Number Of Parasitoid Species Research Articles

Species diversity and abundance of parasitoids of fall armyworm, Spodoptera frugiperda (Lepidoptera: Noctuidae) from South Sumatra, Indonesia

Abstract. Herlinda S, Suwandi S, Irsan C, Adrian R, Fawwazi F, Akbar F. 2023. Species diversity and abundance of parasitoids of fall armyworm, Spodoptera frugiperda (Lepidoptera: Noctuidae) from South Sumatra, Indonesia. Biodiversitas 24: 6184-6190. The parasitoid species attacking Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) have never been reported from South Sumatra. The objectives of this research were to identify and analyze the species diversity of egg and larval parasitoids of S. frugiperda and to determine their abundance in corn fields from South Sumatra. Surveys were carried out in Ogan Komering Ilir District, Ogan Ilir District, Muara Enim District, and Palembang City. The results showed that fourteen species of parasitoids were found attacking eggs and larvae of S. frugiperda in South Sumatra. Two species were egg parasitoids (Telenomus remus (Nixon) and Trichogramma sp.), and 12 species of larval parasitoids (Chelonus formosanus Sonan, Chelonus oculator F., Chelonus annulipes Wesm., Chelonus cautus (Cresson), Microplitis manilae Ashmead, Microplitis marshallii Kokujev, Euplectrus corriemoreauae Hansson, Compsilura concinnata (Meigen), Sarcophaga sp., Macrocentrus sp., Exorista sp., and Megaselia sp.). The most abundant species of the parasitoids found was T. remus. The highest species diversity was found in Muara Enim District. The number of parasitoid species was greater in the dry season compared to the rainy season. Egg parasitism rates were significantly higher at the corn vegetative stage (59.03%) compared to the generative stage (53.56%).

First record of parasitoids Megastigmus sp. and Quadrastichus mendeli as potential biological control agents of eucalyptus gall inducers in Tanzania

Leptocybe invasa and Ophelimus maskelli (Hymenoptera: Eulophidae) are serious pests causing damage to eucalypt plantations in Tanzania. Biological control is considered the best alternative to other control methods, both ecologically and economically. Thus far, no parasitoid of the eucalyptus gall wasps documented or reported. Likewise, the number of parasitoid species and their parasitic capacities are unknown. Therefore, the study investigated the parasitoids of the eucalypt gall inducer from October 2021 to April 2022. Galls were collected from E. tereticornis and E. grandis x E. camaldulensis clones and reared until wasps emerged. The emerged wasps were sorted and identified at the Sokoine University of Agriculture, Tanzania, and the Insect Biosystematics Laboratory at IPB University, Indonesia. Two species of parasitoids of eucalyptus gall-inducers in Tanzania were first collected and identified as Megastigmus sp. (Torymidae) and Quadrastichus mendeli (Eulophidae). In Korogwe, North Ruvu, and Morogoro plantation areas, the percentages of parasitization for the two parasitoids combined were 29.7%, 64%, and 33.3%, respectively. A higher parasitization rate was observed from L. invasa galls in the E. grandis x E. camaldulensis clones. These parasitoids can be potential biological control agent candidates to control the pest. However, future monitoring is needed to determine their distribution, host specificity, interactions, and efficacy.

Changing Host Plants Causes Structural Differences in the Parasitoid Complex of the Monophagous Moth Yponomeuta evonymella, but Does Not Improve Survival Rate.

Recently in Poland, cases of host expansion have frequently been observed in the typically monophagous bird-cherry ermine moth (Yponomeuta evonymella), which has moved from its native host plant, bird cherry (Prunus padus), to a new, widely distributed plant that is invasive in Europe, black cherry (P. serotina). We attempted to verify the reasons behind this host change in the context of the enemy-free space hypothesis by focusing on parasitoids attacking larval Y. evonymella on one of three host plant variants: The primary host, P. padus; initially P. padus and later P. serotina (P. padus/P. serotina); or the new host, P. serotina. This experiment investigated if changing the host plant could be beneficial to Y. evonymella in terms of escaping from harmful parasitoids and improving survival rate. We identified nine species of parasitoids that attack larval Y. evonymella, and we found that the number of parasitoid species showed a downward trend from the primary host plant to the P. padus/P. serotina combination to the new host plant alone. We observed a significant difference among variants in relation to the percentage of cocoons killed by specific parasitoids, but no effects of non-specific parasitoids or other factors. Total mortality did not significantly differ (ca. 37%) among larval rearing variants. Changing the host plant caused differences in the structure of the parasitoid complex of Y. evonymella but did not improve its survival rate. This study does not indicate that the host expansion of Y. evonymella is associated with the enemy-free space hypothesis; we therefore discuss alternative scenarios that may be more likely.

Parasitoid Wasps in Flower Heads of Asteraceae in the Brazilian Cerrado: Taxonomical Composition and Determinants of Diversity.

This study provides the first survey of the parasitoid fauna reared in flower heads of Asteraceae in the Brazilian cerrado. We investigated the relative importance of herbivore richness and plant species commonness to differences in parasitoid species richness among the plant species. A total of 15,372 specimens from 192 morphospecies belonging to 103 genera of Hymenoptera were reared from the flower heads of 74 Asteraceae species. Chalcidoidea and Ichneumonoidea were the most common superfamilies, with Eulophidae and Braconidae as the main families of parasitoid wasps. Singletons and doubletons accounted for 45% of total parasitoid species richness. The number of parasitoid species per plant species ranged from 1 to 67, and the variation in parasitoid species richness among plants was mainly explained by the number of sites in which the plants were recorded. This study shows that there is a highly diversified fauna of Hymenoptera parasitoids associated with flower heads of Asteraceae in the Brazilian cerrado. Our findings suggest that the accumulation of parasitoid species on plants is mainly determined by the regional commonness of plant species rather than the number of herbivore species associated with the plants.

Structure of a herbivore–parasitoid community: Are parasitoids shared by different herbivore guilds?

Summary Plant–herbivore–parasitoid interactions are a common occurrence in terrestrial food webs. Few parasitoids are thought to be shared by host insects of different feeding guilds because different parasitism strategies are required to use hosts of different feeding types. However, this assumption has rarely been tested using data from nature. To clarify whether parasitoids are shared among host guilds, I examined the structure of parasitoid communities on herbivore guilds associated with two Rhododendron species (Ericaceae) in a temperate secondary forest in central Japan. Leaf- and flower-feeding insects were collected from Rhododendron reticulatum and Rhododendron macrosepalum shrubs and reared in the laboratory for 3 years from April 1999 to March 2002. In total, 79 species of holometabolous herbivores (Lepidoptera, Diptera, Coleoptera, and Hymenoptera) were recorded, with 62 species on R. reticulatum and 51 species on R. macrosepalum . A total of 81 parasitoid species (Hymenoptera and Diptera) was recorded from the sampled herbivores, with 48 species from those on R. reticulatum and 50 species from those on R. macrosepalum . In total, 36 herbivore species were parasitised by 1–18 parasitoid species per host species, although the number of parasitoid species was strongly affected by sample size. Parasitoids that had two or more host species frequently attacked herbivore species from different families or on different host plants, whereas they did not attack species from different herbivore guilds; no parasitoids were shared between external feeders and rollers. Therefore, my results support the hypothesis that few parasitoids are shared among herbivores of different feeding guilds.

Structure and Function of Parasitoid Assemblages Associated withPhyllonorycterLeafminers (Lepidoptera: Gracillariidae) on Deciduous Oaks in Japan

Parasitoid assemblages associated with Phyllonorycter spp. leafminers (Lepidoptera: Gracillariidae) were examined on six deciduous oak species (Quercus, Fagaceae) in Japan to understand how host leafminers, host food plants, and geographic location influence the structure and function of parasitoid assemblages. The parasitoid assemblages on five of the six oak species showed similar species richness (18–20 spp.), regardless of the number of host leafminer species and the abundance of hosts. Species composition was influenced by geographic location as well as host food oaks, and to a lesser extent by the leafminers. The assemblages varied in guild structure but showed nearly equal ratios of koinobiont/idiobiont species. The ratio was almost the same as that in Great Britain. These results suggest that the well-known argument that parasitoid communities are mostly influenced by host food plants is not universal, and that parasitoid assemblages may be organized with a balance between numbers of koinobiont and idiobiont species regardless of species richness, species composition, or geographic location. Total rate of parasitism did not correlate with the number of parasitoid species or the evenness of the assemblage. This implies that the host–parasitoid system is not under top-down control.

Hotspots are rare in the evolution of parasitoid virulence and host resistance

Insect parasitoids lay their eggs in or on other insects. Their development results in the death of the host, thus setting the scene for a coevolutionary arms race. If the host recognizes the eggs of an internal parasitoid as foreign, it might react via a cellular immune response and encapsulate the egg in hemocytes. These cells then fuse, melanin is deposited and a hard capsule is formed, resulting in the death of the parasitoid egg. Parasitoids in turn can prevent encapsulation by molecular mimicry, by concealment of the egg from circulating hemocytes and by active destruction of the immune system using toxins or symbiotic viruses. Parasitoids, therefore, are a favourite model with which to study the coevolution of virulence and resistance. Ecologists familiar with the high mortality rates that parasitoids can inflict on their hosts must wonder whether coevolutionary arms races between hosts and parasitoids are common in nature and, if so, why the host is so often on the losing side. A new paper by Lapchin [1xHost–parasitoid association and diffuse coevolution: when to be a generalist?. Lapchin, L. Am. Nat. 2002; 160: 245–254Crossref | PubMed | Scopus (24)See all References[1] provides answers to these questions.Often, coevolution between interacting organisms is restricted to a particular region called a hotspot. Recent theoretical advances in community ecology provide insight into the community dynamics that determine whether a community is a hotspot. In a constant environment, parasitoids can evolve a preference for a particular host species and coevolution between that host and the parasitoid rapidly evolves. If more parasitoid species attack a host, effective resistance against all of them becomes difficult. As fitness benefits of defence decreases with the number of parasitoid species attacking, allocation to defence might have no benefit and tolerance could become the optimal strategy. Nevertheless, it might pay for a host to evolve specific resistance against the most common parasitoid.Lapchin now shows that, when the frequencies of attack by different parasitoid species fluctuate over time, evolution does not favour specialist host resistance. However, when the frequencies of host species encountered fluctuate over time, specialist parasitoid virulence against the most frequent host still might evolve. This asymmetry follows on from the fact that the parasitoid is able to choose its host, but the host cannot choose its parasitoid. As most environments are fluctuating and most communities comprise different host and parasitoid species, Lapchin's model offers an explanation for the observations that coevolutionary arms races between parasitoid and host pairs are not common and that the parasitoids often win.

Sunflower stem weevil and its larval parasitoids in the Central and Northern Plains of the USA

The sunflower stem weevil, Cylindrocopturus adspersus (LeConte) (Coleoptera:Curculionidae), is apest of cultivated sunflower (Helianthusannuus L) from the southern to the northernGreat Plains. The incidence of weevilinfestation in fields from the six differentstates sampled during 1996 and 1997 ranged from33% (Minnesota) to 100% (Kansas, Colorado,Nebraska). Weevil populations in the fieldssampled were statistically greater in thecentral Plains (Colorado, Kansas, Nebraska)with a mean of 12.3 and 19.5 larvae per stalkcompared with the northern Plains (North andSouth Dakota, Minnesota) of 0.7 and 1.3 larvaeper stalk in 1996 and 1997, respectively.Parasitization of weevils varied from field tofield ranging from 1 to 100%, but was usuallyless than 20%. The nine species oflarval parasitoids recovered were allHymenoptera and included: Nealioluscurculionis (Fitch), N. collaris(Brues), Bracon sp. (Braconidae); Neocatolaccus tylodermae (Ashmead), Chlorocytus sp., Pteromalus sp.(Pteromalidae); Quadrastichus ainslieiGahan (Eulophidae), Eurytoma tylodermatisAshmead (Eurytomidae); and Eupelmus sp.(Eupelmidae). Nealiolus curculionis wasthe most prevalent parasitoid reared from C. adspersus, and it was recovered from allstates sampled. Parasitoid species richness wasgreatest in the central Plains. Thereduced number of parasitoid species foundattacking C. adspersus in the northernPlains may be caused by low host populationlevels, slow migration by parasitoids into theregion, or lack of adaptation to climaticconditions. Additional work to understandthe population dynamics of the parasitoidcomplex associated with C. adspersus mayresult in improved biological control of thesunflower stem weevil in cultivatedsunflower.

The Importance of Parasitoids in Apple Orchards

ABSTRACT Sixty seven parasitoid species have been reared from leaf miners (Phyllonorycter blancardella Fabr., Ph. corylifoliella Haw., Leucoptera malifoliella Costa, Nepticula malella Stt.) and leaf rollers (Adoxophyes orana F.v.R., Pandemis heparana Den. et Schiff., Archips rosana L.). The lowest number of parasitoid species occurred in the conventional orchard, while the highest number were found in the integrated and in the untreated ones. The most important parasitoid species were Sympiesis sericeicornis Nees, S. gordius Walk., Pnigalio pectinicornis L., P. soemius Walk., Holcothorax testaceipes Ratz., Chrysocharis pentheus Walk., Pediobius pyrgo Walk., Tetrastichus ecus Walk., Achrysocharoides atys Walk., Baryscapus galactopus Ratz., Neochrysocharis chlorogaster Erd. (Chalcidoidea), Pholetesor bicolor Nees, Macrocentrus pallipes Nees and M. linearis Nees (Braconidae). The larvae and pupae of leaf miners were parasitized to 35–45%, occasionally to 80%. At the same time the larvae of leaf rollers were parasitized only to 10–20%, seldom to 30–40%. The difference in species composition and in the efficiency of the parasitoids depends on the population density of the host, on the type and intensity of the treatment of the orchard, and on the character of the surroundings.

Structural refuges in two stem‐boring weevils onRumex crispus

Abstract.Differences in feeding positions, parasitoid complexes and parasitization rates of the two dominant insect species in stems ofRumex crispuswere investigated.Apion miniatum(inhabiting the lower 10% of the stem) andApion violaceum(occurring all along the stem) exploited distinctly different feeding positions, partly due to differences in time of oviposition.A.miniatumsuffered less parasitization thanA.violaceum, measured both by number of parasitoid species and parasitization rates. Its feeding position constitutes a refuge.Parasitization ofA.violaceumwas least in individuals feeding in basal, thick parts of the stem. There is a trend that the developed refuge increases with increasing stem diameter.The refuge ofA.violaceumin basal positions only affected idiobiont ectoparasitoids, because koinobiont endoparasitoids attack the weevils before they enter the stem. Moreover, the koinobiont did benefit from the refuge itself by avoiding hyperparasitism.Densities ofA.violaceumincreased with plant size, whereas percentage parasitism did not differ. Its three most abundant parasitoid species showed small‐scale density‐independent patterns of attack over all plants. Therefore a constant proportion of weevil larvae mine within the refuge independent of its potential size.Synchronization between weevils and plants, as well as between parasitoids and hosts, appears to be the dominant factor for the spatial community structure of the stem borersof Rumex crispusand their enemies.

Comparison of Community Composition of Parasitoids that Attack Leaf-Mining Moths (Lepidoptera: Gracillariidae)

Environ. Entomol. 24(4): 879-888 (1995) Parasitoid assemblages associated with Phyllonorycter leaf miners (Lepidoptera: Gracillariidae) were examined on the 2 deciduous oaks, Quercus dentata and Q. mongolica, in Hokkaido, northern Japan, and those on 2 others, Q. acutissima and Q. variabilis, in Nara, central Japan. To address to what extent interspecific competition is important in organizing parasitoid communities, I compared species richness, species composition, and levels of parasitism by guilds at different host immature stages among the parasitoid assemblages. Parasitoids were separated into 5 guilds according to parasitism modes (idiobiosis and koinobiosis) and host immature stages attacked and killed. Pooled data showed that the number of parasitoid species per host leafminer species in Japan (3.1) was similar to that in the United Kingdom (4.1) and that idiobionts (potential generalists) exceeded koinobionts (specialists) in species number (62.5%). A koinobiont guild and 2 idiobiont guilds had an inverse relationship in level of parasitism between 2 assemblages at each study area. These results may suggest that interspecific competition is important in organizing parasitoid communities. Nevertheless, dominant species and guilds varied among the assemblages, resulting in different patterns of percentage of parasitism by guilds in relation to host stage among the assemblages. This implies underuse of hosts at some stages by parasitoids, and interspecific competition is unlikely to be severe. Interspecific competition, therefore, seems to partially contribute to parasitoid community organization.

Species Richness and Structure in the Parasitoid Complexes of Tortricoid Hosts

1. The influence of host-plant category, host larval feeding site and host pupation site on the species richness and structure of the parasitoid complexes of tortricoid hosts (Lepidoptera: Tortricoidea) was examined using data from the published literature. 2. Parasitoid species richness remained almost constant across host-plant categories with no evidence of increased richness with host-plant size and no differential representation of parasitoid lifestyles (generalists vs. specialists) in relation to host-plant category. 3. Host larval feeding site has a major influence on parasitoid species richness and accounts for 36.2% of the variation in number of parasitoid species per host among conifer-feeding hosts

Evolutionary theory of host and parasitoid interactions

Abstract The challenge of developing a theory on the evolution of insect host and parasitoid interactions is addressed. Stages in the development of theory are recognized as the identification of pattern in nature, the development of hypotheses to account for pattern, and the further study that will validate or refute perceived patterns and processes. Patterns are identified in the context of vegetational ecological succession. Along this gradient there are an increasing number of parasitoid species per host species and an increasing proportion of more generalized (idiobiont) parasitoid species per host species. As the number of parasitoid species per host herbivore species increases, the expectation of higher mortality inflicted upon host populations increases. This expectation is justified on the basis of attempts at biological control that show a correlation between the number of parasitoid species per host and the probability of successful regulation by parasitoids. A predicted pattern is that, in host-parasitoid interactions along vegetational succession, innate responses to semiochemicals by searching parasitoids will be strong in early succession, and learned responses will predominate in late successional communities. Hypotheses that account for the mechanisms in generating pattern are reviewed, based on the literature, and their applications to a theory of biological control are discussed.