Biological Control of Anastrepha spp. (Diptera: Tephritidae) in Mango Orchards through Augmentative Releases of Diachasmimorpha longicaudata (Ashmead) (Hymenoptera: Braconidae)

Diachasmimorpha longicaudata (Ashmead) parasitoids were released by air on a weekly basis over 1600 ha of commercial mango orchards, backyard orchards, and patches of native vegetation, at a density of ca. 940 parasitoids/ha. Releases were made during 2 consecutive years, beginning at flower onset and lasting until the end of the production cycle. Two areas, 7 km apart, were compared. In one area parasitoids were released, whereas the other area was used as a control. During the 2nd year treatments were reversed. Fruit was sampled in commercial mango orchards and in backyard orchards to assess levels of parasitism in fruit fly larvae. Highly significant differences in percentage parasitism were found in release and control zones in backyard orchards. Furthermore, trapping results indicated that D. longicaudata releases were associated with ca. 2.7-fold suppression of Anastrepha spp. populations in backyard orchards. Results suggest that suppression might be affected by environmental conditions and by the parasitoid:fly ratio achieved. Anastrepha obliqua McQuart populations were suppressed more effectively by use of parasitoids than those of Anastrepha ludens Loew, perhaps due to the type of host fruits used by each species. Augmentative parasitoid releases in marginal areas surrounding commercial orchards (backyard orchards, wild vegetation) can substantially suppress fly populations. Through this approach, the number of flies that later move into commercial orchards can be significantly reduced. Such a strategy, when combined with sound orchard management schemes, can allow growers to produce clean fruit without the need to resort to the widespread use of insecticides.     

Biological control ofAphis pomi [Hom.: Aphididae] ofAphidoletes aphidimyza [Dip.: Cecidomyiidae]; a predator-prey model

Predation ofAphis pomi DeGeer [Hom.: Aphididae] byAphidoletes aphidimyza (Rondani) [Dipt.: Cecidomyiidae] was simulated in Michigan apple orchards using a computer and output validated against field data collected from sleeve cages enclosing aphid infested apple terminals. Lower and upper temperature thresholds for development were 2.9 and 35°C for nymphs ofA. pomi with a mean immature developmental period of 162.3 heat units. Median survivorship of adultA. pomi was 364.3 heat units with an average fecundity of 60.7 offspring per female.A. aphidimyza egg and larval lower threshold and developmental periods were 10.5 and 25.5, 8.1°C and 65.5 heat units, respectively. Larval functional response showed Type II behavior with a y-asymptote of 45 aphids killed per predator. Multiple generation model runs performed under different initial predator: prey densities indicated that current critical predator: prey ratios used in the field for control decisions may underestimate predator efficacy.      

Parasites ofMonellia caryella [Hom.: Aphididae]: Phenology and effect on the aphid population in pecan orchards in Israel

One primary parasite,Trioxys pallidus (Haliday) (Hym.: Braconidae), and a secondary parasite,Aphidencyrtus sp., were identified from the blackmargined aphid,Monellia caryella (Fitch) (Hom.: Aphididae), in Israeli pecan orchards. The average total parasitism for all locations sampled was 13.5%. Although a hyperparasite was discovered, it had no significantly detrimental effect on the parasite. Contribution from the Agricultural Research Organization, The Volcani Center, Bet Dagan, Israel, No. 2034-E, 1987 series.     

Interference between parasitoids [Hym.: Aphidiidae] and fungi [Entomophthorales] attacking cereal aphids

In field populations of cereal aphids parasitism levels declined through the season as fungal infection increased. In laboratory trials the fungusErynia neoaphidis Remaudiere & Hennebert took 3 to 4 days to kill the rose-grain aphid,Metopolophium dirhodum (Walker), whereas the parasitoidAphidius rhopalosiphi De Stefani-Perez took 8 to 9 days at 20°C. When aphids were infected by the fungus less than 4 days after being parasitized the parasitoids were prevented from completing their development. Conversely, when infection occurred more than 4 days after parasitization development of the fungus was significantly impaired. There was no histological evidence that the fungus invaded the tissues of the parasitoid when both attacked the same aphid. Interference between parasitoids and fungal pathogens must be taken into account when estimating the impact of these mortality agents on pest populations.     

Incompatibility alleles in Corylus avellana L. cultivars

Summary Pollen-stigma compatibility relationships are reported for 55 filbert cultivars (cvs) (Corylus avellana L.). A total of 11 S-alleles have been identified amongst 36 cvs for which one or both S-alleles have been established. For the 20 cvs with only one known allele and the 17 for which neither allele have been identified further information is provided as to which alleles can be excluded as possibilities.Oregon Agricultural Experiment Station Technical Paper No. 4985. Corvallis, Oregon 97331     

RearingTetrastichus gallerucae [hymenoptera: Eulophidae] for biological control of the ELM leaf beetleXanthogaleruca luteola

Tetrastichus gallerucae (Fonscolombe) was collected in southern France in 1985 and is being reared at the Division of Biological Control in Albany, Ca for use against the elm leaf beetle (ELB),Xanthogaleruca luteola (Müller) in northern California. This egg parasitoid can be reared easily by keeping the beetle eggs on a moist substrate to prevent desiccation and by inhibiting the growth of mold with air currents. A laboratory colony of ELB adults provides a constant supply of fresh eggs for the parasitoids. In 1985 and 1986 over 80,000T. gallerucae were released at 17 sites.      

Natural enemies of the pumpkin caterpillarDiaphania indica [Lepidoptera: Pyralidae] in Tamil Nadu

The survey for the natural enemies associated with the pumpkin caterpillar,Diaphania indica revealed the presence of 20 species of parasitoids, predators and pathogens. Of these, 16 were parasitoids belonging to the familiesBraconidae, Ichneumonidae, Bethylidae, Elasmidae andChalcididae. Except for 3 species the remaining parasitoids were new records forD. indica. The predators recorded were ants and spiders. A microsporidia also was recorded for the first time onD. indica.      

Parasitoids of the gall-forming aphidSmynthurodes betae [Aphidoidea: Fordinae] in Israel

In an ecological investigation of the gall-forming aphid,Smynthurodes betae Westw., we discovered that more than 20% of the fundatrix galls were parasitized byMonoctonia pistaciaecola Stary (Aphidiidae). This is a new host record for this parasitoid. A Pteromalid hyper-parasite was identified asPachyneuron? leucopiscida Mani. Ecological information on the parasitoid is provided, and the low frequency of parasitoids known from gall-forming aphids, compared with freeliving ones, is discussed.     

Influence of laboratory hosts on the biological attributes ofChelonus blackburni [Hym.: Braconidae]

Among 6 laboratory hosts tested, the egg-larval parasitoidChelonus blackburni Cameron completed its development in only 3;Corcyra cephalonica Stainton,Phthorimaea operculella (Zeller) andAchroia grisella (Fabricius). The parasitoid failed to develop inSpodoptera litura (Fabricius),Galleria mellonella L. andSitotroga cerealella (Olivier). The development period of the parasitoids obtained from permissive hosts correspond to the development period of their hosts. Development period ofP. operculella, A grisella andC. cephalonica were 24.7±2.0, 39.5±2.1 and 50.5±4.1 days respectively while the development period of the parasitoid reared from these hosts were 25.8±1.6, 36.4±3.5 and 42.5±3.5 days respectively. The fecundity of the parasitoids reared onA. grisella, P. operculella andC. cephalonica were 365.2±52.8, 287.9±101.9 and 248.7±50.8 respectively. The size of the parasitoids reared from the above 3 hosts also followed the similar trend. However, no significant difference was observed on the percent parasitism and the longevity of the parasitoids reared on different hosts. This study was conducted at a temperature of 24±2°C and 60±5% RH. Contribution No 46001 of Biological Control Centre (NCIPM), Bangalore.     

Importation,colonization and establishment ofAnagyrus indicus [Hym.: Encyrtidae] onNipaecoccus viridis [Hom.: Pseudococcidae] in Jordan

Anagyrus indicus Shafeeet al. was collected on the island of Guam and released in the Jordan River Valley of Jordan in order to regulateNipaecoccus viridis (Newstead) on citrus.A. indicus was originally released in February 1984 and became colonized by April of the same year. It also dispersed by natural means up to 61 km following the original release and colonized that same year on infestedZizyphus sp. By spring of 1985 it became the dominant parasitoid attackingN. viridis. Another parasitoid,Anagyrus kamali Moursi, was collected in Jordan in June of 1985 for the first time. This latter parasitoid apparently moved into the Jordan River Valley by means of natural dispersal from a neighboring country. Infestations ofN. viridis have been greatly reduced in areas whereA. indicus became established. This paper reports the results of research only. Mention of a proprietary product does not constitute an endorsement for its use by USDA.     

The effect of insecticides on the distribution of foracing parasitoids,Diaeretiella rapae [Hym.: Braconidae] on plants

Foraging aphid parasitoids,Diaeretiella rapae M'Intosh, were exposed to sublethal doses of the insecticides pirimicarb, permethrin and malathion on brusslls sprouts plants. Observations on wasp distribution over time revealed that wasps spent less time on sprayed plants, relative to controls and, while on these plants, tended to concentrate activity on unsprayed surfaces. For permethrin and malathion, pesticide residues reversed the stereotypic upward foraging pattern of the wasp. Negative consequences of sublethal pesticide doses for parasitoid foraging efficiency are discussed.      

A survey of black scale,Saissetia oleae [Hom.: Coccidae] parasitoids [Hym.: Chalcidoidea] in southern California

A survey of black scaleSaissetia oleae (Olivier) parasitoids present in southern California was conducted between September 1987 and September 1989. From 308 collections of black scale-infested citrus, olive, and oleander twigs from 19 sites in southern California, 1,610 specimens were collected. Nine primary and six secondary parasitoid species were identified. Four primary species were abundant in southern California:Metaphycus bartletti Annecke & Mynhardt,M. helvolus (Compere),Scutellista caerulea (Fonscolombe) (=S. cyanea Motschulsky), andDiversinervus elegans Silvestri. The most common secondary parasitoids wereMarietta mexicana (Howard),Cheiloneurus noxius Compere, andTetrastichus minutus (Howard). In the coastal region of southern California,M. bartletti was the most abundant parasitoid, followed in order byD. elegans, S. Caerulea, andM. helvolus. In the intermediate and interior regions,M. helvolus was most abundant.D. elegans was second most abundant in the intermediate region, but was rare in the interior region.M. bartletti was second in abundance in the interior region and third in the intermediate region.      

Fruit infesting tephritids [Dipt.: Tephritidae] and associated parasitoids in Chiapas,Mexico

A total of 1,302 parasitoids representing 8 species and 4 families were recovered from 9,818 fruit fly host fruits sampled. The most common parasitoid species wasDiachasmimorpha longicaudata (Ashmead). Average percent parasitism ranged between 0.44 and 29.23%. Parasitoid emergence data indicate thatAnastrepha ludens (Loew),A. obliqua (Sein),A. serpentina (Wiedeman),A. striata (Schiner) andToxotrypana curvicauda (Gerstaecker) were subject to parasitism. We provide information on the population fluctuation ofAnastrepha ludens, A. obliqua, A. serpentina, A. distincta (Greene),A. striata, A. fraterculus (Wiedeman),A. chiclayae (Greene),A. montei (Costa Lima),A. leptozona (Hendel) andA. tripunctata (Wulp).Anastrepha ludens andA. obliqua were the most common species, representing 95.3% of all fruit fly species caught in McPhail traps.      

Effect of parent density on fecundity of two parasitoids [Hym.: Pteromalidae] of the olive beetle,Phloeotribus scarabaeoides [Col.: Scolytidae]

Under laboratory conditions (22±2°C, 60%±5% H.R.; and 16L.: 8D. photoperiod), the rearing of the 2 main parasitoids ofPhloeotribus scarabaeoides (Bernard, 1788) in Southern Spain:Cheiropachus quadrum (Fabricius, 1787) andRaphitelus maculatus Walker, 1834 (Hym.: Pteromalidae) has been carried out. Several densities of population of the parasitoids have been tested in order to determine their reproductive behaviour, and this is significant if the output of a rearing is to be increased. A great competition among the individuals of the same sex has been observed; in the case of the ΦΦ, a potential negative correlation with the increase of density of population, has been noted. The biotic potential belonging to the 2 principal parasitoids species with and without competition, are calculated, and the aspects concerning the parasitoid colonization of the olive tree beetle infestation spots, are discussed.      

Host-specificity of fiveAnacassis species [Col.: Chrysomelidae] introduced into australia for the biological control ofBaccharis halimifolia [Compositae]

Foliage-feeding beetles of the genusAnacassis [A. phaeopoda Buzzi,A. fuscata (Klug),A. fuscata var.unicolor (Burmeister),A. cribrum (Klug) andA. dubia (Boheman)] were collected fromBaccharis spp. andBaccharidastrum spp. in South America. Specificity studies showed that they were restricted to these 2 host genera. Between 1974 and 1976 these species were introduced into Australia for the control ofBaccharis halimifolia. A. phaeopoda andA. fuscata were first released in 1976. One field colony ofA. fuscata persisted for up to 3 years but no recoveries ofA. phaeopoda were made after the 1st field generation. The other species died out in quarantine and were not released.      

Hymenopterous parasitoids of bark beetles [Scolytidae] in Israel: Host relation,host plant,abundance and seasonal history

Twenty six species of parasitoids were recorded from 15 species of bark beetles in Israel. Parasitoids were collected from infested cut branches of broadleaves and trap-trees of pine and cypress. Most of the parasitoids are oligophagous and range fromEcphylus caudatus, a monophagous species exclusive toHypoborus ficus, toHeydenia pretiosa, which develops on 11 species.Scleroderma domesticus, Agrilocida ferrieri andEupelmus nearurozonus are occasional parasitoids of bark beetles.Cephalonomia hypobori, Israelius carthami, S. domesticus, Entedon ergias, Cerocephala eccoptogasteri andRoptocerus xylophagorum are cryptoparasitoids and search for their host in the galleries. Known parasitoids are listed from 15 tree genera belonging to 8 botanical families. A typical range for the common parasitoids is presented with within-tree distribution of pine parasitoids. Relatively monophagous species are usually dominant parasitoids in a specific beetle population, whereas relatively polyphagous parasitoids vary in abundance among different host populations.Calosota spp., 2Eurytoma spp. andDendrosoter hartigii are usually present in small numbers. Information concerning the seasonal history of the parasitoids suggests that the major species may raise about 5 to 7 annual generations. Contribution from the Agricultural Research Organization, Bet Dagan, Israel N^o 1331-E, 1984 series     

Release and recovery in South Africa of the exotic aphid parasitoid <Emphasis Type="Italic">Aphelinus hordei</Emphasis> verified by the polymerase chain reaction

The exotic aphid parasitoid Aphelinushordei Kurdjumov (Hymenoptera: Aphelinidae) was released at five Russian wheat aphid [Diuraphis noxia (Mordvilko)] infested wheat fields in the eastern parts of the Free State Province of South Africa during the 1998 and 1999 growing seasons. Except for differences in the setae on the ventralside of the forewings, this species is verysimilar in colour and structure to A.varipes (Foerster) and A. albipodusHayat & Fatima, which also parasitise D.noxia. It is therefore difficult todistinguish between them, and to determinetheir establishment. Therefore a polymerasechain reaction, using specific primers for bothITS2 and mitochondrial 16s DNA sequencesof the three parasitoids, followed by HinfIrestriction endonuclease digestion and agarosegel electrophoresis, was tested to distinguishbetween them. Parasitoid recoveries were madeat the release sites within weeks after theywere released. Putative individuals of A.hordei were also collected during 1999 and2000 on D. noxia in Lesotho, whichis situated on the eastern border of the FreeState Province. The procedure separated the three Aphelinus spp.reliably. Between 94 and 100% of theindividuals recovered during the two fieldseasons were identified as being A.hordei, thus verifying recovery of this exoticaphid parasitoid in South Africa.     

Successful colonization ofEretmocerus debachi (Hym.: Aphelinidae) in the eastern mediterranean citrus region of Turkey

The whitefly,Parabemisia myricae (Kuwana) is one of the most serious citrus pests in the Eastern Mediterranean region of Turkey. In 1986, a host-specific parasitoid ofP. myricae, the aphelinidEretmocerus debachi Rose and Rosen, was imported from California to Turkey and released into citrus orchards along the Eastern Mediterranean coast. In the following yearsP. myricae-populations were rapidly reduced from about 17 whitefly-immature stages per leaf to less than 0.1 stages per leaf in all citrus orchards where the parasitoids were released. Furthermore,E. debachi was shown to be a good disperser and it is well adapted to the climatic conditions in the Eastern Mediterranean region. Since the successful colonization ofE. debachi, the whitefly is no longer a serious pest and it is difficult to find unparasitized individuals in the Eastern Mediterranean region of Turkey.     

ReleasingAmblyseius spp. [Acarina: Phytoseiidae] to controlThrips tabaci [Thysanoptera: Thripidae] on cabbage

Two species of predaceous mites,Amblyseius barkeri (Hughes) [=A. mckenziei Schuster & Pritchard] andA. cucumeris (Oudemans) [Acarina: Phytoseiidae] were evaluated as potential biological control agents forThrips tabaci Lindeman [Thysanoptera: Thripidae] on cabbage.A. barkeri colonized cabbage heads in preliminary trials. Field releases of different numbers of mites per plant during 1987 showed thatA. barkeri reduced the number of thrips in cabbage heads at harvest, and the reduction was proportional to the number of mites released, but thrips damage was unaffected. ReleasingA. cucumeris at different times during 1988, but releasing the same number of mites each time, we found that earlier releases resulted in fewer thrips and less damage at harvest; these relationships were not present, however, in plots treated with pyrethroid insecticides. We conclude that inoculative release ofAmblyseius spp. is a potentially useful thrips management strategy, but improvements in release timing and strategy will be required to provide commercially acceptable control.      

In vitro rearing ofLysiphlebus fabarum [Hym.: Braconidae]

In vitro rearing of the aphid endoparasitoidLysiphlebus fabarum (Marshall) (Hymenoptera, Braconidae) was attempted. Successful permanent cultures ofAphis fabae Sc. andMyzus persicae Sulz. cells were not obtained. Therefore, parasitoid larvae were reared in 2 unnatural media rone of which included cells ofCeratitis capitata Wied. (Diptera, Trypetidae). A group of larvae was reared in a substrate to which parasitoid teratocytes had been added. SinceLysiphlebus fabarum females did not oviposit into paraffin droplets including the substrates, the larvae were directly transferred from parasitized aphids into the rearing media. Several larvae reached the final instar, but only 2 out of the 48 tested in the 3 substrates became adults. The meaning of teratocytes inin vitro rearing of Aphidiine, Braconids is discussed. This work was supported by a grant from the italian Ministry of Education (M.P.I. 40%).