Lysiphlebus Fabarum Research Articles

Aphids (Aphididae) and their parasitoids in selected vegetable ecosystems in Slovenia

Sucking insects, which representatives are also aphids, can cause important economic damage on cultivated and wild-growing plants in vegetable ecosystems. Our research was based on the aim of biological control, which is to limit or to control the pests with the use of their natural enemies. From April to November 2006 living aphids and their mummies were sampled together with their host plants in four locations in Slovenia. The samples have been taken from vegetables, weeds, within-crops plants and from the plants in the field borders. The occurrence of 18 aphid species was confirmed - 14 of them were parasitised. In our research 365 parasitoid specimens (17 species from 8 genera - Aphidius, Binodoxys, Diaeretiella, Ephedrus, Lipolexis, Lysiphlebus, Monoctonus, and Praon - of the family Aphidiidae) were recorded and identified. The most abundant parasitoid species were Aphidius matricariae (32.2 %) and Lysiphlebus fabarum (29.3 %). Parasitoid L. fabarum had the widest range of hosts; it parasitised aphids on the plants from 7 different botanical families. Sex ratio in our research confirmed the known fact, that in natural ecosystems female parasitoids are more numerous than the male parasitoids; this ratio in our research was 71 % : 29 %.

マメアブラムシの寄生蜂Lysiphlebus fabarumの発育と繁殖特性

The developmental period, adult longevity, fecundity, age-specific survival rate (lx), age-specific fecundity (mx) and body size effects on the longevity and fecundity of Lysiphlebus fabarum (Marshall) from the population of Memuro, Hokkaido, which parasitizes the cowpea aphid Aphis craccivora Koch, were examined. The mean developmental period, adult longevity, and fecundity (20°C and 16L8D photoperiod) were 11.8 days, 6.6 days, and 60.4, respectively. All progeny produced were females, indicating that the population is thelytokous. On the basis of the results, the estimated intrinsic rate of the natural increase (rm) of this parasitoid was 0.241. A positive significant correlation was found between female body size and longevity, but no significant correlation was found between body size and fecundity.

Microsatellite DNA markers for the aphid parasitoid Lysiphlebus fabarum and their applicability to related species

AbstractThe aphid parasitoid Lysiphlebus fabarum is suspected to form distinct, host‐associated lineages and exhibits poorly understood variation in reproductive mode including thelytokous and arrhenotokous populations. As a tool to study these issues, we developed 11 polymorphic microsatellite markers. The observed number of alleles ranged from two to 35, and the observed heterozygosity ranged from 0.01 to 0.64. Cross‐species amplification tests demonstrated their utility for several congeners, but revealed very limited applicability to more distantly related species.

Parasitic Entomofauna in Urban and Agricultural Landscapes of the Pomorze and Kujawy Region I. Primary Parasitoids of Aphids from the Aphis Genera

13 species of parasitoids were determined of which 12 belonged to the family Aphidiidae. Similarity in species composition between the areas compared, measured with Marczewski-Steinhaus’s index (MS) was 81.2%, with 8 species present in all three types of ecosystems (61.5%). The following parasitoid species were dominants in all three types of ecosystems: Lysiphlebus fabarum (dominance index D: 48.7-27.7%) and Trioxys angelicae (D: 36.5-35.6%); other numerous species included Lysiphlebus cardui, Aphelinus chaonia, Aphidus matricariae and Praon abjectum. In terms of basic ecological parameters, dominance and frequency, L. fabarum and T. angelicae (most common dominants and constants in guilds) turned out to be the species typically associated with colonies of aphids of the genus Aphis, irrespective of the type of ecosystem. Guilds of parasitic hymenopterans in all three types of habitats examined were similar in their dominance structure (species composition – MS=72.9%, on average and ratios between species – Renkonen’s index: Re=79.1, on average). Generally, the composition of species of parasitoids of the genus Aphis in the urban landscape was highly similar to rural areas (similarity rate over 70%).

Parasitoid complex (Hymenoptera, Braconidae, Aphidiinae) of Aphis craccivora Koch (Hemiptera: Aphidoidea) in Iran

The parasitoids (Hymenoptera, Braconidae, Aphidiinae) of the cowpea aphid, Aphis craccivora Koch, were investigated throughout two far distant provinces, Tehran and Sistan-Baluchestan. Colonies of the cowpea aphid were collected from different host plants and reared under laboratory conditions until the parasitoids emerged. The aphids were parasitized by an expected range of parasitoids. The species were Aphidius colemani Viereck, Lysiphlebus fabarum (Marshall), Lysiphlebus confusus Tremblay and Eady, Lysiphlebus testaceipes (Cresson), Binodoxys acalephae (Marshall), Binodoxys angelicae (Haliday), Praon volucre (Haliday) and Ephedrus persicae Froggatt. L. testaceipes is reported here for the first time in Iran. The most common species was L. fabarum followed by B. acalephae and L. confusus. A key is provided for identification and host plant associations are considered.

Parasitoids associated with the common pistachio psylla, Agonoscena pistaciae, in Iran

The parasitoids associated with the common pistachio psylla, Agonoscena pistaciae Burckhardt and Lauterer, were investigated at three pistachio plantations in Rafsanjan, Iran. Of the 6504 wasps emerging from mummified psyllids, 46% were the primary parasitoid Psyllaephagus pistaciae Ferrière, and the remaining 54% represented six species of hymenopterous hyperparasitoids, including Chartocerus kurdjumovi (Nikol’skaja), Marietta picta (André), Pachyneuron aphidis (Bouché), Pachyneuron muscarum (Linnaeus), Psyllaphycus diaphorinae (Hayat), and Syrphophagus aphidivorus (Mayr). Lysiphlebus fabarum Marshall, the parasitoid of Aphis gossypii Glover and Aphis craccivora Koch present on weeds, was found to be an alternative host for three major hyperparasitoids of A. pistaciae. The most abundant hyperparasitoid was S. aphidivorus, appearing during the growing season in all trial locations on psyllids and aphids in pistachio orchards. The weed-infesting aphids, along with their primary parasitoid, can act as a reservoir of A. pistaciae secondary parasitoids. Therefore, parasitized aphids allow populations of secondary parasitoids to increase and consequently to apply higher pressure on P. pistaciae. We detected that two primary parasitoid species, including P. pistaciae and L. fabarum, attacking different species of hosts interact indirectly through shared secondary parasitism. It is suggested that the community structure of A. pistaciae may be influenced by apparent competition, although more work is needed to provide firm evidence.

The cytogenetics of thelytoky in a predominantly asexual parasitoid wasp with covert sex.

Asexual lineages in the parasitoid wasp Lysiphlebus fabarum (Hymenoptera: Braconidae: Aphidiinae) have previously been shown to have occasionally undergone sexual reproduction and recombination with males from related sexual populations. In the present study, the cytogenetic system of asexual females in this species is shown by 4',6-diamidino-2-phenylindole dihydrochloride (DAPI) staining to be central fusion automixis. This system has the potential to allow occasional sex and recombination without leading to an elevation of ploidy and with the maintenance of at least some heterozygosity. No evidence of the bacterial symbiont Wolbachia was found, and the observed system was compared with that in parasitoid wasps where asexuality is the result of Wolbachia infection.

Intraguild predation on the aphid parasitoid Lysiphlebus fabarum (Marshall) (Hymenoptera: Aphidiidae): mortality risks and behavioral decisions made under the threats of predation

Abstract Intraguild predation (IGP) is a primordial mortality factor that generates consequences for the coexistence of species in natural communities as well as for the implementation of antagonists in biological control programs. Among parasitoids and predators the most frequent form of IGP is asymmetric. Because it exerts a strong selection pressure on the inferior parasitoids it seems to be likely that these antagonists have evolved strategies to minimize IGP. Our study traced the behavior of the aphid parasitoid Lysiphlebus fabarum (Marshall) which is able to exploit the enemy free space in ant protected aphid colonies. In the agricultural landscape, L. fabarum frequently forages in aphid colonies without ant protection where it is exposed to situations with an extraordinary high risk of predation by aphidophagous predators. In the current study, we investigated predation risks for different developmental stages of L. fabarum and behavioral decisions made under the risk of predation by foraging females. All developmental stages of L. fabarum suffered from a high risk of predation in confrontations with most of the tested aphidophagous predators. Only aphid mummies turned out to be a less frequent IG-prey compared to unparasitized aphids when found simultaneously with adult Coccinella septempunctata L. and larvae of Episyrphus balteatus de Geer. Nevertheless, foraging females of L. fabarum did not avoid the presence of predators nor displayed an effective defense behavior in direct confrontations with any of the tested predator species. Coccinellids, syrphids as well as chrysopids proved capable of killing an adult parasitoid. The discrepancies between the observed predation risks and the lack of behavioral adaptations of adult L. fabarum are discussed in different contexts.

Dittrichia viscosa andRubus ulmifolius as reservoirs of aphid parasitoids (Hymenoptera: Braconidae: Aphidiinae) and the role of certain Coccinellid species

The role of the self-sown shrubsDittrichia viscosa (L.) W. Greuter andRubus ulmifolius Schott as reservoirs of aphid parasitoids was investigated. In the field studies conducted,D. viscosa grew adjacent to crops of durum wheat and barley andR. ulmifolius grew adjacent to cotton. The relative abundance of the parasitoids of(a) Capitophorus inulae (Passerini) onD. viscosa, (b) Rhopalosiphum padi (Linnaeus) on durum wheat and barley,(c) Aphis ruborum (Borner) onR. ulmifolius, and(d) Aphis gossypii Glover on cotton in various parts of Greece, was assessed during the years 1996–2000. In 2000, the fluctuation of parasitization of the above four aphid species was recorded and the action of the aphidophagous predators of the family Coccinellidae was studied. It was observed thatAphidius matricariae Haliday predominated onC. inulae andR. padi in all sampling cases. In contrast,Lysiphlebus fabarum (Marshall) was the dominant species parasitizingA. ruborum onR. ulmifolius andA. gossypii on cotton in Thessaly (central Greece) and Macedonia (northern Greece), whereasLysiphlebus confusus Tremblay et Eady andBinodoxys acalephae (Marshall) were the dominant parasitoid species in Thrace (northern Greece).Coccinella septempunctata Linnaeus was the most abundant coccinellid species on durum wheat, whereasAdonia variegata (Goeze) predominated on cotton. However, coccinellid individuals were scarce on bothD. viscosa andR. ulmifolius. The present study indicated that these two shrubs can be regarded as useful reservoirs of aphid parasitoids.

Parasitoids (Hymenoptera: Braconidae, Aphidiinae; Aphelinidae) of four principal pest aphids (Homoptera: Aphididae) on greenhouse vegetable crops in Japan.

Aphidiine and aphelinid parasitoids of four principal pest aphids on greenhouse vegetable crops in Japan, Aphis gossypii, Myzus persicae, Macrosiphum euphorbiae and Aulacorthum solani, were surveyed to find native parasitoids that would be useful as biological control agents. A total of 19 species (Aphidiinae: 13 species in 7 genera, Aphelinidae: 6 Aphelinus species) were confirmed as parasitoids of the four pest aphids from field collection and breeding experiments. Of these, six species (Lysiphlebus fabarum and 5 Aphelinus species) were new to Japan. In total, 145 tritrophic (parasitoid–host aphid–plant) relationships are reported. The principal aphidiine parasitoids were Lysiphlebus japonicus and Binodoxys communis on A. gossypii, Aphidius gifuensis and Diaeretiella rapae on M. persicae, and A. gifuensis on A. solani. There were no predominant species among the parasitoid spectrum of M. euphorbiae in Japan. Aphelinus gossypii, A. varipes, A. albipodus and A. asychis showed a high degree of suitability for Aphis gossypii, Aphis gossypii and M. persicae, M. persicae and M. euphorbiae, and all four principal pest aphids, respectively. A key to the parasitoid species associated with the four pest aphids in Japan is provided. The potential using the native parasitoids as biological control agents against the four pest aphids is discussed.

Lysiphlebus Förster (Hymenoptera: Braconidae: Aphidiinae) in Australia

AbstractRecords are provided of the aphidiine parasites of aphids, Lysiphlebus fabarum (Marshall) and L. testaceipes (Cresson), parasitizing species of Aphis Linnaeus, Rhopalosiphum Koch and Toxoptera Koch in eastern Australia. Both species of Lysiphlebus were imported into Australia in 1982 for purposes of biological control, evidently with little or no initial success. Lysiphlebus testaceipes, however, has been reared in abundance in eastern Australia since 1997. A brief account is given of the history of the parasites in Australia and the possible provenance of recently collected material is discussed. Characters to distinguish between the two species are provided.

Effects of intraguild predation on aphid parasitoid survival

AbstractTo assess the potential selection pressure caused by intraguild predation between predators and parasitoids of aphids an estimate was made of the predation risk to Aphis fabae Scop. mummified by Lysiphlebus fabarum (Marshall, 1896) on sugar beet. Mummified aphids were exposed to a natural community of predators. Their survival time was estimated during a 10‐day field survey. Additionally, the role of alternative prey on parasitoid survival was investigated by adding unparasitised aphids to half of the mummy aggregations.The field data were evaluated by survival analysis. Two covariates were tested within a Cox proportional hazard model: (i) the presence of the alternative prey and (ii) the patch structure (number of proximal mummies attacked). Within 4–5 days after exposure predators destroyed approx. 50% of the mummies. The model with both covariates revealed a significant difference concerning survival of the mummies in the two treatments (Likelihood ratio test, χ2= 78.03, P = 0.0001). Alternative prey reduced the predation risk on mummies by 29%, while a high level of predation on proximal mummies increased the individual predation risk by 4%. The results are discussed in the context of prey location by predators and the evolution of anti‐predator mechanisms.

Intraguild predators and the spatial distribution of a parasitoid.

An experimental plot of the aphid Aphis fabae on various host plant species was colonized by natural populations of the aphidiine parasitoid Lysiphlebus fabarum and insect predators, especially coccinellids. Parasitism of A. fabae by L. fabarum was significantly depressed on plants bearing coccinellids. The number of parasitized aphids increased with aphid abundance on three plant species (Papaver dubium, Rumex obtusifolius, Vicia faba), but not on the plant species (Chenopodium album) which bore very high numbers of coccinellids. In complementary laboratory experiments, L. fabarum offered a choice between odours of plants infested with A. fabae and/or coccinellids selected the odour fields from coccinellid treatments at significantly lower frequency than the odour fields of other treatments. It is concluded that avoidance of coccinellids by L. fabarum contributes to the negative association between the abundance of coccinellids and parasitoids in the field.

Biology and distribution of microbe‐associated thelytokous populations of aphid parasitoids (Hym., Braconidae, Aphidiinae)

Abstract: Some phenomena of the biology and ecology of the microbe (Wolbachia)‐associated thelytokous populations of aphid parasitoids are presented for the first time. Thelytokous virgin females were found to refuse the mating attempts by males of biparental populations, although males occurred quite rarely among the offspring. The host range was found to be about identical in conspecific biparental and thelytokous populations, whereas the association of solely biparental populations with a certain host group might be considered as a marker of the presence of sibling species in the area. The relative frequency of conspecific biparental and thelytokous populations varied, depending upon the area and host species. The microbe‐induced thelytokous populations were confirmed in three species of the genus Lysiphlebus Foerst. (Lysiphlebus cardui Marsh., Lysiphlebus confusus Tremblay and Eady, Lysiphlebus fabarum Marsh.) and probably some other, as yet undescribed, species only in the West Palearctic subregion, whereas the other known congeneric species in the subregion as well as in the Nearctic and the Neotropical regions were determined as strictly biparental species. Microbe‐induced thelytokous populations did not change due to host species alternation and/or distribution area (purposeful introductions as biocontrol agents).

OLFACTORY ORIENTATION OF THE PARASITOID WASP LYSIPHLEBUS FABARUM TO ITS HOST FOOD PLANTS1)

Abstract Lysiphlebus fabarum (Hymenoptera: Aphidiidae) is a generalist parasitic wasp species which can oviposit in several aphid species, including the bean aphid, Aphis craccivora (Homoptera Aphidinae), and the soybean aphid, A. glycines. The response of female L. fabarum and one of its host aphid species, A. glycines, to odors of undamaged host food plant (UD), mechanically damaged host food plant (MD), aphid‐damaged plant (AD+, with aphid on, and AD˜, aphid washed off), and host aphid alone were studied in a wind tunnel. The positive orientation frequency of L. fabarum, which emerged from Aphis craccivora, to AD+ and AD˜ was significantly greater than to the UD, MD. Similarily, L. fabarum that emerged from A. glycines significantly flew more often to AD+ than to UD and aphid alone. And there was no significant difference among the positive response frequency of L. fabarurn to UD, MD, and aphid alone. All these suggested that herbivore feeding induced the attraction of the damaged plant to natural enemy of herbivore. It is also found that the condition of soybean seedling, being damaged or undamaged, did not have direct impact on host plant location of aphid.

Parasitism of the black bean aphid (Aphis fabae) by Lysiphlebus fabarum (Hym., Aphidiidae): the influence of host plant and habitat1

Abstract: The black bean aphid (Aphis fabae) was heavily parasitized by the aphid parasitoid, Lysiphlebus fabarum both on agricultural crops (broad bean, fodder beet) and on associated weeds (goosefoot, chamomile, tansy). Parasitization rates increased during the season and were lower on broad bean than on other host plants. Habitat diversity contributed to an increase of parasitism on fodder beet but not on broad bean. Ant‐attendance lead to increased parasitism on all host plants. The findings of the field studies were confirmed by laboratory experiments on foraging and oviposition behaviour of L. fabarum females on the various host plants.

Reactions of adult female parasitoids, particularly Aphidius rhopalosiphi, to volatile chemical cues from the host plants of their aphid prey

Abstract. In Y‐tube olfactometer tests, Aphidius ervi Hal., Trioxyssp., Praon sp., Aphelinus flavus (Nees), Lysiphlebus fabarum (Marsh.) and Aphidius rophalosiphi De Stef. responded positively to the odour of the plant on which aphid mummies containing them had been collected. The response to host plant odour was greater than the response to the odour of host aphids, their honeydew or a combination of the two. The strongest response was to a combination of plant and host aphids. A. rhopalosiphi showed a strong positive response to three wheat volatiles (cis‐3‐hexenyl acetate, cis‐3‐hexen‐1‐ol and trans‐2‐hexenal) as well as to indole‐3‐acetaldehyde (a breakdown product of tryptophan in aphid honeydew). In both olfactometer tests with odours and choice trials with whole plants, newly emerged A. rhopalosiphidistinguished and preferred the variety of wheat on which their development had occurred to other wheat varieties.

Suitability of five species of Aphidiidae (hymenoptera) for the biological control of the banana aphidPentalonia nigronervosacoq. (Homoptera, Aphididae) in the south pacific

Abstract Five aphid parasitoids were tested for their suitability as biocontrol agents of the banana aphid Pentalonia nigronervosa Coq.: Lysiphlebus testaceipes, Lysiphlebus fabarum, Trioxys angelicae, Aphidius colemani and Ephedrus plagiator. L. testaceipes and A. colemani were successfully mass‐reared on P. nigronervosa for five generations in the laboratory. Both species showed no obvious preferences for certain host instars or morphs (apteriform or alatiform larvae). Their capability to alternate between P. nigronervosa and Aphis fabae did not diminish within five generations. It is concluded that both species could have the potentials of suitable biological control agents against P. nigronervosa. Screening of two other parasitoids (E. plagiator and L. fabarum) is promising.

The potential host ranges in Australia of some imported aphid parasites [Hym: Ichneumonoidea: Aphidiidae

Host selection trials on restricted populations of the aphidiid parasites,Lysiphlebus fabarum (Marshall) andL. testaceipes (Cresson), imported into Australia as biological control agents ofAphis craccivora Koch, the cowpea aphid, have shown that these imported parasites are not widely polyphagous, and thus support a view that the 2 species, as presently recognized, each represent a complex of host-restricted biotypes or of sibling species. Whereas both of the importedLysiphlebus readily oviposited in species ofAphis andToxoptera, and developed successfully to adulthood inA. craccivora, A. gossypii Glover andT. aurantii (Boyer de Fonscolombe), they failed to complete development inA. citricola van der Goot, one of the most common aphid species in Australia, and only a small number completed development inT. citricidus (Kirkaldy). Both of these hosts, then, act as “egg traps” for theLysiphlebus. A. nerii Boyer de Fonscolombe was a suitable host forL. testaceipes but not forL. fabarum. NeitherL. fabarum notL. testaceipes oviposited inCavariella aegopodii (Scopoli),Brevicoryne brassicae (L.),Brachycaudus helichrysi (Kaltenbach),B. persicae (Passerini),Hyperomyzus lactucae (L.),Acyrthosiphon kondoi Shinji,A. pisum (Harris),Macrosiphum euphorbiae (Thomas) orM. rosae (L.); andL. fabarum did not oviposit inRhopalosiphum padi (L.) orMyzus persicae (Sulzer). The prognosis for the effective establishment in Australia of these 2 parasites is therefore not good

INSECT PREDATORS OF MUMMIFIED PEA APHIDS

Aphid parasite larvae in early stages of development are frequently destroyed when insect predators feed on active aphid prey. Stary (1966) discussed insect predators that may feed on living aphids, and thus destroy parasite eggs or larvae. He noted, however, only one case of direct attack on an aphid mummy: that of chrysopid larvae on Aphis fabae Scopoli parasitized by the braconid Lysiphlebus fabarum (Marshall). No observations were reported of direct attacks on mummified aphids by coccinellids, syrphids, or other aphidophagous insects.