Presence Of Parasitoids Research Articles

Strength of enemy release from parasitoids is context-dependent in the invasive African Fig Fly, Zaprionus indianus.

Understanding the mechanisms underlying the success of biological invasions is essential to employ effective prediction and management strategies. Escape from natural enemies in invaded regions (enemy release hypothesis, ERH) and increased competitive ability are hallmarks of invasive species; however, these two processes are rarely studied within the same context. Here, we examined the effect of enemy release on the competition outcomes of a successful invasive insect pest in North America, the African fig fly (Zaprionus indianus). Parasitoid wasps such as Leptopilina heterotoma that parasitize drosophilid larvae may seek out established species with known host suitability over a novel species, so we hypothesized Z. indianus may have low susceptibility to parasitoids, giving them a competitive advantage over co-occurring drosophilids. We tested this hypothesis by comparing the adult emergence rates from Z. indianus larvae reared alone or in competition with Drosophila hydei or D. simulans larvae in the presence and absence of parasitoid wasps under low and high larval densities. At low larval densities, Z. indianus emerged at equal rates to D. hydei but outcompeted D. simulans, and these outcomes were not affected by parasitoids. However, at high densities, the addition of parasitoids shifted competition outcomes in favor of Z. indianus, suggesting enemy release provides a competitive advantage under some circumstances. These results indicate that the strength of enemy release in Z. indianus is widely dependent on contextual factors such as density and competitor species. This study emphasizes how a community approach to testing the ERH is vital as the overall interpretation of the presence and strength of enemy release differed between intraspecific and interspecific experiments. Further investigation of how these results apply to field environments could offer insight into how Z. indianus alters ecosystems and how productive biological control may limit the spread of Z. indianus.

Evaluation of biological control option for Bagrada bug (Bagrada hilaris (Burmeister)) in Kenya

Brassica production is important for economic development of Kenya. Bagrada bug, a significant pest of brassicas, affects their yields and quality, currently posing a threat to both local and commercial vegetable production in Kenya. Biological control of bagrada bug using natural enemies is a cheaper and environmentally friendly method. The study aimed to identify native egg parasitoid species in Kenya. A field prospection survey of the bagrada bug egg parasitoid was done by a series of bagrada bug egg exposure in different parts of the country. Freshly laid bagrada bug eggs in cards were exposed for possible parasitism in the field for three days. The eggs were later carried to the laboratory at NSRC to await hatching. Two egg parasitoid species Trissolcus basalis (Hymenoptera, Scelionidae) and Gryon sp. were identified during the study after a period of bagrada bug egg exposure in Machakos and Kisumu. Two cards with parasitized bagrada bug eggs were recovered from Machakos from which one card yielded four parasitoids of one species Trissolcus basalis and the other yielded two parasitoids Trissolcus basalis and Gryon sp. One card with two parasitized eggs by Trissolcus basalis was recovered from Kisumu, however, there were no parasitoids identified in Nanyuki, Naivasha and Kitengela where bagrada bug is also prevalent. Results showed parasitoid presence in fields with high bug populations compared to areas with few or no Bagrada bug infestations. Conducting trials in both laboratory and field settings is recommended to obtain clear data on the effectiveness of the identified egg parasitoid in managing the bagrada bug population.

Species composition of Bactrocera fruit flies (Diptera: Tephritidae) and their parasitoids on horticultural commodities in Batu City and Malang District, East Java, Indonesia

Abstract. Setiawan Y, Hamdoen FM, Muhammad FN, Hata K, Tarno H, Wang J. 2024. Species composition of Bactrocera fruit flies (Diptera: Tephritidae) and their parasitoids on horticultural commodities in Batu City and Malang District, East Java, Indonesia. Biodiversitas 25: 305-311. Bactrocera Macquart, 1835 fruit flies (Diptera: Tephritidae) are among the most important pests in horticultural commodities worldwide, including horticultural crops in Indonesia. Trapping is suggested to control, eradicate, and suppress fruit flies. The presence of natural enemies is a very important factor in the indicators of agroecosystem balance. This study aimed to monitor the species composition of Bactrocera fruit flies and their parasitoids in several horticultural commodities such as apples, large chili, red guava, sweet citrus, and tomatoes in Batu City and Malang District. Trapping and host-rearing methods were used in this research. A total of 7,124 individuals of Bactrocera were collected using a Steiner trap baited with methyl eugenol. They consisted of six species: Bactrocera carambolae Drew & Hancock, 1994; Bactrocera cucurbitae (Coquillett, 1899); Bactrocera dorsalis (Hendel, 1912); Bactrocera verbascifoliae Drew & Hancock, 1994; Bactrocera papayae Drew & Hancock, 1994; and Bactrocera umbrosa (Fabricius, 1805). The B. carambolae, B. dorsalis, and B. papayae were the three predominant species collected using Steiner traps baited with methyl eugenol. Based on the host-rearing method, B. carambolae and B. dorsalis were found in red guava fruit. Only one parasitoid species, Opius sp., was found in red guava fruit. These results provide valuable insights into the distribution of Bactrocera on horticultural commodities in Batu City and Malang District and the potential challenges regarding parasitoid presence.

Effect of Rickettsiella viridis endosymbionts introduced into Myzus persicae aphids on parasitism by Diaeretiella rapae: A combined strategy for aphid control?

Aphids are major crop pests in southeastern regions of Australia. Some aphid species harbor heritable facultative endosymbionts that may induce beneficial or detrimental impacts on aphids under certain ecological conditions. Aphid-parasitoid interactions can be greatly affected by facultative endosymbionts but there is still limited research on many species of economic significance. Here we assessed the effects of a facultative endosymbiont, Ricketsiella viridis, on parasitism of the major aphid pest, Myzus persicae, by Diaeretiella rapae. We found that R. viridis does not provide M. persicae with significant protection against D. rapae, with parasitoids showing a preference for probing aphids infected with R. viridis. The fecundity of M. persicae is reduced due to infection with R. viridis regardless of the presence of parasitoids. Moreover, we show that parasitoids may facilitate horizontal and subsequent vertical transmission of facultative endosymbionts in aphids which could increase the spread of deleterious effects associated with R. viridis. Based on these findings, simultaneous release of D. rapae and M. persicae infected with R. viridis in the early cropping season (lower population densities and cooler conditions) may contribute to an effective strategy for efficient management of this pest.

Parasitoids of the cabbage seed weevil deliver high and consistent parasitism in variable landscapes: A showcase of conservation biocontrol.

Insect pest resistance to insecticides and societal pressure to reduce pesticide load has increased oilseed rape (OSR) farmers' motivation to protect and exploit parasitoids for pest control. However, parasitoid presence and parasitism must be made visible to influence farmers' spraying decisions. Parasitism of cabbage seed weevil (CSW) (Ceutorhynchus obstrictus (Marsham)) reduces damage to OSR immediately, making them a good case for demonstrating conservation biocontrol to farmers. We assessed the occurrence and activity of CSW parasitoids in 84 OSR fields over 2 years and identified the impact of associated local landscape factors. Mean cabbage seed weevil infestation rates were 11% and 10% in 2020 and 2021, and parasitism rates were high in both years (75% and 74%, respectively). Temporal and spatial dynamics of OSR in the landscape surrounding the focal fields were important for both CSW and parasitoid numbers, suggesting a dilution effect for increasing OSR area since the previous year. A multimodel inference analysis showed that OSR-related factors were important predictors for both the infestation rate of CSW and the number of parasitoids. For parasitoids, protected nature areas and hedgerows were important. Parasitism rates were high and largely unaffected by landscape factors. CSW and its parasitoids respond similarly to interannual changes in the OSR resource; in addition, parasitoids benefit from uncropped areas in the surrounding landscape. The complexity of the pest and parasitoid response to landscape factors limits the prospect of designing landscapes for improved pest control by the parasitoids. Parasitoids of CSW may be present as local populations in agricultural landscapes with the potential for consistent and substantial parasitism. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

First record of the occurrence of parasitoids of genus Eurytoma and Eupelmus (Hymenoptera: Calcidoidae) associated to the seeds of Cassia leptophylla in Brazil

The presence of parasitoids, predators, and pathogens that utilize the biological control of pest is important to agriculture and forestry is imperative as a dynamic equilibrium factor in agroecosystems. The insects of the order Hymenoptera possess a great diversity of habitats and are a species of insectivores predominate in population, frequencies, and effectiveness, in which they attack pest. The knowledge of the species that forms an ecosystem is one of the basic assumptions within a program of integrated pest management. This study objective identifies the parasitoid species of Cydia tonosticha and Pygiopachymerus lineola obtained from fruits of Cassia leptophylla (Fabaceae: Caesalpinoideae) collected from trees in an urban area of the municipal of Santa Maria, Rio Grande do Sul, and sent to the Entomology Laboratory of the Department of Plant Defense at the Federal University of Santa Maria (UFSM). The species found were identified as genus Eurytoma (Eurytomidae) and Eupelmus (Eupelmidae), and found as the first record of these parasitoids associated with the gold medallion tree (C. leptophylla).

Models for the practitioner: Predicting the efficient biocontrol of Tuta absoluta under different management scenarios

Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) is one of the most destructive pests of solanaceous crops. One possible biological control strategy is the augmentative release of parasitoids. However, parasitoid intervention efficacy is highly sensitive to the release timing and intensity. Virus-based biopesticides are additional control means since they are highly selective and can be combined with natural enemies. We developed a stage-structured population model, validated with results from a semi-field experiment, to investigate and predict the population dynamics of the pest T. absoluta and one of its parasitoids, Necremnus tutae Ribes & Bernardo (Hymenoptera: Eulophidae). The aim of the study was to assess the best release parameters of N. tutae to control the pest in four different management scenarios: without any other control method, with a biopesticide (PhopGV, Baculoviridae), with the natural presence of the parasitoid, and when combining the natural presence of the parasitoid with a biopesticide. Moreover, in each scenario, two growing seasons of different lengths were compared. To achieve the same control level, 3–45% fewer parasitoids are necessary in a long growing season than in a shorter one. Biopesticide applications reduce the number of required parasitoids by 66% and 78%, whereas the natural presence of parasitoids reduces it by 11% and 17% for short and long growing seasons, respectively. On average, with biopesticide application, the parasitoid intervention can be delayed by a month and remains efficient. These findings highlight the importance of mathematical models in applied pest management drawing precise predictions crucial for efficient control.

Factors affecting distribution of emerald ash borer parasitoids in an urban environment

Invasive woodboring insects such as emerald ash borer (EAB), Agrilus planipennis, cause significant economic and environmental harm to both traditional and urban forests. Hymenopteran biological control agents were introduced to North America for protection of non-insecticide treated ash trees. Urbanization is known to impact arthropod abundance, richness, and services, and yet few studies specifically examine biocontrol agent distribution or services within urban environments. While EAB biocontrol agents are successfully establishing in traditional forests, it is not known whether urban forests are sufficiently hospitable for their establishment and persistence. In this study, we investigate how urban land cover impacted both the establishment and distribution of introduced biocontrol agents and the presence of EAB-associated endemic native parasitoids. Over the three year study period we detected a persistent negative impact of urbanization on presence of two parasitoids, the introduced Spathius galinae and native Atanycolus spp, while another native, Phasgonophora sulcata, was only negatively impacted by urbanization in the first sampling year. Presence of the introduced Tetrastichus planipennisi was negatively correlated with tree size, but not urbanization. Presence of all parasitoids was greater on trees with declining canopy health. This study indicates that while some parasitoids appeared to be negatively affected by urbanization, biological control agents of EAB successfully established and are generally widely distributed in Syracuse, NY.

Defensive symbiosis in the wild: Seasonal dynamics of parasitism risk and symbiont-conferred resistance.

Parasite-mediated selection can rapidly drive up resistance levels in host populations, but fixation of resistance traits may be prevented by costs of resistance. Black bean aphids (Aphis fabae) benefit from increased resistance to parasitoids when carrying the defensive bacterial endosymbiont Hamiltonella defensa. However, due to fitness costs that come with symbiont infection, symbiont-conferred resistance may result in either a net benefit or a net cost to the aphid host, depending on parasitoid presence as well as on the general ecological context. Balancing selection may therefore explain why in natural aphid populations, H. defensa is often found at intermediate frequencies. Here we present a 2-year field study where we set out to look for signatures of balancing selection in natural aphid populations. We collected temporally well-resolved data on the prevalence of H. defensa in A. f. fabae and estimated the risk imposed by parasitoids using sentinel hosts. Despite a marked and consistent early-summer peak in parasitism risk, and significant changes in symbiont prevalence over time, we found just a weak correlation between parasitism risk and H. defensa frequency dynamics. H. defensa prevalence in the populations under study was, in fact, better explained by the number of heat days that previous aphid generations were exposed to. Our study grants an unprecedentedly well-resolved insight into the dynamics of endosymbiont and parasitoid communities of A. f. fabae populations, and it adds to a growing body of empirical evidence suggesting that not only parasitism risk, but rather multifarious selection is shaping H. defensa prevalence in the wild.

The diversity and abundance of weeds in sugarcane (Saccharum officinarum) plantations and its relationships with Hymenoptera parasitoids diversity

Abstract. Wibowo D, Rahardjo BT, Karindah S, Muhammad FN. 2023. The diversity and abundance of weeds in sugarcane (Saccharum officinarum) plantations and its relationships with Hymenoptera parasitoids diversity. Biodiversitas 24: 2342-2349. Sugarcane (Saccharum officinarum L.) is an important plantation commodity in Indonesia. One of the strategies to improve sugarcane production is by controlling pest populations in sugarcane plantations which can be done by increasing the role of natural enemies as control agents, such as Hymenoptera parasitoids. The presence of parasitoids is influenced by the diversity of vegetation, including weed plants, due to the nectar contained in its flowers. The aim of this study was to investigate the diversity, abundance and composition of weeds in sugarcane plantations and their relationships with the diversity and abundance of Hymenoptera parasitoids that have the potential to control pests in sugarcane plantations. The study was conducted from June to August 2022 in four locations in East Java, i.e. Karangploso and Kalipare (Malang), Pasirian (Lumajang) and Gandusari (Blitar). Observation of weed vegetation was carried out by taking samples using 1 m x 1 m frame inside the observation point at each observation plot. Collection of Hymenoptera parasitoids used yellow pan trap and modified farmcop to determine the diversity of Hymenoptera parasitoids in the field. Observations were made at intervals of 1 week. We found that the highest abundance of weeds found across the four sugarcane plantations was Digitaria ciliaris (Retz.) Koeler, Ipomoea triloba L. and Ageratum conyzoides L. The highest abundance of Hymenoptera parasitoid species found were Trichogramma chilonis Ishii and Telenomus dignus Gahan. There were positive relationships between weed density and Hymenoptera parasitoid diversity and abundance at each sugarcane plantation. Weed species with the most presence of Hymenoptera parasitoids were A. conyzoides, I. triloba and Mimosa pudica L. In conclusion, the presence of weed vegetation on sugarcane plantations affected the composition of the Hymenoptera parasitoid community. The results of this study can be the rationale that the conservation of wild weeds in sugarcane fields is very important to support the existence of beneficial parasitoids.

Efficacy of the parasitic wasp, Dinarmus basalis Rondani (Hymenoptera: Pteromalidae), in reducing infestations by the cowpea beetle, Callosobruchus maculatus (L.) (Coleoptera: Chrysomelidae: Bruchinae)

BackgroundCowpea seed beetle, Callosobruchus maculatus (L.) (Coleoptera: Chrysomelidae: Bruchinae), is the most important pest of stored cowpea in tropical regions. This study was designed to determine the presence of parasitoids associated with C. maculatus, investigate the efficacy of the parasitic wasp, Dinarmus basalis Rondani (Hymenoptera: Pteromalidae), in controlling C. maculatus as influenced by time and number of applications and ascertain the use of olfactory cues by D. basalis in host searching. Three markets in Ibadan, Southwest Nigeria, namely: Bodija, Mapo and Ojoo, were purposively surveyed for parasitoids associated with C. maculatus. Two pairs of D. basalis were released at 3-day intervals into cowpea seeds previously infested with C. maculatus. Treatments included: four times of parasitoid applications (4-TPA), three applications (3-TPA), two applications (2-TPA), 1 application (1-TPA) and a control without parasitoid application (0-TPA). All treatments were replicated four times in a completely randomized design to determine F1 progeny of C. maculatus and seed damage. Olfactory bioassay was carried out with D. basalis adults placed in a Y-tube olfactometer; and their preference for infested or uninfested three cowpea varieties, namely: Ife Brown, Ife BPC (Branching Peduncle) and Oloyin, as well as infested cowpea grains or pure air was evaluated.ResultsAmong the previously known parasitoids associated with C. maculatus, only D. basalis was found in the sampled markets. F1 progeny of adult C. maculatus reduced from 4.75 individuals (0-TPA) to 1.25 (2-TPA), 0.25 (3-TPA) and 0 (4-TPA). Concurrently, the number of exit holes on cowpea seeds significantly (p < 0.05) ranged from 5.25 (0-TPA) > 3.21 (1-TPA) > 2.20 (2-TPA) > 2.18 (4-RAP) > 1.39 (3-TPA). Adults D. basalis were more attracted to infested grains of Ife Brown (χ2 = 4, df = 1, p = 0.0455) and infested grains of Ife BPC (χ2 = 4, df = 1, p = 0.0455) than clean air. Similarly, adults D. basalis were more attracted to infested Ife Brown than the uninfested (χ2 = 5, df = 1, p = 0.0254). The results further showed that there were non-significant differences between the infested and uninfested grains of Ife BPC (χ2 = 0.2, df = 1, p = 0.6547) and Oloyin (χ2 = 3.2, df = 1, p = 0.0736) varieties.ConclusionsAdult D. basalis reduced emergence of C maculatus and reduced damage in cowpea seeds. Olfactory cues played a necessary role in host-searching efforts of D. basalis.

The Relationship Between the Presence of Sunn Pest Eurygaster testudinaria Geoffroy and Its Egg Parasitoids in Najaf Province

A field study was carried out to find presence egg parasitoids on egg masses of sunn pest Eurygaster testudinaria Geoffroy and effect of some climatic conditions such as temperature and relative humidity in Kufa/Najaf province during 2017-2020 seasons. the results showed difference in the prevalence of parasitoids according to the species of parasitoids. The parasitoid O. telenomicida is the most common egg parasitoid in region of study and percentage parasitism ranged 6.06 -18.80% in March and 32.24-55.04% in April for all season. The results also showed that egg parasitoids activity begin in the early spring. The time of presence of parasitoid in the field has varied from year to year depending on the presence of Sunn pest and prevailing weather conditions of temperatures and relative humidity.

Impacts of seed-feeding beetles and their parasitoids on seed germination of Leucaena leucocephala and Senna multijuga (Fabaceae) in Brazil

We investigated the influence of seed-feeding beetles (Chrysomelidae, Bruchinae) and their parasitoids on the germination performance of two Fabaceae, Leucaena leucocephala and Senna multijuga. We collected 150 fruits per species in forest fragments in the city of Lavras, Minas Gerais, Brazil, between July and August 2020. Seeds were examined and separated into predated and non-predated categories. The predated category was divided into two subcategories: predated by Coleoptera (Bruchinae) (PCO) and predated in the presence of Coleoptera parasitoids (PARCO). The non-predated category was divided into artificially injured (AI), intact seeds without insect infestation (IS), and intact seeds with insect infestation (SIF). Seeds of S. multijuga and L. leucocephala germinated to 40% and 30%, respectively. PCO and PARCO seeds not only had a negative and restricting influence on S. multijuga germination (no germination) but also contributed to a large proportion of non-viable predated seeds (38%). PCO (7%) and PARCO (23%), on the other hand, improved L. leucocephala germination. This work represents one of the first attempt to evaluate the parasitoid effect on seeds germination. Our results contribute to a better understanding of the effect of herbivore predation and the presence of parasitoids on host plant seed germination, which can be critical to mother plant fitness depending on plant species. Further studies are necessary to determine the extend seed consumption by beetles and the presence of their parasitoids may facilitate or impair seed germination, and consequently plant fitness in other systems.

Abundance of arthropod in the various intensity of pesticide applied on shallots crop Local Palu

Excessive use of pesticides confers several ecological and environmental consequences. In this research, we evaluated arthropod occurrence on shallot crops in Palu Valley, Central Sulawesi as an impact of pesticide application in different frequencies. Almost all farmers used synthetic pesticides for controlling pests and diseases where 46.7%, 43.3%, 10.0% of them applied in high, moderate, and low frequency, respectively. By comparing to the last application, the first reduced arthropod diversity index, evenness index, and abundance by 13.8%, 6.7%, and 70.6%, while the second by 7.3%, 2.3%, and 33.5%, respectively. Analysis of the dynamic abundance of pests and natural enemies in seven weeks observation indicated that the pests abundance at low and moderate levels was no different. Whereas predator abundance at low frequency was significantly different with moderate and high rate and between the last two not distinct and the presence of parasitoids was not observed at all, it means the natural enemies were susceptible to pesticides. These data showed the negative impact of pesticides application to arthropods including pests resistance and natural enemies lost; therefore it is necessary to minimize the use of pesticides and integrated pests.

Liturgusa maya, Saussure &amp; Zehntner, 1894 (Mantodea-Liturgusidae), una especie de mantis frecuente en cultivos de cacao en la región Tumbes, Perú

Liturgusa Maya is a cryptic species that travels on cacao and citrus stems. The objective of this study was to determine some aspects of their biology and behavior and to identify ootheca parasitoids. Nymphs and adults were collected in the cocoa stems to obtain ootheques and determine the incubation period and the number of individuals per ootheca, ootheca were also collected to determine the presence of parasitoids. Incubation fluctuates between 15 and 17 days and individuals per ootheca between 23 and 37. The adult female stage measures an average of 25.30 mm in length and the male 20.38. Three species of parasitoids were recovered from the ootheques collected in the field: Podagrion sp., Eupelmus sp., and Horismenus sp., belonging to the families Torymidae, Eupelmidae and Eulophidae, the most important species belongs to the genus Horismenus. The present study seeks to establish the interactions that L. maya fulfills in the cacao agroecosystem and to define if its presence is related to the management of organic crops.

Incidence of banana leaf roller and diversity of it is parasitoids in Central Sulawesi, Indonesia

Abstract. Pasaru F, Yunus M, Toana MH, Edy N, Anshary A, Saleh S. 2021. Incidence of banana leaf roller and diversity of it is parasitoids in Central Sulawesi, Indonesia. Biodiversitas 22: 5023-5029. Incidence of banana leaf roller and diversity of it is parasitoids in Central Sulawesi, Indonesia. Indonesia is still facing banana losses due to the leaf roller (Erionota thrax). Fortunately, it has several natural enemies potentially to control them. Therefore, a survey was done to measure the incidence of banana leaf roller (BLR) at different altitudes and banana cultivars as well as the diversity and parasitism of its parasitoids. The pra-imago stages of BLR were collected at different altitudes and banana cultivars in Central Sulawesi, Indonesia, and transported to the laboratory for rearing and parasitism observation. The study revealed that the incidence of E. thrax in the surveyed locations varied from 28.6% to 85.8%, whereas the parasitism level of the BLR parasitoids was 0.0 to 22.1%. Incidence of E. thrax tended to be higher at a higher altitude while Kepok cultivar seemed to be less prone to BLR infestation compared with Raja and Mas cultivars. A total of nine parasitoids of BLR were recorded. They were Agiommatus sumatraensis, Pediobius erionotae, Ooencyrtus pallidipes, Brachymeria lasus, Brachymeria thracis, Cotesia erionatae, Xanthopimpla gampsura, Casinaria sp, and Palexorista solennis. Among them, B. lasus was the most abundant, widely distributed, and had the highest parasitism rate. Our study figured out that BLR infestation is a major problem in Central Sulawesi. Nevertheless, the presence of parasitoids recorded in this study may potentially be used as the biological control.

Hymenoptera Parasitoid Diversity in Oil Palm Plantation on PT. Mopoli Raya, Aceh Tamiang, Indonesia

Hymenopteran parasitoids are biological control agents that contribute mortality to economically important pest of oil palm plantations. In this research we investigated the diversity and abundance of Hymenopteran parasitoids at PT. Mopoli Raya, Aceh Province, Indonesia. Data were collected by adopted a purposive sampling method in mature and immature plantations by using light trap, malaise trap, and yellow-pan trap. Specimens were identified at Universitas Syiah Kuala and final taxonomic confirmation was conducted at Gadjah Mada University. We found that the species richness and evenness of the Hymenoptera parasitoid species in mature oil palm plantations tended to be higher than in immature plantations. It is suspected that in immature oil palm plants (4 years) synthetic pesticide application is more intensive and it has a negative impact on the presence of parasitoids compared to the mature.

Screening insectary refugia plants that increase the performance of Diadegma semiclausum Hellen (Hymenoptera: Ichneumonidae) against diamondback moth larvae

Abstract. Asmoro PP, Dadang, Pudjianto, Winasa IW. 2021. Screening insectary refugia plants that increase the performance of Diadegma semiclausum Hellen (Hymenoptera: Ichneumonidae) against diamondback moth larvae. Biodiversitas 22: 4254-4260. Habitat manipulation through the planting of insectary refugia plants is one way of controlling pests. These refugia plants serve as the source of nutrients that improve the fitness of parasitoid against insect pests. In the cabbage agroecosystem, the presence of refugia plants is expected to benefit the parasitoid D. semiclausum. This study aimed to select insectary refugia plants beneficial for the D. semiclausum in term of attracting and increasing their longevity, and parasitization ability against P. xylostella larvae. Ten species of refugia plants were used in this study, i.e., Ageratum conyzoides, Galinsoga parviflora, Sphagneticola trilobata, Synedrella nodiflora, Portulaca oleracea, Rorippa indica, Brassica rapa, Apium graveolens, Ocimum basilicum, and Arachis pintoi. The methods used in this study included testing the response of the imago olfactory to refugia plants and its effect on the longevity and parasitization level. The results showed that of the ten species of investigated, R. indica and A. graveolens were the most attractive for the presence of parasitoids. The two refugia plants could also increase the longevity and parasitization rate compared to the water treatment. R. indica and A. graveolens are recommended as refuge plants in the cabbage agroecosystems to control P. xylostella.

First report of a gall midge as a parasitoid of weaver ants

Gall midges (Diptera: Cecidomyiidae) comprise a diverse family of small nematoceran flies. While most species are phytophagous, the family also includes predatory species, and endoparasitoids. Endoparasitic species have been reared from aphids and psyllids. We discovered parasitoid-infected weaver ant, Oecophylla longinoda (Latreille) (Hymenoptera: Formicidae) in nests on mango trees in coastal Kenya. Examination of 5 colonies revealed the presence of parasitoids in all of them, with parasitism rates ranging from 2 to 21%. Morphological examination of larval parasitoids indicated that they were gall midges, and molecular data were consistent with the identification. Attempts to rear adults were unsuccessful. This study presents to the best of our knowledge the first report of Cecidomyiidae parasitising Hymenoptera, as well as the first report of a parasitoid of weaver ants. This species should be investigated further because its damage may limit the ability of weaver ants to control pests of cultivated fruits and other insects.

The cost of parasitism: High larval developmental mortality following attacks by a parasitoid fig wasp on a fig pollinating wasp

Parasitoids contribute to controlling phytophagous insect populations. Their action on a host is often measured by numbers of emerging adult parasitoids. However, parasitoid oviposition attempts may lead to host mortality and sometimes both host and parasitoid die during larval development. Therefore, establishing the effect of parasitoids on host populations requires estimating total effect of parasitoids.The communities of wasps developing in figs (the closed inflorescences of Ficus) have become a model system to investigate micro-hymenopteran interaction networks. A galled ovule produces either a single galling wasp or a single parasitoid providing a simple way to measure costs. However, some galled flowers produce no wasps. We show that about one quarter of galled flowers fail to produce pollinator offspring in the absence of parasitoids. In the presence of parasitoids, the number of empty galls is increased. For each emerging parasitoid, 1.9 pollinator larvae were killed. Hence, host mortality induced by parasitoids is much larger than actual parasitoid production, a feature documented in some other host-parasitoid interactions and that may be pervasive in nature.