A mite parasitoid,Pyemotes zhonghuajia,negatively impacts the fitness traits and immune response of the fall armyworm,Spodoptera frugiperda

Parasitoids are key regulators in ecological communities and widely used as agents in biocontrol programmes.The fall armyworm,Spodoptera frugiperda,recently invaded multiple continents and caused substantial economic losses in agriculture.Pyemotes zhonghuajia,a newly identified mite parasitoid,has shown potential for controlling various agricultural insect pests.Therefore,this study tested the performance of P.zhonghuajia in parasitising S.frugiperda.We also investigated the sublethal effects of parasitism by P.zhonghuajia on host fitness traits,transgenerational impacts,and cellular and humoral immunity.Our result showed that the fifth-instar larvae of S.frugiperda parasitised by 40 P.zhonghuajia were all dead(i.e.,a lethal effect),while parasitism by 5 or 10 P.zhonghuajia was considered sublethal since many S.frugiperda survived to adulthood and produced offspring after mating.The sublethal influences from parasitism by P.zhonghuajia resulted in reduced pupal weight,adult emergence rate and fecundity,but increased developmental time and longevity.Parasitism at both lethal(40 mites)and sublethal(10 mites)levels impaired the cellular and humoral immunity of S.frugiperda.This study presents the first empirical evidence that mite parasitoids can negatively influence host immunity.Moreover,it provides insights into the biocontrol potential of mite parasitoids and their interactions with hosts.

Efficacy of Botanicals on Parasitoids of Mango Fruit Flies in Burkina Faso

The effect of Capsicum annuum and Strophantus hispidus formulations was evaluated on Diachasmimorpha longicaudata. The formulations were obtained from the crude total extracts of C. annuum;S. hispidus and the adjuvant previously developed. The formulations were prepared according to three concentrations of extracts of each plant species (low, medium and high). These concentrations were calculated on the basis of 1.5 mg/mL of each formulation causing 18% and 15% mortality respectively in Ceratitis cosyra within 72 h. The effect of the formulations on D. longicaudata was tested using a Fisher block design with 8 treatments (C. annuum (3.75;7.5;12.5 g/L);S. hispidus (4.5;9;15 g/L);Success bait 2.4 g/L;control) and 5 replicates. For each formulation, 1.5 mL was poured into a vial containing 0.25 g of cotton. Then 20 adults of the parasitoid were added and the whole was covered with muslin and held in place with rubber bands. The parasitoids were examined after 24 and 72 hours, and those that did not react to the touch of a fine brush were considered dead. The results showed a difference between the treatments. After 24 hours of exposure, the parasitoid showed high mortality at the S. hispidus concentrations (15 g/L;4.5 g/L) followed by the Success bait. These concentrations resulted in mortality rates of 22.50% for S. hispidus and 20.50% for Success bait. After 72 h, low parasitoid mortality (35.81%) was obtained with 3.75 g/L C. annuum, but high mortality was observed with S. hispidus (59.95%;64.20%;57.15%) and Success bait (54.80%). The use of C. annuum formulations at 3.75 g/L could be recommended for conserving D. longicaudata in the nature.

Inventory of Host Plants and Parasitoids of the Fall Armyworm (FAW), Spodoptera frugiperda (JE Smith), in the Southern Agricultural Zone of Niger

The fall armyworm, Spodoptera frugiperda (JE Smith), is a polyphagous pest reported in sub-Saharan Africa since 2016 and has expanded rapidly in almost Africa. In Niger, Spodoptera frugiperda (JE Smith) is considered like a major pest of maize, to which it causes significant damage, in a context where proven control methods against this moth remain almost non-existent. The objective of the present study was to determine the economic importance of FAW through the damage caused to the different host plants and to identify the parasitoids of this caterpillar. The study was conducted in the southern agricultural zone of Niger, specifically in the regions of Dosso, Maradi, Tahoua and Zinder. FAW eggs and caterpillars were collected from six villages in each region and then incubated and reared in the entomology laboratory of INRAN in Maradi. The rate of infestation of the different crops by FAW was determined as well as the observation of the beneficiaries. The results obtained indicate the presence of FAW on millet with an attack rate varying from 45.7% to 68%, sorghum with 47.2% to 62.25% and sesame with 9.7%. This work also revealed an oophagous parasitoid, Telenomus remus with 138 ± 23 and larval parasitoids, Cotesia sp with 16 ± 1 maximum number of individuals emerged from the collected material. Also, it was identified the parasitoid Cotesia icipe with a rate of parasitism from 4.6% to 5.75%;the Charops ater whose rate of parasitism varies from 4.5% and 12.25% but for Chelonus insularis with 17.25% and Tachnidae with 53%. These very interesting results will constitute a basis for the development of biological control and a component of an agroecological management strategy of caterpillar.

Host-Parasitoid系统的分岔与混沌控制

用数值模拟的方法,研究了Host-Parasitoid模型.该模型是一类非线性离散系统,反映了在一定的时间和空间内,寄生虫和寄宿主之间的生存状态.通过调节各种影响下的分岔参数,可以观察到系统具有周期泡,倍周期分叉,间歇混沌和Hopf分岔等复杂非线性动力学现象,揭示了系统通向混沌的途径.利用不同周期遍历下的奇怪吸引子和具有分形边界的吸引盆对系统的非线性特性进行了深入的探讨.最后利用参数开闭环控制法对系统的混沌状态进行了有效的控制.数值仿真和理论分析表明,选择相应的控制参数可将该系统的混沌状态控制到不同的稳定周期运动.

Parasitoid wasps as effective biological control agents

Biological control(biocontrol) is a safe, sustainable approach that takes advantage of natural enemies such as predators, parasitic insects or pathogens to manage pests in agroecosystems. Parasitoid wasps, a very large evolutionary group of hymenopteran insects, are well-known biological control agents for arthropod pests in agricultural and forest ecosystems. Here, we summarize the recent progress on the application of parasitoid wasps in biocontrol in China for the last five years. These include species diversity of parasitoid wasps, identification of dominant parasitoid wasps associated with insect pests and biocontrol practices(three types of biological control, i.e., classical, augmentative and conservation biological control) in several Chinese agroecosystems. We then treat different mass-rearing and release technologies and the commercialization of several parasitoid wasp species. We also summarize other work that may have a potential use in biocontrol, including the effect of plant volatiles on parasitoids and recent advance in the molecular mechanisms underlying the host regulation by parasitoid wasps. Future research area and applied perspectives are also discussed, noting that advances in biocontrol technologies in Chinese agriculture informs research at the global level.

Advance of Studies on Pesticides Resistance of Parasitoids

抗性寄生蜂的应用是IPM中生防和化防相结合的重要措施之一。本文综述了寄生蜂与杀虫剂的关系、寄生蜂抗药性与其性别的关系、寄生蜂抗药性的稳定性及其抗性机理。

High temperatures do not decrease biocontrol potential for the host-killing parasitoid Neochrysocharis formosa(Hymenoptera:Eulophidae)on agromyzid leafminers

Temperature, as a critical abiotic factor, might influence the effectiveness of biological control by parasitoids in hostparasitoid systems. In this study, Neochrysocharis formosa(Westwood), a larval endoparasitoid, is used to investigate the efficacy of biological control on a vegetable agriculture pest, Liriomyza sativae Blanchard, reared on kidney bean(Phaseolus vulgaris L.), at four constant temperatures(26, 29, 32, and 35℃) under laboratory conditions. Our results show that high temperatures(29, 32, and 35℃) do not significantly affect lifetime host-killing events of female adults by increased daily host-killing events compared to temperature of 26℃, although their lifespans decrease with an increase in temperatures. Each life-history trait of female adults(lifespan, parasitism, stinging, or non-reproductive host-killing events) present a linear relation with temperatures and host-feeding events, respectively. Our findings contribute to a better understanding of biocontrol efficacy of parasitoid N. formosa against agromyzid leafminers at high-temperature seasons or environments.

Study on the parasitoids of Pissodes nitidus Roel

A systematic observation and intensive study on the parasitoids of Pissodes nitidus were made in Langxiang and Xin’qing Forestry Bureau in Xiaoing’an Mountain area in 1996-1999, including the diagnosis, life history, biological characteristics of Eurytoma sp. and parasitoid complex of Pissodes nitidus. There were about 70 species of parasitoids on Pissodes nitidus, including Eurytomidae, Ichneumonidae and Braconidae etc. Among them, Eulytoma sp. is a dominant species and a braconid, lpobracon sp. is a subdominant species, and they play an important role in controlling the pest.

Indigenous parasitoids as effective natural enemies of Phyllocnistis citrella(Lepidoptera:Gracillariidae)in Korea

This study is aimed to investigate the occurrence of Phyllocnistis citrella Stainton （citrus leafminer; CLM）, which has recently caused increasing damage to citrus farms in southern South Korea, and its natural enemies, which can act as biological control agents. In the present study, CLM monitoring using sex pheromone traps were conducted in the major citrus farms in the Jeju region in South Korea. Also a survey of parasites was carried out to detect the effective control agent for CLM. During the investigation from 2011 to 2015, a relatively large number of adult CLM （2,386,990） were observed in the sex pheromone traps. The mean annual occurrence of CLM was 477,398, which showed an increasing trend with the increase in temperature. A survey of parasites was conducted in November 2015. Six parasites were found, of which, Quadrastichus sp. and Sympiesis sp. showed the highest rates of parasitism. The mean rate of parasitism during the survey period was 3.97 %. We discovered four new species of parasites of CLM in South Korea.

Species and Occurrence of Parasitoids of Cnaphalocrocis medinalis in Nanning,Guangxi,China

[ Objective] To specify the parasitoid species of Cnaphalocrocis medinalis in Nanning, Guangxi Zhuang Autonomous Region, and provide theoretic ref- erences for the reasonable utilization and using natural enemy. [ Method] Field investigation and indoor rearing observation were adopted to figure out species and quantity of parasitoids of C. medinalis in Nanning in 2011 -2013. [ Result] There are 19 parasitoid species of C. medinalis in Nanning, belonging to Ich- neamonoidea, Chalcidoidea. Of Ichneamonoidea, there are 11 species from Ichneumonidae and Braconidae. Of Chalcidoidea, there are 8 species from Chalcididae, Eulophidae, Elasmidae, Trichogrammatidae and Encyrtidae. Among these species, Stenomesius maculatus Liao and Apanteles cypris Nixon are dominant parasitoids in larval stage. In natural control conditions, S. maculatus Liao is most-widely distributed species with the most population, especially in the first half year, accounting for 89.7 % of the total parasitoid quantity ; in pesticide application field, the quantity of S. maculatus Liao accounts for 69.1% of the total parasitoid quantity, and in nonpesticide field, it accounts for 78.5%. [ Conclusion] Application of chemical pesticide has serious impact on the natural populations of parasitoids, therefore, chemical pesticides should be applied reasonably to ensure the survival of parasitoids.

Diversity and surge in abundance of native parasitoid communities prior to the onset of Torymus sinensis on the Asian chestnut gall wasp(Dryocosmus kuriphilus) in Slovenia,Croatia and Hungary

Since the rapid spread of the Asian chestnut gall wasp(ACGW) throughout south-east Europe in the last few years,the possibilities of its control have been increasingly investigated.Due to constraints in available suppression measures in forest stands,biological control is recognized as the most suitable action to lower the abundance of the new invasive pest.Torymus sinensis,as a specialized parasitoid chalcid wasp of ACGW,was introduced to suppress the pest in Italy in 2005,and later in Croatia,Hungary(2014) and Slovenia(2015).We investigated the native parasitoid complex associated with ACGW in Slovenia,Croatia and Hungary over 8 years of sampling.We found 41 species of native parasitoids,eight of which are the first records on ACGW in Europe,adding up to a total of 51 species known to parasitize ACGW.These findings represent a large complex of cynipid-parasitoid fauna.Moreover,the abundance of native parasitoid populations on ACGW have demonstrated a temporal surge between the invasion of a new alien host(ACGW) and the onset of its specialized parasitoid,T.sinensis.Our results indicate that the introduced parasitoid acts as a very successful biocontrol of ACGW,outcompeting native parasitoids.This outcome should be considered as beneficial through the maintenance of ecological balance in affected forest ecosystems.

Relationship of egg parasitoids of rice planthoppers between rice and non-rice habitats

Egg parasitoids,Anagrus spp.and Oligositaspp.have been found to be important biologi-cal agents in suppressing rice planthoppers inAsian countries.However,most of these stud-ies have been confined to conditions within ricefields.In this study,field surveys were madeto study the floral and faunal diversity in vari-ous habitats surrounding rice fields.The riceand grass(Echinochloa spp.)plants were in-

Effects of Transgenic Cry1Ac plus CpTI Cotton on the Bioecology of Main Parasitoids in Laboratory Studies

Effects of transgenic Cry1Ac plus CpTI cotton(double genes cotton) on development of main parasitoids were studied in the laboratory.Compared with the traditional cotton,the differences of

Parasitoids of Agricultural Importance Collected at Atlantic Forest Biomes in Brazil:A Bibliographic Summary

Its ecological processes evolved from the eocene,when the continents were already relatively willing as they are today.Currently,the Atlantic Forest has only 7%of its original area.Parasitoids are organisms that cause the death of their hosts to complete their development and act as parasites only in the larval stage,when they develop in only one host,with adults having a free life.The objective of the six studies was to verify the groups of parasitoids present in Atlantic Forest Biomes in Brazil with a bibliographic summary.The Hymenoptera Parasitica were collected in the Atlantic Forest biome from 2002 to 2021.

Galls as a Disputed Resource for Female Parasitoid Wasps Contests

We investigated how the parasitoid Torymus sp. (Hymenoptera: Torymidae) attacking galls of Schismatodiplosis lantanae (Diptera: Cecidomyiidae) on Lantana camara (Verbenaceae) behaves in the presence of a conspecific female competitor in the patch. Presence of a competitor greatly changed resident exploitation behavior. Wasps alone spent more time in gall exploitation behaviors (walk-antennate and probe) and in post-oviposition behaviors (stationary and groom), and when intruders were present they spent more time walking. The attack strategy was through threatening: raising wings and pointing the antennae towards the opponent. Different from theoretical expectations, residents were not always the attacker. Number of galls in the patch and female wasp size did not affect contest outcomes, although gall exploitation time and time on leaf were significant factors for the probability of having attacks. Overall, the study highlights the fact that intruder interest in the host was the main cause of contests and also this is a unique report both in terms of the target species and the nature of the disputed resource, a gall-inducer inside a singular spatial unit, the gall.

Biological Control of Tortricidae in Tea Fields in Japan Using Insect Viruses and Parasitoids

Tea is a perennial and evergreen plant. Cultivated tea trees provide a habitat for insect pests and their natural enemies. In Japan, granuloviruses (GVs) have successfully controlled two of the most important pests of tea, Adoxophyes honmai and Homona magnanima (Tortricidae: Lepidoptera). The GVs are produced in vivo and a single application sustains pesticidal efficacy throughout a year, which encompasses 4 to 5 discrete generations of both species. A. honmai and H. magnanima also have various natural enemies, especially hymenopteran parasitoids. Such resident natural enemies also play a role in reducing the pest density in virus-controlled fields, but the effect of virus infection on parasitoids sharing the same host larva has not been well studied. Survival of one of the major parasitoids of A. honmai, Ascogaster reticulata (Braconidae: Hymenoptera), is reduced by virus infection of the host. Viruses, including GV and entomopoxvirus (EPV), and certain koinobiont endoparasitoids, including A. reticulata, are both known to regulate host endocrinology. However, the GV and EPV have distinct host regulation mechanisms, and consequently have different impacts on the survival of A. retuculata, when A. reticulata parasitizes a host that is infected with either GV or EPV. These additional effects on host regulation displayed by both viruses and parasitoids affect the outcome of virus-parasitoid interactions.

The Parasitoid Factor in the Virulence and Spread of Lepidopteran Baculoviruses

Insect parasitoids and baculoviruses play important roles in the natural and strategic biological control of insects. The two parasites are frequent competitors within common hosts and much research has focused on the negative impact that baculoviral host infections have on parasitoids. This review summarizes the impacts that parasitoids may have on the virulence and spread of lepidopteran baculoviruses. By changing host behavior and development, parasitoids have been shown to decrease baculovirus virulence and productivity within parasitized baculovirus-susceptible hosts; however, studies of the tools used by hymenopteran parasitoids to overcome their hosts'immune systems, suggest that parasitoids may, in some cases, facilitate baculoviral infections in less susceptible hosts. Laboratory and field research have demonstrated that parasitoids can mechanically transmit baculoviruses between insects, and in this way, increase the efficacy of the viruses. Instances of new, more virulent isolates of baculoviruses have been recorded from specifically parasitoid-targeted hosts suggesting other possible benefits from the transmission or activation of baculoviruses by parasitoids.

Immunosuppressive,antimicrobial and insecticidal activities of inhibitor cystine knot peptides produced by teratocytes of the endoparasitoid wasp Cotesia flavipes(Hymenoptera:Braconidae)

Teratocytes are specialized cells released by parasitoid wasps into their hosts.They are known for producing regulatory molecules that aid the development of imma-ture parasitoids.We have recently reported the primary structures of cystine-rich peptides,including some containing inhibitor cystine knot(ICK)motifs,produced by teratocytes of the parasitoid Cotesia flavipes(Hymenoptera:Braconidae).ICKs are known for their stability and diverse biological functions.In this study,we produced four putative ICK peptides from the teratocytes of C.Jlavipes using solid-phase peptide synthesis or recom-binant expression in E.coli,and investigated their functions on host immune modulation as well their potential to impair the development of two lepidopterans after ingestion of the peptides.In addition,the peptides were assayed against pathogens and human cells.The peptides did not influence total hemocyte count but suppressed cellular immunity,detectable as a reduction of hemocyte encapsulation(CtICK-I,CftICK-II,CtICK-I)and spread indexes(CftICK-IV)in the host.None of the peptides influenced the activi-ties of prophenoloxidase and phenoloxidase in the hemolymph of larval Diatraea sacchar-alis(Lepidoptera:Crambidae).CftICK-I and CftICK-II with previously unknown function showed antifungal activity against Candida albicans but were non-toxic to human cells.CtICK-I,CftICK-II,and CftICK-II increased larval mortality and reduced leaf consump-tion of D.saccharalis,a permissive host for C.flavipes.The CftICK-III also increased larval mortality and reduced leaf consumption of Spodoptera frugiperda(Lepidoptera:Noctuidae),a non-permissive host for C.flavipes.This study highlights biological func-tions and biotechnological potential of ICK peptides from the teratocytes of C.flavipes.

Two new species of Eurytoma(Hymenoptera:Eurytomidae),parasitoids of Bradybatus sp.(Coleoptera:Curculionidae)damaging seeds of Acer truncatum in China

Two new species of Eurytoma,E.truncatumi Yang,Liu&Cao,sp.nov.and E.acutibialis Yang,Liu&Cao,sp.nov.,are described and illustrated,as the solitary larval and pupal ectoparasitoid of Bradybatus sp.(Coleoptera:Curculionidae),a serious pest of purpleblow maple,Acer truncatum Bunge(Aceraceae).Photographs of the characters of the new species were provided.Typical materials were deposited in Insect Museum,Chinese Academy of Forestry,Beijing.The biological characters observed and their biocontrol potential were also discussed.