Efecto del flufenoxuron sobre la actividad copuladora del macho de spodoptera littoralis (Boisd.) (Lepidoptera: Noctuidae)

Ha sido evaluado el efecto de benzoilfenylureia sobre la capacidad copuladora de machos de Spodoptera littoralis (Boisd.) (Lepdoptera: Noctuidae). Dos grupos de larvas de 3º estadio fueron tratados con el flufenoxuron, uno por ingestión y el otro por contacto, con una concentración del producto igual a la DL60. Cuando hubo la emergencia de los adultos, 10 machos por tratamiento fueron individualizados en cilindros de papel de filtro y puestos a copular con hembras vírgenes, que eron sustituídas diariamente, hasta la muerte de las mismas. Las hembras que fueron ofrecidas a los machos, al morir, eron dissecadas para verificar se estaban o no copuladas, a través de la observación de la presencia de espermatóforos en la bursa copulatrix. Fue observado que los machos de S. littoralis provenientes de larvas tratadas con el flufenoxuron, no tuvieron su capacidad copuladora alterada. La metodología fue considerada adecuada para evaluar la atividad copuladora y el número de copulaciones realizadas por el macho de esta especie.

Feeding non-preference by Spodoptera frugiperda and Spodoptera eridania on tomato genotypes

Larvae of the genus Spodoptera spp. are highly polyphagous and can cause economical losses in several agricultural crops. Given their growing importance in the tomato crop, especially for industry, this work aimed to evaluate the feeding non-preference by larvae of Spodoptera frugiperda (J. E. Smith, 1797) and Spodoptera eridania (Cramer, 1782) on tomato genotypes and classify them by the levels of resistance. The commercial cultivar Santa Clara was set as the susceptible standard and line PI 134417 as the resistant standard to evaluate the lines PI 134418, PI 126931, LA 462 and LA 716. Feeding non-preference tests were performed under non-choice and free-choice conditions to evaluate the genotype attractiveness to larvae at predetermined times after their release, as well as the leaf area consumed. Overall, the genotypes LA 716 and PI 126931 were the least attractive to S. frugiperda, whereas Santa Clara was the most attractive and consumed. For S. eridania, the genotypes PI 126931, LA 462, LA 716 and PI 134418 were the least preferred for feeding, and Santa Clara and PI 134417 were the most attractive and consumed. The genotypes LA 716 and PI 126931 are moderately resistant to S. frugiperda and S. eridania; PI 134418 and LA 462 are moderately resistant to S. eridania; PI 134417 is susceptible to S. frugiperda and S. eridania; and Santa Clara is highly susceptible to both S. frugiperda and S. eridania.

Comportamento de parasitismo de Trichogramma atopovirilia Oatman & Platner e Trichogramma pretiosum Riley (Hymenoptera, Trichogrammatidae) em posturas de Spodoptera frugiperda (J. E. Smith) (Lepidoptera, Noctuidae)

The parasitism behavior of Trichogramma atopovirilia and T. pretiosum in Spodoptera frugiperda eggs was evaluated focusing on the features related to the associative learning (alpha conditioning) and recognition of the egg parasitized by the female after the first oviposition experience. Females of both species were observed to recognize the parasitized egg, which takes place after the female drills into the host egg. Following oviposition, 43.59% and 67.53 of females began to feed with an average feeding time of 73.26 ± 11.57 and 64.04 ± 7.05 seconds for T. atopovirilia and T. pretiosum, respectively. The time elapsed in each step of the parasitism behavior significantly decreased after the first oviposition experience, with a trend to stabilize after the 2nd or 3rd egg parasitized, indicating associative learning in these Trichogramma species.

Disposição espacial e injúrias da lagarta-do-cartucho Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae) em milho

O conhecimento dos padrões de dispersão populacional de Spodoptera frugiperda (J. E. Smith), a mais importante praga do milho, no Brasil, é fundamental para o estabelecimento de técnicas eficientes de monitoramento e manejo. Este trabalho objetivou conhecer a distribuição espacial da praga na cultura. A distribuição espacial foi avaliada em cinco campos experimentais, de um hectare cada, divididos em 100 unidades experimentais, onde se avaliaram de cinco a dez plantas por parcela. Foi testado o ajuste das frequências observadas às esperadas, de acordo com as distribuições de Poisson, Binomial Negativa e Binomial Positiva. Spodoptera frugiperda ocorreu em elevados índices populacionais na área amostral, com correlação significativa entre a nota de injúria 3 e o número de lagartas médias, o que também ocorreu para o número de plantas infestadas com pelo menos uma lagarta média. Não houve correlação significativa entre a nota de injúria 3 e lagartas pequenas. O modelo que melhor se aproximou dos dados de distribuição da oviposição foi a Binomial Positiva, enquanto a disposição espacial de lagartas, atacando a espiga, foi descrita como aleatória. O modelo de distribuição Binomial Positiva foi o que melhor representou a distribuição espacial da população de plantas infestadas; a distribuição das lagartas de tamanho médio teve padrão de distribuição agregada.

Supplementary feeding programs: a critical analysis

A critical analysis of the Supplementary Feeding Programs which have been undertaken around the world is presented. Although only a few programs have been rigorously evaluated it seems that in relation to their main objectives, most of them have not proved to be successful. Some suggestions for improvement are put forward and the particular case of the Brazilian programs is assessed in detail.

Factors associated with infant feeding practices after hospital discharge

OBJECTIVE: To assess factors associated with infant feeding practices on the first day at home after hospital discharge. METHODS: A total of 209 women, who had a child aged four months or less and were living in Itapira, Brazil, were interviewed during the National Immunization Campaign Day in 1999. Statistical analysis was performed using the Chi-square test and a logistic regression model was used for verifying an association between dependent and independent variables. RESULTS: Women aged 25.5 years on average and 18.2% were teenagers. Fifty-three percent of the women delivered vaginally and most vaginal deliveries (78.5%) took place in the public hospital. The prevalence of exclusive breastfeeding on the first day at home was 78.1% and 11.6% of the infants were receiving formula at this time. The only factor associated with EBF on the first day at home was being a teenaged-primiparous mother (OR=9.40; 95% CI: 1.24-71.27). This association remained statistically significant even after controlling for type of delivery and hospital where the birth took place. Feeding formula on the first day at home was only significantly associated with the hospital (i.e., birth at the city hospital was a protective factor (OR=0.33; 95% CI: 0.13-0.86), even after controlling for vaginal delivery. CONCLUSIONS: On the first day at home after hospital discharge, teenaged-primiparous mothers were more likely to exclusive breastfeeding as well as those infants born in the municipal public hospital. Further studies are needed from a multidisciplinary approach.

Determinants of using pacifier and bottle feeding

OBJECTIVE To analyze the factors associated with the use of pacifiers and/or bottle feeding in infants aged under one year.METHODS This is a cross-sectional study with 34,366 children and using data from the database of the 2nd Nationwide Survey of Breastfeeding Prevalence performed in the Brazilian capitals and Federal District in 2008. Cluster sampling was used. The questionnaire included questions about the use of artificial nipples in the last 24 hours. The analysis considered three outcomes: exclusive use of pacifier, exclusive use of bottle feeding, and use of artificial nipples (pacifier and bottle feeding). Prevalence ratios were obtained using Poisson regression with robust variance following a hierarchical model.RESULTS The following factors were associated with exclusive use of the pacifier: mother working outside the home, primiparity, child was not breastfed within the first hour, and child had consumed tea on the first day at home. The following factors were associated with exclusive use of bottle feeding: mother working outside the home, primiparity, low birth weight, child not breastfed within the first hour, and child had consumed milk formula and tea on the first day at home. The following factors were associated with use of artificial nipples (pacifier and bottle feeding): mother working outside the home, primiparity, cesarean delivery, the male gender, low birth weight, born in a hospital not accredited as “baby friendly”, required health baby monitoring in the Primary Health Care Unit (PR = 0.91), and child had consumed milk formula, water, or tea on the first day at home.CONCLUSIONS This study identified profiles of exclusive users of pacifiers, bottle feeding, and both. The provided information can guide preventive practices for child health.

Lethality of triatomines (Hemiptera: Reduviiae), vectors of Chagas' disease, feeding on blood baits containing synthetic insecticides, under laboratory conditions

A laboratory study was conducted to test the toxicity of synthetic insecticides added to defibrinated sheep blood kept at room temperature and offered as food to the following triatomine species: Triatoma infestans, Panstrongylus megistus, Triatoma vitticeps, Triatoma pseudomaculata, Triatoma brasiliensis and Rhodnius prolixus. The insecticides used, at a concentration of 1g/l, were: HCH, DDT, Malathion and Trichlorfon, and the lethalithy observed at the end of a 7-day period varied according to the active principle of each. HCH was the most effective by the oral route, killing 100% of the insects, except P. megistus (95.7%) and T. pseudomaculata (94.1%). Trichlorfon killed the insects at rates ranging from 71.8% (T. vitticeps) to 98% (R. prolixus). Malathion was slightly less efficient, killing the insects at rates from 56.8% (T. vitticeps) to 97% (T.brasiliensis). DDT was the least effective, with a killing rate of 10% (T. vitticeps) to 75% (T.brasiliensis). Since the tests were performed at room temperature, we suggest that baits of this type should be tried for the control of triatomines in the field.

Feeding sources and trypanosome infection index of Rhodnius pallescens in a Chagas disease endemic area of Amador County, Panama

The sylvatic triatomine Rhodnius pallescens is considered to be the most important and widespread vector of Trypanosoma cruzi and Trypanosoma rangeli in Panama. However, its behavior and biological characteristics have only been partially investigated. Thus, to achieve sustainable and efficient control over Chagas disease in Panama, a better understanding of the ecology and biology of R. pallescens is essential. In this study we evaluated R. pallescens host feeding sources using a dot-blot assay, and the trypanosome infection index by PCR analysis in a Chagas disease endemic area of central Panama. It was found that in peridomestic palm trees, 20.3% of the examined bugs had fed on opossums (Didelphis marsupialis). However, we observed an increased anthropophagy (25.4%) for those bugs collected inside houses. Considering the domestic and peridomestic habitats as a whole, the proportion of collected R. pallescens infected with trypanosomes was 87.4%. In the two habitats the predominant infection was with T. cruzi (80-90%). Between 47-51% of the analyzed triatomines were infected with T. rangeli. Mixed infections (40-51%) were also detected. These findings provide a better basis for the implementation of a rational control and surveillance program for Chagas disease in regions where R. pallescens is endemic.

Comparison of feeding and defecation patterns between fifth-instar nymphs of Triatoma patagonica (Del Ponte, 1929) and Triatoma infestans (Klug, 1934) under laboratory conditions

Among the vectors of Chagas disease, Triatoma patagonica is a species in the process of adaptation to the human environment. However, its vector competence is not well known. This study had the aim of evaluating and comparing feeding and defecation patterns among fifth-instar nymphs of Triatoma patagonica and Triatoma infestans that were fed ad libitum. The results showed that nymphs of Triatoma patagonica had a feeding pattern similar to that of Triatoma infestans. Sixty nine percent and 58% of nymphs of Triatoma patagonica and Triatoma infestans, respectively, produced their first defecation within five minutes after being fed. Triatoma patagonica defecated during feeding, with an average time until first defecation that was shorter than that of Triatoma infestans (3.4 and 6.2 min, respectively). The nymphs of Triatoma patagonica were capable of defecating during or immediately after feeding.

Blood feeding patterns of Nyssomyia intermedia and Nyssomyia neivai (Diptera, Psychodidae) in a cutaneous leishmaniasis endemic area of the Ribeira Valley, State of São Paulo, Brazil

Introduction The aim of this study was to identify the blood feeding sources of Nyssomyia intermedia (Ny. intermedia) and Nyssomyia neivai (Ny. neivai), which are Leishmania vectors and the predominant sandfly species in the Ribeira Valley, State of São Paulo, Brazil, an endemic area for cutaneous leishmaniasis. Methods Specimens were captured monthly between February 2001 and December 2003 on a smallholding and a small farm situated in the Serra district in the Iporanga municipality. The blood meals of 988 engorged females were tested using the avidin-biotin immunoenzymatic enzyme-linked immunosorbent assay (ELISA). Seven blood meal sources were investigated: human, dog, chicken, bovine, pig, horse and rat. Results The results showed that among the females that fed on one or more blood sources, the respective percentages for Ny. intermedia and Ny. neivai, respectively, were as follows: human (23% and 36.8%), pig (47.4% and 26.4%), chicken (25.7% and 36.8%) and dog (3.9% and 0%), and the differences in the blood sources between the two species were statistically significant (p = 0.043). Conclusions Both species had predominant reactivity for one or two blood sources, and few showed reactivity indicating three or four sources. Many different combinations were observed among the females that showed reactivity for more than one source, which indicated their opportunistic habits and eclecticism regarding anthropic environmental conditions.

Eclectic feeding behavior of Lutzomyia (Nyssomyia) intermedia (Diptera, Psychodidae, Phlebotominae) in the transmission area of American cutaneous leishmaniasis, state of Paraná, Brazil

Introduction The blood meal source of sandflies provides valuable information about the vector/host interaction and allows for an understanding of American cutaneous leishmaniasis (ACL) transmission mechanisms. The aim of this study was to identify the blood meal sources of Lutzomyia (Nyssomyia) intermedia in an endemic area of leishmaniasis in Brazil's State of Paraná using a precipitin test. Methods Sandflies were collected in the rural locality of Epitácio Pessoa within the City of Adrianópolis, State of Paraná, in southern Brazil. A total of 864 female sandflies were captured, and 862 (99.8%) were identified as L. intermedia species. However, two unidentified specimens were considered to be part of the genus Lutzomyia. Results Among the females examined, 396 specimens presented reactions to a certain type of tested antiserum, and most (67.9%) reacted to the simple type. These sandflies fed mainly on the blood of birds, opossums, and rodents, but specimens that fed on the blood of humans, dogs, horses, cattle, and cats were also found. Among the cross-reactions found (32.1%), bird/rodent, bird/opossum, bird/dog, bird/human, and horse/dog cross-reactions were the most common. Conclusions These results demonstrate a tendency in the eclectic feeding behavior of L. intermedia and support its potential role as a vector for ACL in the study area.

Effect of feeding frequency on the reproductive efficiency of two species of Triatoma with different epidemiological importance

Introduction In Triatominae, reproductive efficiency is an important factor influencing population dynamics, and a useful parameter in measuring a species' epidemiological significance as a vector of Trypanosoma cruzi (Chagas, 1909). The reproductive efficiency of triatomines is affected by food availability; hence, we measured and compared the effects of feeding frequency on the reproductive parameters of Triatoma patagonica (Del Ponte, 1929) and Triatoma infestans (Klug, 1934), and the effects of starvation on T. patagonica. Methods Couples from both species were fed weekly, or every 3 weeks; in addition, females in couples of T. patagonica were not fed. Each couple was observed weekly and reproductive efficiency was assessed on the following parameters: fecundity (eggs/female), fertility (eggs hatched/eggs laid), initiation and end of oviposition, initiation of mating, number of matings/week, and number of reproductive weeks. Relative meal size index (RMS), blood consumption index (CI), and E values (eggs/mg blood) were also calculated. Results Changes in feeding frequency affected the reproductive parameters of T. patagonica only, with a decrease in fecundity and number of reproductive weeks for those fed every 3 weeks, or not fed. The reproductive period, RMS index, and CI were lower for T. patagonica than T. infestans. However, despite the lower fecundity of T. patagonica, this species required less blood to produce eggs, with an E values of 2 compared to 2.94 for T. infestans. Conclusions Our results suggest that the differences in fecundity observed between species reflect the availability of food in their natural ecotopes.

Habitat preferences, diet, feeding strategy and social organization of the black spider monkey [Ateles paniscus paniscus Linnaeus 1758] in Surinam

A Socioecological Field Study.This monograph reports on a 26 month socioecological study of black spider monkeys (Ateles paniscus paniscus)in the Raleigh-vallen — Voltzberg Nature Reserve, Surinam. It recognizes the fundamental importance of food to the behavior and the regulation of population density fox this primate. It clarifies the complex temporal and spatial effects of tropical rain forest food sources on the behavior of a group of spider monkeys, concentrating on food category, food plant identity and phenology, and quantity, density and dispersion of the most important food sources. In addition, the present study describes habitat choice, optimal feeding strategy and sexual behavior of the spider monkey, and discusses implications of diet for social behavior. This study is also fundamental to conservation. Specialized in eating mature fruits, the spider monkey is a very important dispersal agent for many trees and lianes, particularly canopy species. However, the spider monkey is probably the most vulnerable monkey species in Surinam and it is disappearing rapidly throughout the remainder of its range. Unfortunately, it is large and noisy and can be easily tracked and hunted. It is largely restricted to undisturbed high forest, and consequently habitat destruction has more effect on it than on most other species. Together with its slow reproductive rate (a female gives birth only once every four or five years), this means that the species is poorly adapted to recover from exploitation. In order to implement proper measures for conservation, data on forest type preferences, diet and social behavior of the species, or on closely related species, in undisturbed areas, such as the one described in this monograph, are essential tools for assessing the potential of proposed protected areas.