Multiple nymphoid reproductives in the nests of the neotropical termite, Armitermes euamignathus (Isoptera, Termitidae, Nasutitermitinae)

Armitermes euamignathus Silvestri (Termitidae, Nasutitermitinae) is a mound building termite that is common in Brazilian regions of the Cerrado vegetation. Multiple neotenic reproductives were found in three isolated nests of these species localized in other secondary habitats different from Cerrado vegetation. The number of second form queens was always higher than the number of secondary males. In two of these nests, the primary king was present along with the second form reproductives. Eggs and brood were found in the three nests but mature alates were present in only one. Multiple neotenic reproductives were never found in the studied Cerrado region where the nests contained only the primary pair. A study of oviposition rate between primary queens and nymphoid reproductives showed an increased number of eggs in the colony headed by neotenic reproductives.

Morphological prediction of worker size discrimination and relative abundance of sympartic species of Pseudacteon (Dipt., Phoridae) parasitoids of the fire ant, Solenopsis saevissima (Hym., Formicidae) in Brazil

Patterns of attack for collected species of phorids are predicted using multivariate morphometrics of female Pseudacteon species and worker size distributions of parasitized fire ants, Solenopsis saevissima. The model assumes that there is a direct correlation between phorid size and the size range of the worker ant attacked, and presumes that worker sizes are a resource that is divided by sympatric phorid species to minimize joint parasitism. These results suggest that the community of sympatric Pseudacteon species on only one host species coexists by restricting the size of workers attacked, and secondarily by differing diel patterns of ovipositional activity. When we compared relative abundance of species of Pseudacteon with the size distribution of foragers of S. saevissima, our observed distribution did not differ significantly from our predicted relative abundance of females of Pseudacteon. The activity of Pseudacteon may be a factor determining forager size distributions.

Lignoids; flavonoids and polyketides of Virola surinamensis

From the seeds of Virola surinamensis, which were collected near Altamira and near Maraba, Para State, Brazil, the following substances were isolated by chromatographic techniques: two dibenzylbutanediol lignans, dihydrocubebin and the new dihydrocubebin monolaurate, two furofuran lignans, sesamin and asarinin, three dibenzylbutyrolactol lignans, cubebin, β-O- methylcubebin and α-O-methylcubebin, one dibenzylbutyrolactone lignan, hinokinin, one aryltetralin neolignan, galbulin, two tetrahydrofuran neolignans, galgravin and the new 4'-hydroxy-3'-methoxy-3,4-methylenedioxy- 8.8',7.O.7'-neolignan, one flavone, tithonine, one isoflavone, irisolidone, and two new polyketides, 3-hydroxy-1-(15-phenylpentadecanoyl)-2,6- cyclohexanedione and 1-(5-phenylpentanoyl)-2,6-cyclohexanedione. Different chemical constitutions of the fruits from the two localities were observed.

Swarming and incipient colonies of Coptotermes havilandi (Isoptera, Rhinotermitidae)

Coptotermes havilandi Holmgren is an oriental species introduced into Brazil. Despite its economic impact as structural pest, very little is known about the biology of this termite. This paper describes observations of C. havilandi swarming in the city of Rio Claro (SP, Brazil), and reports the first data on incipient colonies reared in a laboratory in Brazil. The preoviposition period lasted about a week after pairing; oviposition began in most of the incipient colonies during the second week. Antennal mutilation occurred on all reproductives. The mean number of the first batch of eggs was 13. In general, first instar brood hatched 60-70 days after set up of the colonies. After two years of pairing there was a small population (less than 100 individuals) and limited soldier production (n=2) in incipient colonies of C. havilandi.

Effect of temperature on development and population growth of Acarophenax lacunatus (Cross and Krantz) (Prostigmata: Acarophenacidae) on Rhyzopertha dominica (F.) (Coleoptera: Bostrichidae)

The parasitic mite Acarophenax lacunatus kills the eggs upon which it feeds and seems to have potential as a biological control agent of stored grain pests. The lack of biological studies on this mite species led to the present study carried out in laboratory conditions at eight different temperatures (ranging from 20 to 41°C) and 60% relative humidity using Rhyzopertha dominica as host. The higher the temperature, the faster: (1) the attachment of female mites to the host egg (varying from 1 to 5 h); (2) the increase in body size of physogastric females (about twice faster at 40°C than at 20°C); and (3) the generation time (ranging from 40 to 220 h). In addition, the higher the temperature, the shorter the maximum female longevity (ranging from about 75 to 300 h). The two estimated temperature thresholds for development of A. lacunatus on R. dominica were 18 and 40°C. The average number of female and male offspring per gravid mite were 12.8 and 1.0, respectively, with sex ratios (females/total) ranging from 0.91 to 0.94 (maximum at 30°C). The net reproductive rate and intrinsic rate of increase also presented maximum values at 30°C (12.1 and 0.04, respectively).

Expanded food choice as a possible factor in the evolution of sociality of Vespidae (Hymenoptera)

A recent theory suggests that economic considerations are more important than genetic ones in the emergence and maintenance of social behavior. Evolution of social behavior in wasps, thus, could be based on the development of worker castes, which increase the efficiency of brood care and energy use of the colony. If so, social wasps should collect a larger range of prey, favoring polyethism, as social behavior should increase the adaptive value of social species among wasps by increasing the range of prey accessible. We explored the literature and showed that the Eumeninae, which are mostly solitary, draw prey from significantly fewer orders of arthropods than wasps in the subfamily Vespinae and Polistinae, which are mainly social, supporting the hypothesis that social behavior may have emerged as a more efficient way to feed and care for the young by opening a wider range of food sources, increasing the amount of food and quality of care provided to the young. Two alternative explanations of this data are also discussed.

Metacercárias de Diplostomum (Austrodiplostomum) compactum Lutz, 1928 (Digenea, Diplostomidae) em peixes do rio Paraná, Brasil. Prevalência, sazonalidade e intensidade de infecção

This paper aims at evaluating the occurrence of Diplostommn (Anstrodiplostomum compactum (Digenea: Diplostomatidae) in the eyeball of Plagioscion sqnamosissimus (corvina) and Cichla ocellaris (tucunaré), monthly captured in Paraná river, Presidente Epitácio, state of São Paulo, Brazil. From 61 corvinas under analysis, 56 of them contained parasites (92%) with intensity rate of 42.0 host parasites. From an amount of 81 tucunarés, 45 contained parasites (55%) with intensity rate of 9.3 parasites. Corvinas showed prevalence from 71 to 100% with the highest intensity rates (103.3 and 106.9) from February to March, 2001. Comparatively, the tucunaré showed the highest prevalence from November 2000 (90%) to February 2001 (80%). The tucunaré highest intensity rates occurred on September, 2000 (12.7), December, 2000 (12.2) and February, 2001 (16.1). Metacercariae showed a hollow womb body and a posterior region of a sinuous conic protuberance, an oral sucker smaller than the acetabulae, a simple acetabulae located in the pre-equatorial region of helminto. A short pre-pharynx followed by a muscular pharynx, genital pore next to acetubulae. Corvina metacercariae presents 1.434,0 μm (880 to 1.840) long by 611.2 ± 93.4 μm (400 to 792) wide. Tucunaré metacercariae, 1.462.4 μm (960 to 2.480) by 710.8 μm (560 to 960). Authors confirmed corvina great susceptibility to Diplomastum and the relationship between the parasitism and the aquatic and climatic parameters.

Fecundity of the mangrove crab Ucides cordatus (Linnaeus, 1763) (Brachyura, Ocypodidae)

Females of the mangrove crab Ucides cordatus were collected in a monthly basis along a 2-year period at the mangrove areas of Iguape, SP, Brazil. Ovigerous individuals were measured (CW, carapace width) and weighed (WW, wet weight). Each brood was weighed (WWE, wet weight of eggs), dried (DWE, dry weight of eggs) and the number of eggs (EN) was recorded. Scatter plots for the relationships EN/CW, EN/WW and EN/WWE were produced, and the data were subjected to regression analysis. Relative average fecundity (F 1) was calculated in different seasons and compared to verify if there were any temporal variation of reproductive intensity. Fecundity in U. cordatus varied from 36.081 to 250.566 eggs according to the size-dependent relationship EN = 15.27CW 2.24 (N = 66; R 2 = 0.69; p<0.001). The other expressions obtained for the relationships were: EN = 3797.6WW 0.813 (N = 56; R 2 = 0.72; p<0.001); EN = 29226WWE 0.775 (N = 54; R 2 = 0.70; p<0.001); and EN = 1093586DWE 0.769 (N = 66; R 2 = 0.86; p<0.001). Ovigerous females were found only during spring and summer, and relative average fecundity differed between these seasons. Relative average fecundity was higher in spring and relative frequency of ovigerous females was higher during summer. Overall reproductive intensity was similar between these seasons. The observed trends are regarded to be related to temperature and photoperiod variations.

Temporal polyethism in workers of Ectatomma edentatum (Formicidae: Ponerinae)

In the present study, adult ants emerged from five nests kept under laboratory conditions were individually monitored in order to determine their longevity and observe their individual behavior in relation to age (temporal polyethism). Our results showed that most of the tasks related to colony maintenance were executed during the three first age intervals (comprising from 1 to 150 days of age), namely brood care, followed by grooming activities (self and allogrooming), nest maintenance activities (such as floor and nest inspection), and social related activities (antennating and food exchange among adults). Foraging activities were performed by ants in the higher age intervals.

Piranha Attacks on Humans in Southeast Brazil: Epidemiology, Natural History, and Clinical Treatment, with Description of a Bite Outbreak

There are many tales describing ferocious schools of piranha attacking humans, but there are few scientific data supporting such behavior. The very few documented instances of humans attacked and eaten by piranha schools include 3 that occurred after death by other causes (eg, heart failure and drowning). These predaceous fishes, however, do occasionally injure bathers and swimmers in lakes and rivers. The characteristic profile of most injuries is a single bite per victim, generally related to the fish defending its brood. This paper describes an outbreak of piranha bites in a dammed river portion in southeast Brazil. The outbreak was caused by the speckled piranha, Serrasalmus spilopleura, a widespread species which benefits from the growing tendency of damming rivers all over Brazil. This article focuses on the epidemiological and clinical aspects of the injuries, as well as on piranha biology, to gain a better understanding of the natural history of bite outbreaks.

Influência de cultivares de batata-doce resistentes e suscetíveis a Euscepes postfasciatus fairmaire (Coleoptera: Curculionidae) sobre o parasitismo, sobrevivência e a biologia de Catolaccus grandis burks (Hymenoptera: Pteromalidae)

The influence of four resistant and two susceptible genotypes of sweet potato to Euscepes postfasciatus Fairmaire on parasitism and biology of Catolaccus grandis Burks were evaluated under laboratory conditions. Six sweet potato roots of each genotype were infested with E. postfasciatus adults during 40 days. After this period the larvae were taken, weighted and encapsulated in parafilm. Five larvae were offered in free choice and no choice tests to C. grandis pregnant females for 12h. Five replications were used. The parasitized larvae and the eggs of the parasitoid were counted. Three daily observations were made to determine the developmental time of phases and parasitoid survival. C. grandis females can distinguish E. postfasciatus larvae reared on susceptible and resistant roots, prefering to parasitize larvae reared on susceptible roots. C. grandis survival was higher when the parasitoid was reared on larvae originated from susceptible roots and the number of emerged females was higher on larvae reared on hosts originated from susceptible roots.

Comparative study of the cuticular hydrocarbon composition of Melipona bicolor Lepeletier, 1836 (Hymenoptera, Meliponini) workers and queens

In social insects, cuticular hydrocarbons are involved in species, kin, caste and nestmate recognition. Gas chromatography and mass spectrometry were used to compare the cuticular hydrocarbon composition of workers, males and queens of Melipona bicolor. The cuticular hydrocarbon composition of this species was found to consist mainly of C23, C25:1, C25, C27:1, C27, C29:1 and C29, which are already present in imagoes that have not yet abandoned the brood cell. This composition varied quantitatively and qualitatively between and within the castes and sexes. The newly emerged workers and young queens (virgins) had similar cuticular hydrocarbon profiles, which were different from those of the males. When the females start executing their tasks in the colony, the cuticular hydrocarbon profile differences appear. The workers have less variety, while the queens conserve or increase the number of cuticular hydrocarbon compounds. The queens have more abdominal tegumentary glands than the workers, which apparently are the source of the new cuticular compounds.

Is the number of antennal plate organs (sensilla placodea) greater in hygienic than in non-hygienic Africanized honey bees?

Hygienic behavior is a desirable trait in honey bees (Apis mellifera L.), as hygienic bees quickly remove diseased brood, intermpting the infectious cycle. Hygienic lines of honey bees appear to be more sensitive to the odors of dead and diseased honey bee brood, and Africanized honey bees are generally more hygienic than are European honey bees. We compared the number of sensilla placodea, antennal sensory structures involved in the perception of odor, in 10 bees from each of six hygienic and four non-hygienic colonies of Africanized honey bees. The sensilla placodea of three of the terminal segments (flagellomeres) of the right antenna of each bee were counted with a scanning electron microscope. There were no significant differences in the mean numbers of sensilla placodea between the hygienic and non-hygienic bees, though the variance was higher in the hygienic group. Flagellomere 4 had significantly more sensilla placodea than flagellomeres 6 and 8. However, there was no significant difference between the other two flagellomeres. As hygienic bees are capable of identifying dead, injured, or infested brood inside a capped brood cell, sensilla placodea probably have an important role in enabling worker bees to sense sick brood. However, we did not find greater numbers of this sensory structure in the antennae of hygienic, compared to non-hygienic Africanized honey bees.

Tabela de vida ecológica do minador-dos-citros, Phyllocnistis citrella stainton (Lepidoptera: Gracillariidae)

The construction of ecological life tables is a useful tool to understand the population dynamics of insects in the field. In this work, ecological life tables were developed for Phyllocnistis citrella (Stainton) in an orchard of Citrus sinensis situated in Santa Rita do Passa Quatro, Sao Paulo State, during 2002. The occurrence of generation overlay in the field was avoided by obtaining the eggs from infestation on young citrus plants (Citrus limonia) kept under controlled conditions. The samples were taken every other day and the number of live, dead, predated and parasitized individuals were recorded. The occurrence of arthropod predators was determined through visual search on the plants of the orchard. The key factors of mortality acting on P.citrella populations were: pupae parasitism caused by Ageniaspis citricola (Logvinovskaya), action of uncertain factors on prepupae and predation of 3rd-instar larvae. The most abundant arthropod predators belonged to the families Formicidae, Chrysopidae, Coccinellidae, Reduviidae e Araneae. In two of five generations of P. citrella, approximately 4% of A. citricola pupae were hyperparasitized by Galeopsomyia fausta (LaSalle) (Hymenoptera: Eulophidae).

Avaliação da eficiência dos métodos Direto, COPROTEST e Rugai no diagnóstico da estrongiloidíase

Strongyloidiasis, a relatively common parasitism in tropical and sub-tropical areas, is the result of the infection by the smaller nematode, the Strongyloides stercoralis. Humans can be infected by this parasite, which has in its vital cycle free-life forms of male and female individuals able to live in the ground, and with another step necessary parasitism in the intestinal wall. The diagnostic of the infection is routinely done by the microscopic observation of the larva in stool samples and the high sensibility of urn method over another one allows an trustable and efficient diagnostic. The efficiency of three methods (Direct, COPROTEST and Rugai) used in the Parasitology Sector of the NAC-LACAL in Araraquara (SP) to diagnosis the strongiloidiasis were evaluated. A number of 2346 samples of stool of patients from NAC-LACAL and Nestor Goulart Reis Hospital were analyzed in the period between August and December of 2002. The Rugai Method with an positivity index of 65 % was elected as the most efficient of thee ones.