Quality control of Cotesia flavipes (Cameron) (Hymenoptera: Braconidae) from different Brazilian bio-factories

The goal of this study was to evaluate the quality of Cotesia flavipes from different bio-factories as biological control agents. We evaluated biological characteristics of the parasitoids throughout their lifespan, and measured the body length and width, abdomen width, thorax width and width and length of the right forewing of female and male parasitoids. Our results showed that the number of males and pupal viability were similar among the bio-factories; the number of emerged females was greater in bio-factories I and II; the egg-pupa period and the pupal period were shorter in bio-factory IV; and a greater longevity was found in bio-factories II and III. Sex ratio (at approximately 60% females) was satisfactory (in terms of suitability for release) across all bio-factories. For morphometric measurements, the body, abdomen and wing widths were similar in males; however, thorax width was greater in the males from bio-factory I; bio-factory III produced females with the highest body length; bio-factory I produced females with the greatest abdomen width; bio-factories III and IV produced females with the greatest wing length. Among the bio-factories studied, bio-factory IV produced the best quality C. flavipes, with respect to the greatest number of parasitoids per pupal mass (a mean of 57% more parasitoids) in a satisfactory sex ratio, and with the shortest developmental time, which facilitates faster rearing in the laboratory. Studies such as this, which assess the quality of a mass-produced C. flavipes, are crucial for the continued use of this parasitoid in controlling Diatraea saccharalis in the field.     

Foraging behavior and life history of the stemborer parasitoidCotesia flavipes (hymenoptera: Braconidae)

The gregarious parasitoidCotesia flavipes (Hymenoptera: Braconidae) attacks larvae of pyralid and noctuid stemborers by entering the stemborer tunnel. The short-range foraging behavior of femaleC. flavipes was studied on stemborerinfested plants, in patches with host-related products and in artificial transparent tunnels. In addition, the longevity under specific conditions and the potential and realized fecundity of femaleC. flavipes were determined. Larval frass, caterpillar regurgitate, and holes in the stem are used in host location byC. flavipes. The response to host products byC. flavipes seems not to be host species specific. FemaleC. flavipes respond to frass from four stemborer species and one leaf feeder. No differences are found in the behavior ofC. flavipes on maize plants infested with the suitable host,Chilo partellus (Lepidoptera: Pyralidae), or the unsuitable host,Busseola fusca (Lepidoptera: Noctuidae). Attacking a stemborer larva inside the stem is risky for the parasitoid. The mortality rate of the parasitoids inside the stem is high: 30–40% of the parasitoids are killed by the spitting and biting stemborer larva.C. flavipes is relatively shortlived: without food the parasitoids die within 2 days; with food and under high-humidity conditions they die within 5–6 days.C. flavipes is proovigenic and has about 150 eggs available for oviposition. A relatively large proportion of the available egg load (20–25%) is allocated to each host, so femaleC. flavipes are egg depleted after parasitizing only five or six hosts.     

Mitochondrial DNA phylogeography of the Cotesia flavipes complex of parasitic wasps (Hymenoptera: Braconidae)

The Cotesia flavipes species complex of parasitic wasps are economically important worldwide for the biological control of lepidopteran stem borers. The complex currently comprises three species: Cotesia flavipes Cameron, C. sesamiae (Cameron) and C. chilonis (Matsumura) (Hymenoptera: Braconidae), which appear morphologically similar. Despite their economic importance, little is known about the genetic diversity and phylogeography of these parasitoids. Differences in the biology of geographic populations have generally been interpreted as genetic divergence among strains, but direct genetic evidence is lacking. In Australia, several stem borer pests in neighbouring countries have been identified as significant threats to the sugar industry. However, the status of C. flavipes in Australia is unknown. To examine the genetic variation among worldwide populations of the C. flavipes complex and investigate the status of the Australian C. flavipes-like species, partial sequence data were generated for mitochondrial gene regions, 16S rRNA and COI. Parsimony, minimum evolution and Bayesian analyses based on 21 geographic populations of the complex and four outgroups supported the monophyly of the complex and the existence of genetically divergent populations of C. flavipes and C. sesamiae. The geographically isolated Australian haplotypes formed a distinct lineage within the complex and were ~3.0% divergent from the other species. The results indicated that historical biogeographic barriers and recent biological control introductions play an important role in structuring lineages within these species. This study provides a phylogeographical context for examining adaptive evolution and host range within biologically divergent strains of the C. flavipes complex.     

Diachasmimorpha longicaudata and D. kraussii (Hymenoptera: Braconidae), potential parasitoids of the olive fruit fly

The olive fruit fly, Bactrocera oleae (Tephritidae), is a significant threat to California's olive industry. As part of a classical biological control program started in 2002, the parasitoids Diachasmimorpha kraussii and D. longicaudata (Hymenoptera: Braconidae) were imported to California from laboratory colonies in Hawaii. Studies on their biology and behavior as parasitoids of the olive fruit fly were conducted in quarantine. Both species tend to oviposit into 2nd and young 3rd instars, with the offspring completing development in the flies’ puparia. Most eggs are deposited in the first two weeks of adult life. Observed lifetime fecundity was low, possibly as a consequence of the relatively poor quality of the harvested olives used as a host substrate. Both pre-imaginal development and adult longevity were limited at constant temperatures above 30°C, which may indicate that these species will have difficulty establishing in the warmest regions of California.     

Fitness consequences of superparasitism and mechanism of host discrimination in the stemborer parasitoid Cotesia flavipes

The fitness consequences of superparasitism and the mechanism of host discrimination in Cotesia flavipes, a larval parasitoid of concealed stemborer larvae was investigated. Naive females readily superparasitized and treated the already parasitized host as an unparasitized host by allocating the same amount of eggs as in an unparasitized host. However, there was no significant increase in the number of emerging parasitoids from superparasitized hosts due to substantial mortality of parasitoid offspring in superparasitized hosts. Furthermore, the developmental time of the parasitoids in a superparasitized host was significantly longer than in a singly parasitized host and the emerging progeny were significantly smaller (body length and head width). Naive females entered a tunnel in which the host was parasitized 4 h previously and accepted it for oviposition. Experienced females (oviposition experience in unparasitized host) refused to enter a tunnel with a host parasitized by herself or by another female. In experiments where the tunnel and/or host was manipulated it was demonstrated that the female leaves a mark in the tunnel when she parasitizes a host. The role of patch marking in C. flavipes is discussed in relation to the ecology of the parasitoid.     

Behavioural evidence for a female sex pheromone in Cotesia flavipes (Hymenoptera: Braconidae)

Abstract.  The mating behaviour of Cotesia flavipes Cameron, 1891 (Hymenoptera: Braconidae) was observed under laboratory conditions. The results demonstrate that chemical stimuli play an important role in bringing males and females together for mating. Females from this species release chemical compounds to attract males, which exhibit a distinct courtship behaviour divided into three main steps: (i) antennation, (ii) lateral bouncing and (iii) wing fluttering. Ethological tests using hexane extracts from two different parts of the female's body (head plus thorax and abdomen) demonstrate that males are more attracted and also display a courtship behaviour when a filter paper containing hexane extracts from the abdomen is presented to them, indicating that the abdomen is the source of the sex pheromone of this species. Naive males of this species respond to hexane extracts of this gland by displaying courtship behaviour. Furthermore, additional tests show that C. flavipes females mate only once, whereas virgin males do not show any preference for virgin or mated females, suggesting that mated females of this species continue to produce sex attractants after mating.     

The influence of light and moisture gradients on the attack rate of parasitoids foraging for hosts in a laboratory arena (Hymenoptera: Pteromalidae)

Microhabitat preferences of four parasitoids (Hymenoptera: Pteromalidae) of house fly pupae were measured in a two-dimensional arena containing perpendicular light and moisture gradients. Parasitism by Muscidifurax raptorand Nasonia vitripenniswas greatest in dry substrates, with the latter preferring bright illumination and the former tending to prefer dark. Urolepis rufipesselected bright illumination and moist substrates, attacking the most hosts at bright-moist and dim-moist microhabitats. Spalangia cameroniexhibited no main-effect preference for light intensity or moisture, although parasitism was highest at dim-moist, dark-wet, and dark-moist microhabitats. These results demonstrate that simple abiotic attributes, such as light intensity and substrate moisture concentration, are important in defining some dimensions of the niches of these 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 immature 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. flavipes using solid-phase peptide synthesis or recombinant 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 (CftICK-I, CftICK-II, CftICK-III) and spread indexes (CftICK-IV) in the host. None of the peptides influenced the activities of prophenoloxidase and phenoloxidase in the hemolymph of larval Diatraea saccharalis (Lepidoptera: Crambidae). CftICK-I and CftICK-II with previously unknown function showed antifungal activity against Candida albicans but were non-toxic to human cells. CftICK-I, CftICK-II, and CftICK-III increased larval mortality and reduced leaf consumption 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 functions and biotechnological potential of ICK peptides from the teratocytes of C. flavipes.     

Sensilla on antennae,ovipositor and tarsi of the larval parasitoids,Cotesia sesamiae (Cameron 1906) and Cotesia flavipes Cameron 1891 (Hymenoptera: Braconidae): a comparative scanning electron microscopy study

Two braconid parasitoids of cereal stemborers in eastern Africa, Cotesia sesamiae and Cotesia flavipes, have been shown to display a similar hierarchy of behavioural events during host recognition and acceptance. In order to understand the mechanisms underlying host recognition and acceptance, the morphology of antennal sensilla on the last antennomeres, on the ovipositor, and on the fifth tarsomere and pretarsus of the prothoracic legs tarsi were studied using scanning electron microscopy followed by selective silver nitrate staining. It appeared that female C. sesamiae and C. flavipes shared the same types and distribution of sensory receptors, which enable them to detect volatiles and contact chemical stimuli from their hosts. In both parasitoids, four types of sensilla were identified on the three terminal antennomeres: (i) non-porous sensilla trichodea likely to be involved in mechanoreception, (ii) uniporous sensilla chaetica with porous tips that have gustatory functions, (iii) multiporous sensilla placodea, which are likely to have olfactory function, and (iv) sensilla coeloconica known to have thermo-hygroreceptive function. The tarsi of both parasitoids possessed a few uniporous sensilla chaetica with porous tips, which may have gustatory functions. The distal end of the ovipositor bore numerous dome-shaped sensilla. However, there were no sensilla coeloconica or styloconica, known to have gustatory function in other parasitoid species, on the ovipositors of the two braconid wasps.     

Fitness of two sibling species of Asobara (Braconidae:Alysiinae), larval parasitoids of Drosophilidae in different microhabitats

Abstract. 1. Two sibling species of larval endoparasitoids of Drosophilidae: Asobara tabida (Nees) and A.rufescens (Foerster) occur in the same macrohabitat, but inhabit different microhabitats. Each species is most attracted by odours of its own microhabitat.
2. In order to assess the adaptive value of the microhabitat preference we studied the survival of both parasitoids in the major host species that occur in these microhabitats.
3. Survival in the major host in the preferred microhabitat was shown to be 40% higher for A.tabida and 30% higher for A.rufescens when compared to survival in the major host in the non-preferred microhabitat.
4. Measurements of developmental rates, specific mortalities and dry weights of the parasitoids suggest that the differential survival is due to differences in synchronization with the hosts.
5. The possible evolutionary consequences of some biological characteristics in Asobara are discussed. Microhabitat selection, differential survival, development and mating behaviour are attributes likely to have played a role in the reduction of gene flow between populations of the ancestral species, either in primary or in secondary sympatry.     

螟黄足盘绒茧蜂复合群支序系统学研究（膜翅目：茧蜂科：小腹茧蜂亚科）

对螟黄足盘绒茧蜂复合群Cotesia flavipes complex (膜翅目：茧蜂科：小腹茧蜂亚科)分布全世界的5个种和外群侧沟茧蜂Microplitis 及荻茧蜂Diolcogaster 的25个性状,以及复合群5个种和外群螟蛉盘绒茧蜂Cotesia ruficrus、粘虫盘绒茧蜂Cotesia kariyai、粉蝶盘绒茧蜂Cotesia glomerata 的24个性状,分别进行比较研究,并运用支序分析的方法探讨该复合群内5个种种间的系统发育关系。支序分析表明螟黄足盘绒茧蜂复合群是一单系群,二化螟盘绒茧蜂C. chilonis 和大螟盘绒茧蜂C. sesamiae 近缘,芦螟盘绒茧蜂C. chiloluteelli 和汉寿盘绒茧蜂C. hanshouensis 近缘,螟黄足盘绒茧蜂C. flavipes相对独立。 以上研究表明无论是以近缘属作外群还是以同属其它种作外群,所得结果基本上都能反映螟黄足盘绒茧蜂复合群各种之间的分类地位。     

Improvement of quality control methods for augmentative releases of the fruit fly parasitoids,Diachasmimorpha longicaudata and Psyttalia fletcheri (Hymenoptera: Braconidae)

Criteria were established to improve quality control methods for augmentative releases of the opiine parasitoids, Diachasmimorpha longicaudata (Ashmead) and Psyttalia fletcheri (Silvestri). These included correlating puparial weight with adult emergence and sex ratio at the Honolulu rearing facility, and determining the effect of air shipments and field releases on parasitoid emergence and subsequent mortality. There was a positive relationship between the weight of 7–10‐day‐old host puparia and percentage of emergence for both D. longicaudata and P. fletcheri. Standardization of shipping methods included placement of ice blocks in the top levels of the ice chests, prompt shipment and pick‐up of samples, and cooling of puparia before shipment to minimize metabolic heat generated in the samples, and to delay emergence of samples. Before standardization, emergence losses of up to 58% were observed for D. longicaudata and 18% for P. fletcheri. When shipping methods were standardized, emergence was no longer reduced. In addition, low emergence rates were associated with reduced flight propensity of D. longicaudata (R_s = ‐ 0.45 at Kilauea and ‐ 0.54 at Kealia). At the two release sites, 88–95% of adult D. longicaudata that did not escape the release containers were males.     

Opiine parasitoids (Hymenoptera: Braconidae) and biological control of fruit flies (Diptera: Tephritidae) in Australia: Past,present and future

Opiine braconids are parasitoids of the immature stages of frugivorous tephritids. The female wasp lays her eggs into the eggs or larvae of the fruit fly host, where the immature wasp develops before emerging as a next-generation adult from the now dead host pupal case. In support of a new generation of Australian fruit fly parasitoid research, this paper comprehensively reviews what is known about the Australian fruit fly infesting opiines. Based on the most recent taxonomic revision 11 fruit fly infesting opiine species are documented to occur in Australia, but we consider as doubtful the record for Diachasmimorpha longicaudata and consider the record for Fopius illusorius to be tentative without further collections. We identify that the systematics and taxonomy of the Australian native fruit fly infesting opiines are in urgent need of further work. The history of fruit fly biological control in Australia is comprehensively reviewed, including the export of native Australian opiines for fruit fly control elsewhere in the world. Australia was actively involved in three major classical biological control programmes against fruit flies from the turn of the 1900s until the mid-1960s. Despite the introduction of 11 opiine species, plus numerous other natural enemies, only Fopius arisanus established in eastern Australia, where in South-east Queensland it can now cause between 30 and 40% mean parasitism. In addition to the exotic F. arisanus, the native species Diachasmimorpha kraussii and Diachasmimorpha tryoni also cause fruit fly parasitism in agriculturally important crops: both species have also been liberated widely outside of Australia for fruit fly control. Other Australian opiines have not been reared from flies infesting commercial crops and appear biologically restricted to the fruits and environs of Australian east-coast rainforests. The biology literature for D. tryoni and D. kraussii is comprehensively reviewed, while for F. arisanus, already reviewed elsewhere, key literature only is covered. Forward looking, we consider the potential for inoculative or inundative releases of opiines in areas where they do not currently occur to be good, while conservation biological control may help to increase the impacts of parasitoids in areas where they are already established.     

Responses of the stem borer larval endoparasitoid Cotesia flavipes (Hymenoptera: Braconidae) to plant derived synomones: Laboratory and field cage experiments

Laboratory and field cage experiments investigated the response of females of the stem borer larval endoparasitoid Cotesia flavipes to two synthetic synomone components, the terpenoid (E)-β-farnesene and the green leaf volatile, (Z)-3-hexenyl acetate, both compounds identified previously in headspace volatiles of maize plants damaged by stem borer (Chilo partellus). In dose response tests performed in a Y-tube olfactometer, parasitoids were significantly more attracted to the arms bearing 10 or 15 µg of (Z)-3-hexenyl acetate and (E)-β-farnesene than to the control arm. (E)-β-Farnesene was as attractive as the essential oil from the plant Hemizygia petiolata (Lamiaceae) rich in the same compound (80% relative amount). The plant essential oil elicited responses from females of the parasitoid comparable to those elicited by two positive controls, stem borer larval frass and adult parasitoid diet (20% honey solution), tested in the laboratory assays. In field cage trapping experiments, captures in traps baited with the terpenoid, the plant essential oil, (Z)-3-hexenyl acetate and the control of 20% honey solution, were not significantly different relative to captures in unbaited traps. Addition of the green leaf volatile (Z)-3-hexenyl acetate to the plant essential oil to yield a 1:1 two-component blend captured significantly more female parasitoids than traps baited with either of the two components alone. The results show that blends of green leaf volatiles and sesquiterpenoids may have potential in monitoring C. flavipes populations in the field.     

Evolutionary patterns of host utilization by ichneumonoid parasitoids (Hymenoptera: Ichneumonidae and Braconidae)*

The four major biological strategies of ichneumonoid parasitoids, koinobiont and idiobiont, ecto-and endoparasitism, are discussed and the evolutionary radiations of the two families Ichneumonidae and Braconidae compared in an attempt to relate differences in patterns of host utilization to differences in evolutionary history. The most primitive members of both families are idiobiont ectoparasitoids of hosts concealed in plant tissue. Idiobiont ectoparasitic braconids are all still primarily associated with such hosts, but idiobiont ectoparasitic ichneumonids have radiated to attack hosts in other situations, such as in aculeate nests or in cocoons. A shift in emphasis between the behavioural steps, host habitat location and host location, is envisaged as being important in such evolutionary change. Idiobiont endoparasitism is postulated as having arisen amongst ectoparasitoids attacking cocooned hosts, as an adaptation that allows them to exploit pupae and puparia in relatively exposed positions; it is a fairly common strategy in the Ichneumonidae, but virtually unknown in the Braconidae. Koinobiosis is perceived as having evolved in association with hosts which feed in a relatively weakly concealed position, but pupate in a more secluded and safe location. The strategy is advantageous as it allows a parasitoid to oviposit on an easily discoverable host, but to use the host's pupation concealment to complete its own development. The evolution of koinobiosis has allowed parasitoids to exploit hosts that feed in exposed positions, and to attack hosts at a younger and numerically more common stage in the host's life cycle. Koinobiont ectoparasitism is envisaged, in some braconid and ichneumonid groups, to occupy an evolutionary transitional position between idiobiosis and endoparasitic koinobiosis; only in the Ichneumonidae have large radiations of koinobiont ectoparasitoids occurred. Endoparasitic koinobiosis is hypothesized as having arisen in the Braconidae in association with lepidopterous/coleopterous hosts, whilst in the major lineage of endoparasitic koinobiont ichneumonids, this habit is hypothesized as having arisen in association with symphytan hosts. The great majority of braconids are koinobiont endoparasitoids, but only about 50% of the Ichneumonidae have this habit. Very few koinobiont braconids develop as endoparasitoids of hymenopterous hosts, although many endoparasitic ichneumonids attack Hymenoptera. However, lineages of the Braconidae have radiated to exploit adult insects and exopterygote nymphs; ichneumonids do not utilize such hosts.     

Analysis of mitochondrial COI sequences of the Diachasmimorpha longicaudata (Hymenoptera: Braconidae) species complex in Thailand

Diachasmimorpha longicaudata is an Opiinae parasitoid used to control tephritid fruit flies, which cause tremendous economic losses of fruits worldwide. In Thailand, D. longicaudata is classified as three sibling species, DLA, DLB and DLBB, based on the morphological and biological species concepts but their genetic variation has not been studied. Therefore, we investigated the genetic differentiation of the mitochondrial COI gene to clarify the ambiguous taxonomy of this species complex. The 603‐bp COI region was sequenced from laboratory‐bred colonies and field‐collected specimens from seven locations representing five geographical regions in Thailand. DLA was associated with the host Bactrocera correcta while DLB and DLBB were associated with Bactrocera dorsalis. The interspecific nucleotide differences of COI sequences among the three groups ranged from 6.70% to 7.62% (Kimura 2‐parameter distance), which adequately separates species complexes within the order Hymenoptera and supports the current sibling species classification. The neighbor joining, maximum likelihood and consensus Bayesian phylogenetic trees constructed from COI sequences revealed that the three sibling species of laboratory and field‐collected D. longicaudata are monophyletic with 100% support. The high genetic variation and molecular phylogeny of the COI sequences were shown to discriminate between the D. longicaudata species examined in this study.     

Intraspecific and Interspecific Competition Between Cotesia flavipes and Cotesia sesamiae (Hymenoptera: Braconidae), Gregarious Larval Endoparasitoids of Lepidopteran Stemborers

Super and multiple parasitism of Chilo partellus (Lepidoptera: Pyralidae) and Sesamia calamistis (Lepidoptera: Noctuidae) by Cotesia flavipes Cameron and Cotesia sesamiae (Cameron) (Hymenoptera: Braconidae) were investigated in the laboratory. Progeny production of Co. flavipes increased as a result of increasing the number of ovipositions, from one to three per one Ch. partellus host larva, then decreased as a result of four and five ovipositions per larva. Cocoon weight, sex ratio and emergence of the parasitoid progeny were not affected by superparasitism. Low progeny production of Co. sesamiae and poor survival of Ch. partellus host larvae were found as a result of superparasitism. When S. calamistis was the host, the duration of immature stages of Co. flavipes , parasitoid emergence, progeny production and sex ratio were not affected by superparasitism, but cocoon weight, adult longevity and the potential fecundity of adult females decreased. Superparasitism of S. calamistis by Co. sesamiae did not affect emergence, longevity or sex ratio of adult progeny of the parasitoid, but prolonged immature development, lowered cocoon weight and decreased potential fecundity of adult female progeny. Co. flavipes out-competed Co. sesamiae when Ch. partellus was parasitized by both species. The potential for local displacement of Co. sesamiae by Co. flavipes in areas dominated by Ch. partellus in East Africa is discussed.     

Use of ablated stalks to assess field rates of parasitism of Diatraea saccharalis (Lepidoptera: Crambidae) by Cotesia flavipes (Hymenoptera: Braconidae)

We evaluated a technique that used ablated sections of corn stalks infested with larvae of Diatraea saccharalis F. to assess parasitism by Cotesia flavipes (Cameron) in a corn field. Stalkborer larvae were retrieved successfully from the artificially infested, ablated stalks for at least 96 h after deployment in the field. Levels of parasitism in ablated stalks attached to corn plants were comparable to levels of parasitism measured using whole plants that were artificially infested. Olfactometer comparisons showed preference by female C. flavipes for both whole plants and ablated stalks containing larval D. saccharalis, over uninfested stalks and plants. This technique provides a means to estimate parasitism of stalkborer larvae by C. flavipes without destructive sampling of agronomic plants.     

稻纵卷叶螟绒茧蜂对寄主的搜索行为

稻纵卷叶螟绒茧蜂是稻纵卷叶螟幼虫的重要天敌。以Y形嗅觉仪测定了稻纵卷叶螟2—3龄幼虫虫粪、4—5龄幼虫虫粪、健康水稻、稻纵卷叶螟幼虫为害后水稻在纵卷叶螟绒茧蜂对寄主的搜索过程中的作用。结果表明已交配的雌蜂显著趋向稻纵卷叶螟2—3龄幼虫虫粪和4—5龄幼虫虫粪,不趋向健康水稻、稻纵卷叶螟幼虫为害后的水稻。雄蜂、处女雌蜂不显著趋向健康水稻、稻纵卷叶螟幼虫为害后水稻、稻纵卷叶螟2—3龄幼虫虫粪、稻纵卷叶螟4—5龄幼虫虫粪。利用固相微萃取(SPME)及气相色谱/质谱(GC/MS)联用分析稻纵卷叶螟2—3龄幼虫虫粪的化学成分,并通过Y-形嗅觉仪测试已交配雌蜂对稻纵卷叶螟2—3龄幼虫虫粪化学成分标准品的嗅觉反应,结果表明已交配的雌蜂显著趋向1-十一烯和异缬草醛,稻纵卷叶螟幼虫虫粪中的1-十一烯和异缬草醛可能是稻纵卷叶螟绒茧蜂搜索寄主的利他素。