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The use of a non-destructive technique, such as the propagation-based X-ray phase contrast radiography (PBR) can be an innovative method for automatic parasitism analysis, especially if it presents standard structures. Herein, an artificial intelligence (AI) model is applied in order to establish a computer vision of egg parasitoids in PBRs of parasitized moth eggs acquired at the Synchrotron Radiation for Medical Physics (SYRMEP) beamline at ELETTRA. PBRs of eggs parasitized in four different stages of parasitism (0 days, 3 days, 5 days and 7 days) have been tested. The AI model performance was evaluated by using different metrics. Average Precision (AP), which measures the accuracy of object detection, was found to be 0.866 and 0.741 for the moth eggs and for the parasites, respectively. Additionally, we found that as stage of parasitism becomes longer, the accuracy of parasitism detection also increases (76 % at 7 days).

Trissolcus japonicus (Ashmead) (Hymenoptera: Scelionidae) is an egg parasitoid of the invasive Asian pest, brown marmorated stink bug, Halyomorpha halys (Stål) (Hemiptera: Pentatomidae). Also native to Asia, adventive T. japonicus populations have been detected in North America since 2014, and are currently reported from 15 U.S. states, the District of Columbia, and two Canadian provinces. Yellow sticky cards (YSC) have proven effective for monitoring the presence, seasonal abundance, and distribution of these adventive populations. Our research has utilized YSC deployed in the midcanopy of H. halys host trees, following a study in which all leaves on felled tree of heaven, Ailanthus altissima (Mill.) Swingle, were inspected for H. halys egg masses, yielding eggs parasitized by T. japonicus only from mid- and upper-canopy leaves. However, given that other investigators have captured T. japonicus using YSC deployed in the lower-canopy, and that the effect of YSC placement in trees on T. japonicus captures had not been examined, captures of T. japonicus on YSC in the mid- and lower-canopy of individual A. altissima were compared. Traps were replaced weekly for five weeks and assessed for scelionid species. In 2020 and 2021, T. japonicus represented ≥53% of all Scelionidae captured, and there was not a significant effect of YSC location in the canopy on its captures. Deploying YSC at either canopy height was effective for measuring the relative abundance of T. japonicus, but sampling from the lower canopy substantially improved the efficiency and convenience of T. japonicus surveillance.

This study aimed to assess the effectiveness of releases of different amounts of Telenomus podisi for the control of Euchistus heros in soybean crops. In addition, productivity was determined between treatments. The experiments were conducted in commercial areas of soybean production during the 2017/2018 crop season. The experiments were installed in three experimental areas in different locations of São Paulo state, Brazil; Pardinho (Farm Santa Fe), Tatuí (Farm Dos Lagos), and Angatuba (Farm Santa Irene). The experimental design was that of random blocks with five treatments and five repetitions. The statistical analysis of the experimental data applied was of variance homogeneity (Hartley Test), variance analysis (ANOVA), and Tukey’s average discrimination test, at 5% of probability. The treatments evaluated were: T1- 2,000 eggs/ha; T2- 3,500 eggs/ha; T3- 5,000 eggs/ ha; T4- 6,500 eggs/ha; T5- Control (Without T. podisi release). The release of adult parasitoids was carried out manually in the center of the plots. The parasitoid release interval was made from the presence of two nymphs or average adults of E. heros per linear meter, considering the end of the vegetative phase and physiological maturation. The sampling of nymphs and adults of E. heros were performed at weekly intervals (1, 7, 14, and 21 days) prior to the releases of T. podisi. The reduction in the number of nymphs and adults of E. heros, following the release of parasitoids was assessed. Additionally, productivity between treatments was evaluated. The release of 6,500 adults of T. podisi significantly reduced the number of nymphs and adults of E. heros and showed to be more effective regarding other treatments. The productivity between the treatments evaluated did not show significant statistical differences., Este estudio tuvo como objetivo evaluar la eficacia de las liberaciones de diferentes cantidades de Telenomus podisi para el control de Euschistus heros en el cultivo de soya. Además, se determinó la productividad entre los tratamientos. Los experimentos fueron conducidos en áreas comerciales de producción de soya, durante el año agrícola 2017/2018. Los experimentos fueron instalados en tres áreas experimentales en diferentes localidades del estado de São Paulo, Brasil; Pardinho (Hacienda Santa Fé), Tatuí (Hacienda Dos Lagos) y Angatuba (Hacienda Santa Irene). El diseño experimental fue de bloques al azar con cinco tratamientos y cinco repeticiones. El análisis estadístico de los datos experimentales aplicado fue la homogeneidad de varianzas (Prueba de Hartley), el análisis de varianza (ANOVA) y la prueba de discriminación de medias de Tukey, al 5% de probabilidad. Los tratamientos evaluados fueron: T1- 2.000 huevos /ha; T2- 3.500 huevos/ha; T3- 5.000 huevos/ha; T4- 6.500 huevos/ha; T5- Control (Sin liberación de T. podisi). La liberación de los parasitoides adultos fue realizada manualmente, en el centro de las parcelas. El intervalo de liberación de los parasitoides se realizó a partir de la presencia de dos ninfas y/o adultos promedio deE. heros por metro lineal, entre el final de la fase vegetativa y la maduración fisiológica. Los muestreos de ninfas y adultos de E. heros, fueron realizados en intervalos semanales (1, 7, 14 y 21 días) previamente a las liberaciones de T. podisi. Se evaluó la reducción del número de ninfas y de adultos de E. heros, posterior a la liberación de los parasitoides. Además, se evaluó la productividad entre los tratamientos. La liberación de 6,500 adultos/ha de T. podisi redujo significativamente el número de ninfas y adultos de E. heros y fue más eficaz en relación a los otros tratamientos. La productividad entre los tratamientos evaluados, no presentaron diferencias estadísticas significativas entre sí

Within the Brassicaceae, wild as well as crop species are challenged by specialist herbivores including cabbage white butterflies (Pieris spp.). The wild crucifer Brassica nigra responds to oviposition by Pieris butterflies by the synergistic expression of two egg-killing traits. Genotypes that express a hypersensitive response (HR)-like necrosis (direct egg-killing) also emit oviposition-induced plant volatiles (OIPVs) attracting Trichogramma egg parasitoids (indirect egg-killing). This so-called double defense line can result in high butterfly egg mortalities. It remains unknown whether this strategy is unique to B. nigra or more common in Brassica species. To test this, we examined the response of different Trichogramma evanescens lines to OIPVs emitted by B. nigra and three close relatives (Brassica napus, Brassica rapa, and Brassica oleracea). Furthermore, we evaluated whether HR-like necrosis played a role in the attraction toward plant volatiles. Our results show a specificity in wasp attraction to different plant species. Three out of four plant species attracted a specific T. evanescens strain, including the crops B. rapa and B. napus. Parasitoid attraction was positively affected by presence of HR-like necrosis in one plant species. Our findings imply that, despite being a true generalist in terms of host range, T. evanescens shows intraspecific variation during host searching, which should be taken into account when selecting parasitoid lines for biocontrol of certain crops. Finally, we conclude that also crop plants within the Brassicaceae family possess egg-killing traits and can exert the double-defense line which may enable effective selection of egg-killing defense traits by cabbage breeders.

Due to a growing demand of food production worldwide, new strategies are suggested to allow for sustainable production of food with minimal effects on natural resources. A promising alternative to the application of chemical pesticides is the implementation of crops resistant to insect pests. Plants produce compounds that are harmful to a wide range of attackers, including insect pests; thus, exploitation of their natural defense system can be the key for the development of pest-resistant crops. Interestingly, some plants possess a unique first line of defense that eliminates the enemy before it becomes destructive: egg-killing. Insect eggs can trigger (1) direct defenses, mostly including plant cell tissue growth or cell death that lead to eggs desiccating, being crushed or falling off the plant or (2) indirect defenses, plant chemical cues recruiting natural enemies that kill the egg or hatching larvae (parasitoids). The consequences of plant responses to eggs are that insect larvae do not hatch or that they are impeded in development, and damage to the plant is reduced. Here, we provide an overview on the ubiquity and evolutionary history of egg-killing traits within the plant kingdom including crops. Up to now, little is known on the mechanisms and on the genetic basis of egg-killing traits. Making use of egg-killing defense traits in crops is a promising new way to sustainably reduce losses of crop yield. We provide suggestions for new breeding strategies to grow egg-killing crops and improve biological control.

No Abstract.

Natural control of the teak defoliator, Hyblaea puera Cramer by a large number of larval and pupal parasitoids has been reported (Chatterjee and Misra, ]974; Sudheendrakumar, 1985). However, only very very little information IS available on egg parasitoids of the teak defoliator (Beeson, 1941; Nair et al.. 1994).

Clavigralla spp. (Hemiptera: Coreidae) eggs are laid inclusters. Field collections at International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) over three seasons from 1992-93 to 1994-95 showed that cluster size ranges from 2 to 62 eggs with a mean of 17.7 eggs. A majority of egg clusters (72%) contained between 7 and 24 eggs. Gryon clavigrallae Mineo (Hymenoptera: Scelionidae) parasitized up to 69 per cent of eggs and up to 100 per cent of egg clusters each season. Overall, more than 39 per cent of Clavigralla spp. eggs were parasitized by G. clavigrallae. The percentage of egg clusters parasitized and the percentage of eggs parasitized in a cluster were positively correlated with the size of the egg cluster. The percentage of eggs and egg clusters parasitized by G. clavigrallae increased through the season.

The eggs of Tenodera aridifolia sinensis (Saussure) were parasitised by Podagrion sp. in Nagaland. The per cent oothecae parasitised was 28 and 40.6 during 1987 and 1988, respectively.

The egg parasitoids of Helopeltis antonii Signoret existing in neem endemic area (coastal and hinterland of Tamil Nadu) and in non-neem endemic area (western ghats of Tamil Nadu and coastal Karnataka) are Telenomus sp. laricis group (Scelionidae), Erythmelus helopeltidis Gahan (Mymaridae), Chaetostricha sp. and Ufens sp. (Trichogrammatidae). Telenomus sp. is very much dominant in non-neem endemic areas, whereas Ufens sp. is quite prominent in neem endemic areas. When the eggs of H. antonii laid on neem were exposed for natural parasitism, neem has not exerted any adverse interaction on Telenomus sp.

Direct observation of searching patterns and residence times of Trichogramma brassicae Bezdenko on maize plants were made at 18 degrees C and 25 degrees C. Temperature had a strong effect on the residence times: parasitoids spent an average of 44.9 minutes on the plant at 18 degrees C and 20.8 minutes at 25 degrees C. Observations on single plants showed that parasitoids mainly walked from one leaf to another. The leaf part closest to the stem was the most often visited and longest searched leaf area. At 18 degrees C, many parasitoids went to the lower leaf side and stopped searching. Leaf level, leaf side or size of the leaf where the parasitoid landed had no effect on residence time. Although about 20% of total searching time was spent in following the leaf edge and mid rib, Ostrinia (Hubner) egg masses touching the mid rib were not found more often than those away from the mid rib. Host finding was also not influenced by the position of egg masses relative to the stem, or by the leaf height. Naturally laid egg masses were found twice as often as artificially placed egg masses. The scales that O. nubilalis adults left in small patches on the plant seemed to be as effective a cue as host cues artificially confined to a small area around the host egg mass. When maize plants were covered with fine netting and a number of O. nubilalis kept close to the plant for one night in such a way that the moths were unable to touch the plants, host finding and residence times of T. brassicae were significantly higher on these plants than on untreated plants. This indicates that volatile cues left by O. nubilalis had an arresting effect and were used in host finding by T. brassicae.

An experiment on the management of rice leaf folder and stem borer in two rice varieties, viz., PR 116 and Basmati 386, was conducted in the organic field area of Department of Agronomy and Agromet, PAU, Ludhiana, by comparing three treatments, viz, organic, recommended and integrated practices. Organic practices and integrated practices (seven releases of Trichogramma chilonis and T. japonicum @ 100000 each at weekly interval starting 30 DAT) proved to be effective in the management of rice leaf folder and stem borer in both the rice varieties.

The lepidopteran predator, Eublemma amabilis Moore, is a major pest of lac and causes colossal losses to the lac crop to the magnitude of about 40 per cent. Three species of trichogrammatid egg parasitoids, namely, Trichogramma achaeae Nagaraja and Nagarkatti, T. exiguum Pinto and Platner and T. ostriniae Pang et Chen were evaluated in the present study on lac crop raised on the bushy host plant, Flemingia macrophylla O. Kytze and were found extremely useful as a substitute for chemical pesticides. All the three egg parasitoids were able to suppress the population of E. amabilis. The reduction in the population of E. amabilis was 77 to 86 per cent in case of rangeeni crop and 52 to 72 per cent in case of kusmi crop with a dose of 20 egg parasitoids per bush. In general, trichogrammatids were found more effective in ease of rangeeni lac than kusmi. All the three parasitoids were found equally effective in suppressing the population of E. amabilis.

We investigated the differentiation and reproductive isolation among different geographic populations of Gonatocerus morrilli, egg parasitoids of the glassy-winged sharpshooter (Homalodisca coagulata), to confirm previous observations that there may exist a cryptic species complex or a new species. Two mitochondrial genes [cytochrome oxidase subunits I (COI) and II (COII)] and the internal transcribed spacer region 2 (ITS2) of several individuals per population were sequenced. G. morrilli populations from Texas (TX), Florida (FL), California (CA), and an outgroup (G. ashmeadi) were analyzed. For comparison, a population from Argentina (G. annulicornis) morphologically similar to G. morrilli was also included. For all three sequence fragments, percentage sequence divergence (%D) demonstrated that both the TX and FL populations (TX/FL) were closely related and therefore determined to be the same species; in contrast, the %D between TX/FL and CA fell within the range of the outgroup, making the CA population a new species or sp. n. Neighbor-joining distance trees also clustered the TX/FL and CA populations or species into two well supported distinctive clades. The near G. morrilli sp. n. was more closely related to G. annulicornis than to the TX/FL species. Mating studies demonstrated that the populations or species from CA and TX were reproductively incompatible, producing no female offspring in both direct and reciprocal crosses; whereas, the heterogamic crosses between TX and FL produced fertile offspring and relative compatibility indices similar to the homogamic crosses. Unidirectional cytoplasmic incompatibility was ruled out as a cause for the lack of reproduction since both males and females were infected in equal portions with Wolbachia.

Plants can defend themselves against herbivorous insects before the larvae hatch from eggs and start feeding. One of these preventive defence strategies is to produce plant volatiles, in response to egg deposition, which attract egg parasitoids that subsequently kill the herbivore eggs. Here, we studied whether egg deposition by Pieris brassicae L. (Lepidoptera: Pieridae) induces Brussels sprouts plants to produce cues that attract or arrest Trichogramma brassicae Bezdeko (Hymenoptera: Trichogrammatidae). Olfactometer bioassays revealed that odours from plants with eggs did not attract or arrest parasitoids. However, contact bioassays showed that T. brassicae females were arrested on egg-free leaf squares excised from leaves with 72 h-old egg masses, which are highly suitable for parasitisation. We tested the hypothesis that this arresting activity is due to scales and chemicals deposited by the butterflies during oviposition and which are thus present on the leaf surface in the vicinity of the eggs. Indeed, leaf squares excised from egg-free leaves, but contaminated with butterfly deposits, arrested the wasps when the squares were tested 1 day after contamination. However, squares from egg-free leaves with 72 h-old butterfly deposits had no arresting activity. Thus, we exclude that the arresting activity of the leaf area near 72 h-old egg masses was elicited by cues from scales and other butterfly deposits. We suggest that egg deposition of P. brassicae induces a change in the leaf surface chemicals in leaves with egg masses. A systemic induction extending to an egg-free leaf neighbouring an egg-carrying leaf could not be detected. Our data suggest that a local, oviposition-induced change of leaf surface chemicals arrests T. brassicae in the vicinity of host eggs