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.

Effect of Host Plants on Development,Fecundity and Enzyme Activity of Spodoptera exigua (Hübner)(Lepidoptera:Noctuidae)

The beet armyworm,Spodoptera exigua （Lepidoptera：Noctuidae）,is an economically important pest of crops worldwide,attacking plants from over 20 families including trans-continental agricultural cotton,corn and citrus crops.In this study,performance and subsequent enzyme activity of beet armyworm reared on host plants from five families were investigated.Significant differences were found in development,fecundity and enzyme activity on different host plants.Survival rate was the highest （42.8%） on asparagus lettuce （Lactuca sativar var.asparagina） and the lowest （17.0%） on sweet pepper （Capsicum annuum）.Larval duration was the shortest on asparagus lettuce （12.0 d）,and was 43.4% longer on sweet peppers （21.2 d）.The activity of acetylcholine esterase （AChE） and carboxylesterase （CarE） in 3rd instar larvae,and soluble carbohydrate and crude protein contents in different host plants were determined.AChE activity was the highest in the larvae feeding on Chinese cabbage （Brassica rapa）,but declined by nearly 60% on maize （Zea mays） seedlings.The ratio of soluble carbohydrate content to crude protein content in host plants was found to have a positive effect on oviposition and a negative correlation with larval duration and life time （from larval to adult stages） of the insect.

Effect of Pesticides on Growth of Rhizobia and Their Host Plants During Symbiosis

Effect of various pesticides (insecticides, fungicides and herbicides) has been studied on growth and efficiency of symbiotic properties of 3 fast growing Rhizobium sp. under green house conditions. The results revealed adverse effects on plant growth and nitrogen fixing capacity as measured by dry weight and total nitrogen content of plants infected with pesticide treated Rhizobium. Of the pesticides tested, herbicides were found to be more effective on the above parameters than the insecticides and fungicides.

Alternative Host Plants of Calidea panaethiopica (Hemiptera: Scutelleridae) and Aphtona whitfieldi (Coleoptera: Chrysomelidae), Insect Pests of Jatropha curcas, South Burkina Faso

Jatropha curcas is subject to the attacks of many insect pests, including Calidea panaethiopica Kirkaldy 1909 (Hemiptera: Scutelleridae) whose larvae and adults feed on flowers, fruit and seeds of the shrub resulting in quantitative and qualitative losses;the shrub is also attacked by Aphthona whitfieldi Bryan (Coleoptera: Chrysomelidae) which feeds on the leaves causing complete defoliation in severe attack. Despite their economic importance, very little is known about the alternative host plants of these insect pests. The study of the ecology of these species is a pre-requisite for the development of appropriate control methods. The identification of alternative host plants of C. panaethiopica and A. whitfieldi was conducted from June 3rd 2013 to November 30th 2014 in the Sissili province, South Burkina Faso. During that period, four J. curcas’ plantations of six locations in the province were prospected for alternative host plants of the two insect pests. In each plantation, observations were done across a diagonal up to 500 m away from the plantation. Fallows in the vicinity of the J. curcas plantations were particularly examined. Potential host plants of the two insect pests were collected and bred in the laboratory in Léo where they were used to feed the insect pests. Only Jatropha gossypiifolia, a cousin of J. curcas, was found to be a common alternative host plant of both insect pests.

Alternative Host Plants of <i>Calidea panaethiopica</i>(Hemiptera: Scutelleridae) and <i>Aphtona whitfieldi</i>(Coleoptera: Chrysomelidae), Insect Pests of <i>Jatropha curcas</i>, South Burkina Faso

Jatropha curcas is subject to the attacks of many insect pests, including Calidea panaethiopica Kirkaldy 1909 (Hemiptera: Scutelleridae) whose larvae and adults feed on flowers, fruit and seeds of the shrub resulting in quantitative and qualitative losses;the shrub is also attacked by Aphthona whitfieldi Bryan (Coleoptera: Chrysomelidae) which feeds on the leaves causing complete defoliation in severe attack. Despite their economic importance, very little is known about the alternative host plants of these insect pests. The study of the ecology of these species is a pre-requisite for the development of appropriate control methods. The identification of alternative host plants of C. panaethiopica and A. whitfieldi was conducted from June 3rd 2013 to November 30th 2014 in the Sissili province, South Burkina Faso. During that period, four J. curcas’ plantations of six locations in the province were prospected for alternative host plants of the two insect pests. In each plantation, observations were done across a diagonal up to 500 m away from the plantation. Fallows in the vicinity of the J. curcas plantations were particularly examined. Potential host plants of the two insect pests were collected and bred in the laboratory in Léo where they were used to feed the insect pests. Only Jatropha gossypiifolia, a cousin of J. curcas, was found to be a common alternative host plant of both insect pests.

Selectiveness of Cnaphalocrocis medinalis to Host Plants

A field experiment was conducted to study the selectiveness of Cnaphalocrocis medinalis Guenee （commonly known as the rice leaffolder or rice leafroller） towards five rice varieties （Yangfujing 8, Yangdao 6, Shanyou 136, Huaidao 9 and Nin.gjing 1） and three weed species （Echinochloa crusgalli, Leptochloa chinensis and Leersia hexandra）. The results showed that the rice varieties carried significantly higher numbers of C. medinalis moths and eggs than the weed species. Among the rice varieties, Yangfujing 8 was associated with a higher moth number. However, there was little difference in the number of C. medinalis eggs among the rice varieties. Additionally, a laboratory experiment was performed to investigate the olfactory response of female C. medinalis towards volatile compounds from different rice varieties, as well as its oviposition preference towards these rice varieties. The volatiles of Yangfujing 8, Yangdao 6 and Shanyou 136 attracted C. medinalis similarly to those of TN 1. In contrast, the volatiles of Huaidao 9 and Ningjing 1 clearly deterred C. medinalis. Nevertheless, C. medinalis did not exhibit clear oviposition preference towards any of the five tested rice varieties.

Inter-species mRNA transfer among green peach aphids,dodder parasites,and cucumber host plants

mRNAs are transported within a plant through phloem.Aphids are phloem feeders and dodders(Cuscuta spp.)are parasites which establish phloem connections with host plants.When aphids feed on dodders,whether there is trafficking of mRNAs among aphids,dodders,and host plants and if aphid feeding a匚fects the mRNA transfer between dodders and hosts are unclear.We constructed a green peach aphid(GPA,Myzus persicae)-dodder(Cuscuta austra/is)-cucumber(Cucumis sativus)tritrophic system by infesting GPAs on C.australis,which parasitized cucumber hosts.We found that GPA feeding activated defense-related phytohormonal and transcriptomic responses in both C.australis and cucumbers and large numbers of mRNAs were found to be transferred between C.australis and cucumbers and between C.australis and GPAs;importantly,GPA feeding on C.australis greatly altered inter-species mobile mRNA profiles.Furthermore,three cucumber mRNAs and three GPA mRNAs could be respectively detected in GPAs and cucumbers.Moreover,our statistical analysis indicated that mRNAs with high abundances and long transcript lengths are likely to be mobile.This study reveals the existence of inter-species and even inter-kingdom mRNA movement among insects,parasitic plants,and parasite hosts,and suggests complex regulation of mRNA trafficking.

Extensive Inter-plant Protein Transfer between Cuscuta Parasites and Their Host Plants

Cuscuta species(dodders)are holoparasites that totally rely on host plants to survive.Although various mobile proteins have been identified to travel within a plant,whether and to what extent protein transfer between Cuscuta and host plants remain unclear.We found that hundreds to more than 1500 proteins were transferred between Cuscuta and the host plants Arabidopsis and soybean,and hundreds of interplant mobile proteins were even detected in the seeds of Cuscuta and the host soybean.Different hosts bridge-connected by dodder were also found to exchange hundreds of proteins.Quantitatively,the mobile proteins represent a few to more than 10%of the proteomes of foreign plants.Using Arabidopsis plants expressing different reporter proteins,we further showed that these reporter proteins could travel between plants and,importantly,retained their activity in the foreign plants.Comparative analysis between the interplant mobile proteins and mRNAs indicated that the majority of mobile proteins were not de novo synthesized from the translocated mRNAs,but bona fide mobile proteins.We propose that large-scale inter-plant protein translocation may play an important role in the interactions between host plants and dodder and even among the dodder bridge-connected hosts.

Long-term seasonal fluctuations of lepidopteran cereal stemborers and their natural enemies on maize and wild host plants in southern Benin

The seasonal fluctuation oflepidoptcran cereal stemborers on maize and wild host plants （i.e., grasses and a few sedges） was investigated in southern Benin from 1988 to 1998 by time series analysis and repeated-measures analysis of variance （ANOVA）. In addition, a walk-in light trap was used to study the flight behavior of adult moths. On both cereals and grasses, the noctuid Sesamia calaraistis was the predominant species, followed by the pyralid Eldana saccharina. The noctuid Busseolafusca was rare on both maize and wild host plants. In general, pest populations increased during the course of the year to reach peak densities during the second short rainy season, and then crashed to close to zero during the dry season. On wild host plants, egg masses and other immature stages were collected throughout the year but they were higher on wild grasses than maize during the off-season. Thus wild host plants can be considered as refuge for both borers and natural enemies during the off-season, when maize is not available. However, only four out of the eleven wild host species played a discernable role. S. calamistis egg densities appeared to be influenced by density-dependent factors, suggesting an effect of natural enemies. Temperature and rainfall had a negative effect on egg abundance. Larval parasitism by a Kenyan strain of the braconid Cotesia sesamiae, which was released in southern Benin in the early 1990s, and by the tachinid Sturmiopsisparasitica varied between seasons and years but there were no discernable patterns. For both parasitoids and borer host species, parasitism was positively correlated with trap catches of adult moths. The recovery of C. sesamiae during a 2-year period suggests that the parasitoid has established its population in southern Benin.

Diversity, Host Plant Range and Distribution of Thrips spp. (Thysanoptera: Thripidae) in Three Vegetable Production Basins in Burkina Faso

Onion is the most important vegetable produced in Burkina Faso. It contributes to food and nutrition security and is a source of income for farmers. Thrips, which feed on the leaves of the plant, are the main insect pest of onion. The objective of this study was to access the diversity, the host range and the distribution of Thrips spp. in three main onion production areas in Burkina Faso. Three sites were chosen in each vegetable production basin, and plant species present were sampled and inspected to determine their thrips’ infestation status. Seventeen cultivated or wild plant species were attacked by thrips. The incidence of attacks was highest on zucchini plants followed by cucumber, eggplant, and onion, respectively. Six thrips species were recorded of which Thrips tabaci (Lindemman) represented more than 70% of the total. The average density of Thrips spp. per plant varied significantly between production basins and plant species. The highest average number of Thrips spp. per plant was recorded on zucchini (40.28 ± 10.28;17.43 ± 13.48 and 14.33 ± 7.11 respectively in the North, Hauts Bassins, and Central Plateau). This study provided basic information that can lead to further research and the development of control methods.

Host plants and natural enemies of Bemisia tabaci （Hemiptera： Aleyrodidae）in China

The sweetpotato whitefly, Bemisia tabaci, has been a destructive pest in China for over the past two decades. It is an extremely polyphagous insect, being recorded feeding on hundreds of host plants around the world. Potential host plants and natural enemies of B. tabaci in the south, southeast, middle, north and northwest of China were investigated during the last decade. In total 361 plant species from 89 families were recorded in our surveys. Plants in the families Compositae, Cruciferae, Cucurbitaceae, Solanaceae and Leguminosae were the preferred host species for B. tabaci, which therefore suffered much damage from this devastating pest due to their high populations. In total, 56 species of parasitoids, 54 species of arthropod predators and seven species of entomopathogenic fungi were recorded in our surveys. Aphelinid parasitoids from Encarsia and Eretrnocerus genera, lady beetles and lacewings in Coleoptera and Neuroptera were found to be the dominant arthropod predators of B. tabaci in China. The varieties of host plant, their distribution and the dominant species of natural enemies of B. tabaci in different regions of China are discussed.

The Efficiency of Southern rice black-streaked dwarf virus Transmission by the Vector Sogatella furcifera to Different Host Plant Species

Southern rice black-streaked dwarf disease is a new rice disease that severely affects rice production in South China.To understand transmission capacity of the vector Sogatella furcifera to Southern rice black-streaked dwarf virus（SRBSDV） among different host plant species,potential host plants of SRBSDV collected from the diseased rice field and/or adjacent to the field in Hunan Province,China,were determined by RT-PCR,and the transmission rates of SRBSDV by S.furcifera among different host plant species were investigated.The results showed that host plants of SRBSDV in the rice fields were five of family Gramineae（Oryza sativa,Echinochloa crusgalli,Zea mays,Paspalum distichum,Alopecurus aequali） and two of family Cyperaceae（Juncellus serotinus and Cyperus difformis）.S.furcifera could not transmit SRBSDV between gramineous plants and cyperaceous plants,and could not transmit SRBSDV between the gramineous plants,J.serotinus and C.difformis as well.However,SRBSDV could be transmitted by S.furcifera within gramineous plants.S.furcifera could transmit SRBSDV between interspecies among three species plants（O.sativa,E.crusgalli and Z.mays）,and between P.distichum and A.aequali.At 15,20,25,30,and 35°C,both macropterous and brachypterous adult of S.furcifera could transmit SRBSDV from the plants（e.g.,E.crusgalli,Z.mays and O.sativa） infected with SRBSDV to rice seedlings.The transmission rates were first increased and then decreased with the increase of temperature.Macropterous adults transmitted SRBSDV from the viruliferous E.crusgalli,Z.may and rice plants to the healthy rice seedlings,and the infected rates of rice seedlings were 26.2,18.8 and 23.7% at 15°C,56.6,64.6 and 53.6% at 25°C,and was 11.2,10.2 and 7.3% at 35°C,respectively.Transmission capacity of brachypterous adults was significantly higher than that of macropterous adults at 15,20 and 25°C（P0.05）,while transmission capacity of brachypterous adults was relatively lower compared with that of macropterous ones at 35°C.These results offer evidence on the transmission of SRBSDV via the vector S.furcifer among different host plants,which can be helpful to control Southern rice black-streaked dwarf disease by the appropriate cultural measures in South China.

Large-scale interplant exchange of macromolecules between soybean and dodder under nutrient stresses

Parasitic plants and their hosts communicate through haustorial connections.Nutrient deficiency is a common stress for plants,yet little is known about whether and how host plants and parasites communicate during adaptation to such nutrient stresses.In this study,we used transcriptomics and proteomics to analyze how soybean(Glycine max)and its parasitizing dodder(Cuscuta australis)respond to nitrate and phosphate deficiency(-N and-P).After-N and-P treatment,the soybean and dodder plants exhibited substantial changes of transcriptome and proteome,although soybean plants showed very few transcriptional responses to-P and dodder did not show any transcriptional changes to either-N or-P.Importantly,large-scale interplant transport of mRNAs and proteins was detected.Although the mobile mRNAs only comprised at most 0.2%of the transcriptomes,the foreign mobile proteins could reach 6.8%of the total proteins,suggesting that proteins may be the major forms of interplant communications.Furthermore,the interplant mobility of macromolecules was specifically affected by the nutrient regimes and the transport of these macromolecules was very likely independently regulated.This study provides new insight into the communication between host plants and parasites under stress conditions.

Investigation on Host Species and Damage Degree of Bemisia tabaci (Gennadius) in Shaanxi Area

The host plants of 8emisia tabaci （Gennadius） in Shaanxi were investigated, and its damage degree was evaluated by hazard index in 2013 and 2014. There were 73 species （variants） of host plants of B. tabaci belonging to 28 families, mainly concentrated in Cueurbitaceae, Crueiferae, Solanaceae, Laguminosae md Malvaceae. There were seven species of vegetables that suffered the damage of grade 4. B. tabaci was more serious in southern Shaanxi and lighter in northern Shaanxi. According to the distribution of host plants, the occurrence status of B. tabaci in Shamvd Province was analyzed and its development tendency was oredicted.

Transcriptome and metabolome analysis reveal that oral secretions from Helicoverpa armigera and Spodoptera litura influence wound-induced host response in cotton

Cotton(Gossypium hirsutum)is an important fiber crop worldwide.Insect attack causes cotton yield and quality losses.However,little is known about the mechanism of cotton response to insect attack.We simulated insect feeding by applying insect oral secretions(OS)to wounds,and combined transcriptome and metabolome analysis to investigate how OS from two major pest species(Helicoverpa armigera and Spodoptera litura)affect cotton defense responses.We found that respectively 12,668 and 13,379 genes were differentially expressed in comparison with wounding alone.On addition of OS,the jasmonic acid signaling pathway was rapidly and strongly induced,whereas genes involved in salicylic acid biosynthesis were downregulated.On constructing a coexpression gene network,we identified a hub gene encoding a leucine-rich repeat receptor kinase that may play an important role in early signal recognition and transduction.OS from the two insect species altered the abundance of flavonoid-related compounds in different patterns.Gossypol remained in lower concentration after OS application than after wounding alone,suggesting a suppressive effect of OS on cotton defense response.This study illustrated transcriptional and metabolic changes of cotton in responding to OS from two chewing insect species,identified potential key response genes,and revealed evidence for OS inhibition of wounding-induced cotton defense response.

Different genotypes regulate the microbial community structure in the soybean rhizosphere

The soybean rhizosphere has a specific microbial community,but the differences in microbial community structure between different soybean genotypes have not been explained.The present study analyzed the structure of the rhizosphere microbial community in three soybean genotypes.Differences in rhizosphere microbial communities between different soybean genotypes were verified using diversity testing and community composition,and each genotype had a specific rhizosphere microbial community composition.Co-occurrence network analysis found that different genotype plant hosts had different rhizosphere microbial networks.The relationship between rhizobia and rhizosphere microorganisms in the network also exhibited significant differences between different genotype plant hosts.The ecological function prediction found that different genotypes of soybean recruited the specific rhizosphere microbial community.These results demonstrated that soybean genotype regulated rhizosphere microbial community structure differences.The study provides a reference and theoretical support for developing soybean microbial inoculum in the future.

Plants affect the horizontal transmission of a new densovirus infecting the green peach aphid Myzus persicae by modulating honeydew production

In a tritrophic context of plant-insect-entomopathogen,plants play important roles in modulating the interaction of insects and their pathogenic viruses.Currently,the influence of plants on the transmission of insect viruses has been mainly studied on baculoviruses and some RNA viruses,whereas the impact of plants on other insect viruses is largely unknown.Here,we identified a new densovirus infecting the green peach aphid Myzus persicae and tested whether and how host plants influence the transmission of the aphid densovirus.The complete single-stranded DNA genome of the virus,M.persicae densovirus 2,is 5727 nt and contains inverted terminal repeats.Transcription and phylogenetic analysis indicated that the virus was distinct from other a few identified aphid densoviruses.The virus abundance was detected highly in the intestinal tract of aphids,compared with the lower level of it in other tissues including head,embryo,and epidermis.Cabbage and pepper plants had no obvious effect on the vertical transmission and saliva-mediated horizontal transmission of the virus.However,the honeydew-mediated horizontal transmission among aphids highly depended on host plants(65%on cabbages versus 17%on peppers).Although the virus concentration in the honeydew produced by aphids between 2 plants was similar,the honeydew production of the infected aphids reared on peppers was dramatically reduced.Taken together,our results provide evidence that plants influence the horizontal transmission of a new densovirus in an aphid population by modulating honeydew secretion of aphids,suggesting plants may manipulate the spread of an aphid-pathogenic densovirus in nature.

A new species of Zanclognatha Lederer and three new records of the families Erebidae and Noctuidae(Lepidoptera,Noctuoidea)from Korea,with notes on larval feeding habits

A new species of Zanclognatha Lederer,1857 of the family Erebidae,Z.querciella sp.n.,one species of Family Erebidea,Asota egens(Walker,1854)and two species of Family Noctuidae:Meganephria retinea Gyulai and Ronkay,1999 and Amphipyra subrigua Bremer and Grey,1853,are reported for the first time from Korea.In addition,larval feeding habits with their host plants for three species are newly recognized from Korea.Illustration of adults,larvae for Zanclognatha querciella and Meganephria retinea,and the genitalia of male or female for all species are provided.

Field Evaluation of the Asian Corn Borer Control in Hybrid of Transgenic Maize Event MON 810

In this study, a transgenic Bt maize hybrid (event MON 810 from Monsanto Company) expressing Cry1Ab protein derived from Bacillus thuringiensis (Bt) and its negative isoline hybrid were evaluated for control of the Asian corn borer, Ostrinia furnacalis (Guenée) (Lepidoptera: Pyralidae), in a field trial. Maize plants were artificially infested with neonate larvae of Asian corn borer at the mid-whorl (first-generation), pre-tassel (first- and/or second-generation), and silk (second-generation) growth stages. The transgenic Bt maize hybrid sustained significantly less leaf feeding damage (rating 1.0±0.0) than its negative isoline control (rating 7.3±0.1). With the Bt maize, 1.36.8% of plants were damaged by corn borer tunneling with <0.5 cm tunneling per stalk under different levels of infestation, compared with 100% of plants damaged with 9.325.0 cm tunneling per stalk for the negative isoline control. On average, transgenic Bt maize hybrids had only 0.010.05 tunnels per stalk and no stems were broken. In contrast, the negative isoline control had 3.118.36 tunnels per stalk and 31.273.9% of stems broken. Yields were significantly higher in transgenic Bt maize than in the control. These results demonstrate that transgenic Bt maize can significantly minimize yield losses caused by the Asian corn borer through resistance to the first- and second-generation larvae.

Evaluating Protective Terpenoid Aldehyde Compounds in Cotton (Gossypium hirsutum L.) Roots

Cotton (Gossypium hirsutum L.) has epidermal glands containing terpenoid aldehyde (TA) compounds that protect the plant from pests and diseases. One TA, gossypol, has two forms (+) and (-) that are present in varying amounts. This study evaluated the variation in roots for TA compounds and how environment affected the levels of these compounds. Similar to seed, gossypol was the predominant TA in roots. No heliocides were detected with only trace amounts of other TAs, such as hemigossypolone or hemigossypol, detected in a few lines. Among the glanded lines, there were significant differences in gossypol content. Percent plus gossypol was consistently 4% - 10% higher in roots than seed. One line, “Mac7”, had 12 - 14 ug/mg gossypol in roots and 18 ug/mg in seed as well as >90% (+) gossypol in both roots and seed. Unlike other tissues in glandless cotton, the roots of glandless lines consistently produced detectable amounts of gossypol with 77% to 82% in the (+) form. Multi-year field tests showed that although gossypol levels in the roots were more affected by insect pressure or other environmental conditions than seed, there was selectable variation in upland cotton for root gossypol content. Unlike other parts of a glandless plant, the roots retained a functioning biochemical pathway for gossypol production.