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.

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.

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.

APPLICATION OF WYATT-WHITE METHOD TO CALCULATING INTRINSIC RATES OF INCREASE FOR HYMENOPTEROUS PARASITOIDS

The method developed by Wyatt and White (1977) was applied to calculate the intrinsic rates of increase for parasitoids based on 23 fecundity data sets from the literature. The studies showed that there existed the linear relationship between the accurate values of rm and In f (Md) / d or In (A/d/2) / d, that is, 1) rm= 0.845 In (Md) / d or 2) rm= 0.880 In (Md/ 2) / d. Where d is the prereproductive time, Md is the number of female offspring produced per original female from the first to the dthday of reproduction, and Md/2 is the number of female offspring produced per original female from the first to the (d/ 2) th day of reproduction. These equations can provide the accurate estimates of rm for parasitoids in this study. The approach is advantageous because it does not require the construction of detailed fecundity tables for estimating parasitoid rates of increase. Of course, whether these equations are appropriate for the other taxa will need to be further studied.

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.

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.

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.

Tritrophic interactions between parasitoids and cereal aphids are mediated by nitrogen fertilizer

Host plant nutritional quality can directly and indirectly affect the third trophic levels. The aphid-parasitoid relationship provides an ideal system to investigate tritrophic interactions （as the parasitoids are completely dependent for their development upon their hosts） and assess the bottom up forces operating at different concentrations of nitrogen applications. The effects of varying nitrogen fertilizer on the performance of Aphidius colemani （V.） reared on Sitobion avenae （E） and Aphidius rhopalosiphi （D.） reared on Rhopalosiphum padi （L.） were measured. Parasitism and percent emergence ofparasitoids were positively affected by nitrogen fertilizer treatments while developmental duration （egg, larval, and pupal stages） was not affected by increasing nitrogen inputs. In males and females of both parasitoid species, adult longevity increased with the increasing nitrogen fertilizer. Hind tibia length and mummy weight of both parasitoid species increased with nitrogen fertilizer concentrations, as a result of larger aphids. This study showed that nitrogen application to the soil can have important consequences for aboveground multitrophic interactions.

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.

Factors shaping life history traits of two proovigenic parasitoids

What shapes the relative investment in reproduction versus survival of organisms is among the key questions in life history.Proovigenic insects mature all their eggs prior to emergence and are short lived,providing a unique opportunity to quantify their lifetime investments in the different functions.We investigated the initial eggloads and longevity of 2 proovigenic parasitoid wasps:Anagrus erythroneurae and Anagrus daanei,(Hymenoptera:Mymaridae)that develop within leafhopper eggs in both agricultural vineyards and natural riparian habitats in Northern California.We collected Vitis spp.leaves containing developing parasitoids from 3 natural sites(Knight Landing,American River and Putah Creek)and 3 agricultural vineyards(Solano Farm,Davis Campus and Village Homes).We recorded eggloads at parasitoid emergence and female parasitoid longevity with or without honey-feeding.Theory predicts that parasitoids from vineyards(where hosts are abundant)would have higher initial eggloads and lower longevity compared with parasitoids from riparian habitats(where hosts are scarce).Although host density and parasitoid eggloads were,indeed,higher in vineyards than in riparian habitats,parasitoid longevity did not follow the predicted pattern.Longevity without feeding differed among field sites,but it was not affected by habitat type(natural vs agricultural),whereas longevity with feeding was not significantly affected by any of the examined factors.Moreover,longevity was positively,rather than negatively,correlated with eggloads at the individual level,even after correcting for parasitoid body size.The combined results suggest a more complex allocation mechanism than initially predicted,and the possibility of variation in host quality that is independent of size.

The evolutionary ecology of symbiont-conferred resistance to parasitoids in aphids

Aphids may harbor a wide variety of facultative bacterial endosymbionts. These symbionts are transmitted maternally with high fidelity and they show horizontal trans-mission as well, albeit at rates too low to enable infectious spread. Such symbionts need to provide a net fitness benefit to their hosts to persist and spread. Several symbionts haveachieved this by evolving the ability to protect their hosts against parasitoids. Reviewing empirical work and some models, I explore the evolutionary ecology of symbiont-conferredresistance to parasitoids in order to understand how defensive symbiont frequencies are maintained at the intermediate levels observed in aphid populations. I further show thatdefensive symbionts alter the reciprocal selection between aphids and parasitoids by augmenting the heritable variation for resistance, by increasing the genetic specificity of thehost-parasitoid interaction, and by inducing environment-dependent trade-offs. These effects are conducive to very dynamic, symbiont-mediated coevolution that is driven by frequency-dependent selection. Finally I argue that defensive symbionts represent a problem for biological control of pest aphids, and I propose to mitigate this problem byexploiting the parasitoids＇ demonstrated ability to rapidly evolve counteradaptations to symbiont-conferred resistance.

Insect immune resistance to parasitoids

Insect host-parasitoid interactions involve complex physiological, biochemical and genetic interactions. Against endoparasitoids, immune-competent hosts initiate a blood cell-mediated response that quickly destroys the intruders and envelops them in a multilayered melanotic capsule. During the past decade, considerable progress has been made in identifying some of the critical components of the host response, mainly because of the use of efficient molecular tools. This review examines some of the components of the innate immune response of Drosophila, an insect that has served as an exceptionally good experimental model for studying non-self recognition processes and immune cell signaling mechanisms. Topics considered in this review include hematopoiesis, proliferation and adhesion of hemocytes, melanogenesis and associated cytotoxic molecules, and the genetic aspects of the host-parasitoid interaction.

Cellular and humoral immune interactions between Drosophila and its parasitoids

The immune interactions occurring between parasitoids and their host insects,especially in Drosophila-wasp models,have long been the research focus of insect immunology and parasitology.Parasitoid infestation in Drosophila is counteracted by its multiple natural immune defense systems,which include cellular and humoral immunity,Occurring in the hemocoel,cellular immune responses involve the proliferation,differentiation,migration and spreading of host hemocytes and parasitoid encapsulation by them.Contrastingly,humoral immune responses rely more heavily on melanization and on the Toll,Imd and Jak/Stat immune pathways associated w ith antimicrobial peptides along with stress factors.On the wasps'side,successful development is achieved by introducing various virulence factors to counteract immune responses of Drosophila.Some or all of these factors manipulate the host's immunity for successful parasitism.Here we review current knowledge of the cellular and humoral immune interactions between Drosophila and its parasitoids,focusing on the defense mechanisms used by Drosophila and the strategies evolved by parasitic wasps to outwit it.

Differential attraction of parasitoids in relation to specificity of kairomones from herbivores and their by-products

Infochemicals are used by foraging parasitoids in the host selection process from habitat preference until host recognition. Kairomones from the herbivore host plays a vital role in the attraction of parasitoids, particularly in the micro-habitat. Parasitoids are specifically attracted to their respective herbivore species even when different herbivores are present on the same plant. Chemicals emitted from different stages of host （eggs, larvae, pupae, adult）, host by-products （e.g., frass, exuviae, mandibular gland secretions, defense secretions etc.）, or intra-specific infochemicals （pheromones） can be main signals for the parasitoids. Parasitoids can differentiate between host and non-host, between different hosts and host stages by perceiving specific volatile and contact kairomones from the host itself, host along with its by-product, by-products alone or intra-specific infochemicals; of which frass （by-product） and intra-specific infochemicals are the most reported ones. Adult and larval parasitoids have been reported to be attracted to kairomones of their target stage or byproduct of their host. Pupal parasitoids have been found to utilize kairomones from the preceding host stage while egg parasitoids are known to exploit a variety of host infochemicals, for example, either from eggs themselves or other non-target host stages, especially adults and adult-related by-products. The kairomonal chemicals identified so far include various groups, but mainly hydrocarbons. A high degree of host specificity and host acceptance is important for the parasitoids as any mistake may result in the loss of fitness.

When parasitoids deal with the spatial distribution of their hosts: consequences for both partners

Insect parasitoids developing inside hosts face a true challenge: hosts are scattered in the field and their localization and selection require the use of complex and sometime confusing information. It was assumed for a long time that small-brained organisms like parasitoids have evolved simple and efficient behavioral mechanisms, leading them to be adapted to a given ecological situation, for example, the spatial distribution o f hosts in the habitat. However, hosts are not static and their distribution may also vary through generations and within the life of parasitoid individuals. We investigated if and how parasitoids deal with such a spatial com plexity in a m esocosm experiment. We used the Aphidius rhopalosiphi/Sitobion avenae parasitoid/host system to investigate if parasitoid females experiencing different host aggregation levels exhibit different foraging behaviors independently of the number of hosts in the environment. We showed that A. rhopalosiphi females exploited hosts more intensively both within and among patches at higher host aggregation levels. We discussed the adaptiveness of such behaviors in the light of evolution and biological control.

Thelytokous Diglyphus wani:A more promising biological control agent against agromyzid leafminers than its arrhenotokous counterpart

Diglyphus wani(Hymenoptera:Eulophidae)is a dominant parasitoid that attacks agromyzid leafminers.Two reproductive types occur in D.wani:arrhenotoky(in which virgin females produce only male offspring;and virgin females mate with males to produce bisexual offspring)and thelytoky(in which virgin females produce female offspring).As a potential biological control agent,exploring the differences in the relevant biological parameters of both strains is necessary.In this study,comparisons between the two strains of D.wani were performed by evaluating the life table and host-killing rate.The thelytokous strain exhibited significantly better life table parameters than its arrhenotokous counterpart.Higher values for the intrinsic rate of increase,finite rate of increase,net reproductive rate,and fecundity were found in the thelytokous strain.The thelytokous strain also performed better than the arrhenotokous strain in terms of net parasitism,host-feeding,host-stinging,and total host-killing rates.Thus,populations of the thelytokous strain could grow fast and kill more hosts.In conclusion,the thelytokous strain of D.wani may be the more promising biological agent against agromyzid leafminers compared to its arrhenotokous counterpart.Also,since the thelytokous strain of D.wani is only known to produce females,it should be given priority in future biocontrol applications owing to the cost savings of breeding only females.