Exploitation of mitochondrial nad6 as a complementary marker for studying population variability in Lepidoptera

The applicability of mitochondrial nad6 sequences to studies of DNA and population variability in Lepidoptera was tested in four species of economically important moths and one of wild butterflies. The genetic information so obtained was compared to that of cox1 sequences for two species of Lepidoptera. nad6 primers appropriately amplified all the tested DNA targets, the generated data proving to be as informative and suitable in recovering population structures as that of cox1. The proposal is that, to obtain more robust results, this mitochondrial region can be complementarily used with other molecular sequences in studies of low level phylogeny and population genetics in Lepidoptera.

Desenvolvimento ovariano e influência da cópula na maturação dos ovários de Diaphorina citri Kuwayama (Hemiptera: Psyllidae) / Ovarian development and analysis of mating effects on ovary maturation of Diaphorina citri Kuwayama (Hemiptera: Psyllidae)

As many other insects with a restricted diet, the citrus psyllid Diaphorina citri Kuwayama, which vector the causing agent of the Huanglongbing, the bacteria Candidatus Liberibacter spp., is intimately associated with symbiotic microorganisms. These mutualist symbionts play a key role on their host nutritional ecology, and are vertically transmitted to the progeny. However, despite the role symbionts play on host development and reproduction, and the growing opportunities of exploitation of the association insect-symbiont to control insect vectored-pathogens, there are very few studies on the host reproductive biology and on the symbiont transovarial transmission. Therefore, we aimed at analyzing the ovary development during D. citri adulthood, and at verifying for the mating requirement as a trigger to initiate ovary development. Newly-emerged D. citri females were grouped as virgin or mated and ovary development was observed during adulthood. Newly-emerged females have immature ovaries, and ovaries remain without any mature eggs until females mate. Once female mates, the vitellogenesis synthesis and uptake are estimulated, and oocytes are quickly developed. Oocytes maturation in ovarioles is metachronic, with only one oocyte developing at a time in each oogenic cycle. Morphological observations of the reproductive system including the ovaries and spermatheca, after the first cluster of eggs is laid, indicated D. citri is polyandrous, and may require multiple mating to develop additional oogenic maturation cycles.

Efeito da alimentação da fase adulta na reprodução e longevidade de espécies de Noctuidae, Crambidae, Tortricidae e Elachistidae / Effects of adult feeding on the reproduction and longevity of Noctuidae, Crambidae, Tortricidae and Elachistidae species

This research evaluates the effect of the adult diet on the reproduction of Anticarsia gemmatalis Hübner, Heliothis virescens (Fabr.), Spodoptera frugiperda (J. E. Smith) (Noctuidae), Diatraea saccharalis (Fabr.) (Crambidae), Gymnandrosoma aurantianum Lima (Tortricidae) and Stenoma catenifer Walsingham (Elachistidae). Adults of all species were fed either water or a 10 percent honey solution. The egg viability for the 1st and 2nd egg masses, adult fecundity, longevity, number of mating and the ovigeny index (OI) (degree of ovarian maturation) were evaluated. Fecundity of A. gemmatalis and H. virescens was drastically reduced when females were fed only on water. Egg viability from both 1st and 2nd egg masses was variable between treatments. Females of A. gemmatalis, H. virescens and S. frugiperda, and males of some species had a reduced longevity when fed only on water. The number of matings was higher for A. gemmatalis and D. saccharalis when fed on water only. The OI was < 1.0 for all species evaluated indicating that all females may develop new oocytes as they age. Based on the OI and the reduced fecundity of A. gemmatalis and H. virescens, one observes that adult feeding is important for the reproduction of both species, and the IO is not a good parameter to indicate such condition. Spodoptera frugiperda, G. aurantianum, D. saccharalis and S. catenifer do not require any source of carbohydrates as adults to sustain their reproduction.

Influência da temperatura na freqüência de cópula de Anticarsia gemmatalis Hübner e Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) / Temperature effects on the mating frequency of Anticarsia gemmatalis Hüebner and Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae)

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.

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.