals with the influence of temperature on the mating frequency of two lepidopterans, Anticarsia gemmatalis Hübner and Spodoptera frugiperda (J.E. Smith), which use different strategies of allocation, and with the utilization of nutrients for their reproductive activities. The insects were reared on artificial diets at 25ºC, and the adults were exposed to five temperatures (15, 20, 25, 30, and 35ºC) to observe the influence of each temperature on their mating frequency, fecundity, fertility and longevity. The temperature affectedthe mating frequency of both species, being more evident at 15ºC and 35ºC, mainly for A. gemmatalis, which presented a drastic reduction on mating activities. The highest number of matings were observed from 20ºC to 30ºC, with S. frugiperda presenting mating activity (0-8) much higher than that of A. gemmatalis (0-2), but no correlation was observed among the number of matings and all other biological parameters evaluated (fecundity, fertility and longevity). However, S. frugiperda showed a positive correlation between fecundity and mating activity of females (r = 0.589; P = 0.003) at 25ºC. The highest fecundities were observed at temperatures from 20ºC to 30ºC for S. frugiperda and at 25ºC for A. gemmatalis. For both species, the longevity of males and females decreased as temperature increased

Recommended pesticides persistence for integrated citrus production on ectoparasitoid Tamarixia radiata (Waterston, 1922) (Hymenoptera: Eulophidae)

Tamarixia radiata (Waterston, 1922) is the main biological control agent of the psyllid Diaphorina citri Kuwayama, vector of bacteria associated with Huanglongbing in citrus. However, indiscriminate use of chemicals affects its control rate. Thus, this study assessed the biological persistence of 22 insecticides, two oils and 16 acaricides recommended for the control of citrus pests, on the parasitoid T. radiata. For this, the parasitoid adults were exposed to waste products sprayed on citrus seedlings of the variety Valencia. After 3, 7, 10, 17, 24 and 31 days after spraying, leaves were removed and in the laboratory, leaf discs of 4.0 cm diameter were obtained with the aid of a metallic punch , and were placed in Petri dishes (4.5 cm diameter) on a gelled mixture of water-agar to 2.5%. Thereafter, 10 parasitoid adults of 48 hours of age were placed on each plate and, then, placed in a climate clamber (25 ± 1 ºC, 70 ± 10%, 14L10D). Each treatment had five replicates. Insect mortality was evaluated 24 hours after exposure to residues. Insecticides Saurus, Turbo, Mimic 200 SC and Azamax; mineral oil Argenfrut; vegetable oil Nortox and acaricides Vertimec 18 EC, Envidor, Sanmite, Torque 500 SC, Cascade 100, Borneo, Dicofol, Micromite 240 SC and Savey WP were classified as short lived, and insecticides Tracer and Dicarzol and acaricide Marshall Star were classified as persistent. Therefore, it is essential to use selective products in integrated pest management to preserve the parasitoid

Recommended pesticides persistence for integrated citrus production on ectoparasitoid Tamarixia radiata (Waterston, 1922) (Hymenoptera: Eulophidae)

Tamarixia radiata (Waterston, 1922) is the main biological control agent of the psyllid Diaphorina citri Kuwayama, vector of bacteria associated with Huanglongbing in citrus. However, indiscriminate use of chemicals affects its control rate. Thus, this study assessed the biological persistence of 22 insecticides, two oils and 16 acaricides recommended for the control of citrus pests, on the parasitoid T. radiata. For this, the parasitoid adults were exposed to waste products sprayed on citrus seedlings of the variety Valencia. After 3, 7, 10, 17, 24 and 31 days after spraying, leaves were removed and in the laboratory, leaf discs of 4.0 cm diameter were obtained with the aid of a metallic punch , and were placed in Petri dishes (4.5 cm diameter) on a gelled mixture of water-agar to 2.5%. Thereafter, 10 parasitoid adults of 48 hours of age were placed on each plate and, then, placed in a climate clamber (25 ± 1 ºC, 70 ± 10%, 14L10D). Each treatment had five replicates. Insect mortality was evaluated 24 hours after exposure to residues. Insecticides Saurus, Turbo, Mimic 200 SC and Azamax; mineral oil Argenfrut; vegetable oil Nortox and acaricides Vertimec 18 EC, Envidor, Sanmite, Torque 500 SC, Cascade 100, Borneo, Dicofol, Micromite 240 SC and Savey WP were classified as short lived, and insecticides Tracer and Dicarzol and acaricide Marshall Star were classified as persistent. Therefore, it is essential to use selective products in integrated pest management to preserve the parasitoid

Parasitismo de Trichogramma pretiosum em ovos da traça-das-crucíferas sob diferentes temperaturas Parasitism of Trichogramma pretiosum on diamondback moth eggs under different temperatures

Estudou-se a capacidade de parasitismo de Trichogramma pretiosum Riley (Hymenoptera: Trichogrammatidae), em ovos de Plutella xylostella (L.)(Leptoptera: Plutellidae) nas temperaturas de 18; 20; 22; 25; 28; 30 e 32ºC, avaliando-se número de ovos parasitados diariamente, porcentagem acumulada de parasitismo, número total de ovos parasitados por fêmea e longevidade de fêmeas. O ritmo de parasitismo durante as primeiras 24 horas, oscilou de 1,6 a 16 ovos parasitados por fêmea de T. pretiosum nas temperaturas entre 18 e 32ºC. O parasitismo acumulado de ovos de P. xylostella, nas temperaturas de 18; 20; 22; 25; 28; 30 e 32ºC, atingiu 80%, aos 2; 16; 11; 3; 5; 4 e 7 dias, por T. pretiosum. As maiores taxas de parasitismo ocorreram nas faixas térmicas de 25; 28 e 30ºC. A longevidade média de fêmeas de T. pretiosum nas faixas térmicas compreendidas entre 18 e 32ºC, variaram de 2,3 a 13,3 dias.<br>The parasitism capacity of Trichogramma pretiosum Riley (Hymenoptera: Trichogrammatidae) on eggs of Plutella xylostella (L.) (Lepidoptera: Plutellidae) was studied, under temperatures of 18; 20; 22; 25; 28; 30 and 32&deg;C aiming to evaluate the number of days with parasitism, cumulated parasitism, total number of eggs parasitized per female and their longevity. Parasitism during the first 24 hours ranged from 1.6 to 16 eggs of P. xylostella per T. pretiosum female in the range of 18 to 32&deg;C. Cumulated egg parasitism of P. xylostella by T. pretiosum reached 80% after 2; 16; 11; 3; 5; 4 and 7 days at 18; 20; 22; 25; 28; 30 and 32&deg;C. Higher parasitism rates were recorded at 25; 28 and 30&deg;C while longevity of T. pretiosum females varied from 2.3 to 13.3 days under temperatures of 18 to 32&deg;C