Resumo em Inglês:

Reproduction of most insects depend on nutrients accumulated during the larval stage, but many lepidopteran species will also depend on nutrients obtained at the adult stage. Feeding at the adult stage allows the intake of carbohydrate and amino acid rich solutions, which may have an effect on the species reproduction and population growth. The objectives of the current study were to characterize the effects of sugar consumption by adults of the potato tuber moth, Phthorimaea operculella (Zeller), on its reproduction. To initially test the food intake by adults, a 10% honey solution or water (control), both containing a liquid dye were offered to adult insects 24h after emergence, and the presence of the dye was observed by analysis of their digestive system. The effects of adult feeding on a 10% honey solution on the reproductive performance of P. operculella were evaluated by assessing the oviposition rate, fecundity and fertility. Adult feeding was proved by the presence of the dye within the digestive system of adults of P. operculella. Although the oviposition rate and fertility were not affected by adult feeding, female fecundity was higher in honey-fed females as compared to the water-fed females.

Resumo em Inglês:

The mite Tetranychus mexicanus (McGregor) is considered a pest of a variety of plant species in the Americas. Although this mite apparently causes economic damage to Annonaceae, little is known about its biology. Here we studied the biology of T. mexicanus on soursop (Annona muricata), sweetsop (Annona squamosa) and araticum (Annona coriaceae). The first two species are the most important economical Annonaceae species in northeast Brazil; araticum is commonly found in the region, but not commercially explored. The mites were collected in the field from leaves of A. muricata and maintained in the laboratory for six months on detached leaves of A. muricata, A. squamosa and A. coriaceae, respectively, before observations started. Tetranychus mexicanus developed more slowly on A. squamosa than on the two other hosts, but oviposition was considerably lower on A. coriaceae. As indicated by the calculated life table parameters, biotic potential was higher on A. muricata than on the other hosts. Despite the observed differences in the T. mexicanus biology on the different evaluated hosts, development and reproduction were satisfactory in all of the hosts used.

Resumo em Inglês:

Crocidosema aporema (Walsingham) is a major pest of legumes in the southern cone of Latin America. The mating behaviour of two allopatric populations (Uruguay and Brazil) of C. aporema kept in captivity was studied by observing the posture of calling females, the temporal pattern of pheromone emission and mating, and the response of males to calling females in olfactometer tests. Female calling and mating was observed during the scotophase, from the first to the seventh night after adult emergence. Male response was evaluated at night using a single calling female in a Y-shaped olfactometer. Females adopted a characteristic calling posture, extruding the pheromone gland from the tip of the abdomen. Most females started calling during the second scotophase, and all females called from the third, between the fifth and seventh hours after the onset of the scotophase. Most of the couples mated once throughout the experiment, between the third and sixth night and during the middle of the dark phase. Males preferentially chose the female arm in olfactometer tests, considering both the first arm chosen and the number of visits during the observation period. Our results describe for the fi rst time the temporal pattern associated to the reproductive behaviour of C. aporema. We also provide evidence that this tortricid is monoandrous, and that pheromones are used in intersexual communication for mate finding. Our data will be used to optimize the collection of female sex pheromones for chemical characterization in order to develop a monitoring tool for this pest.

Resumo em Inglês:

The oriental fruit moth, Grapholita molesta (Busck), stands out as one of the most important pest in Rosaceae orchards in Brazil. During feeding, caterpillars bore into shoots, branches and fruits, impairing the commercial production. This work aimed to study the effect of endogenous factors in the chemical perception and in the species chemotactic behavior, seeking to optimize monitoring and the behavioral control of this pest. We evaluated male electroantennographical (EAG) and chemotactical (olfactometry) responses to the synthetic sex pheromone in different ages, virgins or mated and fed or unfed. The EAG responses of males did not differ for all evaluated factors. Nevertheless, the chemotactical behavior of males seems to decrease with age, not varying as a function of mating or feeding conditions. The knowledge about the interference of these factors in G. molesta may help with the interpretation of field results, allowing the development of suitable and reliable control measures based on infochemicals for behavioral control.

Resumo em Inglês:

The two spotted spider mite, Tetranychus urticae Koch, is a nontarget herbivore of Bt-cotton, but acquires and accumulates higher levels of Cry toxin than that expressed by transgenic plants. This work investigated the development and reproduction of T. urticae and of the predator Phytoseiulus macropilis Banks, during three successive generations looking for potential nontarget effect. In addition, behavioral studies on feeding preference, oviposition, and predation were carried out on Bt and non-Bt cottons. The development and reproduction of T. urticae and P. macropilis was conducted using leaf discs of Bt and non-Bt cottons. Arena containing leaf discs from both cotton types connected by a slide coverslip were also used in the behavioral studies. Averages of the three generations showed that the Bt-cotton does not affect the development, survival of immature stages, and reproductive output of T. urticae and of the predator P. macropilis. Furthermore, the preference for feeding and oviposition of T. urticae and P. macropilis were similar on both cotton types. In addition, P. macropilis exhibited similar predatory behavior on T. urticae fed on both cotton types. Levels of Cry1Ac toxin in T. urticae was 3.97 times greater than that found in the Bt-cotton plants as determined using a ELISA test. Despite of the amount of toxin acquired by the prey (T. urticae), no detectable levels of Cry1Ac were found in the predatory mite P. macropilis.

Resumo em Inglês:

The distribution of muscid species (Diptera) in grasslands fragments of southern Brazil was assessed using null models according to three assembly rules: (a) negatively-associated distributions; (b) guild proportionality; and (c) constant body-size ratios. We built presence/absence matrices and calculated the C-score index to test negatively-associated distributions and guild proportionality based on the following algorithms: total number of fixed lines (F L), total number of fi xed columns (F C), and the effect of the average size of the populations along lines (W) for 5000 randomizations. We used null models to generate random communities that were not structured by competition and evaluated the patterns generated using three models: general, trophic guilds, and taxonomic guilds. All three assembly rules were tested in each model. The null hypothesis was corroborated in all F L X F C co-occurrence analyses. In addition, 11 analyses of the models using the W algorithm showed the same pattern observed previously. Three analyses using the W algorithm indicated that species co-occurred more frequently than expected by chance. According to analyses of co-occurrence and guild proportionality, the coexistence of muscid species is not regulated by constant body size ratios. In fl ies of the grasslands, no rule was identified. Yet, a consensus did emerge from our analyses: species co-occur more frequently than expected by chance, indicating that aggregation is a recurring phenomenon among flies with saprophagous adults and predatory larvae. Therefore, competition does not seem to play an important role in the determination of muscid assemblages in the grasslands in Southern Brazil.

Resumo em Inglês:

Studies show that Apiaceae may provide concentrated vital resources for predator insects, stimulating their abundance, diversity and persistence in agricultural systems, thereby increasing their efficiency as biological control agents. Among the predatory insects, Coccinellidae (Coleoptera) on many different species both as larvae and adults, complementing their diet with pollen and/or nectar. This study aimed to determine the diversity and relative abundance of Coccinellidae species visiting plants of Anethum graveolens (dill), Coriandrum sativum (coriander) and Foeniculum vulgare (sweet fennel) (all Apiaceae), particularly in their blooming seasons, and to evaluate the potential of these aromatic species for providing the resources for survivorship and reproduction of coccinelids. Coccinellids were collected by removal of samplings from September to October, 2007. Besides one unidentified species of Chilocorinae, five species of Coccinellinae were collected: Coleomegilla maculata DeGeer, Coleomegilla quadrifasciata (Schönherr), Cycloneda sanguinea (L.), Eriopis connexa (Germar) and Hippodamia convergens Guérin-Meneville. Dill provided a significant increase in the abundance of coccinellids as compared to coriander and sweet fennel. These aromatic species were used by coccinellids as survival and reproduction sites, providing food resources (pollen and/or prey), shelter for larvae, pupae and adults, and mating and oviposition sites as well.

Resumo em Inglês:

Several annual and perennial crops are severely attacked by mites from the family Eriophyidae, Tenuipalpidae and Tetranychidae. A suitable alternative commonly used in several countries for the control of these pest mites involve the use of predatory mites in the family Phytoseiidae. The phytoseiid fauna in the Brazilian natural vegetation is very rich, but nothing is known about the biology of most of these species, as it is the case with Proprioseiopsis cannaensis (Muma). The objective of this study was to determine biological parameters of P. cannaensis fed on pest mite species such as Phyllocoptruta oleivora (Ashmead) (Eriophyidae), Brevipalpus phoenicis (Geijskes) (Tenuipalpidae) and Tetranychus urticae Koch (Tetranychidae). To enable a comparison for different food sources, one of the treatments consisted of pollen from Typha angustifolia L. The study was conducted in the laboratory at 25 ± 1ºC, 80 ± 10% RH and Photophase of 12h. Proprioseiopsis cannaensis did not complete the development when it was fed on P. oleivora. Its fecundity was very low with all other food sources (maximum of 3.3 eggs/female with pollen of T. angustifolia). The values of r m for P. cannaensis were -0.05, -0.09 and 0.002 when fed on B. phoenicis, T. urticae and pollen respectively. The unsatisfactory results from the four types of food sources do not permit us to conclude that P. cannaensis utilizes mites from the family Eriophyidae, Tenuipalpidae, Tetranychidae or pollen from different plant species as principal sources of food in nature.

Resumo em Inglês:

Many studies over the past twenty years have documented the richness of arthropod galling species around the world, and some have proposed hypotheses to explain local and global patterns of galling species richness. However, few studies have been directed toward understanding how the gall-inducing species are locally distributed. The aim of this study was to determine the distribution of gall-inducing arthropods species at Coiba National Park, a tropical habitat on the Pacific coast of Panama. Our results suggest that more gall-inducing species had an aggregated distribution, and gall-inducing arthropod diversity shows a strong beta diversity component. Geographic distance was not correlated with similarity in gall-inducing species composition between the studied sites. This fact has important implications when trying to estimate gall-inducing arthropod richness and general patterns, and could cause contradictory results for hypotheses that attempt to explain the local and global patterns of galling species richness.

Resumo em Inglês:

The genetic structure of five Periplaneta americana (L.) populations from three cities (Cali, Popayán and Buenaventura) located in southwestern Colombia was estimated using the AFLP molecular marker technique. A set of 174 loci were analyzed, 120 of which were polymorphic. Genetic diversity was estimated at different geographic levels for the total population and between cities. Genetic diversity averaged 0.32. The largest gene flow was detected between two population from Cali (F ST = 0.088; Nm = 2.6) and the lowest from the third population in this city (Univalle) and Popayán and Buenaventura (F ST = 0.13; Nm = 1.6 and F ST = 0.12; Nm = 1.8, respectively). The individuals' low mobility, the population' geographic separation, and possibly genetic drift have resulted in the population of this cockroach species having a significant degree of structuring, both between cities (Φst = 0.13; P < 0.001) and within them (Φst = 0.87; P < 0.001). These results suggest a high degree of subdivision within the P. americana population studied.

Resumo em Inglês:

The nesting behavior of Centris (Hemisiella) vittata Lepeletier was studied in the Urbano Santos Cerrado in the northeast of Maranhão State, Brazil. To date, this species has only been studied in trap-nests. The nesting behavior of this species in a natural condition is recorded for the first time. Nesting occurred in preexisting holes in dead trunks of aroeira, Astronium myracrodruon (Anacardiaceae), at the end of the rainy season. The cells were constructed with a mixture of sand and oil. After finishing the nests, females used only oil to line the entrance wall. Two females collected sand at the same time to build their nests, and another one was seen collecting resources at Byrsonima sp. (Malpighiaceae). The pollen load of one bee was analyzed and was found to contain mainly Hymenaea courbaril (Leg-Caesalpiniaceae). Development from egg to adult took about 60 days. Protandry was observed, being males smaller than females. The nests were parasitized by Coleoptera and Diptera. However, the females only showed aggressive behavior against females of the same species or genus.

Resumo em Inglês:

The adult female of Neohydatothrips denigratus (De Santis) is redescribed, the male and immature stages (larva, prepupa and pupa) are described for the first time, and aspects of the biology of this species are made known. Descriptions of the different stages of development were made from laboratory-reared specimens on using twigs of Phaseolus vulgaris as a feeding and oviposition substrate. Neohydatothrips denigratus undergoes its life cycle on the leaves of P. vulgaris, no immature stages were found in flowers or fruits. Under controlled conditions (21 ± 2ºC; 80 ± 4% RH; photophase: 12h), this species needed 21.6 ± 1.60 d to complete development (egg: 7.0 ± 1.00 larva I: 3.7 ± 1.40; larva II: 4.2 ± 1.10; prepupa: 1.8 ± 0.70, pupa: 5 ± 1). Longevity was 6.0 ± 2.00 days and observed sex ratio was 2:1. From the sixteen plants belonging to ten families recorded as hosts to this species, larvae were found only on two species of Fabaceae and one of Solanaceae.

Resumo em Inglês:

Five Coccus on Coffea arabica from the states of Bahia, Espírito Santo and Minas Gerais were studied. Females were prepared and mounted in Canada balsam. Coccus brasiliensis Fonseca and Coccus lizeri (Fonseca) were redescribed and Coccus alpinus De Lotto, Coccus celatus De Lotto and Coccus viridis (Green) were characterized. A key to species and illustration of all of them are included. Coccus alpinus and C. celatus are new records for Brazil and the Neotropical Region.

Resumo em Inglês:

Immature stages of Memphis moruus stheno (Prittwittz) were subject of a behavior, biological and morphological study. The morphological study was carried out through observation by stereoscopic microscopy with camera lucida and micrometric lens attached for illustrations and measurements, respectively; and scanning electron microscopy for ultrastructural analysis. Behavioral data were obtained through direct observation in the field and laboratory. Eggs were laid on the underside of leaves of two Lauraceae species. The first to third instars build frass chains, the fourth and the fifth instars build a conical shelter using a single leaf of the host plant. Before pupation, larvae bend its body ventrally and the pupae are incapable of movement. Descriptions, illustrations and photographs of egg, all five instars and pupa are given. The cephalic morphology and chaetotaxy of first instar were described and illustrated. Results are compared with other Charaxinae immature stages.

Resumo em Inglês:

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.

Resumo em Inglês:

Spodoptera frugiperda (J E Smith) is an important pest of several crops, but especially on maize in Brazil. The implementation of biological control measures hinges on the identification of its predators and other natural enemies. As a means of identifying predators, antibodies against S. frugiperda eggs were generated by inoculating rabbits with macerated S. frugiperda eggs, and the production of antibodies against S. frugiperda egg proteins was verifi ed by double immunodiffusion (DID). These antibodies were then utilized in another serological technique, counterimmunoeletrophoresis (CIE), to identify insects that could have ingested S. frugiperda eggs. Macerates of entire insects collected in maize plantations and of individual parts of their digestive tract, including the crop, were the source of antigens in the CIE, while predators fed S. frugiperda eggs in the laboratory served as the control. Antibodies produced by the inoculated rabbits were effective in detecting S. frugiperda egg proteins, especially if crop macerates were used as antigens. Among the species of insects collected from maize plantations, Lagria villosa Fabricius (Coleoptera: Lagriidae) and a species of Lygaeidae (Hemiptera) were identified as possible S. frugiperda predators.

Resumo em Inglês:

From September 2001 through September 2002, house fly and stable fly pupae were collected weekly from three fly habitats at the University of Florida Research dairy in northcentral Florida and evaluated for parasitism. Varying parasitism percentages were observed throughout the study but they were not affected by temperature, precipitation or fly abundance. Of the 6,222 house fly pupae and 1,660 stable fly pupae that produced either a host fly or a parasitoid, 26.9% and 26.7% were parasitized, respectively. Ten parasitoid species were recovered, with the genus Spalangia accounting for 85.7% of the total; the most common parasitoids attacking house fly and stable fly pupae were Spalangia endius Walker (33.9% and 27.3%), S. cameroni Perkins (27.9% and 40.6%), and S. nigroaenea Curtis (21.0% and 24.8%), respectively. Other parasitoids included one specimen of S. erythromera Förster and four specimens of Phygadeuon fumator Gravenhörst (Ichneumonidae). The percentage parasitism of pupae collected from bunker silos was higher than that of pupae from calf pens and open pastures. Spalangia cameroni was consistently recovered through the entire year. Spalangia nigroaenea was predominant in July, August, and September. Spalangia endius was most active from October to May with a peak of relative abundance in January.

Resumo em Inglês:

In two field-collected populations of de Bemisia tabaci (Gennadius) B biotype previously selected with the neonicotinoid insecticide thiamethoxam (NEO-R, NEO-N), and a population susceptible to insecticides (SUSC), the level of response to the insecticide thiametoxam, as well as the life and fertility tables were determined. At LC95, the NEO-R population showed a resistance ratio (RR95) value of 8.8-fold, an intrinsic rate of increase (r m) of 0.72. The fitness of the NEO-R and NEO-N populations in relation to the SUSC was 1.5 and 2.0, respectively. The RR95 value for NEO-N was 1.9-fold; it's r m value was 0.082, while in the SUSC population was 0.041. The developmental time of egg and adult were longer in NEO-R population, while the nymph and pupa lasted longer in the NEO-N and SUSC populations. The developmental time was different in the three NEO-R, NEO-N, and SUSC populations with 19.7 d (315.84 degree days or dd), 15.7 d (250.4 dd) and 18.5 d (296.6 d), respectively. The populations previously selected with thiamethoxam did not reproduce faster than their susceptible counterpart.

Resumo em Inglês:

Spiromesifen is an insecticide that inhibits the synthesis of lipids and, in Mexico, its use against the Tomato-Potato Psyllid, Bactericera cockerelli (Sulc), on chili pepper (Capsicum annum), tomato (Lycopersicon sculentum) and potato (Solanum tuberosum) began in 2005; however more information is needed to understand its toxicity on this insect pest. The aim of this research was to determine the toxicity of spiromesifen against each of the biological stages of tomato-potato psyllid, its effect on fertility and viability of eggs deposited by treated females, as well as the female preference to lay eggs on treated and non treated plants. The relative toxicity at 95% mortality (highest LC95 value /LC95 value of the respective biological stage) of spiromesifen in egg, nymph 1, nymph 2, nymph 3, nymph 4, and nymph 5 were 517.5; 31316.2; 2950.1; 315.6; 18.2 and 1-fold, respectively. There were no differences in the toxicity of spiromesifen between adult males and females. The number of laid eggs was reduced as the spiromesifen concentration used to treat female increased and egg hatch was reduced in all tested doses. In the "no choice" test, females deposited 38.6 ± 2.01 eggs by leaf of non treated chili pepper type jalapeño, while in the treated with 360 mg L-1 we observed 0.3 ± 0.08 eggs by leaf. In the "choice" test, the oviposition decreased as the dose increased. There were no eggs on plants treated with 2400 mg L-1 of spiromesifen.

Resumo em Inglês:

The false stable fly, Muscina stabulans (Fallén), was surveyed along an urban-rural gradient at Almirante Brown, Buenos Aires province, Argentina. Samples were taken at monthly intervals from May 2005 to April 2007. Hourly captures of adult flies (10:00 am - 04:00 pm) were taken at each sampling date with a hand net. The baits used were 250 g of rotten cow liver and 250 g of fresh dog faeces exposed in shaded and sunny areas. The entire sample accumulated 358 specimens. The number of specimens captured during the second year was higher than in the fi rst year. Muscina stabulans was more abundant at urban-suburban sites. Females showed significant preferences for cow liver. We caught more specimens in shaded areas. The hourly activity increased toward the afternoon at the three sites. The present work was the first ecological study related to a muscid species in Argentina.

Resumo em Inglês:

We report the first occurrence of Telenomus podisi (Ashmead) and Trissolcus urichi (Crawford) parasitizing eggs of the Rice Stem Bug, Tibraca limbativentris (Stål), in Santa Catarina, Brazil. These species have a high potential of parasitization, pointing them as an alternative for biological control of T. limbativentris.

Resumo em Inglês:

This is the first record of immature stages of species belonging to the subgenus Nyssorhynchus (Blanchard) in eutrophized breeding habitats. Larvae of Anopheles (Nys.) evansae (Brethes), Anopheles (Nyssorhynchus) rangeli (Gabaldon et al), Culex nigripalpus (Theobald) and Culex quinquefasciatus (Say) (Diptera: Culicidae) were collected in a rural eutrophized dam in Rio de Janeiro State, in Southeastern Brazil. Eutrophication was substantiated by the low diversity of mosquitoes, the high incidence of Cx. quinquefasciatus (42%) and of Daphinia sp. and, the high levels of both organic nitrogen (0.28 mg/l) and total phosphorus (0.02 mg/l).

Resumo em Inglês:

Amblyomma scalpturatum Neumann has been reported in Brazil in the northern (States of Amazonas, Pará and Rondônia) and mid-western regions (States of Mato Grosso and Mato Grosso do Sul). It has been found in association with large and medium sized mammals, as Artiodactyla, Perissodactyla, Xenarthra and Carnivora. In this paper, this tick species is reported for the first time in the Brazilian states of Paraná and Roraima, southern and northern regions, respectively.

Resumo em Inglês:

A survey of the green lacewings associated with the melon agroecosystem was carried out with the aim of including lacewings into the integrated management program of melon pests. Three species of this predator were found: Ceraeochrysa cubana (Hagen), Chrysoperla externa (Hagen) and Chrysoperla genanigra Freitas. A key to these species is presented.