Specialist Parasitoid Research Articles

Landscape structure and agricultural intensification are weak predictors of host range and parasitism rate of cereal aphids

Proportions of specialist and generalist primary parasitoids have been described by the resource breadth and the trade-off hypothesis. These alternative hypotheses predict either decreased or increased, respectively, parasitism rate of shared aphid species by specialist parasitoids. We tested both hypotheses and the confounding effects of landscape structure and agricultural intensification (AI) using extensive samplings of aphids and their parasitoids in Polish agricultural landscapes. Abundances, species composition of aphids, primary parasitoids, and parasitism rate of aphids by specialists and generalist parasitoids were analysed. Contrary to our expectations we found equally decreased parasitism rates by both types of primary parasitoids at higher aphid densities and thus proportion of specialists to generalists did not change with increasing host density. In line with the resource breadth hypothesis, specialist parasitoids had always lower abundances and parasitism rates than generalist parasitoids. Landscape diversity and agricultural intensification did not influence the host-parasitoid population dynamics. We speculate that these contrasting results could be caused by the additional density effects of secondary parasitoids. We conclude that simplistic two-trophic-level population models are not able to fully describe the complex dynamics of trophic networks. We also argue that agricultural intensification has lower effects on abundance and effectiveness of parasitoids than predicted by respective predator–prey models and empirical studies performed in controlled and artificial conditions.

Density dependence and environmental factors affect population stability of an agricultural pest and its specialist parasitoid

Host–parasitoid dynamics are intrinsically unstable unless the risk of parasitism is sufficiently heterogeneous among hosts. Spatial aggregation of parasitoids can contribute to this heterogeneity, stabilising host–parasitoid population dynamics and thereby reducing pest outbreaks. We examined the spatial distribution of mango gall fly (Procontarinia matteiana, Kiefer and Cecconi), a non-native pest of South African mango orchards, which is controlled by a single parasitoid (Chrysonotomyia pulcherrima, Kerrich). We assessed whether spatial aggregation of parasitoids is associated with proximity to natural vegetation and/or to host density-dependent and host density-independent factors at three spatial scales. We found evidence for higher parasitism rates near natural vegetation at the field scale, and inverse host-density dependent and density-independent parasitoid aggregation at both the leaf scale and field scale. Therefore, we conclude that natural vegetation plays a role in promoting stabilising aggregation of parasitoids, possibly through provision of non-host resources (nectar, pollen), in this system.

Spatial Distribution and Interaction of Eriosoma lanigerum and Aphelinus mali on Apple Under Dry-Temperate Conditions of India

Knowledge of the seasonal abundance and type of spatial distribution of any insect pest is the prerequisite to formulate a reliable sampling programme for that species. Apple woolly aphid, Erosoma lanigerum (Hausmann) (Hemiptera: Aphididae), is one of the most important insect pests of apple throughout the world. The present study was aimed to study the seasonal abundance and spatial distribution of this pest and its specialist parasitoid, Aphelinus mali (Haldeman) (Hymenoptera: Aphelinidae) under dry temperate conditions of Himachal Pradesh, India during 2013 and 2014. Various dispersion indices were calculated to determine the type of spatial distribution and optimum number of samples. E. lanigerum assumed activity in the month of June and remained active till December by following negative binomial distribution during both the years. The aphelinid parasitoid acted in a density dependent manner by coinciding well with its host and also followed negative binomial distribution except at very low densities. Optimum number of samples required for the aphid and the parasitoid varied with the mean density and the desired precision level.

Investigating Biological Control Agents for Controlling Invasive Populations of the Mealybug Pseudococcus comstocki in France.

Pseudococcus comstocki (Hemiptera: Pseudococcidae) is a mealybug species native to Eastern Asia and present as an invasive pest in northern Italy and southern France since the start of the century. It infests apple and pear trees, grapevines and some ornamental trees. Biocontrol programmes against this pest proved successful in central Asia and North America in the second half of the 20th century. In this study, we investigated possible biocontrol agents against P. comstocki, with the aim of developing a biocontrol programme in France. We carried out systematic DNA-barcoding at each step in the search for a specialist parasitoid. First we characterised the French target populations of P. comstocki. We then identified the parasitoids attacking P. comstocki in France. Finally, we searched for foreign mealybug populations identified a priori as P. comstocki and surveyed their hymenopteran parasitoids. Three mealybug species (P. comstocki, P. viburni and P. cryptus) were identified during the survey, together with at least 16 different parasitoid taxa. We selected candidate biological control agent populations for use against P. comstocki in France, from the species Allotropa burrelli (Hymenoptera: Platygastridae) and Acerophagus malinus (Hymenoptera: Encyrtidae). The coupling of molecular and morphological characterisation for both pests and natural enemies facilitated the programme development and the rejection of unsuitable or generalist parasitoids.

Defensive insect symbiont leads to cascading extinctions and community collapse.

Animals often engage in mutualistic associations with microorganisms that protect them from predation, parasitism or pathogen infection. Studies of these interactions in insects have mostly focussed on the direct effects of symbiont infection on natural enemies without studying community‐wide effects. Here, we explore the effect of a defensive symbiont on population dynamics and species extinctions in an experimental community composed of three aphid species and their associated specialist parasitoids. We found that introducing a bacterial symbiont with a protective (but not a non‐protective) phenotype into one aphid species led to it being able to escape from its natural enemy and increase in density. This changed the relative density of the three aphid species which resulted in the extinction of the two other parasitoid species. Our results show that defensive symbionts can cause extinction cascades in experimental communities and so may play a significant role in the stability of consumer‐herbivore communities in the field.

Nitrogen-Mediated Interaction: A Walnut-Aphid-Parasitoid System.

The effects of plant quality on natural enemies are often overlooked in planning and executing biological control programs for insect pests in agriculture. Plant quality, however, could help to explain some of the observed variation in effectiveness of biological control, as it can indirectly influence natural enemy populations. In this study, we used the walnut aphid Chromaphis juglandicola (Kaltenbach) to address the effect of increased nitrogen availability to the host plant on parasitism by the specialist parasitoid Trioxys pallidus (Haliday). In laboratory experiments with walnut seedlings, a higher chlorophyll content index of the foliage in response to added nitrogen was correlated with a decrease in the number of mummies produced by female parasitoids over a 24-h period but an increase in the proportion and the size of female offspring. In field sampling of walnut orchards, there was no relationship between the percent parasitism of walnut aphids by T. pallidus and the chlorophyll content index of the trees. Nitrogen fertilizer and plant quality can clearly affect biological control and should be given greater consideration in integrated pest management.

Resource dependence in a new ecosystem: A host plant and its colonizing community

The introduced black locust (Robinia pseudoacacia) has become an invasive plant species in Europe. The introduction of alien plants such as the black locust may modify ecosystem composition and functioning. In response to the presence of a potential host plant, herbivores can adapt and shift to the consumption of the new host plant. In Eastern-Central Europe, the seed predator Bruchophagus robiniae (Hymenoptera: Eurytomidae) is an important consumer of black locust seeds which presumably shifted from its formerly host species to black locust. We tested the influence of host plant abundance on a seed predator – parasitoid community. We found that the seed predator B. robiniae was present in higher numbers in woodlots than in small patches of black locust. The density of the specialist parasitoid Mesopolobus sp. was lower in woodlots than in small patches, while the generalist parasitoid Eupelmus urozonos was evenly distributed between woodlots and small patches of black locust. We found that parasitoid species are influenced by the patch size of host plants, thus characteristics of introduced host plants can also manifest in higher trophic levels.

Tritrophic association on dandelion in a European capital city: a pilot quantitative study on the herbivore weevil Glocianus punctiger and its parasitoid wasp Entedon costalis

This study is a first attempt to estimate the degree of tritrophic association between the common dandelion Taraxacum officinale complex, the herbivorous weevil Glocianus punctiger and its parasitoid Entedon costalis, as an environmental marker in urban ecosystems. The study was conducted on 3926 dandelion flowering stems spread across 24 sample plots situated within the municipal borders of Kyiv (Ukraine). Eighteen plots were infested by the weevils, and 14 plots were infested by E. costalis. Of all the examined dandelion stems, 359 (9.1 %) were infested by weevils, and 21.4 % of these weevil-infested stems were parasitized by E. costalis. Thirty-two incidents of superparasitism were registered in nine sample plots. Seven environmental variables were chosen for characterization of the sample plots and for testing their possible effects on the tritrophic association. The results indicate that the infestation of dandelions by weevils is strongly limited by the grasslands’ mowing. Apart from that, the presence of anthropogenic barriers bounding the study areas negatively affected the parasitism of G. punctiger by E. costalis. This is regarded as an example of the crucial effect of habitat fragmentation on the specialist herbivore and the specialist parasitoid of this tritrophic system. Both the mowing and habitat fragmentation are linked with human land-use regimes on the sample plots.

The costs and effectiveness of chemical defenses in herbivorous insects: a meta‐analysis

Abstract The evolution of defensive traits and strategies depends on the intensity of selection imposed by natural enemies and on the fitness costs of defenses against these enemies. We tested several hypotheses about the evolution of chemical defenses in plant‐feeding insects using a meta‐analysis. We analyzed the effectiveness (in terms of prey survival; 159 publications) and costs (in terms of reduction in performance due to defense production; 33 publications) of chemical defenses in various prey–predator systems (140 herbivore species and 124 enemy species). The chemical defenses of insect herbivores, on average, were effective against generalist predators, were not effective against specialist predators and generalist parasitoids, and increased the risk of parasitism by specialist parasitoids. The defenses were more effective against vertebrate than against invertebrate predators and most effective against birds. Defensive compounds synthesized de novo and derived from the herbivore's food plants did not differ in the magnitude of their effects. Externalization of chemical defenses enhanced their effects on naïve vertebrate predators but simultaneously increased the risk of parasitism. The defenses of specialist herbivores were more effective than those of generalists, mostly due to species that sequestered plant allelochemicals for their own defenses. Advertising of chemical defenses by warning display enhanced their effectiveness only against vertebrate predators. Aposematic colors and patterns were more effective warning signals than other types of conspicuous coloration against both experienced and naïve vertebrate predators, suggesting that certain colors and/or patterns were more important than conspicuousness for both learning and innate avoidance. The meta‐analysis did not reveal physiological costs of the production of chemical defenses across 22 herbivore species, although the results varied strongly with the method used to measure these costs. We conclude that the cost–benefit trade‐offs driving the evolution of chemical defenses in herbivorous insects are affected by ecological costs (i.e., increased susceptibility to parasitoids) more than by costs in terms of resources. Still, a favorable cost–benefit ratio, i.e., great effects for a small expenditure, may partly explain the prevalence of chemical anti‐predator defenses in insects.

Biological control of invasive Dryocosmus kuriphilus with introduced parasitoid Torymus sinensis in Croatia, Slovenia and Hungary

Background and purpose: Dryocosmus kuriphilus is considered as one of the major pests of sweet chestnut and the effective method of controlling its populations and damage is the biological control with its introduced parasitoid Torymus sinensis. T. sinensis is a univoltine, host specific parasitoid, phenologically synchronized and morphologically adapted to D. kuriphilus . It has a good dispersal ability, it builds up populations quickly and it effectively controls the pest already few years after the release. In this paper we describe the first results of the introduction and release of T. sinensis for controlling the populations of invasive D. kuriphilus in sweet chestnut forests and orchards in Croatia, Hungary and Slovenia. Materials and methods: Withered D. kuriphilus galls with T. sinensis larvae were collected in Torino vicinities, Italy, in March 2014 and March 2015. After emergence, males and females were put together, kept at 14°C and fed with liquid honey until the release. To confirm the establishment of the population of T. sinensis on release site from 2014 in Croatia morphological and DNA identification were used. Fresh galls from the release site of Pazin, Croatia were collected in spring 2015 and parasitism rates of T. sinensis were calculated. Results and conclusions: In total 10,590 females and 5,295 males of T. sinensis were released in sweet chestnut forests in Croatia, Hungary and Slovenia in 2014 and 2015. The minimum release number of T. sinensis was 100 females/50 males and the maximum was 1,200 females per site. Subsequent releases with a larger number of females (1,200 and 800 in two years) resulted in a rapid establishment of the population of T. sinensis and parasitism rates of 76% only one year after the first release was done . The establishment of the population of T. sinensis was confirmed with molecular analyses and morphological identification. Obtained haplotype sequences of T. sinensis have shown similarities with Torymus beneficus. Prior to the release of T. sinensis , all advantages and disadvantages of the introduction of this alien biocontrol species into natural stands in Croatia, Hungary and Slovenia have been considered.

Reproductive and developmental biology of the emerald ash borer parasitoid Spathius galinae (Hymenoptera: Braconidae) as affected by temperature

Emerald ash borer Agrilus planipennis Fairmaire (Coleoptera: Buprestidae) is an invasive pest of serious concern in North America. To complement ongoing biological control efforts, Spathius galinae Belokobylskij and Strazenac (Hymenoptera: Braconidae), a recently-described specialist parasitoid of emerald ash borer larvae, is being released for the first time in the United States. To better understand its reproductive and developmental biology, and to improve outcomes of mass-rearing, we investigated the effects of constant ambient temperature (15, 20, 25, 30, and 35°C) on immature development time, sex ratio, pre-oviposition period, fecundity and survivorship. Results show that between 20 and 30°C immature development time was inversely associated with temperature, with adults emerging ≈38, 32, and 25d after oviposition at 20, 25, and 30°C, respectively. At 15°C larvae developed to 5th instars and spun cocoons before development was arrested, while at 35°C parasitoid eggs desiccated and did not hatch. Sex ratio of adult progeny that were exposed to different temperatures, from eggs, was not affected. When newly (⩽24h-old) emerged female parasitoids were provided larval hosts throughout their lifetimes, adults parasitized at all temperatures except 35°C, although parasitism rate was highest (35%), as was lifetime fecundity (43 progeny/female), when females lived at 25°C. Survivorship was inversely associated with temperature, with ovipositing females living for >60d when maintained at 15°C, and females held at 35°C living for <10d. Life table analyses showed S. galinae had the highest net reproductive rate (R0=27.8) and intrinsic rate of increase (rm=0.29) when female parasitoids were maintained at 25°C for their lifetimes, suggesting this is the optimal temperature to rear S. galinae.

Biological control of invasive Dryocosmus kuriphilus with introduced parasitoid Torymus sinensis in Croatia, Slovenia and Hungary

Background and purpose: Dryocosmus kuriphilus is considered as one of the major pests of sweet chestnut and the effective method of controlling its populations and damage is the biological control with its introduced parasitoid Torymus sinensis. T. sinensis is a univoltine, host specific parasitoid, phenologically synchronized and morphologically adapted to D. kuriphilus. It has a good dispersal ability, it builds up populations quickly and it effectively controls the pest already few years after the release. In this paper we describe the first results of the introduction and release of T. sinensis for controlling the populations of invasive D. kuriphilus in sweet chestnut forests and orchards in Croatia, Hungary and Slovenia. Materials and methods: Withered D. kuriphilus galls with T. sinensis larvae were collected in Torino vicinities, Italy, in March 2014 and March 2015. After emergence, males and females were put together, kept at 14°C and fed with liquid honey until the release. To confirm the establishment of the population of T. sinensis on release site from 2014 in Croatia morphological and DNA identification were used. Fresh galls from the release site of Pazin, Croatia were collected in spring 2015 and parasitism rates of T. sinensis were calculated. Results and conclusions: In total 10,590 females and 5,295 males of T. sinensis were released in sweet chestnut forests in Croatia, Hungary and Slovenia in 2014 and 2015. The minimum release number of T. sinensis was 100 females/50 males and the maximum was 1,200 females per site. Subsequent releases with a larger number of females (1,200 and 800 in two years) resulted in a rapid establishment of the population of T. sinensis and parasitism rates of 76% only one year after the first release was done. The establishment of the population of T. sinensis was confirmed with molecular analyses and morphological identification. Obtained haplotype sequences of T. sinensis have shown similarities with Torymus beneficus. Prior to the release of T. sinensis, all advantages and disadvantages of the introduction of this alien biocontrol species into natural stands in Croatia, Hungary and Slovenia have been considered.

Parasitoid complex of leaf miner Pyllonorycter comparella (Lepidoptera, Gracillariidae) in Hungary

Abstract Between 2011 and 2014, 1,154 mines of Phyllonorycter comparella (Duponchel) were collected at 12 locations in Hungary and were put into single-mine rearing containers. A total of 574 parasitoid specimens belonging to 29 parasitoid species (26 Chalcididae, 2 Encyrtidae and 1 Braconidae) emerged. Of these species, 13 have not yet been mentioned in either international or in Hungarian literature as a parasitoid of the P. comparella. The species assemblages of the parasitoid complexes varied greatly among the sample sites. The primary dominant species of the total samples was found to be Sympiesis sericeicornis (Nees), an abundant idiobiont solitary ectoparasitoid. Among the species reared, we have found specialist parasitoids such as Achrysocharoides scaposa (Erdős) and even species never recorded from Populus (Zagrammosoma variegatum (Masi)) according to the Universal Chalcidoidea Database.

Oviposition preference of cabbage white butterflies in the framework of costs and benefits of interspecific herbivore associations.

When deciding where to oviposit, herbivorous insects consider: (i) the plant’s value as a food source, (ii) the risks of competing with con- and heterospecific herbivores, and (iii) the risks of parasitism and predation on the host plant. The presence of con- and/or heterospecific competitors would further affect the oviposition preference, because the preceding herbivores induce direct/indirect defences in plants against forthcoming herbivores, and thereby alter oviposition decisions. In previous studies, the abovementioned factors have not been studied in an integrative manner. We performed here a case study of this by assessing the oviposition preferences of a small white butterfly, Pieris rapae, for plants occupied by combinations of conspecific larvae, heterospecific larvae (Plutella xylostella), specialist parasitoids of Pi. rapae (Cotesia glomerata) and generalist predators (ants). We previously reported that the females showed equal preference for Pl. xylostella-infested and uninfested plants. Here, we showed that Pi. rapae females preferred uninfested plants to conspecific-infested ones, and Pl. xylostella-infested plants to Pi. rapae-infested ones. We discuss these oviposition preferences of Pi. rapae females in the framework of costs and benefits of interspecific herbivore associations from the above point of view.

Are generalist Aphidiinae (Hym. Braconidae) mostly cryptic species complexes?

AbstractAphidiinae are mostly composed of specialist parasitoids and the few species described as generalist are suspected to be composed of cryptic specialists, almost indistinguishable based on morphological characteristics. The use of molecular markers has proven to be a useful tool for revealing cryptic species complexes and here we use seven mitochondrial and nuclear gene fragments to study possible genetic differentiation among seven Aphidiinae generalists. Maximum likelihood (ML) trees and Bayesian Poisson tree processes (bPTP) models were conducted on each gene separately and on the seven genes together. The standard cytochrome c oxidase I barcode region appeared to be the most polymorphic and probably the best marker to reveal putative cryptic species. However, we showed with ML trees and bPTP models that a complementary use of mitochondrial and nuclear genes was the most relevant approach to reliably identify cryptic genetic clades in the Aphidiinae. Overall, most of the analysed generalist morphospecies were shown to be composed of subgroups related to the aphid host, some of them revealed as cryptic species by the species delimitation analysis. Further studies are needed to reveal the generality of this result in Aphidiinae.

Artificial nighttime light changes aphid-parasitoid population dynamics.

Artificial light at night (ALAN) is recognized as a widespread and increasingly important anthropogenic environmental pressure on wild species and their interactions. Understanding of how these impacts translate into changes in population dynamics of communities with multiple trophic levels is, however, severely lacking. In an outdoor mesocosm experiment we tested the effect of ALAN on the population dynamics of a plant-aphid-parasitoid community with one plant species, three aphid species and their specialist parasitoids. The light treatment reduced the abundance of two aphid species by 20% over five generations, most likely as a consequence of bottom-up effects, with reductions in bean plant biomass being observed. For the aphid Megoura viciae this effect was reversed under autumn conditions with the light treatment promoting continuous reproduction through asexuals. All three parasitoid species were negatively affected by the light treatment, through reduced host numbers and we discuss induced possible behavioural changes. These results suggest that, in addition to direct impacts on species behaviour, the impacts of ALAN can cascade through food webs with potentially far reaching effects on the wider ecosystem.

Optimizing Crops for Biocontrol of Pests and Disease.

Volatile compounds and extrafloral nectar are common defenses of wild plants; however, in crops they bear an as-yet underused potential for biological control of pests and diseases. Odor emission and nectar secretion are multigene traits in wild plants, and thus form difficult targets for breeding. Furthermore, domestication has changed the capacity of crops to express these traits. We propose that breeding crops for an enhanced capacity for tritrophic interactions and volatile-mediated direct resistance to herbivores and pathogens can contribute to environmentally-friendly and sustainable agriculture. Natural plant volatiles with antifungal or repellent properties can serve as direct resistance agents. In addition, volatiles mediating tritrophic interactions can be combined with nectar-based food rewards for carnivores to boost indirect plant defense.

Aphid parasitoid generalism: development, assessment, and implications for biocontrol

Host specialization in aphid parasitoids is important both from a theoretical and an applied point of view. It arises from various ecological mechanisms involving their interactions with aphids, host plants, and endosymbiotic bacteria, as well as with potential competitors and enemies. From an applied point of view, host specialization in aphid parasitoids has a great importance as it determines the biological control they provide through their capacity to switch between different hosts, to persist in the agrosystem in the absence of the pest, and to regulate pest outbreaks in a rapidly changing system. It also conditions the risk of undesirable effects on non-target species in the case of introduction or augmentation of populations of parasitoids. Biocontrol literature that looks at the benefits of generalist and specialists natural enemies is mainly focused on differences between different guilds of natural enemies and does not consider the differences in host specialization within a single guild. This review synthesizes the mechanisms related to host-use by aphid parasitoids, focusing on the differences between generalist and specialist species. Second, this work describes the difficulty to determine the host range of generalist parasitoid species. Our review points out some observational artifacts, as is the existence of cryptic species or spatiotemporal variability in host acceptance, which may lead to misinterpretations about host specialization and result in pest management failures. Regarding biological control services, moderately generalized species that could use various host species to sustain their populations may ensure the long-term control, whereas specialist species would provide higher parasitism rates. At the community level, the co-occurrence of specialist and generalist parasitoids may maximize biological control services both in terms of efficiency and in terms of stability in space and time.

Population dynamics of an invasive forest insect and associated natural enemies in the aftermath of invasion: implications for biological control

Summary Understanding the population dynamics of exotic pests and associated natural enemies is important in developing sound management strategies in invaded forest ecosystems. The emerald ash borer (EAB) Agrilus planipennis Fairmaire is an invasive phloem‐feeding beetle that has killed tens of millions of ash Fraxinus trees in North America since first detected in 2002. We evaluated populations of immature EAB life stages and associated natural enemies over a 7‐year period (2008–2014) in six stands of eastern deciduous forest in southern Michigan, where Tetrastichus planipennisi Yang and two other Asian‐origin EAB parasitoids were released for biological control between 2007 and 2010. We observed ≈90% decline in densities of live EAB larvae in infested ash trees at both parasitoid‐release and control plots from 2009 to 2014 and found no significant differences in EAB density or mortality rates by parasitoids, avian predators or other undetermined factors between parasitoid‐release and control plots. The decline in EAB larval density in our study sites was correlated with significant increases in EAB larval parasitism, first by native parasitoids, then by T. planipennisi. Life table analyses further indicated that parasitism by the introduced biocontrol agent and the North American native parasitoids contributed significantly to the reduction of net EAB population growth rates in our study sites from 2010 to 2014. Synthesis and applications. Our findings indicate that successful biocontrol of emerald ash borer (EAB) may involve suppression of EAB abundance both by local, generalist natural enemies (such as Atanycolus spp.) and by introduced specialist parasitoids (such as T. planipennisi). Biological control programmes against EAB in the aftermath of invasion should focus on establishing stable populations of T. planipennisi and other introduced specialist parasitoids for sustained suppression of low‐density EAB populations. Moreover, we recommend releasing the introduced specialist biocontrol agents as soon as possible to prevent the outbreak of EAB populations in both newly infested and aftermath forests when EAB densities are still low.

Arms Race Between Leaf Rollers and Parasitoids

The family Attelabidae show diverse feeding niches of immatures, e.g., there are shoot/petiole/seed borers, leaf miners, and leaf roll feeders to be found, even in closely related species. We evaluated the relative importance of ecological and phylogenetic factors in deciding the community structure using Attelabidae–parasitoid relationships. The studies revealed that parasitoid community is more influenced by feeding niche reflecting maternal plant-manipulation behavior, than it is by the phylogeny of hosts, parasitoids, and host plants. Our results support the idea that niche diversification in herbivorous insects, including leaf roll construction of Attelabidae, might have evolved as a result of the avoidance of parasitoids. A leaf roll constructed and cut off by a female Henicolabus lewisii (Coleoptera; Attelabidae). Photo by Chisato Kobayashi. A female Paratracelophorus longicornis constructing a leaf roll using a leaf of Clethra barbinervis and its specific parasitoid, Poropoea sp., trying to oviposit into an egg in the leaf roll. Photo by Chisato Kobayashi. A female Paropolapoderus pardalis constructing a leaf roll. Photo by Takuo Sawahata. These photographs illustrate the article "Arms race between leaf rollers and parasitoids: diversification of plant-manipulation behavior and its consequences" by Chisato Kobayashi, Kazunori Matsuo, Kyohei Watanabe, Nobuaki Nagata, Yukari Suzuki-Ohno, Masakado Kasata, and Makoto Kato, published in Ecological Monographs 85(2):253–268. http://dx.doi.org/10.1890/14-0280.1