Thermal Constant of an Experimental Population of Muscina stabulans (Fallén 1817) (Diptera:Muscidae) in the Laboratory

A study was conducted to investigate the thermal constant in an experimental population of Muscina stabulans (Fallén 1817). A natural population was obtained from a livestock and their F1 generations were maintained at four constant temperatures (16°C, 20°C, 26°C and 31°C). The thermal constant was calculated by the hyperbole method using the base temperature, tb = 4.4°C and the thermal constant K = 35.3 GD. Ricker's geometric regression, considering tb = 7.8°C and K = 28.9 GD was also calculated.

Thermal Constant of an Experimental Population of Muscina stabulans (Fallén 1817) (Diptera:Muscidae) in the Laboratory

A study was conducted to investigate the thermal constant in an experimental population of Muscina stabulans (Fallén 1817). A natural population was obtained from a livestock and their F1 generations were maintained at four constant temperatures (16°C, 20°C, 26°C and 31°C). The thermal constant was calculated by the hyperbole method using the base temperature, tb = 4.4°C and the thermal constant K = 35.3 GD. Ricker's geometric regression, considering tb = 7.8°C and K = 28.9 GD was also calculated.

Biological characteristics and thermal requirements of a Brazilian strain of the parasitoid Trichogramma pretiosum reared on eggs of Pseudoplusia includens and Anticarsia gemmatalis

A new strain of the parasitoid Trichogramma pretiosum, was collected in Rio Verde County, State of Goias, Central Brazil, and designated as T. pretiosum RV. This strain was then found to be the most effective one among several different strains of T. pretiosum tested in a parasitoid selection assay. Therefore, its biological characteristics and thermal requirements were studied, aiming at allowing its multiplication under controlled environmental conditions in the laboratory. The parasitoid was reared on eggs of Pseudoplusia includens and Anticarsia gemmatalis at different constant temperatures within an 18-32 degrees C temperature range. The number of annual generations of the parasitoid was also estimated at those temperatures. Results have shown that T. pretiosum RV developmental time, from egg to adult, was influenced by all temperatures tested within the range, varying from 6.8 to 20.3 days and 6.0 to 17.0 days on eggs of P. includens and A. gemmatalis, respectively. The emergence of T. pretiosum RV from eggs of A. gemmatalis was higher than 94% at all temperatures tested. When this variable was evaluated on eggs of P. includens, however, the figures were higher than that within the 18-30 degrees C range (more than 98%), and were also statistically higher than the emergence observed at 32 degrees C (90.2%). The sex ratio of the parasitoids emerged from eggs of A. gemmatalis decreased from 0.55 to 0.29 at 18-32 degrees C, respectively. However, for those emerged from eggs of P. includens, the sex ratio was similar (0.73, 0.72 and 0.71) at 20, 28 and 32 degrees C, respectively. The lower temperature threshold (Tb) and thermal constant (K) were 10.65 degrees C and 151.25 degree-days when the parasitoid was reared on eggs of P. includens; and 11.64 degrees C and 127.60 degree-days when reared on eggs of A. gemmatalis. The number of generations per month increased from 1.45 to 4.23 and from 1.49 to 4.79 when the parasitoid was reared on eggs of P. includens and A. gemmatalis, respectively, following the increases in the temperature. (C) 2009 Elsevier Inc. All rights reserved.

Biology and thermal requirements of Telenomus remus reared on fall armyworm Spodoptera frugiperda eggs

Este trabalho teve como objetivo estudar a biologia de Telenomus remus Nixon criado em ovos de Spodoptera frugiperda (J.E. Smith) em diferentes temperaturas. Com base no desenvolvimento do ciclo (ovo-adulto), foram determinados as exigências térmicas e o número de gerações dos parasitóides em temperaturas constantes. Inicialmente, ovos de S. frugiperda, com 24 horas de idade, foram submetidos ao parasitismo por T. remus, durante cinco horas, sendo então transferidos para câmaras climatizadas reguladas para as temperaturas de 15, 20, 25, 28, 31 e 35°C. A duração do ciclo (ovo-adulto) foi influenciada pela temperatura variando de 8,3±0,01 a 47,2±0,01 dias para fêmeas e 8,1±0,01 a 46,8±0,01 dias para machos de T. remus nas temperaturas de 31 e 15°C, respectivamente. A porcentagem de emergência (viabilidade) de T. remus em ovos de S. frugiperda também foi influenciada pela variação da temperatura, apresentando redução significativa apenas nas temperaturas extremas. Foi observada redução na viabilidade a 15°C e não houve desenvolvimento biológico do parasitóide a 35°C. A razão sexual de T. remus não sofreu influência da temperatura. em relação às exigências térmicas, a constante térmica (K) e temperatura base (Tb) foram maiores para as fêmeas de T. remus (158,88 graus dias e 12,52°C) quando comparadas aos machos (154,12 graus dias e 12,59°C). A estimativa do número de gerações anuais para T. remus para machos e fêmeas em condições de laboratório foi respectivamente 5,6 e 5,6; 16,9 e 17,3; 28,3 e 29,0; 35,1 e 36,0; 39,6 e 40,7 nas temperaturas de 15, 20, 25, 28 e 31°C.

The biology and thermal requirements of the fennel aphid Hyadaphis foeniculi (Passerini) (Hemiptera: Aphididae)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Biological Characteristics and Thermal Requirements of the Biological Control Agent Telenomus remus (Hymenoptera: Platygastridae) Reared on Eggs of Different Species of the Genus Spodoptera (Lepidoptera: Noctuidae)

The biological characteristics of Telenomus remus Nixon, 1937 (Hymenoptera: Platygastridae) on eggs of Spodoptera albula (Walker, 1857); S. cosmioides Walker 1858, S. eridania (Cramer, 1782); and S. frugiperda (Smith, 1797) (Lepidoptera: Noctuidae) were evaluated under different temperatures (19, 22, 25, 28, 31, and 34 degrees C +/- 1 degrees C). The duration of the T remus egg-to-adult period on eggs of all four Spodoptera species and the longevity of adults of T. remus were both inversely proportional to the increase in temperature. Parasitoid emergence was higher than 80% at temperatures from 19 to 28 degrees C when the parasitoid was reared on eggs of S. eridania and S. frugiperda. Differently, when the parasitoid was reared on eggs of S. albula and S. cosmioides, T. remus emergence at rates of 80% or higher just occurred from 22 to 25 degrees C and at 22 degrees C, respectively. At 34 degrees C, this parameter was lower than 30% for T reams reared in all hosts. The sex ratio was 64-86% females, except for T. remus in S. cosmioides eggs at 34 C, in which temperature it was 39%. The estimated thermal requirements of T. remus, for the thermal constant (K) and the base temperature (T(base)), were: 125.39 DD and 15.139 degrees C; 125.56 DD and 14.912 degrees C; 142.98 DD and 14.197 degrees C; and 149.16 DD and 13.846 degrees C, for S. cosmioides, S. frugiperda, S. albula, and S. eridania, respectively. In general, T. remus showed good parasitism potential on all the hosts, although eggs of S. frugiperda, S. eridania, and S. albula proved to be the most suitable for mass rearing of T reams in the laboratory. Eggs of S. cosmioides are less suitable because of the lower parasitoid emergence observed at most of the temperatures with exception of 22 degrees C.

Biologia e exigências térmicas de cinco linhagens de Trichogramma pretiosum Riley (Hymenoptera: Trichogrammatidae) criadas em ovos de Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae)

Artigos científicos defesa fitossanitária.

Exigências térmicas de Culex quinquefasciatus (Diptera, Culicidae) em Pelotas, Rio Grande do Sul, Brasil

The thermal requeriments of Culex quinquefasciatus (Say, 1823) and the number of generations in the year are determined. The colony to obtain eggs, larvae, pupae and adults was established under laboratory conditions. Every stage was maintained at constant temperature (15, 20, 25 and 30ºC), in cameras, with relative humidity of 80% ± 5 and photophase of 12 hours, to settle down the thermal inferior limit and the thermal constant by the method of the hiperbole. The thermal inferior limit to phase of egg, larvae and pupa were respectively 10.0, 9.1 and 10.2ºC, and 10.2ºC to all the aquatic cycle, with a thermal constant of 207.2 degree-day, with the mean of 15.5 generations per year in Pelotas, State of Rio Grande do Sul.

Exigências térmicas para o desenvolvimento de Palmistichus elaeisis (Hymenoptera, Eulophidae) em pupas de cinco espécies de lepidópteros

The thermal requirements of Palmistichus elaeisis Delvare & LaSalle, 1993 were determined by rearing this pupal parasitoid in the following lepidopteran hosts: Diatraea saccharalis (Fabricius, 1794) (Crambidae), Anticarsia gemmatalis (Hübner, 1818), Heliothis virescens (Fabricius, 1777), Spodoptera frugiperda (J.E. Smith, 1797) (Noctuidae) and Thyrinteina arnobia (Stoll, 1782) (Geometridae). The experiment was set in laboratory conditions (temperatures between 18ºC and 30ºC, RH=70 ± 10% and 14-hour photoperiod). The life cycle (egg-adult) ranged from 40.4 ± 0.63 days (18ºC, H. virescens) to 18.1 ± 0.13 days (28ºC, D. saccharalis). The thermal constant of the egg-adult period ranged from 353.1 (D. saccharalis) to 407.7 degree-days (S. frugiperda). The lowest thermal threshold ranged from 5.0ºC (A. gemmatalis) to 7.5ºC (D. saccharalis). At 30ºC, all prepupae died. These results suggest that P. elaeisis can be reared in laboratory on all the hosts tested.

Occurrences of flesh flies (Diptera: Sarcophagidae) on human cadavers in Switzerland, and their importance as forensic indicators.

From 1993 to 2008, criminal investigations were conducted in the western part of Switzerland with special attention to blowfly and flesh fly species in order to estimate the post-mortem interval when requested by the police authorities. Flesh flies were found in only 33 cases out of 160. Five species of the genus Sarcophaga were identified (S. africa, S. argyrostoma, S. caerulescens, S. similis and S. sp.). The main species found on corpses (larval stage) was S. argyrostoma. The thermal constant (K) calculated for this species in Switzerland is 380.6 ± 16.3 (mean ± S.D.) degree-days. With the exception of S. caerulescens, found three times in the larval stage on corpses, the three other species are of minor forensic importance. S. argyrostoma is found during summer and indoors. This species colonises dead bodies, usually the same day as blowfly species, and it could be used to estimate the post-mortem interval. Other species are discussed in the light of current knowledge on their biology and ecology. It is recommended that voucher material be deposited in a museum, allowing further studies by relevant specialists, thereby helping investigators and avoiding misidentifications.

Exigências térmicas de Aedes (Stegomyia) albopictus Skuse, 1894 (Diptera, Culicidae) em condições de laboratório

Thermal requirements of Aedes (Stegomyia) albopictus Skuse, 1894 (Diptera, Culicidae) under laboratory conditions. Allochtonous species of Ae. albopictus in the American continent can be found in fourteen Brazilian states - about fifteen years had been elapsed since the first report of the presence of this species in Brazilian territory. Considering its potential epidemiological importance and its adaptation to several habitats, it was determined, for this species, the threshold temperature and the thermal constant for egg, larval and pupal stages under laboratory conditions under four constant temperatures and 12:12 hours light-dark photoperiod. The threshold temperature for the egg phase and for the first instar were quite similar: 9.07 ºC (K=214.46 degree days) and 9.23 ºC (K= 36.64 degree days), respectively. For 2nd, 3rd and 4th instar, the basal-temperature was higher, oscilating between 12.26 ºC and 13.95 ºC. The threshold temperature for the complete larval stage and for the pupal stage were 12.03 ºC (K= 99.48 degree days) and 11.87 ºC (K=32.40 degree days) for males and 11.95 ºC (K=110.11 degree days) and 11.60 ºC (K=35.30 degree days) for females, respectively.

Biological characteristics and parasitism capacity of Trichogramma pretiosum Riley (Hymenoptera, Trichogrammatidae) on eggs of Spodoptera frugiperda (J. E. Smith) (Lepidoptera, Noctuidae)

This study aimed at evaluating the biological characteristics and the capacity of parasitism of a Trichogramma pretiosum Riley, 1869 (Hymenoptera, Trichogrammatidae) strain (T. pretiosum RV) collected in Rio Verde County, State of Goiás, Brazil. The study was carried out on eggs of Spodoptera frugiperda (J. E. Smith, 1797) (Lepidoptera, Noctuidae) and conducted under controlled environmental conditions at different constant temperatures. The biological parameters determined were: developmental time (egg-adult; days); emergence (%); sex ratio; number of progeny/egg; number of generation/year; thermal constant (K); temperature threshold (Tb); daily number of parasitized eggs; cumulative parasitism (%); total number of eggs parasitized by T. pretiosum; and female longevity. To study the T. pretiosum parasitism capacity, 20 S. frugiperda eggs (< 24 h old) were placed into 8.0 cm x 2.0 cm glass vials containing one female (< 24 h old) each. Trials were carried out in a completely randomized experimental design, with 20 replications at each temperature. The environmental chambers (BOD type) were set at 18ºC, 20ºC, 22ºC, 25ºC, 28ºC and 32ºC ± 1ºC, 70 ±10% relative humidity, and 14/10 h (L:D) photoperiod. The eggs of S. frugiperda were replaced daily until parasitoid death. Results have shown an inverse correlation between developmental time and temperature, with statistically significant differences among means, except at 25ºC and 28ºC (10 days). Parasitoid emergence (%) was also influenced by temperature. The lowest percent emergence was observed at 32ºC, and the highest ones at 18ºC and 20ºC temperatures. The temperature did not affect T. pretiosum sex ratio and number of parasitoids per egg, thus allowing changes in the temperature to control insect mass production in the laboratory to meet the needs for field releases.

Effects of different temperatures on the life history of Evania appendigaster L. (Hymenoptera: Evaniidae), a solitary oothecal parasitoid of Periplaneta americana L. (Dictyoptera: Blattidae)

The influence of temperatures on the life parameters of the solitary oothecal parasitoid Evania appendigaster, was investigated in the laboratory. Parasitized oothecae of Periplaneta americana were left to develop under seven constant temperatures: 15, 17, 20, 25, 30, 35, and 40 degrees C. At the end, we found that: (i) E. appendigaster was able to complete development within the temperature range of 17-34 degrees C; (ii) mean adult longevity decreased as temperature increased, with the temperature of 40 degrees C being fatal in a matter of hours; (iii) males lived longer than females between 15 and 30 degrees C; (iv) adult emergence rate was the highest at 25 degrees C, and (v) no wasps emerged at 15 or 40 degrees C. Non-emerged oothecae contained either unhatched eggs or dead larvae. We determined the theoretical lower developmental threshold and thermal constant for the complete development as 12.9 degrees C and 584.8 day-degrees for males, and 13.1 degrees C and 588.2 day-degrees for females, respectively. A good balance between faster development, maximum adult longevity and good egg viability was obtained between 25-30 degrees C, and that would be the best temperature range for rearing E. appendigaster. (C) 2009 Elsevier B.V. All rights reserved.

Desenvolvimento de Oligonychus ilicis em Coffea canephora sob diferentes temperaturas

Oligonychus ilicis (McGregor) (Acari) (Tetranychidae) é uma das principais pragas de Coffea canephora Pierre & Froehner. Neste trabalho, avaliou-se o efeito de diferentes temperaturas no desenvolvimento desse ácaro-vermelho em folhas de C. canephora, em laboratório. Confinaram-se 80 fêmeas em 40 arenas, constituídas de disco foliar de 4 cm, para oviposição nas temperaturas de 21, 24, 27, 30 e 33 ºC. Foram selecionados ao acaso pelo menos dois ovos para avaliar o desenvolvimento embrionário. Após a eclosão da larva, foram realizadas avaliações a cada 12 horas para obtenção da duração e sobrevivência larval. Para avaliar a longevidade foi transferido um ácaro macho da criação para as arenas com uma fêmea para acasalamento. O limite térmico de desenvolvimento inferior e a constante térmica foram determinados para a duração do desenvolvimento de ovo a adulto. O tempo de desenvolvimento das fases imaturas diminuiu com o aumento da temperatura. As fases de ovo, larva, protocrisálida, protoninfa, deutocrisálida, deutoninfa e teleiocrisálida variaram, respectivamente, de 10,4 a 4,3; 2,4 a 1,2; 2,0 a 1,0; 2,3 a 1,2; 1,9 a 1,0; 3,0 a 1,5 e 2,3 a 1,0 dias. O aumento da temperatura afetou o período de desenvolvimento, reduzindo a duração de ovo-adulto e a longevidade. O limite térmico inferior foi de 9,0 ºC para o período de ovo-adulto e constante térmica de 256,4 graus-dias. em condições de laboratório, a faixa de temperatura que favorece o desenvolvimento do ácaro em C. canephora foi de 24 a 30 ºC. O limite térmico inferior não é limitante para ocorrência de O. ilicis em áreas cultivadas com C. canephora no estado do Espírito Santo.

Exigências térmicas e tabelas de vida de fertilidade de Myzus persicae (Sulzer) (Hemiptera: Aphididae) em laboratório

Este estudo visou determinar as exigências térmicas do pulgão Myzus persicae (Sulzer), calcular tabelas de vida de fertilidade, e prever a ocorrência de adultos no campo, por meio de modelo de graus-dia. Os pulgões foram mantidos individualmente em gaiolas fixadas em folhas de couve, Brassica oleracea L. var. acephala DC, em laboratório, às temperaturas de 15, 20, 23, 25 e 30ºC. O limite térmico inferior de desenvolvimento (Tb) e a constante térmica (K) foram 2,2ºC e 165,6 graus-dia, respectivamente. O modelo de graus-dia previu a ocorrência de adultos de M. persicae para 0 a1 dia antes da data em que eles foram observados no campo. Os parâmetros das tabelas de vida estimados na escala de tempo em graus-dia evidenciaram que as temperaturas de 23°C e 25°C foram as que proporcionaram as melhores condições térmicas para o crescimento populacional de M. persicae. Nessas temperaturas observou-se o maior valor da capacidade inata de aumentar em número (r m = 0,012), o menor valor da duração média da geração (T = 303,8 graus-dia e 272 graus-dia, respectivamente) e o menor tempo necessário para a população duplicar em número de indivíduos (TD = 57,8 graus-dia).