Egg Parasitism Research Articles

Endophytic Beauveria bassiana increases galling of 'Rutgers' tomato roots with Meloidogyne incognita.

Beauveria bassiana is endophytic in many plant species and has been shown to protect host plants against insect pests and plant pathogens. However, less is known about its activity against plant-parasitic nematodes. In vitro and plant assays were conducted to determine the effect of B. bassiana 11-98 (Bb) on Meloidogyne incognita (root-knot nematode; RKN). Beauveria bassiana was confirmed as an endophyte in ‘Rutgers’ tomato and colonization patterns of Bb in ‘Rutgers’ (highly susceptible to RKN) were compared with those in ‘Mountain Spring’ (less susceptible to RKN). In greenhouse tests with ‘Rutgers’ at 30 and 60 days after treatment (DAT) with RKN and Bb, there were few differences in plant growth variables among treatments in repeated trials. However, RKN root galling and egg count/root system were enhanced in plants treated with Bb at 60 DAT. In an in vitro assay with egg masses from greenhouse tests, the percentages of hatched eggs, and mobile and immobile nematodes did not differ significantly for RKN and RKN+Bb treatments. The presence of viable Bb from roots was confirmed by collecting egg suspensions from root galls and plating them on selective medium. Colonies of Bb were verified on agar medium, but no parasitism of RKN eggs was observed. Research is needed to investigate factors responsible for increased galling by RKN in the presence of endophytic Bb in ‘Rutgers’ tomato.

Egg Parasitoids of Cabbage Caterpillars in Sri Lanka: A Search for Biocontrol Agents

Purpose : Management of cabbage caterpillar complex through augmentative release of egg parasitoids has been suggested considering the current issues in insecticide application, mainly the effect on human health, non-target effects and environmental pollution. Use of local egg parasitoid species is preferred considering the environmental risk associated with the use of exotic species; therefore, this study was conducted to examine the egg parasitoid guild of cabbage caterpillars in Sri Lanka. Research Method : Field survey was conducted during January 2012 to May 2013 in major cabbage growing areas in the mid-country. Eggs of cabbage caterpillars were collected and reared them until the emergence of host larvae or adult parasitoids. Emerged parasitoids were preserved in 70% ethanol, and prepared the microscopic slides upon the dissection of male genitalia. Parasitoids were identified by using taxonomic keys and Trichogramma literature as per the protocol suggested by Natural History museum, London and the identities were confirmed by the taxonomist in Natural history museum in London. Findings : Trichoplusia ni, Spodoptera litura, Crocidolomia pavonana and Plutella xylostella were found as the members of cabbage caterpillar complex. Two egg parasitoid species: Trichogramma chilonis Ishi and Trichogramma achaeae Nagaraja and Nagarkatti were found attacking eggs of cabbage caterpillars. Trichogramma chilonis has been reported previously in Sri Lanka but Trichogramma achaeae is the first country report. T. chilonis was widely distributed and caused for higher level of parasitism than T. achaeae. The highest level of parasitism (67%) by both species was found in Trichoplusia ni eggs which was significantly different from other species. Level of parasitism of caterpillar eggs was significantly varied between pesticide free fields (16.8%) and conventional fields (13.1%). Research Limitation : The study of behavioral characters of these parasitoids is required to assess the suitability as biocontrol agents; as an initial step for augmentative biocontrol, the locally available egg parasitoids were reported in this study. Originality/ Value : These findings would be contributing Sri Lankan agriculture sector to develop the augmentative biocontrol approach to manage the cabbage caterpillar complex and to produce pesticide residues free crop produce.

Influence of the site of oviposition on the level of egg parasitism in the corn leafhopper, Dalbulus maidis (Hemiptera: Cicadellidae).

The corn leafhopper Dalbulus maidis (DeLong) (Hemiptera: Cicadellidae), transmits three important plant pathogens that adversely affect corn crop and ranges from the USA to Argentina. The vector has a rich natural enemy complex that generates high levels of parasitism, but its populations are persistent and prevalent. We characterized the oviposition sites of D. maidis on young corn plants in order to verify the hypothesis that the vector has an oviposition strategy for mitigating parasitism. Oviposition locations on plants were assessed in the laboratory and eggs within corn plants were exposed to natural parasitism in a cornfield. Eggs were located mostly laid in the unfolded leaves and were attacked by five parasitoid species. Parasitism was significantly affected by the class of leaf and the position of the egg in the leaf. Anagrus virlai Triapitsyn was the most abundant parasitoid species, which emerged significantly higher in the basal blade than other species. Our results suggest that leafhoppers minimize egg parasitism by laying their eggs within concealed locations on the plant.

Parasicity level of Telenomus sp. parasitoid against Spodoptera frugiperda J. E. Smith eggs in the laboratory

Telenomus sp. as a biological agent, can be used to control a new pest, namely Spodoptera frugiperda which attacks maize in Indonesia. The purpose of this study was to count the number of eggs of S. frugiperda parasitized by Telenomus sp. and to calculate the level of parasitization of the parasitoid Telenomus sp. against S. frugiperda in the laboratory. Research method that used in this research were searching for S. frugiperda caterpillars and preparation of Telenomus sp. The data analysis used in this research was inferential analysis. The results of this study were tested using the normality test, as well as the homogeneity test, and continued with the Kruskal Wallis test. The results showed that parasite level of parasitoid in tube I, tube II, tube III, and tube IV, namely 0%, 23.5%, 18.3%, 11.3%, and the calculation of sex ratio on Telenomus sp. were 2 females and 1 male were found. This study concludes that the number of parasitoids Telenomus sp. affects the level of egg parasitization.©2020 JNSMR UIN Walisongo. All rights reserved.

Bio-efficacy of egg parasitoid, Trichogramma chilonis (Ishii) against spotted stem borer, Chilo partellus (Swinhoe) in Kharif maize

Maize stem borer, Chilo partellus, is the most serious and ubiquitous pest of maize not only in India but also throughout the Asian countries where it is a constant threat. The larvae, after hatching, enter the plant whorl and feed inside the plant for rest of the life. Owing to its cryptic behavior, insecticides are not the right choice. Moreover, unwarranted use of pesticides has directly increased the cost of cultivation and accounted for many health as well as environmental hazards. Use of biological control agents is far better than harmful agro-chemicals in terms of health benefits and ecosystem stability, provided they are effective enough to suppress the pest population. Egg parasitoid, Trichogramma chilonis, has proven its worth against many lepidopteran borers and provided satisfactory control in many crops. With this view, an experiment was conducted to evaluate the potency of T. chilonis against spotted stem borer, Chilo partellus at laboratory and research area of CCS Haryana Agricultural University, Regional Research Station, Karnal during Kharif, 2017. In our study, maximum egg parasitization (62.40%) was recorded in treatment with two releases of T. chilonis parasitized eggs @ 1,25,000/ha at 7 and 14 days after germination (DAG) which was at par with two releases of T. chilonis parasitized eggs @ 1,00,000/ha at 7 and 14 DAG (60%) whereas treatment with one spray of Dimethoate 30 EC @ 660 ml/ha had minimal T. chilonis activity (3.5% parasitization). Lower leaf injury rating (LIR), plant infestation and dead hearts were recorded in treatments with two release of T. chilonis parasitized @ 1,25,000 and 1,00,000 eggs/ha at 7 and 14 DAG which were statistically comparable with Dimethoate 30 EC treated plots. Whereas treatments with single release of T. chilonis parasitized eggs did not provide satisfactory control. Treatment with two releases of T. chilonis parasitized eggs @ 1,00,000/ha at 7 and 14 DAG was the most economically remunerative with the highest incremental cost: benefit ratio (1:32.48) and benefit: cost ratio (1.41). Although, pesticide treated plots (Dimethoate 30 EC @ 660 ml/ha at 7 DAG) provided satisfactory monetary return but it is not environmentally compatible and ecologically viable for long run.

No significant effects of insecticide use indicators and landscape variables on biocontrol in field margins

Insecticides are used widely to manage pests, but they may cause mortality in natural enemy populations and non-target prey. On the other hand, resources provided by the landscape – often associated with semi-natural habitat – may enhance natural enemy communities. While there is substantial information on how insecticide use and semi-natural habitats influence biocontrol in crop fields, little is known about how local insecticide use interacts with landscape variables to govern natural biocontrol in field margins. In this 2-year study we assessed predation and parasitism rates of eggs of the cabbage moth (Mamestra brassicae) on potted cabbage plants in field margins adjacent to 20 organically managed fields and 18 conventionally managed fields We analysed egg predation and parasitism rates in field margins using three predictors for insecticide use: (i) farming system (organic or conventional), (ii) frequency of insecticide use in the adjacent focal fields, and (iii) estimated insecticide use quantity within a radius of 1 km from the sampling sites. Insecticide use included foliar or soil-applied applications, including mineral oils. Landscape variables were used as covariables to account for landscape effects. Mean predation and parasitism rates were 14 % and 6%, respectively. There were no significant associations between predation and parasitism rates in field margins with insecticide use in the adjacent field or the wider landscape. Our findings suggest that field margins can be valuable habitats for natural enemies in agricultural landscapes, irrespective of the insecticide use intensity at the local and landscape scale.

Potato cyst nematode-infected soil as a source of egg and cyst parasitic fungi as potential biocontrol agents

Parasitic fungi are an important natural mortality factor of parasitic nematode populations in plants under environmental conditions. Indigenous parasitic fungi are challenging to develop as biological control agents for plant parasitic nematodes, including potato cyst nematode (PCN). Soils that suppress nematode populations are a challenging source of biological agents. This study aimed to explore PCN-infected soil as a source of egg and cyst parasitic fungi. Infected soils associated with healthy plants were compared with soils associated with PCN-infected plants to explore the presence and activity of putative fungal biological control agents. Parasitic fungi in nematode-infected soil were explored, heat treatment was performed to prove the biological ability of parasitic fungi in soil to suppress PCN population, and the biological activity of parasitic fungi was induced using a baiting technique. Results indicated that fungal activity in some PCN-infected areas of soil might suppress PCN population by parasitism of cysts or eggs. Heat treatment of soil eliminated the biological activity of these fungi against PCN cyst population. Baiting soil with PCN cysts promoted the parasitic activity of the fungi in the infected soil. These results indicate that nematode-infected soil is a source of parasitic fungi as candidate biological control agents.

A new paraprobiotic-based treatment for control of Haemonchus contortus in sheep

Haemonchus contortus is a critical parasite of goats and sheep. Infection by this blood-feeding gastrointestinal nematode (GIN) parasite has significant health consequences, especially in lambs and kids. The parasite has developed resistance to virtually all known classes of small molecule anthelmintics used to treat it, giving rise in some areas to multidrug resistant parasites that are very difficult to control. Thus, new anthelmintics are urgently needed. Bacillus thuringiensis (Bt) crystal protein 5B (Cry5B), a naturally occurring protein made by a bacterium widely and safely used around the world as a bioinsecticide, represents a new non-small molecule modality for treating GINs. Cry5B has demonstrated anthelmintic activities against parasites of monogastric animals, including some related to those that infect humans, but has not yet been studied in a ruminant. Here we show that H. contortus adults are susceptible to Cry5B protein in vitro. Cry5B produced in its natural form as a spore-crystal lysate against H. contortus infections in goats had no significant efficacy. However, a new Active Pharmaceutical Ingredient (API) paraprobiotic form of Cry5B called IBaCC (Inactivated Bacterium with Cytosolic Crystals), in which Cry5B crystals are encapsulated in dead Bt cell wall ghosts, showed excellent efficacy in vitro against larval stages of H. contortus and relative protein stability in bovine rumen fluid. When given to sheep experimentally infected with H. contortus as three 60 mg/kg doses, Cry5B IBaCC resulted in significant reductions in fecal egg counts (90%) and parasite burdens (72%), with a very high impact on female parasites (96% reduction). These data indicate that Cry5B IBaCC is a potent new treatment tool for small ruminants in the battle against H. contortus.

Response of the egg parasitoids of the pine processionary moth to host density and forest cover at the southern edge of the range

Abstract Thaumetopoea pityocampa is the most important pine defoliator in the Mediterranean basin. Despite being attacked by a number of natural enemies, populations occur frequently at high density in several areas. Egg parasitism was studied in 27 pine and cedar forests in Algeria, in relation to the host density (tents per tree) and the proportion of forest cover in the landscape. Egg parasitism varied from 2% to 25%, accounted by two parasitoid species, the specialist Baryscapus servadeii and the generalist Ooencyrtus pityocampae. Tent density was negatively correlated with parasitism by B. servadeii but not with that of O. pityocampae. Conversely, parasitism by O. pityocampae increased with the proportion of forest and agricultural cover, but not in the case of B. servadeii. Maximum summer temperature showed no correlation with parasitism rates. Still, temperature frequently exceeded 40 °C during the period of adult parasitoid activity. The low performance of the egg parasitoids at the southern edge of the host range could be explained by the reduced fecundity of the host, climate effects, and phenological mismatching between the parasitoids and the egg development. These and other factors potentially involved the need to be further explored with a long‐term study of population dynamics.

Mortality of light brown apple moth egg masses in coastal California: Impact of resident Trichogramma parasitism and predation

Egg mortality of light brown apple moth (LBAM), Epiphyas postvittana (Walker), was studied during the early years of its discovery and establishment in California from 2008 to 11. Sentinel egg cards were used to quantify mortality by parasitoids and predators at an intensively monitored location in Santa Cruz to reveal seasonality, and at other sites in Santa Cruz and San Francisco to measure spatial variation and parasitoid species composition. In addition to egg mortality, egg mass use efficiency by Trichogramma parasitoids was also examined under field conditions. The egg parasitoids primarily consisted of three Trichogramma species, T. deion, T. fasciatum and T. platneri. Previously unknown to California, T. fasciatum was shown to displace the indigenous T. platneri over a two-year period as the predominant egg parasitoid attacking LBAM egg masses. Based on the number of parasitized eggs per sentinel egg card, it is argued that individual females of at least some Trichogramma species have the capacity to oviposit more than 50 eggs in the egg mass of a host, warranting further studies to document the egg mass use efficiency and oviposition traits of other trichogrammatids under field conditions. Although egg parasitism was limited to causing elevated mortality during the summer and fall only, egg predation occurred more consistently throughout the year and is likely to be of considerable significance in suppressing LBAM populations in California. Combined with the use of a Type II survivorship curve, the importance of using a temperature-dependent physiological time scale to quantify egg mortality is illustrated when sentinel hosts are exposed to natural enemies in the field for less than the entire duration of the ‘window of susceptibility’ to parasitism and predation.

Evaluation of oil dispersion formulation of nematophagus fungus, Pochonia chlamydosporia against root-knot nematode, Meloidogyne incognita in cucumber

Abstract Root-knot nematode, Meloidogyne incognita is considered as one of the major non-insect pests of crops. The management of these root feeders becomes highly challenging due to a strong host-parasitic relationship. Pochonia chlamydosporia is a nematophagus fungus that colonizes eggs of nematodes. This study aimed to test the efficacy of P. chlamydosporia (NAIMCC-SF0039) against M. incognita. An oil dispersion formulation of P. chlamydosporia was prepared using emulsifiers and vegetable oil. This formulation had a shelf-life of 90 days (3.3 × 108 CFU/mL) at room temperature (28 ± 1 °C). The inhibitory effect of oil formulation was tested against M. incognita by inoculating it on the egg mass. We found that colonization of the gelatinous matrix occurred on the third day of inoculation followed by complete egg parasitization on the seventh day. A greenhouse trial was laid out to evaluate the biocontrol potential of P. chlamydosporia in cucumber (Cucumis sativus). The results showed that the application of talc formulation of P. chlamydosporia at the rate of 1 kg per acre during planting, followed by delivery of 1 L of oil dispersion formulation through drip lines at 30-day intervals caused the highest reduction of nematode infestation. This treatment recorded 67.9 and 57.5% reduction in egg masses and soil nematode population respectively than that of control.

Biological control of Halymorpha halys (Stål) (Hemiptera: Pentatomidae) in apple orchards versus corn fields and their adjacent woody habitats: High versus low pesticide-input agroecosystems

Halymorpha halys is an invasive pest in the USA that inflicts damage to specialty crops, and conventional growers have increased use of broad-spectrum insecticides to manage this pest. The impacts of pest management programs on natural enemies of H. halys were examined in high vs. low intensity insecticide input agroecosystems in western North Carolina (USA). Apple orchards and corn fields, with their adjacent wooded habitats, served as the high and low-input environments, respectively. Sentinel egg masses and yellow sticky cards were deployed in these agroecosystems to compare predation and parasitism on H. halys eggs, and presence, abundance, and richness of natural enemies. A total of approximately 85% of all sentinel eggs deployed in apple orchards in both 2018 and 2019 produced a healthy stink bug nymph, higher than all other habitats. A total of 26.6% and 32.9% of eggs deployed in wooded habitats bordering corn exhibited mortality due to natural enemy attack in 2018 and 2019, respectively. Comparatively, eggs deployed in apple borders had 10.0% and 17.8% of total eggs killed by natural enemies, in 2018 and 2019, respectively. Corn agroecosystems generally had greater predation and parasitism of sentinel eggs, and greater richness and abundance of predators detected on yellow sticky cards compared to apple agroecosystems. Wooded habitats bordering crops serve as population reservoirs for H. halys, allowing for egg laying and dispersal into crops. If these areas are protected as refuge areas free from insecticide drift, such as from apple orchards, they can also harbor thriving natural enemy populations that could reduce populations of H. halys. Wooded areas free from harsh broad-spectrum insecticides are an important component for successful conservation and augmentative biological control in neighboring crops.

Between a rock and an egg‐crushing place: selection pressure from natural enemies and plant defences on eggs of the viburnum leaf beetle in its native range

1. The viburnum leaf beetle (VLB) is native to Eurasia and invasive in North America. It lays eggs inside young Viburnum twigs; eggs can be crushed by plant defences (wounding response) and attacked by natural enemies (parasitoids).2. We evaluated plant defences and parasitism rates in 42 field sites in 11 European countries, on three host plants (V. opulus, V. lantana, and V. tinus), and under two main climatic conditions (Mediterranean, oceanic/continental).3. Plant defences killed six times more eggs than natural enemies overall (25.4% vs. 4.1%). This effect was consistent for all host plants and climatic conditions. Egg survivorship and parasitism were lower in Mediterranean sites.4. Parasitism was positively density‐dependent, indicating a higher risk of parasitism on heavily infested twigs, but this effect was confounded with host plant species.5. These results suggest that plant defences have been the dominant selection force driving the evolution of VLB oviposition behaviour.

On Venezuelan pholcid spiders (Araneae, Pholcidae)

We present a comprehensive revision of the pholcid spider collection of M.A. González-Sponga, who between 1998 and 2011 described 22 new genera and 51 new species of Pholcidae from Venezuela. In addition, we treat the pholcid material collected during three expeditions to Venezuela conducted between 2002 and 2020. Of González-Sponga’s pholcid taxa we recognize three genera and 24 species as valid. We describe 43 new species (all from males and females) in one new and 13 previously described genera; four genera are newly recorded for Venezuela. We describe the previously unknown females of 15 species, present new records for 46 previously described species, synonymize one genus and one species, and correct numerous minor errors in previous publications on Venezuelan pholcids. At the generic level, the Venezuelan pholcid fauna now appears fairly well known, but available data on distribution and endemism suggest that many species remain undiscovered and undescribed. Despite the obvious gaps, our data are congruent with previous studies on other taxa that have the highest levels of endemism in the Venezuelan Andes, the Coastal Ranges, and the Guyana Highlands. The Falcón Region in particular shows a complex mosaic of biogeographic relationships with other regions. We provide new biological data on numerous species. We document the first cases of evolutionary microhabitat shifts in the genera Mecolaesthus Simon, 1893 and Priscula Simon, 1893. We document several cases of close congeners sharing localities, usually in slightly to conspicuously different microhabitats, sometimes apparently in identical microhabitats. We document several cases of color polymorphism, mostly intersexual, in Metagonia conica (Simon, 1893) both intersexual and among males. We document further cases of two rare phenomena in Pholcidae: use of specific non-silken structures for retreats (in Pisaboa Huber, 2000) and egg parasitism (in Priscula).

Natural parasitism of eggs of yellow stem borer, Scirpophaga incertulas Walker (Lepidoptera: Crambidae) in rice ecosystem at Tiruchirappalli, Tamil Nadu

Three species of parasitoids viz., Telenomus dignus Gahan, Trichogramma japonicum, Ishii and Tetrastichus schoenobii Ferriere were recorded from the egg masses of rice yellow stem borer, Scirpophaga incertulas (Walker) in a field study. The extent of parasitism was high during Rabi (43.33 – 93.33 %) and low during Kharif (0 - 40.00 %). Parasitism by T. dignus was maximum in October (50.00 %), T. japonicum, in November (23.08 %) and T. schoenobii in February (55.55 %). dignus and T. schoenobii in combination parasitized maximum number of egg masses (41.82 %). Multiple parasitism by the three species was high in December (8.33 %) and January (7.14%). Parasitic potential was maximum, when T. schoenobii alone parasitised the egg masses followed by T. dignus and T. schoenobii in combination. Host density in the field influenced the extent of parasitism.

Performance of Trichogramma chilonis on different host

The laboratory experiment was conducted during 2017-2018 to study the different biological attributes of Trichogramma chilonis Ishii as influenced by host eggs of different ages. Significantly maximum percent egg parasitization was noticed on eggs of Helicoverpa armigera (Hubner) with 62.39 percent which was at par with the Corcyra cephalonica (Stainton) eggs (60.36 percent). This was followed by Earias vittella Fabricius 46.31 percent. Less parasitized eggs were recorded in Leucinodes orbonalis Guenee (10.35 percent). Age of host eggs significantly affected the parasitization by T. chilonis . The maximum parasitization (58.87 percent) was noticed in fresh eggs i.e. 24 hrs old followed by 48 hrs (44.91 percent) while 72 hrs old eggs were less preferred by T. chilonis and could parasitize only 30.56 percent. Development period for parasitoid ranged between 8.66 to 9.44 days on different host eggs. The highest adult parasitoid longevity (7.22 days) was observed from the parasitized eggs of H. armigera which was at par with C. cephalonic a (7.10 days), E. vittella (6.88 days) and L. orbonalis (6.88 days). However, the different lepidopteran eggs as well as age of host eggs did not show significant differences pertaining to percent adult parasitoid emergence. Fresh host eggs of 24 hrs could produce more female progeny of T. chilonis (54.30 percent) compared to 72 hrs old eggs (42.65 percent). The sex ratio (male: female) of emerging parasitoid progeny was observed highest on 24 hrs old eggs (1:1.55) followed by 48 hrs old eggs (1:1.23) while lowest sex ratio was observed on the eggs of 72 hrs old age (1:0.95). The maximum per day fecundity of T. chiloni s was noticed on the 24 hrs old eggs (6.75) followed by 48 hrs old eggs (4.80). The lowest fecundity (2.05) of T. chilon is was observed on the 72 hrs old eggs, whereas the highest male-female ratio and fecundity was noticed on eggs of E. vittella among different hosts.

Characterisation of the secreted apyrase family of Heligmosomoides polygyrus

Apyrases are a recurrent feature of secretomes from numerous species of parasitic nematodes. Here we characterise the five apyrases secreted by Heligmosomoides polygyrus, a natural parasite of mice and a widely used laboratory model for intestinal nematode infection. All five enzymes are closely related to soluble calcium-activated nucleotidases described in a variety of organisms, and distinct from the CD39 family of ecto-nucleotidases. Expression is maximal in adult worms and restricted to adults and L4s. Recombinant apyrases were produced and purified from Pichia pastoris. The five enzymes showed very similar biochemical properties, with strict calcium dependence and a broad substrate specificity, catalysing the hydrolysis of all nucleoside tri- and diphosphates, with no activity against nucleoside monophosphates. Natural infection of mice provoked very low antibodies to any enzyme, but immunisation with an apyrase cocktail showed partial protection against reinfection, with reduced egg output and parasite recovery. The most likely role for nematode secreted apyrases is hydrolysis of extracellular ATP, which acts as an alarmin for cellular release of IL-33 and initiation of type 2 immunity.

An investigation of Caligula japonica (Lepidoptera: Saturniidae) egg distribution and associated parasitoids on walnut trees (Juglans regia L.) in northwestern China

Caligula japonica is a serious defoliator pest of walnut trees, Juglans regia, in China. Important information about the occurrence of C. japonica egg masses on host plants and their indigenous parasitoids under field conditions are rarely documented. Here the distribution of egg masses of C. japonica on the trunks of J. regia and occurrence of its parasitoids in Kangxian, the most important walnut production area in northwestern China, were investigated. The results revealed that the egg masses were mainly located at 109.2 ± 62.3 cm height. The number of egg masses exhibited a significant positive linear relationship with the diameter of trees and a parabolic relationship with host tree height. The natural parasitism rate showed a significant negative linear relationship with the size of egg masses but no relationship with the height of egg masses. The percentage of parasitized egg masses and parasitism percentage of eggs were 49.0% and 7.0%, respectively. We found seven egg parasitoid species belonging to three genera, in which Mesocomys trabalae had the largest Berger-Parker index (0.6963). In addition, the coparasitism of M. trabalae and M. albitarsis accounted for 39.7% of the total coparasitized egg masses. This investigation provides basic information for utilizing egg parasitoids against C. japonica in the future.

First Report of Native Parasitoids of Fall Armyworm Spodoptera frugiperda Smith (Lepidoptera: Noctuidae) in Mozambique.

Simple SummaryIn 2016, a highly destructive insect pest with origin in the Americas was detected in Africa. The pest is known to feed primarily on maize which is a staple food in the continent. Since then, farmers have been using chemical insecticides to control the pest. Chemical insecticides are expensive and harmful to the environment. In this article, the authors Albasini Caniço, António Mexia, and Luisa Santos discuss the possibility of application of an alternative method of control known to be environmentally friendly and economically sustainable in the long term. The method, known as “biological control”, can be easily implemented by farmers, and has the potential to reduce the population of the insect pest and production costs, and bring long term benefits to the environment.The alien invasive insect pest Spodoptera frugiperda Smith (Lepidoptera: Noctuidae), commonly referred to as fall armyworm (FAW), is causing significant losses to maize production in Africa since its detection in 2016. As an emergency response, governments in several countries distributed and/or promoted massive use of synthetic insecticides among smallholder farmers to fight FAW. The inappropriate use of synthetic insecticides by non-trained and ill-equipped farmers raises environmental and health concerns. This study aimed to assess the occurrence of native parasitoids of FAW, their parasitism rates, and relative abundance in the central province of Manica, Mozambique. A field collection of FAW egg masses and larvae was conducted from May to August 2019 (dry season of the 2018/2019 cropping season) and in December 2019 and January 2020 (rainy season of 2019/2020 cropping season). A total of 101 egg masses and 1444 larvae of FAW were collected from infested fields. Five larval parasitoids were recorded, but no egg parasitism was observed. Coccygidium luteum Brullé (Hymenoptera: Braconidae) and Drino quadrizonula Thomson (Diptera: Tachinidae) were the primary parasitoids. Maximum parasitism of 23.68% and 8.86% and relative abundance of 100 and 96.3 were recorded for C. luteum and D. quadrizonula, respectively. Total parasitism by different parasitoid species was at 9.49%. Cultural practices favoring the action of these parasitoids should be advocated.

Why introducing a parasitoid of Paropsis charybdis Stål, 1860 (Coleoptera: Chrysomelidae) larvae is expected to enhance biological control of this Eucalyptus pest in New Zealand

AbstractParopsis charybdis (Coleoptera: Chrysomelidae) has been a major pest of Eucalyptus spp. since invading New Zealand from Australia over 100 years ago. Here, we report on the phenology, egg parasitism and defoliation levels of P. charybdis at two Eucalyptus nitens plantations in the central North Island of New Zealand and assess the establishment prospects and potential impact of a new biological control agent, the larval parasitoid Eadya daenerys. Field monitoring found that 90–100% of first generation P. charybdis eggs emerged, showing that the existing egg parasitoids Enoggera nassaui (Hymenoptera: Braconidae) and Neopolycystus insectifurax (Hymenoptera: Pteromalidae) are ineffective at controlling this generation. Further field monitoring revealed effective control of second generation eggs by E. nassaui and N. insectifurax despite the presence of Baeoanusia albifunicle (Hymenoptera: Encyrtidae), a hyperparasitoid of E. nassaui. Phenology data show that first generation P. charybdis larvae will likely be synchronous with the adult emergence of E. daenerys (Hymenoptera: Braconidae) the new larval endoparasitoid proposed to be introduced from Australia. Climate matching predicts E. daenerys could establish in all areas of New Zealand where P. charybdisimpacted Eucalyptus spp. plantations are grown. The addition of a larval endoparasitoid could significantly contribute to the suppression of P. charybdis by decreasing first generation larval survival.