Functional Response and Parasitism rate of Trichogramma galloi Zucchi (Hymenoptera: Trichogrammatidae), a Parasitoid of Eggs of Sugarcane Borer.

The evaluation of parameters such as functional response and parasitism rates is essential for the choice and use of a control agent, which contributes to a positive or negative outcome of Biological Control. Diatraea saccharalis (Fabricius, 1794) (Lepidoptera: Crambidae), commonly called sugarcane borer, is the main pest of the sugarcane crop and its management can be done by the parasitoid Trichogramma galloi Zucchi, 1988 (Hymenoptera: Trichogrammatidae), which attacks the egg stage of the pest before damage is done to the crop. To better understand this host/parasitoid relationship, the functional response and parasitism rate of T. galloi in 0.4:1 and 1.6:1 (parasitoid:egg) proportions on D. saccharalis eggs were evaluated, the second proportion being carried out in clutch deposited on sugarcane leaves. Trichogramma galloi presented a type II functional response, common among the parasitoids of the Trichogrammatidae family. Although the rate of parasitism on sugarcane borer eggs ranged from 43.36 to 53.77%, there was no significant difference between the evaluated proportions, 0.4:1 and 1.6:1 (parasitoid/egg).

Composition and Food Web Structure of Aphid-Parasitoid Populations on Plum Orchards in Chile.

By increasing plant diversity in agroecosystems, it has been proposed that one can enhance and stabilize ecosystem functioning by increasing natural enemies' diversity. Food web structure determines ecosystem functioning as species at different trophic levels are linked in interacting networks. We compared the food web structure and composition of the aphid- parasitoid and aphid-hyperparasitoid networks in two differentially managed plum orchards: plums with inter-rows of oats as a cover crop (OCC) and plums with inter-rows of spontaneous vegetation (SV). We hypothesized that food web composition and structure vary between OCC and SV, with network specialization being higher in OCC and a more complex food web composition in SV treatment. We found a more complex food web composition with a higher species richness in SV compared to OCC. Quantitative food web metrics differed significantly among treatments showing a higher generality, vulnerability, interaction evenness, and linkage density in SV, while OCC presented a higher degree of specialization. Our results suggest that plant diversification can greatly influence the food web structure and composition, with bottom-up effects induced by plant and aphid hosts that might benefit parasitoids and provide a better understanding of the activity, abundance, and interactions between aphids, parasitoids, and hyperparasitoids in plum orchards.

Composition and structure of winter aphid-parasitoid food webs along a latitudinal gradient in Chile.

All species interact in complex antagonistic or mutualistic networks that may be driven by turnover in species composition due to spatiotemporal environmental filtering. Therefore, studying differences in insect communities along environmental gradients may improve our understanding of the abiotic and biotic factors that shape the structure of trophic networks. Parasitoids are interesting models to do so, due to their intimate eco-evolutionary relationship with their hosts. We explored the differences in cereal aphid-parasitoid food webs during the winter among nine localities in Chilean central-south valley, along a gradient of 1200 km from north (29° S) to south (40° S). We hypothesized that diapause incidence would increase in the coldest areas, resulting in a lower number of parasitoid species active during the winter. Consequently, network specialization, generality, and vulnerability indexes should increase with decreasing latitude, which implies fewer and more weakly connected links per parasitoid species through an increased fraction of basal host species. Based on the severity of winter, three areas along the explored gradient were distinguished, but clustering did not follow a clear north-south latitudinal gradient. Instead, few differences were observed in overwintering strategies, with very low levels of diapause in all localities, and no major differences in food-web composition. The major differences along the gradient were the relative abundances of the different aphid, parasitoid and hyperparasitoid species, with higher levels of spatial and temporal variation observed for the less abundant species. Our results provide a better understanding of the activity and abundance of aphid parasitoids during winter in relation to climatic conditions.

Parasitoids of Drosophilids in the Brazilian Savanna: Spatial-temporal Distribution and Host Associations with Native and Exotic Species.

Host-parasitoid interactions may have a relevant role not only in ecological processes but also in human procedures such as biological control and the management of invasive species. Although the Drosophila-parasitoid system has been widely used for investigating all aspects of host-parasitoid relationships, it is still poorly understood in tropical areas. Here, we investigate the richness, spatial-temporal distribution, and host associations of parasitoids attacking drosophilid flies in the core region of the Brazilian Savanna, a hotspot of biodiversity. Using different methods, we collected wasps on several occasions over 7 years and found 13 species representing families associated with drosophilid larvae (Figitidae, Braconidae) and pupae (Pteromalidae, Eurytomidae, Dipriidae). The dominant species infesting larvae and pupae were Dicerataspis grenadensis Ashmead and Pachycrepoideus vindemmiae (Rondani), respectively. Spalangia simplex Perkins was recorded for the first time in the Brazilian Savanna. Although our study was not designed to evaluate collection methods, we observed that they captured different subsets of the wasp community. The spatiotemporal distribution of wasps followed those of drosophilids: they were more abundant in forests and during the rainy season, suggesting that the abundance of hosts, especially native drosophilids, is an important factor determining the assemblage structure and population dynamics of parasitoids. Common parasitoids and drosophilids were associated with more than one host/antagonist species, suggesting that caution should be used for the selection of biological control agents. This study confirms the role and relevance of natural vegetation in preserving biodiversity and ecosystem services, especially in a biome severely threatened by agricultural expansion.

Microorganismal Cues Involved in Host-Location in Asilidae Parasitoids.

Parasitoids are organisms that kill their host before completing their development. Typical parasitoids belong to Hymenoptera, whose females search for the hosts. But some atypical Diptera parasitoids also have searching larvae that must orientate toward, encounter, and accept hosts, through cues with different levels of detectability. In this work, the chemical cues involved in the detection of the host by parasitoid larvae of the genus Mallophora are shown with a behavioral approach. Through olfactometry assays, we show that two species of Mallophora orient to different host species and that chemical cues are produced by microorganisms. We also show that treating potential hosts with antibiotics reduces attractiveness on M. ruficauda but not to M. bigoti suggesting that endosymbiotic bacteria responsible for the host cues production should be located in different parts of the host. In fact, we were able to show that M. bigoti is attracted to frass from the most common host. Additionally, we evaluated host orientation under a context of interspecific competence and found that both parasitoid species orient to Cyclocephaala signaticollis showing that host competition could occur in the field. Our work shows how microorganisms mediate orientation to hosts but differences in their activity or location in the host result in differences in the attractiveness of different cues. We show for the first time that M. bigoti behaves similar to M. ruficauda extending and reinforcing that all Mallophora species have adopted a parasitoid lifestyle.

First Record and Distribution of Ganaspis brasiliensis (Hymenoptera: Figitidae: Eucoilinae), a Parasitoid of Drosophila suzukii (Diptera: Drosophilidae) in Argentina.

The eucoiline species Ganaspis brasiliensis (von Ihering) (Hymenoptera: Figitidae) is recorded for the first time in Argentina, with confirmation of parasitism of Drosophila suzukii (Matsumura) infesting healthy raspberry fruit (Rubus idaeus L. cv. "Heritage") still on the plant. Drosophila suzukii puparia were recovered from fruit collected in an organic farm in Tafí del Valle, Tucumán, Argentina. One G. brasiliensis specimen was obtained from an isolated D. suzukii puparium. An additional 83 specimens, deposited in the entomological collection of the Museo de la Plata, Argentina, were also identified as G. brasiliensis. This parasitoid species is distributed in four biogeographical provinces of Argentina. The specimens of G. brasiliensis collected in Argentina are assumed to belong to a worldwide distributed and generalist lineage, parasitizing several Drosophila species. A taxonomic key of known Ganaspis species from Argentina is provided.

A new interaction in an invasive plant in Brazil: Horismenus abnormicaulis (Hymenoptera, Eulophidae) parasitizing Acanthoscelides macrophthalmus (Coleoptera, Chrysomelidae, Bruchinae) in seeds pods of Leucaena leucocephala (Fabaceae)

ABSTRACT The parasitism of Acanthoscelides macrophthalmus (Coleoptera, Chrysomelidae, Bruchinae) by the parasitoid Horismenus abnormicaulis (Hymenoptera: Eulophidae) is described for the first time. We harvested 90 Leucaena leucocephala (Fabaceae, Mimosoideae) fruit pods, in June 2019 on the campus of the Federal University of Lavras in the municipality of Lavras, Minas Gerais, Brazil. We found 21 individuals of H. abnormicaulis and 334 of A. macrophthalmus. The presence of cephalic capsule of beetle's pupa and evidence of predation into seed pods from which the wasps emerged suggested H. abnormicaulis is a parasitoid of A. macrophthalmus. Horismenus abnormicaulis has been added to the list of A. macrophthalmus parasitoids, and its occurrence has been expanded to the state of Minas Gerais. This discovery expands our knowledge of H. abnormicaulis biology and distribution in Brazil, as well as the tri-trophic interaction, plant-herbivore-parasitoid in invasive plant systems.

Koinobint life style of the spider wasp Minagenia (Hymenoptera, Pompilidae) and its consequences for host selection and sex allocation.

Spider wasps of the genus Minagenia have evolved koinobiontism as a relatively rare life strategy within the widely diversified hymenopteran family Pompilidae. In this study, we evaluated several aspects of the parasitic strategy of the wasp Minagenia sp. (hereafter, Minagenia) - namely host specificity, ontogeny, and sex determination as a function of host size. We found that Minagenia is highly host specific, being associated only with the genus Lycosa from the family Lycosidae, namely Lycosa u-album (Mello-Leitão, 1938), Lycosa erythrognatha (Lucas, 1836) and Lycosa poliostoma (Koch, 1847) with a parasitism incidence of 18.9%, 15.8% and 12.5%, respectively. Both ecological and taxonomical host traits determine the host selection and sex allocation of Minagenia female wasps. Charnov's host-size model explains Minagenia's host-size-dependent sex ratio in combination with the effect of host development stage, host species, and host foraging strategy. We also found that the final instar larva of Minagenia induces behavioural changes in spider hosts. The manipulated spider builds a protective silk chamber as a shelter for parasitoid pupation. Our results suggest that host manipulation seems to be narrowly connected with koinobiont life style throughout Hymenoptera. This study provides new information about the host-parasitoid koinobiont life strategy among spider wasps, which probably arose convergently in distant taxonomical groups within Pompilidae.

How deadly sarcophagid fly larvae are for anurans? New interactions and review to Neotropical region.

Myiasis is defined as the infestation of living or necrotic tissues of vertebrates by dipteran larvae. In amphibians, it can be caused by fly larvae belonging to families Calliphoridae, Chloropidae, Muscidae, and Sarcophagidae. In this study, we report new records and infestation intensity of myiasis in anurans from two localities of the Atlantic Forest in southern Brazil, and also present a list with myiasis caused by flesh fly Sarcophagidae species in anurans of the Neotropical region. For this, we surveyed anuran communities during two breeding seasons, examined for myiasis signs, and when positive collected the specimens. We found infested individuals of 13 anurans of seven species. Different Sarcophagidae larva morphotypes were collected, and two of them emerged as adult flies of Lepidodexia (Notochaeta) fumipennis and Peckia (Sarcodexia) lambens, which were both found in the tree frog Bokermannohyla circumdata. We compiled 21 cases of myiasis in anurans in the Neotropical region from the literature reviewed. This data indicated that hosts of different lineages and modes of life can be affected and that death is often fast. The diversity of myiasis-causing flies in anurans in nature is probably a lot greater than expected, especially if we consider that the encounters are occasional, but at relatively high intensities, can cause rapid deaths.

A species-level association in Pheidole Westwood (Hymenoptera: Formicidae) ants with a parasitoid wasp of the genus Orasema Cameron (Hymenoptera: Eucharitidae) in Brazil

Abstract Eucharitid wasps are exclusive parasitoids of ants and certain groups of eucharitids have specific associations with their hosts. This type of specificity is widely documented in more inclusive groups (subfamilies and/or genus-groups). However, we do not know if this specificity occurs in less inclusive groups (such as species or populations) or if it is more strongly influenced by local and/or regional environmental constraints. We provide a new association record between Pheidole gibba Mayr, 1887 and Orasema chunpi Burks, Heraty & Dominguez, 2018, while expanding their known distribution to the Brazilian state of Bahia.

Regulation of the Larval Transcriptome of Diatraea saccharalis (Lepidoptera: Crambidae) by Maternal and Other Factors of the Parasitoid Cotesia flavipes (Hymenoptera: Braconidae).

Koinobiont endoparasitoid wasps regulate the host's physiology to their own benefit during their growth and development, using maternal, immature and/or derived-tissue weaponry. The tools used to subdue the wasps' hosts interfere directly with host transcription activity. The broad range of host tissues and pathways affected impedes our overall understanding of the host-regulation process during parasitoid development. Next-generation sequencing and de novo transcriptomes are helpful approaches to broad questions, including in non-model organisms. In the present study, we used Illumina sequencing to assemble a de novo reference transcriptome of the sugarcane borer Diatraea saccharalis, to investigate the regulation of host gene expression by the larval endoparasitoid Cotesia flavipes. We obtained 174,809,358 reads and assembled 144,116 transcripts, of which 44,325 were putatively identified as lepidopteran genes and represented a substantial number of pathways that are well described in other lepidopteran species. Comparative transcriptome analyses of unparasitized versus parasitized larvae identified 1,432 transcripts of D. saccharalis that were up-regulated under parasitization by C. flavipes, while 1,027 transcripts were down-regulated. Comparison of the transcriptomes of unparasitized and pseudoparasitized D. saccharalis larvae led to the identification of 1,253 up-regulated transcripts and 972 down-regulated transcripts in the pseudoparasitized larvae. Analysis of the differentially expressed transcripts showed that C. flavipes regulated several pathways, including the Ca+2 transduction signaling pathway, glycolysis/gluconeogenesis, chitin metabolism, and hormone biosynthesis and degradation, as well as the immune system, allowing us to identify key target genes involved in the metabolism and development of D. saccharalis.

Neotropical Species of Metaphycus (Hymenoptera, Encyrtidae) Parasitoids of Ceroplastes (Hemiptera, Coccidae): New Species, Interaction Records, and a Checklist.

Parasitoids of Ceroplastes Gray were surveyed in the State of São Paulo, Brazil. Among the parasitoids reared, seven species of Metaphycus Mercet (Hymenoptera, Encyrtidae) were obtained. Metaphycusanaluciaesp. nov., M. floridensissp. nov., and M. grandissp. nov., are described as new species, and M. ceros Noyes, M. comes Noyes, M. dardanus Noyes, M. opis Noyes are recorded for the first time from Brazil. Ten new host-parasitoid associations are reported: M. analuciaesp. nov. parasitizing C. formicarius Hempel, C. glomeratus Peronti and C. iheringi Cockerel; M. ceros parasitizing C. cirripediformis Comstock; M. comes parasitizing C. formicarius; M. dardanus parasitizing C. glomeratus; M. floridensissp. nov. parasitizing C. floridensis; M. grandissp. nov. parasitizing C. grandis Hempel; and M. opis parasitizing C. glomeratus and C. janeirensis (Gray). A checklist of Metaphycus species associated with Ceroplastes, their distribution and host ranges are summarized and discussed.

Age and density of eggs of Helicoverpa armigera influence on Trichogramma pretiosum parasitism / Influência da idade e densidade de ovos de Helicoverpa armigera no parasitismo deTrichogramma pretiosum

This study evaluated the parasitism of Trichogramma pretiosum Riley (Hymenoptera: Trichogrammatidae) on eggs of Helicoverpa armigera Hübner (Lepidoptera: Noctuidae) at different ages and densities. The rates of parasitism and emergence, the number of parasitoids emerged per egg and sex ratio of offspring were evaluated in both experiments. Eggs of H. armigera up to 36 hours provided greater parasitism and emergence of adults compared to eggs up to 60 hours old. The number of parasitoids, which emerged per host egg, was greater than one and the sex ratio remained around 80% of females, regardless of the egg development stage. Females of T. pretiosum responded with superior rates of parasitism, emergence and number of parasitoids per egg at the densities of 20 and 25 eggs of H. armigera. These results indicate that T. pretiosum parasite with superior performance in eggs of up to 36h of age and densities of 20 eggs per female day-1 in laboratory conditions. These results will help to establish the intervals between releases of parasitoids, aiming to control this pest, when adjusted with knowledge of the survival of the parasitoids in the field and in pest infestation.(AU)

Este trabalho avaliou o parasitismo de Trichogramma pretiosum Riley (Hymenoptera:Trichogrammatidae) em ovos de Helicoverpa armigera Hübner (Lepidoptera: Noctuidae) em diferentesidades e densidades. As taxas de parasitismo e emergência, número de parasitoides emergidos por ovo erazão sexual dos descendentes foram avaliados em ambos os experimentos. Ovos de H. armigera de até 36horas proporcionaram maior parasitismo e emergência dos adultos em comparação com ovos com até 60horas de idade. O número de parasitoides, que emergiram por ovo hospedeiro, foi superior a 1 e a razãosexual permaneceu em torno de 80% de fêmeas, independentemente do estágio de desenvolvimento doovo. Fêmeas de T. pretiosum responderam com taxas superiores de parasitismo, emergência e número deparasitoides por ovo nas densidades de 20 e 25 ovos de H. armigera. Estes resultados indicam que T.pretiosum parasita com desempenho superior em ovos de até 36h de idade e densidades de 20 ovos porfêmea dia-1 em condições laboratoriais. Estes resultados ajudarão a estabelecer os intervalos entre asliberações de parasitoides, visando o controle desta praga, quando ajustado com o conhecimento dasobrevivência dos parasitoides no campo e na infestação de pragas.(AU)

Age and density of eggs of Helicoverpa armigera influence on Trichogramma pretiosum parasitism / Influência da idade e densidade de ovos de Helicoverpa armigera no parasitismo de Trichogramma pretiosum

This study evaluated the parasitism of Trichogramma pretiosum Riley (Hymenoptera: Trichogrammatidae) on eggs of Helicoverpa armigera Hübner (Lepidoptera: Noctuidae) at different ages and densities. The rates of parasitism and emergence, the number of parasitoids emerged per egg and sex ratio of offspring were evaluated in both experiments. Eggs of H. armigera up to 36 hours provided greater parasitism and emergence of adults compared to eggs up to 60 hours old. The number of parasitoids, which emerged per host egg, was greater than one and the sex ratio remained around 80% of females, regardless of the egg development stage. Females of T. pretiosum responded with superior rates of parasitism, emergence and number of parasitoids per egg at the densities of 20 and 25 eggs of H. armigera . These results indicate that T. pretiosum parasite with superior performance in eggs of up to 36h of age and densities of 20 eggs per female day- 1 in laboratory conditions. These results will help to establish the intervals between releases of parasitoids, aiming to control this pest, when adjusted with knowledge of the survival of the parasitoids in the field and in pest infestation.

Este trabalho avaliou o parasitismo de Trichogramma pretiosum Riley (Hymenoptera: Trichogrammatidae) em ovos de Helicoverpa armigera Hübner (Lepidoptera: Noctuidae) em diferentes idades e densidades. As taxas de parasitismo e emergência, número de parasitoides emergidos por ovo e razão sexual dos descendentes foram avaliados em ambos os experimentos. Ovos de H. armigera de até 36 horas proporcionaram maior parasitismo e emergência dos adultos em comparação com ovos com até 60 horas de idade. O número de parasitoides, que emergiram por ovo hospedeiro, foi superior a 1 e a razão sexual permaneceu em torno de 80% de fêmeas, independentemente do estágio de desenvolvimento do ovo. Fêmeas de T. pretiosum responderam com taxas superiores de parasitismo, emergência e número de parasitoides por ovo nas densidades de 20 e 25 ovos de H. armigera. Estes resultados indicam que T. pretiosum parasita com desempenho superior em ovos de até 36h de idade e densidades de 20 ovos por fêmea dia-1 em condições laboratoriais. Estes resultados ajudarão a estabelecer os intervalos entre as liberações de parasitoides, visando o controle desta praga, quando ajustado com o conhecimento da sobrevivência dos parasitoides no campo e na infestação de pragas.

Humic Fertilizer and Vermicompost Applied to the Soil Can Positively Affect Population Growth Parameters of Trichogramma brassicae (Hymenoptera: Trichogrammatidae) on Eggs of Tuta absoluta (Lepidoptera: Gelechiidae).

The tomato leaf miner, Tuta absoluta (Meyrick), is a devastating pest of tomato worldwide. One of the control measures of T. absoluta is the use of biological control agents, such as Trichogramma wasps. Interactions between natural enemies and insect pests may be affected by application of fertilizers, because changes in plant quality through the fertilizer application may therefore affect herbivore characteristics and suitability of them to parasitism. Laboratory tests were carried out to evaluate the life table parameters of Trichogramma brassicae Bezdenko on T. absoluta eggs reared on tomato plants treated either with vermicompost (40%), humic fertilizer (2 g/kg soil), or control (suitable mixture of field soil and sand). Population growth parameters of T. brassicae were affected by fertilizer treatments. Significant differences were found for immature life period and total fecundity of T. brassicae on the treatments. Differences of intrinsic rate of natural increase (r m), finite rate of increase (λ), net reproductive rate (R 0), mean generation time (T), and doubling time (DT) of T. brassicae among treatments were also significant. The lowest values of r m, λ, and R 0 were recorded for T. brassicae developed on T. absoluta eggs on control treatment, whereas the highest values of these parameters were observed on 2 g/kg humic fertilizer. Furthermore, T. brassicae had the shortest T and DT values on 2 g/kg humic fertilizer and 40% vermicompost treatments. Our results showed that application of humic fertilizer and vermicompost could positively affect population growth parameters of T. brassicae on eggs of T. absoluta fed on tomato plants.

Geographic distribution, large-scale spatial structure and diversity of parasitoids of the seed-feeding beetle Acanthoscelides macrophthalmus.

Bruchine beetles are highly host-specific seed feeders during the larval stage. Although some specific parasitoid families have been recorded attacking bruchine beetles, most studies have been done at small spatial scales. Therefore, the current knowledge about the diversity and the geographic distribution of parasitoid species parasitizing bruchines is scarce, especially at a wide geographic area that extends over large distances through a latitudinal cline (i.e. large-scale spatial structure). The present study determined the species richness and evenness of parasitoids attacking the bruchine beetle Acanthoscelides macrophthalmus feeding on Leucaena leucocephala seeds, examined their geographic distribution, and characterized the large-scale spatial structure in parasitoid species composition. A total of 1420 parasitoids (all Hymenoptera) belonging to four families, five subfamilies and eight species were collected (genera: Horismenus, Paracrias, Urosigalphus, Stenocorse, Chryseida, Eupelmus). Most parasitoid species showed wide spatial distribution, high evenness in species abundance and the species richness estimators were close to stabilization (approximately eight species). Overall, greater similarity was observed in the species composition of plant populations near to each other than those farther apart, revealing a large-scale spatial structure in parasitoid species composition.

Symbiofauna associated to the reproductive system of Cotesia flavipes and Doryctobracon areolatus (Hymenoptera, Braconidae)

The diversity of symbionts associated with insects and the range of effects they exert on their hosts haveprompted studies to understand the role these microorganisms may have on host biology, particularly inrelation to the interaction of their hosts with other trophic levels. There is also a possibility of using suchsymbionts as vectors of genes for insect control or learning on the mechanisms they use to interact with theirhosts for the development of new approaches to insect control. Since most of these symbionts are transmittedtransovarially from one generation to another, we used electron microscopy to assess the occurrence andmorphology of these microorganisms in the female reproductive tissues of two important insect pestparasitoids, the braconids Cotesia flavipes and Doryctobracon areolatus. Cotesia flavipes was associatedwith a polydnavirus (PDV), whereas D. areolatus harbored the rickettsia-like bacterium Wolbachia. Theultrastructural morphology and localization of these symbionts in their host ovaries are described. None ofthe populations of the species studied were associated with non-PDV particles, and their sole associationwith specific symbionts will facilitate studies on the role of these symbionts in the association with theirhosts, and on the associations of their hosts with other trophic levels.

Diversidade e tamanho de himenópteros parasitóides de Brevicoryne brassicae L. e Aphis nerii Boyer de Fonscolombe (Hemiptera: Aphididae) / Diversity and size of parasitic Hymenoptera of Brevicoryne brassicae L. and Aphis nerii Boyer de Fonscolombe (Hemiptera: Aphididae)

Este trabalho teve o objetivo de registrar a diversidade de himenópteros parasitóides dos pulgões Brevicoryne brassicae L. e Aphis nerii Boyer de Fonscolombe em Uberlândia, MG e verificar se o tamanho dos parasitóides se relaciona com o tamanho das múmias de duas espécies de hospedeiros. B. brassicae foram coletados em couve Manteiga (Brassica oleraceae L. var. acephala D.C.) e A. nerii em oficial-de-sala (Asclepias curassavica L.). As coletas foram realizadas mensalmente, no período de maio de 1999 a maio de 2000, em dois Jardins Experimentais. Medidas morfométricas realizadas tanto nas múmias quanto nos parasitóides foram simplificadas pela Análise de Componente Principal, obtendo-se um índice multivariado de tamanho. As espécies de himenópteros parasitas A. nerii foram as mesmas observadas em B. brassicae, porém com freqüências relativas diferentes. Em B. brassicae foram encontrados os parasitóides: Diaeretiella rapae (M'Intoch) (93,2 por cento), Aphidius colemani Viereck (4,5 por cento), Lysiphlebus testaceipes (Cresson) (2,3 por cento) e os hiperparasitóides Alloxysta fuscicornis (Ashmead) (57,7 por cento), Syrphophagus aphidivorus (Mayr) (25,1 por cento) e Pachyneuron sp. (17,1 por cento). Em A. nerii os parasitóides encontrados foram L. testaceipes (96,1 por cento), A. colemani (3,9 por cento) e os hiperparasitóides Pachyneuron sp. (85,2 por cento) e S. aphidivorus (14,8 por cento). O tamanho dos parasitóides correlacionou-se com o tamanho das múmias, tanto em A. nerii quanto em B. brassicae. S. aphidivorus provenientes de A. nerii foram significativamente maiores que os de B. brassicae. O mesmo não ocorreu para L. testaceipes, A. colemani e Pachyneuron sp. Múmias de A. nerii também foram significativamente maiores que as de B. brassicae. Não foi detectado dimorfismo sexual para o tamanho

The objective of this work was to record the diversity of parasitoid of two aphid species, Brevicoryne brassicae L. and Aphis nerii Boyer de Fonscolombe in a site at Uberlândia, MG, and the relationship between parasitoid size and their mummies size, with reference to the host species. B. brassicae were collected on kale (Brassica oleracea L. var. acephala D.C.) and A nerii on milkweed (Asclepias curassavica L.). Samplings were made monthly from May, 1999 to May, 2000 in two experimental gardens. Morphometric measurements for both aphids and parasitoids were simplified by PCA analysis to achieve a multivariate size index. The parasitic Hymenoptera species associated with A. nerii were also found as parasitoids of B. brassicae, but with distinctive relative frequencies. Diaeretiella rapae (M'Intoch) (93.2 percent), Aphidius colemani Viereck (4.5 percent) and Lysiphlebus testaceipes (Cresson) (2.3 percent) were the parasitoids obtained from B. brassicae. Hyperparasitoids associated with these parasitoids were Alloxysta fuscicornis (Ashmead) (57.8 percent), Syrphophagus aphidivorus (Mayr) (25.1 percent) and Pachyneuron sp. (17.1 percent). The parasitoids found in A. nerii were: L. testaceipes (96.1 percent), A. colemani (3.9 percent) and the hyperparasitoids Pachyneuron sp. (85.2 percent) and S. aphidivorus (14.8 percent). Parasitoid size was correlated with mummy size for both A. nerii and B. brassicae. S. aphidivorus from A. nerii were significantly larger than those from B. brassicae. However, such differences were not detected for L. testaceipes, A. colemani or for Pachyneuron. Mummies of A. nerii were significantly larger than those of B. brassicae. No sexual dimorphism for size was detected