External Morphology of the Immatures of Polybia paulista (Hymenoptera: Vespidae)

The immatures of Polybia paulista Ihering were described using light and scanning electron microscopy and the results are compared with previous descriptions within the same or related wasps. This study is based on 2 whole nests collected in the municipality of Rio Claro, São Paulo, in Brazil. We have detected the existence of 5 larval instars. The main morphological alterations over development occur in the relative size of structures, yet certain structures appear with subsequent instars and become more evident later in development: increasing density in the number of body spines and papillae; the appearance of body setae in fifth-instar larvae; opening of spiracles upon second-instar larvae; 2 body shapes in fifth-instar larvae; the appearance of a lateral tooth on the mandibles of fourth instar; presence of spines on the maxillae of fifth-instar larvae; altered shape of galea and palps upon third-instar larvae from a cluster of sensilla to a conical elevation; and the appearance of spines on postmentum upon fourth-instar larvae. This way, the present study presents a detailed description of the immatures of P. paulista, and we hope the presented information can be useful to morphological, taxonomic, and phylogenetic studies.

Fertility life table of Trichogramma pretiosum and Trichogramma acacioi (Hymenoptera : Trichogrammatidae) on Sitotroga cerealella (Lepidoptera : Gelechiidae) eggs at different constant temperatures

Fertility life tables were developed for both Trichogramma pretiosum and Trichogramma acacioi reared on Sitotroga cerealella eggs as an alternative host at five different temperatures. The egg parasitoids were first collected from Nipteria panacea eggs, a lepidopterous pest of avocado. Egg parasitoid females were individualized in small glass vials along with 40 eggs of the host during 24 h for parasitization. For evaluation of the parasitism capacity, a similar procedure was adopted, but cardboards with eggs were replaced every day. The net reproductive rate (Ro), intrinsic rate of increase (rm), finite rate of increase (lambda), and mean generation time (T) were estimated. Temperature affected all parameters for both Trichogramma species. The highest fecundity for both species was observed at 25degreesC. Extreme temperatures such as 15degreesC or 35degreesC negatively affect the development rate of both species.

Resíduos de calda sulfocálcica sobre a eficiência de acaricidas no controle de Brevipalpus phoenicis

O objetivo do trabalho foi verificar a influência dos resíduos de calda sulfocálcica sobre a eficiência de acaricidas empregados no controle de Brevipalpus phoenicis. Inicialmente, o experimento foi instalado em um pomar de citros, em que foram selecionadas 10 plantas que continham frutos com verrugose. Realizou-se a aplicação de calda sulfocálcica (8g i.a. L-1 de água) em cinco plantas e as outras cinco plantas permaneceram sem aplicação de produto fitossanitário. Protegeram-se, com copos de plástico transparente de 500mL, 64 frutos nas plantas tratadas com calda e 64 frutos nas plantas não-tratadas, totalizando 128 frutos protegidos. Decorridos 30 dias da aplicação, os frutos foram colhidos e levados para o laboratório. Estes frutos foram parcialmente parafinados, deixando-se em cada fruto uma arena de 2,5cm de diâmetro com verrugose e sem parafina, delimitada com cola entomológica. em seguida, procedeu-se à aplicação sobre os frutos em Torre de Potter dos seguintes acaricidas nas concentrações expressas em mg de ingrediente ativo por litro de água: propargite a 720mg, óxido de fenbutatina a 400mg, cyhexatin a 250mg, azocyclotin a 250mg, fenpyroximate a 50mg, dicofol a 960mg e dinocap a 738mg e a testemunha sem aplicação de acaricida. Após 1, 7 e 16 dias da aplicação, transferiram-se para cada fruto 10 ácaros B. phoenicis para avaliar a mortalidade. Constatou-se que os resíduos de calda sulfocálcica não prejudicaram a eficiência dos acaricidas avaliados no controle de B. phoenicis.

Primeiro registro de Fidicinoides picea (Walker, 1850) e Fidicinoides poulaini Boulard & Martinelli, 1996 no Brasil

As cigarras são importantes pragas de diversas culturas, entre plantas cultivadas e ornamentais. Estudos de taxonomia e morfologia de insetos são primordiais para pesquisas etológicas e para o emprego de métodos de controle. Ao estudar coleções entomológicas de cigarras, foi constatado o primeiro registro de ocorrência de Fidicinoides picea e Fidicinoides poulaini (Hemiptera: Cicadidae) no Brasil, espécies coletadas nos Estados do Pará e de Manaus, respectivamente. Neste trabalho, são apresentadas as descrições morfológicas da cabeça, do tórax, do abdome e da asa.

Cigarras (Hemiptera: Cicadidae: Tibicinidae) associadas ao cafeeiro: distribuição, hospedeiros e chave para as espécies

É apresentada a distribuição de 10 espécies de cigarras associadas ao cafeeiro, Coffea arabica, nos Estados de Minas Gerais, São Paulo e Paraná, Brasil. A informação sobre a distribuição geográfica destas espécies no Continente Americano, afora o Brasil, foi baseada na literatura. Para o Brasil, as localidades de ocorrência de cigarras foram baseadas na literatura, nos levantamentos realizados e em exemplares de coleções nacionais. Outros sete hospedeiros, além do cafeeiro, foram também registrados: esponjeira (Acacia farnesiana), sibipiruna (Caesalpinia peltophoroides), Cassia spp., amoreira (Morus alba), abacateiro (Persea americana), angico (Piptadenia sp.) e cacaueiro (Theobroma cacao). São apresentadas chaves de identificação, baseadas nas características gerais e na genitália masculina.

Biology of Plutella xylostella L. (Lepidoptera: Plutellidade) Reared on Cauliflower Genotypes

This work was conducted to evaluate biological parameters of Plutella xylostella L. reared on leaves of several cauliflower genotypes under laboratory conditions. The experiment was set in a randomized block design and arranged in a 6 x 2 factorial (genotypes x generations). Leaf disks of the cultivars Barcelona, Verona, Piracicaba Precoce, Sharon, Silver Streak, and Teresopolis Gigante were placed in Petri dishes with 12 newly-hatched larvae. Leaf disks were initially changed after the fourth day, but daily afterwards until the larvae reached the pupal stage. The same procedure was adopted for the second generation. Twenty adults of each sex were separated from each genotype to evaluate their longevity, and I 0 couples from each treatment were used to assess female fecundity. The lowest larval survival was obtained on the 'Silver Streak' (78.9%) and highest on 'Verona' (97.1%). The 'Silver Streak' and `Teresopolis Gigante' showed the lowest pupal weights (4.83 mg and 5.11 mg, respectively), as well as the lowest fecundity, 119.4 and 123.0 eggs/female, respectively, while 'Piracicaba Precoce' the highest (167.7 eggs/female). Males obtained from larvae reared on `Teresopolis Gigante' and 'Silver Streak' lived shorter (5.1 days), while the short-lived females were obtained from larvae reared on 'Barcelona' and 'Verona' (4.9 and 5.0 days). Insect development was prolonged in the second generation in all tested genotypes.

Parisoschoenus obesulus Casey (Coleoptera: Curculionidae) não é praga de frutos novos do coqueiro

This study aimed to evaluate if Parisoschoenus obesulus Casey only attacks naturally aborting coconuts and, consequently, is not a pest of young fruits of coconut tree. Aiming to test this hypothesis, inflorescences at diverse stages of physiological development were offered to individuals of P. obesulus. The results showed that only aborting fruits were colonized by P. obesulus corroborating the established hypothesis.

Parasitismo de Erythmelus tingitiphagus (Soares) (Hymenoptera: Mymaridae) em ovos de Leptopharsa heveae Drake & Poor (Hemiptera: Tingidae), em plantios de seringueira (Hevea brasiliensis Müell. Arg.)

The rubber tree lace bug, Leptopharsa heveae Drake & Poor occurs in high populations in rubber tree plantations and it is a limiting factor in rubber production due to the loss of photosynthetic tissue. The control of the pest has been made mainly with chemical products, which cause environmental contamination. The alternative would be the use of biological control agents, however, information about L. heveae natural enemies are scarce. The parasitoid Erythmelus tingitiphagus (Soares) parasitize eggs of the rubber tree lace bug. The aim of this study was to verify the occurrence of E. tingitiphagus in plantations of several rubber tree clones, located in Itiquira town, Mato Grosso State. The plant leaflets of the clones RRIM 600, PR 255, GT 1, PB 235 and PB 217 were collected weekly from October 2005 to February 2006. Parasitism was recorded during the entire study period. The parasitism rate of L. heveae eggs in the different clones ranged from 16.8 to 20.6%.

Descrição de novas espécies de FidicinoidesBoulard & Martinelli (Hemiptera: Cicadidae) do Brasil

The examination of entomological collections of cicadas of several Brazilian institutions revealed three undescribed species in the genus Fidicinoides Boulard & Martinelli i.e., F. dolosa sp.n., F. carmenae sp.n. and F. rosabasalae sp.n. They are described and illustrated based on the male genitalia, the right anterior femur and the operculum.

Mortality Risk in Insects

Understanding how and why insect numbers fluctuate through time and space has been a central theme in ecological research for more than a century. Life tables have been used to understand temporal and spatial patterns in insect numbers. In this study, we estimated cause-of-death probabilities for phytophagous insects using multiple decrement life tables and the irreplaceable mortality analytic technique. Multiple decrement life tables were created from 73 insect life tables published from 1954 to 2004. Irreplaceable mortality (the portion of mortality that cannot be replaced by another cause) from pathogens, predators, and parasitoids was 8.6 +/- 7.2, 7.8 +/- 4.9, and 6.2 +/- 1.6%, respectively. In contrast, the mean irreplaceable mortality from all non-natural enemy mortality factors (mortality from factors other than natural enemies) was 35.1 +/- 4.4%. Irreplaceable mortality from natural enemies was significantly lower compared with non-natural enemy factors. Our results may partially explain cases of unsuccessful efficacy in classical biological control, after successful establishment, by showing low irreplaceable mortality for natural enemies, including 5.2 +/- 1.6% for introduced natural enemies. We suggest that the environment (i.e., the degree of environmental stability) influences the magnitude of the irreplaceable mortality from natural enemies. Our results lead to several testable hypotheses and emphasize that it is not possible to estimate the effect of any mortality factor without considering its interaction with competing mortality factors, which has far-reaching consequences for population biology and applied ecology.

Movement of Spodoptera frugiperda Adults (Lepidoptera: Noctuidae) in Maize in Brazil

The fall armyworm, Spodoptera frugiperda (J. E. Smith), is one of the most important maize pests in the Americas and particularly in South America. With the adoption of genetically modified plants expressing Bacillus thuringiensis toxins for lepidopterous pest control, there is a need for establishing strategies to delay the development of insect resistance (e.g. refuge areas). Thus, information on target insects' dispersal is essential to improve pest management techniques. The objective of this work was to evaluate the dispersal capacity of S. frugiperda adults using mark-release-recapture techniques. Insects were marked using red oil-soluble dye in the larval artificial diet. Marked adults were released twice in each growing season (dry and wet) in southeastern Brazil in 2006 and 2007. Recapture of marked insects was performed using light and pheromone traps. Males are more attracted to light traps than females and the recapture rate was higher in the dry season than in the rainy season. The most adequate model to explain the relationship between flight distance and number of recaptured insects is y = a(2)/ (1+ (2a(1.8)+ bx))((2.6)), where y is the distance and x is the number captured. The maximum recapture distances were 806 m for males and 608 m for females. Therefore, strategies for establishment of refuges should take such distances into consideration.

Species Diversity of Myrmecofauna and Araneofauna Associated with Agroecosystem and Forest Fragments and their Interaction with Carabidae and Staphylinidae (Coleoptera)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Population Fluctuations of Formicidae (Hymenoptera) and Araneae (Arachnida) in Two Tillage Systems in the Region of Guaíra-SP

The objective of this study was to elucidate population fluctuations of spider and ant species in forest fragments and adjacent soybean and corn crops under no-tillage and conventional tillage systems, and their correlations with meteorological factors. From Nov 2004 to Apr 2007 sampling of these arthropods at Guaira, São Paulo state was done biweekly during the cropping season and monthly during the periods between crops. To obtain samples at each experimental site, pitfall traps were distributed in 2 transects of 200 m of which 100 m was in the crop, and 100 m was in the forest fragment. Temperature and rainfall were found to have major impacts on fluctuations in population densities of ants of the genus, Pheidole, in soybean and corn crops both grown with conventional tillage and no tillage systems.

Toxicidade diferencial de produtos à base de abamectina ao ácaro Brevipalpus phoenicis (Geijskes, 1939) (Acari: Tenuipalpidae) em citros

O ácaro Brevipalpus phoenicis é uma das principais pragas dos citros por ser vetor do Citrus Leprosis Virus (CiLV), agente causal da leprose, uma das mais graves doenças da citricultura. Objetivou-se avaliar o efeito tóxico de produtos à base de abamectina sobre o ácaro B. phoenicis. Foram realizados um experimento de ação direta e três de ação residual no Laboratório de Acarologia do Departamento de Proteção de Plantas (Fitossanidade) da FCAV - UNESP, Jaboticabal-SP. O delineamento adotado nos bioensaios foi o inteiramente casualizado, onde 10 tratamentos foram repetidos 7 vezes, sendo cada repetição composta por um fruto de laranja. Os tratamentos estudados (mL p.c./100 L de água) foram: Acaramik a 20; 30; 40 e 50 mL; Vertimec a 30 e 40 mL; Abamectin Nortox a 30 e 40 mL; Tricofol a 77 mL e uma testemunha sem aplicação. Utilizaram-se frutos com presença de verrugose, que foram lavados e parcialmente parafinados, deixando-se uma área sem parafina, que foi circundada com cola entomológica para contenção dos ácaros. Transferiram-se 20 ácaros adultos B. phoenicis para cada fruto. No bioensaio de ação direta, a transferência foi realizada antes das aplicações e, nos bioensaios de ação residual, aos 5; 10 e 15 dias após a aplicação dos produtos. A aplicação dos produtos sobre os frutos foi realizada em Torre de Potter. Os resultados obtidos nos bioensaios evidenciaram que os melhores tratamentos foram: Tricofol a 77 mL, Acaramik a 40 e 50 mL e Vertimec a 40 mL. de forma geral, os produtos testados podem ser utilizados no controle do ácaro B. phoenicis.