Female Parasites Research Articles

Assessment of the parasitism potential of three parasitoids of fruit fly, Bactrocera spp. (Diptera: Tephritidae) under laboratory conditions

The parasitism potential of a pupal parasitoid, Dirhinus giffardii Silvestri and two larval-pupal parasitoids, Diachasmimorpha longicaudata (Ashmead) and Aganapis daci (Weld) was assessed against Bactrocera spp. under laboratory conditions. Three different types of hosts, viz. Bactrocera zonata (Saunders), Bactrocera dorsalis (Hendel) and Bactrocera cucurbitae (Coquillett) were reared on artificial larval diet and known number of pupae and larvae of each fruit fly species were offered to the respective parasitoids in glass cages in a no choice test. Results on the parasitism potential of D. giffardii towards pupae of different fruit fly species revealed that the highest per female parasitism was recorded on B. zonata (16.72 ±1.67). Adult emergence percentage of D. giffardii did not differ significantly among all the three Bactrocera spp. Sex ratio of the emerged parasitoids revealed maximum percent females (61.64 ± 2.67) from pupae of B. cucurbitae. Similarly per female parasitism by D. longicaudata was also significantly the highest on larvae of B. zonata (26.40 ± 1.79) with maximum adult emergence percentage of 93.41 ± 2.54. Sex ratio of the emerged D. longicaudata did not differ significantly. Parasitism rate of A. daci was significantly the highest on larvae of B. zonata (24.88 ± 2.01) with insignificant differences in the adult emergence percentage. Sex ratio of A. daci showed that percent females from the emerged parasitoids were the highest (54.2 ± 3.44) on B. dorsalis. Relative collective parasitism per female by all the three fruit fly parasitoids revealed that highest parasitism rate (23.7 ± 2.26) was exhibited by D. longicaudata followed by A. daci (22.72 ± 2.14). The study manifested that B. zonata could be the ideal host for laboratory rearing of these parasitoids. Keywords: Bactrocera; Emergence; Fruit fly; Host; Parasitoids; Parasitism; Sex ratio http://dx.doi.org/10.19045/bspab.2019.80099

Characterization of a non-sexual population of Strongyloides stercoralis with hybrid 18S rDNA haplotypes in Guangxi, Southern China.

Strongyloidiasis is a much-neglected but sometimes fatal soil born helminthiasis. The causing agent, the small intestinal parasitic nematode Strongyloides stercoralis can reproduce sexually through the indirect/heterogonic life cycle, or asexually through the auto-infective or the direct/homogonic life cycles. Usually, among the progeny of the parasitic females both, parthenogenetic parasitic (females only) and sexual free-living (females and males) individuals, are present simultaneously. We isolated S. stercoralis from people living in a village with a high incidence of parasitic helminths, in particular liver flukes (Clonorchis sinensis) and hookworms, in the southern Chinese province Guangxi. We determined nuclear and mitochondrial DNA sequences of individual S. stercoralis isolated from this village and from close by hospitals and we compared these S. stercoralis among themselves and with selected published S. stercoralis from other geographic locations. For comparison, we also analyzed the hookworms present in the same location. We found that, compared to earlier studies of S. stercoralis populations in South East Asia, all S. stercoralis sampled in our study area were very closely related, suggesting a recent common source of infection for all patients. In contrast, the hookworms from the same location, while all belonging to the species Necator americanus, showed rather extensive genetic diversity even within host individuals. Different from earlier studies conducted in other geographic locations, almost all S. stercoralis in this study appeared heterozygous for different sequence variants of the 18S rDNA hypervariable regions (HVR) I and IV. In contrast to earlier investigations, except for three males, all S. stercoralis we isolated in this study were infective larvae, suggesting that the sampled population reproduces predominantly, if not exclusively through the clonal life cycles. Consistently, whole genome sequencing of individual worms revealed higher heterozygosity than reported earlier for likely sexual populations of S. stercoralis. Elevated heterozygosity is frequently associated with asexual clonal reproduction.

In vitro schistosomicidal activity of tamoxifen and its effectiveness in a murine model of schistosomiasis at a single dose.

Schistosomiasis is a neglected tropical disease affecting 220 million people worldwide. Praziquantel has proven to be effective against this parasitic disease, though there are increasing concerns regarding tolerance/resistance that calls for new drugs. Repurposing already existing and well-known drugs has been a desirable approach since it reduces time, costs, and ethical concerns. The anti-cancer drug tamoxifen (TAM) has been used worldwide for several decades to treat and prevent breast cancer. Previous reports stated that TAM affects Schistosoma hormonal physiology; however, no controlled schistosomicidal in vivo assays have been conducted. In this work, we evaluated the effect of TAM on female and male Schistosoma mansoni morphology, motility, and egg production. We further assessed worm survival and egg production in S. mansoni-infected mice. TAM induced morphological alterations in male and female parasites, as well as in eggs in vitro. Furthermore, in our in vivo experiments, one single dose of intraperitoneal TAM citrate reduced the total worm burden by 73% and led to a decrease in the amount of eggs in feces and low percentages of immature eggs in the small intestine wall. Eggs obtained from TAM citrate-treated mice were reduced in size and presented hyper-vacuolated structures. Our results suggest that TAM may be repurposed as a therapeutic alternative against S. mansoni infections.

Detection and quantification of Parascaris P-glycoprotein drug transporter expression with a novel mRNA hybridization technique

Macrocyclic lactone-resistant Parascaris have been reported throughout the world. In part, the drug resistant phenotype is hypothesized to be associated with ATP-binding cassette transporters known as P-glycoproteins. In many systems, P-glycoproteins efflux drugs out of cells thereby precluding drug binding to target receptors. Parascaris may evade macrocyclic lactone-mediated death by effluxing drugs away from target receptors in the nervous system. Alternatively, P-glycoprotein expression in the gut or body wall could prevent penetration of drugs into the body of the parasite altogether. In the present study, we evaluate expression of Peq-pgp-11 and Peq-pgp-16 using a novel multiple nucleic acid hybridization method. This method allowed for visualization of individual mRNA transcripts within fixed tissue sections of Parascaris adults. Our investigation revealed expression of Peq-pgp-11 and Peq-pgp-16 in the intestine, body wall, nerves, lateral cords, and reproductive tissues of male and female parasites. These results suggest that Pgp could efflux drugs locally at the level of parasite neuronal tissue as well as at sites of entry for drugs such as the hypodermis and intestine. The multiple nucleic acid hybridization method could be useful for providing tissue context for gene expression in a variety of nematode parasites.

Understanding growth relationships of African cymothoid fish parasitic isopods using specimens from museum and field collections.

Cymothoid isopods are a diverse group of ectoparasites of fish species, and are particularly conspicuous as they are large and attach to the body surface, mouth, and gill chamber of fish hosts. These parasites transition from juvenile to male to female, and how their size changes with ontogeny and correlates with host size is not well understood. To better understand these relationships, data from field and museum collected samples of South Africa were combined to test for the associations between host and parasite length for three mouth and one gill chamber-infesting genera (Ceratothoa, Cinusa, Cymothoa, and Mothocya respectively). Generally, the number of parasites collected from 90 h of museum surveying was similar to that of seven, one-week long field collections. For two of the three mouth-infesting parasites, parasite and host size were significantly and positively correlated for males and females, but not juveniles. For gill chamber-infesting parasites, female and male parasite sizes were weakly and not significantly correlated with host size. These results provide the first morphometric data and growth relationship data for African cymothoid species and their fish hosts, and demonstrate the value and efficiency of using museum collections in ecological research.

MORPHOLOGY AND MORPHOMETRY OF Haemonchus contortus IN GOATS IN YOGYAKARTA, INDONESIA

This research was carried out to determine the morphology and morphometry of Haemonchus contortus in goats. Adult female parasites were collected from abomasum of naturally infected goats and stored in lactophenol. Images of the parasite were acquired using lucida camera and measurement was performed using Axiovision LE software. Basic characters of the morphology and morphometry of Haemonchus spp. were identified by determining the value of the discriminant function of three parameters on spicule. Vulvar morphology was identified by vulvar flap shape. Data were presented in terms of mean, standard deviation, and percentage. A hundred percent of the parasites were H. contortus with discriminant function value 0.63. The size of female parasites was longer and wider (25.5-32.6 mm; 0.38-0.63 mm) than that of male ones (17.3-20.0 mm; 0.24-0.33 mm). There were only 2 varieties of vulvar flap, linguiform (81%), and knobbed (19%). There were 5 subclasses identified in the linguiform type, including linguiform A (39%), linguiform B (22%), linguiform C (17%), linguiform I (1%), and a new subclass of linguiform D (2%). Based on the the type of vulvar flap, H. contortus found in goats in Yogyakarta were different to those found in previous researches. The findings could be used in identifying the parasite species in small ruminants.

Secretome analysis of Strongyloides venezuelensis parasitic stages reveals that soluble and insoluble proteins are involved in its parasitism

BackgroundParasites excrete and secrete a wide range of molecules that act as the primary interface with their hosts and play critical roles in establishing parasitism during different stages of infection. Strongyloides venezuelensis is a gastrointestinal parasite of rats that is widely used as a laboratory model and is known to produce both soluble and insoluble (adhesive) secretions during its parasitic stages. However, little is known about the constituents of these secretions.ResultsUsing mass spectrometry, we identified 436 proteins from the infective third-stage larvae (iL3s) and 196 proteins from the parasitic females of S. venezuelensis. The proteins that were secreted by the iL3s were enriched with peptidase activity, embryo development and the oxidation-reduction process, while those of the parasitic females were associated with glycolysis, DNA binding (histones) and other unknown functions. Trypsin inhibitor-like domain-containing proteins were identified as the main component of the adhesive secretion from parasitic females. An absence of secretion signals in many of the proteins indicated that they are secreted via non-classical secretion pathways.ConclusionsWe found that S. venezuelensis secretes a wide range of proteins to establish parasitism. This includes proteins that have previously been identified as being involved in parasitism in other helminths as well as proteins that are unique to this species. These findings provide insights into the molecular mechanisms underlying Strongyloides parasitism.

AWZ1066S, a highly specific anti-Wolbachia drug candidate for a short-course treatment of filariasis

Onchocerciasis and lymphatic filariasis are two neglected tropical diseases that together affect ∼157 million people and inflict severe disability. Both diseases are caused by parasitic filarial nematodes with elimination efforts constrained by the lack of a safe drug that can kill the adult filaria (macrofilaricide). Previous proof-of-concept human trials have demonstrated that depleting >90% of the essential nematode endosymbiont bacterium, Wolbachia, using antibiotics, can lead to permanent sterilization of adult female parasites and a safe macrofilaricidal outcome. AWZ1066S is a highly specific anti-Wolbachia candidate selected through a lead optimization program focused on balancing efficacy, safety and drug metabolism/pharmacokinetic (DMPK) features of a thienopyrimidine/quinazoline scaffold derived from phenotypic screening. AWZ1066S shows superior efficacy to existing anti-Wolbachia therapies in validated preclinical models of infection and has DMPK characteristics that are compatible with a short therapeutic regimen of 7 days or less. This candidate molecule is well-positioned for onward development and has the potential to make a significant impact on communities affected by filariasis.

Anti-parasitic activity of garlic (Allium sativum) and onion (Allium cepa) juice against crustacean parasite, Lernantropus kroyeri, found on European sea bass (Dicentrarchus labrax)

The copepod parasite Lernantropus kroyeri impairs the productivity of European sea bass (Dicentrarchus labrax) culture by leading to a direct infection or as a vector for other disease agents. In current conditions, the parasitic infections in mariculture are usually treated with the chemicals, mainly with the pesticides. However, therapeutic chemical use has potential risks on the overall aquatic environment. Thus, the aquaculture sector needs to find alternative substances to the treatment or prophylaxis of the diseases instead of chemicals. In the present study, in vitro exposure tests were performed to elucidate the effects of garlic (Allium sativum) and onion (Allium cepa) on adult L. kroyeri. Female individuals of L. kroyeri were exposed to different concentrations of garlic or onion juice (20, 40, 60, 80 and 100% of the plant juice) for a specified time. Garlic juice exposure at a ratio of 100% resulted in instantaneous death of all individuals in five minutes. Although the killing time varied by the concentration, garlic juice killed the L. kroyeri females within 30 min even at the lowest concentration. Onion juice had lower killing effect at low concentrations, however, higher concentrations of onion juice killed the female parasites within 60 min. Results revealed that garlic and onion juices had killing effect on L. kroyeri females in a time and concentration-dependent manner. It can be concluded that against parasitic copepods alternative solutions can be developed in aquaculture, using these plant juices with emphasising necessity of further in vivo tolerance tests in fish.HighlightsGarlic and onion juices had anti-parasitic effect in vitro on the crustacean parasite, Lernantropus kroyeri found on the gills of European sea bass (Dicentrarchus labrax).After exposure of L. kroyeri to garlic and onion juices, the mortality was time and concentration-dependent.The killing activity of garlic juice for L. kroyeri was stronger than that of onion juice.

Efecto de diferentes temperaturas y tiempos de conservación sobre pupas de Apanteles gelechiidivoris (Hymenoptera: Braconidae)

Apanteles gelechiidivoris parasitoide de larvas de tercer estadio de Tuta absoluta, puede generar hasta 80 % de mortalidad de larvas en campo. Para producir masivamente el parasitoide es necesario tener almacenamiento en frío de pupas, para conservar cantidades importantes sin perder características biológicas. Se evaluaron diferentes temperaturas y tiempos de conservación en frío sobre parámetros biológicos en los estados de pupa y adulto. Las pupas se sometieron a 4, 8 y 12 °C por 7, 14, 21 y 28 días de almacenamiento. A 4 y 8 °C se retrasó el tiempo de emergencia después del almacenamiento frío, siendo más corto a siete días en cada temperatura. La emergencia de adultos fue más baja a 4 °C al disminuir significativamente conforme aumentaron los días de almacenamiento. En 8 y 12 °C se presentaron porcentajes de emergencia de 90 y 100, respectivamente, a los siete días de almacenamiento. No hubo efecto entre las temperaturas y días de almacenamiento, o su interacción, en la cantidad de hembras producidas (P > 0,05). La longevidad de adultos disminuyó al aumentar el tiempo de conservación. En 8 °C se presentó la mayor longevidad de adultos (9 días) a 7 y 14 días de almacenamiento. A 4 °C se afectó el parasitismo de las hembras que emergieron de pupas en los días de almacenamiento evaluados; en 8 °C, se obtuvo el porcentaje de parasitismo más alto (80 %) a 7 días de almacenamiento. Los resultados sugieren que las pupas pueden ser almacenadas hasta 14 días a 8 °C, sin afectar efectividad del parasitoide.

Strongyloides stercoralis infection in imported and local dogs in Switzerland: from clinics to molecular genetics.

Strongyloides stercoralis is a worldwide-distributed intestinal nematode affecting mainly humans and dogs. Canine strongyloidosis is generally characterised by diarrhoea, malabsorption and bronchopneumonia, and may be fatal in cases of impaired immunity. In recent years, molecular and epidemiological studies suggested that host-adapted populations of S. stercoralis with different zoonotic potential may exist. Clinical and subclinical cases of S. stercoralis infection have been increasingly diagnosed in imported (France, Belgium, Bulgaria) and locally born dogs in Switzerland, showing that this parasite is currently circulating in Europe. Three of these clinical cases will be described here. All three dogs presented severe disease, characterised by harsh diarrhoea, dehydration, vomiting, respiratory and/or neurologic signs, and needed intensive care and hospitalisation. One of these dogs was related to a Swiss breeding kennel, in which the infection was subsequently diagnosed in several other dogs. Faeces were analysed by three coproscopical methods including (i) the Baermann technique, which consistently identified the typical S. stercoralis first-stage larvae in both clinical and subclinical infections, (ii) the sedimentation-zinc chloride flotation and (iii) sodium acetate-acetic acid-formalin concentration (SAFC) methods, which allowed the additional identification of parasitic females and/or eggs in two of the clinical cases. Interestingly, S. stercoralis isolated from all three independent clinical cases exhibited an identical genetic background on the nuclear 18S rDNA (fragment involving hypervariable regions I and IV) and the mitochondrial cytochrome oxidase subunit I (cox1) loci, similar to that of zoonotic isolates from other geographical regions, and not to that of dog-adapted variants. Due to the clinical relevance and zoonotic potential of this parasite, the awareness of both diagnosticians and clinicians is strongly required.

Rethinking the New Woman in Dracula

The existing canon of scholarship on Dracula asserts that the sexually aggressive female vampires are representative of the New Woman, and thus are evidence of Stoker's conservative reaction to changing gender roles. In contrast, this article offers a reinterpretation Dracula in the light of key writings of the New Woman movement which sought to demonize the Victorian marriage market because of its creation of a class of female parasites: idle middle-class woman entirely dependent on fathers and husbands. A close reading of key sections of the novel demonstrates that the female vampires are characterized as traditionally subordinate Victorian housewives, in contrast to the positive presentation of Mina Harker as a New Woman. This reading reveals a text that argues that work for women is the only antidote to the degeneration inherent in traditional womanhood, through which women are reduced to nothing more than their biological functions.

Bioactivity of ten essential oils on the biological parameters of Trichogramma pretiosum (Hymenoptera: Trichogrammatidae) adults

Trichogrammatidae are biological control agents of agricultural and forest pests. However, chemicals can affect their biological aspects. Essential oils (EOs) are an alternative for pest control, but their effect on biological control agents are not fully known. The objective was to evaluate the effects of EOs of Allium sativum, Carapa guianensis, Citrus sinensis, Mentha piperita, Origanum vulgare, Piper nigrum, Syzygium aromarticum, Thymus vulgaris, Zingiber officinale and Azadirachta indica on the female longevity, parasitism and emergence rates and sex ratio of Trichogramma pretiosum (Riley) (Hymenoptera: Trichogrammatidae) adults of parental, F1 and F2 generations. The longevity of T. pretiosum females in the parental and F1 generations was reduced ∼50% by the EOs of A. sativum and M. piperita in comparison to controls (∼10 days). Eggs of Anagasta kuehniella (Zeller) (Lepidoptera: Pyralidae) treated with Z. officinale were not parasitized, evidencing a strong repellent activity of this EO. Allium sativum and C. guianensis EOs reduced the parasitism rate in 33 and 70%, respectively, of females from the parental T. pretiosum generation. These EOs were classified as slightly harmful (class 2) in relation to parasitism. Carapa guianensis caused the greatest reduction in the emergence rate of the F1 generation (27%); however, this EO continued to be classified as innocuous to T. pretiosum. Sex ratio of the F1 and F2T. pretiosum generations was no affect by these ten EOs. Zingiber officinale was not compatible for T. pretiosum; and A. sativum, C. guianensis and M. piperita are poorly compatible with this parasitoid. The EOs of the other six plant species are promising for integrated pest management with T. pretiosum.

Severe granulomatous hepatitis caused by Capillaria hepatica in a puppy

This report describes the inflammation caused by Capillaria hepatica in the liver of a female stray dog of approximately 2 months old for the first time in Turkey. Histopathological examination revealed severe granulomatous hepatitis with occasional adult nematodes and abundant eggs in the hepatic parenchyma. The present case differs from the other capillariasis cases by the age of the dog and the presence of mature female parasites and severe inflammation.

The Plasmodium falciparum male gametocyte protein P230p, a paralog of P230, is vital for ookinete formation and mosquito transmission

Two members of 6-cysteine (6-cys) protein family, P48/45 and P230, are important for gamete fertility in rodent and human malaria parasites and are leading transmission blocking vaccine antigens. Rodent and human parasites encode a paralog of P230, called P230p. While P230 is expressed in male and female parasites, P230p is expressed only in male gametocytes and gametes. In rodent malaria parasites this protein is dispensable throughout the complete life-cycle; however, its function in P. falciparum is unknown. Using CRISPR/Cas9 methodology we disrupted the gene encoding Pfp230p resulting in P. falciparum mutants (PfΔp230p) lacking P230p expression. The PfΔp230p mutants produced normal numbers of male and female gametocytes, which retained expression of P48/45 and P230. Upon activation male PfΔp230p gametocytes undergo exflagellation and form male gametes. However, male gametes are unable to attach to red blood cells resulting in the absence of characteristic exflagellation centres in vitro. In the absence of P230p, zygote formation as well as oocyst and sporozoite development were strongly reduced (>98%) in mosquitoes. These observations demonstrate that P230p, like P230 and P48/45, has a vital role in P. falciparum male fertility and zygote formation and warrants further investigation as a potential transmission blocking vaccine candidate.

Comparative characterization of two galectins excreted-secreted from intestine-dwelling parasitic versus free-living females of the soil-transmitted nematode Strongyloides

Helminths are complex pathogens that ensure their long-term survival by influencing the immune responses of their host. Excretory/secretory products (ESP) can exert immunoregulatory effects which foster parasite survival. Galectins represent a widespread group of β-galactoside-binding proteins which are involved in a multitude of biological processes operative in parasite-host interaction. We had earlier identified seven galectins in Strongyloides ratti, four of them detected in the ESP of distinct developmental stages of the parasite. In the present report, we focused on the characterization of two of them, Sr-galectin-1 (Sr-Gal-1) and Sr-galectin-3 (Sr-Gal-3). While Sr-Gal-3 expression was strongest in parasitic females, Sr-Gal-1 was predominantly expressed in free-living females. Both proteins were cloned and recombinantly expressed in an E. coli expression system. Their glycan-binding activity was verified by haemagglutination and glycan array analysis. Furthermore, primary immunological activities of the Sr-galectins were initially investigated by the application of an in vitro mucosal 3D-culture model, comprising of mucosa-associated epithelial and dendritic cells. The Sr-galectins stimulated preferentially the release of the type 2 cytokines thymic stromal lymphopoietin and IL-22, a first indication for immunoregulatory activity. In addition, the Sr-galectins dose-dependently fostered cell migration. Our results confirm the importance of these carbohydrate-binding proteins in host-parasite-interaction by indicating possible interaction with the host mucosa-associated cells.

A landscape perspective on rates of multiple paternity and brood parasitism among Greater Prairie-Chickens across Kansas, USA

ABSTRACT Fragmentation and degraded habitat conditions can result in increased competition for critical resources, altered mating systems, and can eventually result in population declines or extinction. We investigated the degree to which habitat degradation and habitat loss impacted the breeding ecology of Greater Prairie-Chickens at 3 study sites across relatively intact grasslands in Kansas, USA. Across all 3 study systems, we found similar rates of multiple mating by females at 14–20% of broods. In addition, we found evidence for facultative nest parasitism of conspecific females. Prairie-chicken females inhabiting more intact and less fragmented landscapes with a higher probability of survival did not engage in parasitic egg laying, whereas ∼17% of females inhabiting a more fragmented and isolated landscape engaged in parasitic egg laying. Parasitic egg layers tended to be older females that parasitized nests of yearling females. Parasitic egg layers only laid parasitically after an initial nesting a...

Density of Diachasmimorpha longicaudata (Ashmead) and host Ceratitis capitata (Wied) larvae for the increase of parasitoid female production

ABSTRACT: The objective of the present study was to evaluate the ratio of Ceratitis capitata larvae/female of Diachasmimorpha longicaudata that results in the increase of parasitism and the production of females in the progeny. We used 8-day-old copulated D. longicaudata females with oviposition parasite experience and third instar larvae of C. capitata from rearing stock maintained at the Laboratory of Biological Control of Universidade Estadual de Montes Claros (Unimontes). Five densities of C. capitata larvae (10, 20, 30, 40, and 50) were offered to parasitoid females that were at five different densities (1, 2, 5, 10, and 15). The larvae were exposed to the parasitoid females by means of “parasitism units” in adapted cages for 1 hour. Sex ratio, percentage of parasitism, and pupal mortality were evaluated. Both host larval density and female parasite density influenced parasitism, female progeny production, and pupal mortality. Higher female production was observed in the progeny in ratios of 1:1 and 2:1 (larvae/females). Ratios above 1:2 reduced the sex ratio, and ratios below 1:1 caused high pupal mortality rates. The females had higher parasitism activity when they were in groups dividing the same space. Equal ratios of Ceratitis capitata larvae and parasitoid females resulted in improved efficiency in progeny females.

Brood parasitism, relatedness and sociality: a kinship role in female reproductive tactics.

Conspecific brood parasitism (CBP) is a reproductive tactic in which parasitic females lay eggs in nests of other females of the same species that then raise the joint brood. Parasites benefit by increased reproduction, without costs of parental care for the parasitic eggs. CBP occurs in many egg-laying animals, among birds most often in species with large clutches and self-feeding young: two major factors facilitating successful parasitism. CBP is particularly common in waterfowl (Anatidae), a group with female-biased natal philopatry and locally related females. Theory suggests that relatedness between host and parasite can lead to inclusive fitness benefits for both, but if host costs are high, parasites should instead target unrelated females. Pairwise relatedness (r) in host-parasite (h-p) pairs of females has been estimated using molecular genetic methods in seven waterfowl (10 studies). In many h-p pairs, the two females were unrelated (with low r, near the local population mean). However, close relatives (r = 0.5) were over-represented in h-p pairs, which in all 10 studies had higher mean relatedness than other females. In one species where this was studied, h-p relatedness was higher than between nesting close neighbours, and hosts parasitized by non-relatives aggressively rejected other females. In another species, birth nest-mates (mother-daughters, sisters) associated in the breeding area as adults, and became h-p pairs more often than expected by chance. These and other results point to recognition of birth nest-mates and perhaps other close relatives. For small to medium host clutch sizes, addition of a few parasitic eggs need not reduce host offspring success. Estimates in two species suggest that hosts can then gain inclusive fitness if parasitized by relatives. Other evidence of female cooperation is incubation by old eider Somateria mollissima females of clutches laid by their relatives, and merging and joint care of broods of young. Merging females tended to be more closely related. Eiders associate with kin in many situations, and in some geese and swans, related females may associate over many years. Recent genetic evidence shows that also New World quails (Odontophoridae) have female-biased natal philopatry, CBP and brood merging, inviting further study and comparison with waterfowl. Kin-related parasitism also occurs in some insects, with revealing parallels and differences compared to birds. In hemipteran bugs, receiving extra eggs is beneficial for hosts by diluting offspring predation. In eggplant lace bugs Gargaphia solani, host and parasite are closely related, and kin selection favours egg donation to related females. Further studies of kinship in CBP, brood merging and other contexts can test if some of these species are socially more advanced than presently known.

Biological Characteristics and Parasitism Capacity of Telenomus podisi (Hymenoptera: Platygastridae) on Eggs of Euschistus heros (Hemiptera: Pentatomidae)

We evaluated the effects of adult mating and temperature on the biological potential and parasitism of Telenomus podisi (Ashmead) (Hymenoptera: Platygastridae) on Euschistus heros (Fabricius) (Hemiptera: Pentatomidae). Females were isolated and the characteristics of the F1 generation were compared with those of females previously copulated. The parasitism capacity of T. podisi on E. heros eggs at 20, 25, 30, 35, and 40 °C was evaluated. The longevity of parental females (days), egg-adult period (days) of the F1 generation, parasitism of parental females (%), and parasitoid emergence (%) were not influenced by the lack or not of the copulation. The offspring of non-copulated females were males, and arrhenotokous parthenogenesis occurred. The temperatures most favorable to the parasitoid were 25 and 30 °C. Even previously copulated females generated mostly males after a few days of oviposition. Therefore, the biological characteristics and reproduction of T. podisi were impacted by adult mating prior to parasitism and by different temperatures. Although parasitism of T. podisi was not affected by mating parasitoid permanence in the field, it may be affected when unmated females are released.