Natural Enemies of Pink Wax Scale, Ceroplastes rubens Maskell (Hemiptera: Coccidae), on Umbrella Trees in Southeastern Queensland

The natural enemy complex of pink wax scale, Ceroplastes rubens , on umbrella trees, Schefflera actinophylla , in southeastern Queensland was investigated. an introduced encyrtid, Anicetus beneficus , was the major primary parasitoid, although high rates of hyperparasitisation by the native encyrtid Coccidoctonus dubius were recorded. Predators and other parasitoids were minor components of the natural enemy complex of C. rubens. Implications of this study's findings on the biological control of C. rubens in citrus by A. beneficus are discussed.     

Native parasitoids associated with the genusAnastrepha (Dipt.: Tephritidae) in Los Tuxtlas,Veracruz, Mexico

In this paper we record the native parasitoids associated withAnastrepha fruit flies collected in a native tropical community from Los Tuxtlas, Veracruz, Mexico. A total of 1600 puparia ofAnastrepha were recovered from infested fruits of ten different host plants. From these puparia we obtained 218 Hymenopteran parasitoids representing the following species:Doryctobracon areolatus (Szépligeti),Utetes (Bracanastrepha) aff.anastrephae (Viereck),Doryctobracon crawfordi (Viereck),Opius hirtus (Fischer),Microcrasis n. sp.,Nealiolus n. sp. (all Braconidae);Odontosema n. sp. andLopheucoila sp. (Cynipidae). The most abundant and frequently encountered parasitoid species observed during this study wasD. areolatus, representing 59.2% of all recovered parasitoids. The analysis of different infestation rates in fruits regarding to degree of parasitization in theseAnastrepha species suggest they are not correlated, meanwhile some host plant characteristics such as fruit size, could play an important role in influencing rates of parasitization.     

Interspecific competition between Cephalonomia stephanoderis and Prorops nasuta (Hym.,Bethylidae), parasitoids of the coffee berry borer, Hypothenemus hampei (Col., Scolytidae)

The competition between Cephalonomia stephanoderis and Prorops nasuta was studied in the laboratory, using coffee fruits infested with the host of these parasitoids, the coffee berry borer Hypothenemus hampei . Experiments were performed under different conditions, using: (a) three temperatures; (b) five densities of infested coffee fruits; and (c) introducing the parasitoids at different times. The effect of competition was determined according to the production of the progeny. When cultured together at the same time, C. stephanoderis produced in general, more progeny than P. nasuta under conditions of 29°C and alternating temperatures of 18–29°C. Nevertheless, there were significant differences at densities of 1 : 3, fruits : parasitoids ( F _0.05=8.9; d.f.=1, 12; P < 0.05) and 1 : 5 ( F _0.05=7.56; d.f.=1, 12; P < 0.05) at 29°C. Under alternating temperatures, there were differences at the same ratios as above in favour of C. stephanoderis , 1 : 3 ( F _0.05=20.08; d.f.=1, 12; P < 0.05) and 1 : 5 ( F _0.05=20.21; d.f.=1, 12; P < 0.05). Prorops nasuta was clearly more successful in all densities at 18°C. When C. stephanoderis was introduced 10 days before P. nasuta , the progeny production was markedly higher in eight from 10 densities at temperatures of 29°C and 18–29°C. Despite being introduced 10 days later, P. nasuta showed better performance at 18°C. When P. nasuta was introduced 10 days earlier than C. stephanoderis , there were significant differences in progeny production in favour of P. nasuta in 13 of 15 fruit densities under the three temperatures. Both parasitoids avoided ovipositing on previously parasitized hosts. Aggressive behaviour or interference was not observed when they were outside coffee fruits.     

Primary and secondary parasitoids (Hymenoptera) of aphids (Hemiptera: Aphididae) on blueberry and other Vaccinium in the Pacific Northwest

Blueberry scorch virus, a commercially important Carlavirus in highbush blueberry, Vaccinium corymbosum L., is vectored by aphids (Hemiptera: Aphididae). We surveyed the aphids, primary parasitoids (Hymenoptera: Aphelinidae, Braconidae), and associated secondary parasitoids (Hymenoptera: Charipidae, Megaspilidae, Pteromalidae) on highbush blueberry and other Vaccinium in the Pacific Northwest from 1995 to 2006, with samples concentrated in 2005 and 2006, to lay the groundwork for augmentative biological control. Ericaphis fimbriata (Richards) was the principal aphid. The dominant parasitoid species were Praon unicum Smith, Aphidius n. sp., A. sp., and Aphidius ervi Haliday. Their frequency in relation to the other primary parasitoids varied significantly with geographical area; P. unicum dominated the frequency distribution in southwestern British Columbia, A. n. sp., west of the Cascades, and A. sp. and A. ervi east of the Cascades. Among the secondary parasitoids, pteromalids dominated, and their frequency in relation to the other secondary parasitoids was lowest in southwestern British Columbia. The parasitization rate for P. unicum and A. n. sp. in southwestern British Columbia increased from May or June to a maximum of 0.080 +/- 0.024 and 0.090 +/- 0.084 (SD), respectively, in late July or early August. P. unicum emerged in the spring 4 wk before A. n. sp. The parasitization rate for P. unicum was lower in conventional than organic fields. Whereas aphid density increased monotonically, P. unicum had two spring peaks. A simulation model showed that these peaks could reflect discrete generations. Releases of insectary-reared P. unicum at 150 or 450 DD above 5.6 degrees C, summing from 1 January, may effectively augment the natural spring populations by creating overlapping generations.     

Within-plant vertical distributions of the scale insect Nipponaclerda biwakoensis and its five parasitoids that exhibit frequent successful multiparasitism on the common reed

Within‐shoot vertical distributions of the scale insect Nipponaclerda biwakoensis, five species of gregarious parasitoid wasps attacking the scale, and successful multiparasitism (emergence of multiple parasitoid species from a single host) by the parasitoids on the common reed were investigated. Each reed shoot collected was longer than 2.0 m, and was divided into pieces of 0.5 m each from the base of the shoot. The mean number of adult female scales per 0.5 m of shoot increased with height, but the mean rate of overall parasitism of the female scales decreased with height. The five parasitoids showed species‐specific within‐shoot distribution patterns, with respect to the rate of parasitism: Astymachus japonicus, Boucekiella depressa and Encyrtidae sp. 2 showed the greatest rates of parasitism at heights of 0–0.5, 0.5–1.0 and 1.0–1.5 m, respectively. The parasitism rate by Aprostocetus sp. was higher at the lower half of the shoots, whereas that by Encyrtidae sp. 1 was higher at the central positions. The distribution of the five parasitoids largely overlapped with each other at the level of scale aggregations. Nevertheless, successful multiparasitism occurred frequently only in several types of species combinations that involved two parasitoid species showing similar within‐shoot distribution patterns. The rate of successful multiparasitism by B. depressa with A. japonicus or Aprostocetus sp., and that by Encyrtidae sp. 2 with Encyrtidae sp. 1 was constantly high at different vertical positions on the shoots. This may be because B. depressa and Encyrtidae sp. 2 preferentially oviposit into scales previously parasitized by these other species.     

Natural enemies of Paropsis atomaria Olivier (Coleoptera: Chrysomelidae) in south-eastern Queensland eucalypt plantations

Abstract  A field survey for natural enemies of Paropsis atomaria was conducted at two south-eastern Queensland Eucalyptus cloeziana plantation sites during 2004–2005. Primary egg and larval parasitoids and associated hyperparasitoids were identified to genus or species, and parasitism rates were determined throughout the season. Predators were identified to family level but their impact was not quantified. P. atomaria adults were also examined as potential hosts for parasitic mites and nematodes. An undescribed species of Neopolycystus (Pteromalidae) was the major primary egg parasitoid species reared from egg batches, parasitising half of all egg batches collected. Three hyperparasitoid species ( Baeoanusia albifunicle (Encyrtidae), Neblatticida sp. (Encyrtidae) and Aphaneromella sp. (Platygasteridae) were present, representing around one-quarter to one-third of all emergent wasps; this is the first host association record for Neopolycystus–B. albifunicle. In contrast to populations of P. atomaria from the Australian Capital Territory, primary larval parasitism was very low, around 1%, and attributable only to the tachinid flies Anagonia sp. and Paropsivora sp. However, the presence of the sit-and-wait larval hyperparasitoid, Perilampus sp. (Perilampidae) was high, emerging from around 17% of tachinid pupae, with planidia infesting a further 40% of unparasitised hosts. Three species of podapolipid mites parasitised sexually mature P. atomaria adults, while no nematodes were found in this study. Spiders were the most common predators and their abundance was positively correlated with P. atomaria adult and egg numbers. Although natural enemy species composition was identical between our two study sites, significant differences in abundance and frequency were found between sites.     

Survey for parasites ofSesamia calamistis (Lep.: Noctuidae) andEldana saccharina (Lep.: Pyralidae) in southwestern Nigeria

Field surveys were conducted during 1990–92 to document the relative abundance of different species of parasites of the lepidopterous stem borersSesamia calamistis Hampson andEldana saccharina Walker in maize fields in southwestern Nigeria. Species of parasitoids detected on both stem borers included the larvalpupal parasitoidsSturmiopsis parasitica Curran (Diptera: Tachinidae) andBrachymeria feae Masi (Hymenoptera: Chalcididae), and the larval parasitoidDolichogenidea polaszeki Walker (Hymenoptera: Braconidae). The braconidCotesia sesamiae (Cameron) was found attackingS. calamistis. The hyperparasitoidExoristobia dipterae (Risbec) (Hymenoptera: Encyrtidae) was detected on a pupa ofS. parasitica. Parasitic nematodes belonging toMermis sp. and/orHexamermis sp. were found infesting larvae of both stem borers. Overall, larval/pupal parasitization levels at Ibadan were low and ranged from 4.2 to 22.8% forS. calamistis and 1.2 to 13% forE. saccharina. Of the parasites found,S. parasitica was the most common, followed by nematodes. Four hymenopteran egg parasitoids were found attackingS. calamistis: Telenomus busseolae Gahan,T. isis Polaszek (Scelionidae),Lathromeris ovicida Risbec, andTrichogrammatoidea eldanae Viggiani (Trichogrammatidae). Egg parasitization ranged from 13.4 to 41.5%. The only egg parasitoid detected onE. saccharina wasTelenomus applanatus Bin and Johnson, which inflicted only 5% parasitization.     

Key to the New Zealand species of Psyllaephagus Ashmead (Hymenoptera: Encyrtidae) with descriptions of three new species and a new record of the psyllid hyperparasitoid Coccidoctonus psyllae Riek (Hymenoptera: Encyrtidae)

Abstract  This paper records seven species of wasps in the genus Psyllaephagus (Hymenoptera: Encyrtidae) from New Zealand. All of these species are primary parasitoids of psylloids (Hemiptera: Psylloidea). Two are species previously described from New Zealand: P. acaciae Noyes and P. pilosus Noyes. Two are described Australian species which have established recently: P. bliteus Riek and P. gemitus Riek. Three new species are described here, from New Zealand: P. breviramus sp. nov., P. cornwallensis sp. nov. and P. richardhenryi sp. nov. All species are probably Australian in origin. A key to all seven Psyllaephagus species known from New Zealand is provided. An earlier first record of the Australian psyllid hyperparasitoid Coccidoctonus psyllae Riek (Hymenoptera: Encyrtidae), previously first recorded from New Zealand in 2006, is noted.     

Interspecific competition between Diadegma semiclausum Hellen (Hym., Ichneumonidae) and Cotesia plutellae (Kurdjumov) (Hym., Braconidae) in parasitizing Plutella xylostella (L.) (Lep., Plutellidea)

Abstract:  Interspecific competition between Diadegma semiclausum and Cotesia plutellae was investigated at 25°C in the laboratory, by exposing the third instar larvae of the diamondback moth, Plutella xylostella to both species together, either species alone or by exposing the host larvae already parasitized by one species, at different intervals, to the other. When host larvae were exposed simultaneously to two species in one arena, parasitism rates of the host by each species were not reduced by the presence of the other species; joint parasitism rate by two species was not significantly higher than that by either parasitoid alone. Both parasitoids could lay eggs into the host larvae which had previously been parasitized by the other species, leading to the occurrence of multiparasitized hosts. When host larvae were parasitized first by D. semiclausum and then being followed within 1–2 h by exposing to C. plutellae , or vice versa, ensuing parasitoid cocoons from the multiparasitized host larvae were nearly all C. plutellae . When host larvae were parasitized initially by C. plutellae and then being followed by D. semiclausum two or more days later, all parasitoids ensued from the multiparasitized hosts were C. plutellae . In contrast, when host larvae were parasitized initially by D. semiclausum and then being followed by C. plutellae two or more days later, most host larvae could not survive to prepupae and most of the ensuing parasitoid adults from the surviving hosts were D. semiclausum . Dissections of host larvae at various time intervals after parasitization by the two parasitoids showed that development of both parasitoids in multiparasitized hosts were somewhat arrested, and that the first instar larvae of C. plutellae could initiate a physical attack on the larvae of D. semiclausum and remove the latter.     

The hymenopteran parasitoids of light brown apple moth, Epiphyas postvittana (Walker) (Lepidoptera: Tortricidae) in Australia

Abstract  Epiphyas postvittana (Walker) is a serious pest of a number of horticultural crops including grapes in Australia and New Zealand. This study brings together information on the parasitoid complex associated with E. postvittana that previously was fragmented and largely inaccessible. We include species reared during a 3-year study of the parasitoids of E. postvittana in the vineyards of the Coonawarra region, South Australia, material from several Australian agricultural insect collections and records from the literature. An illustrated key is presented for 25 species of parasitoids and hyperparasitoids associated with E. postvittana , along with information on the taxonomy, identification, distribution and biology of each species. Taxa newly recorded from this host are Perilampus sp. (Perilampidae), and six species of Ichneumonidae: Euceros sp., Labium sp., Netelia sp., Plectochorus sp., Temalucha minuta (Morley) and Eriborus epiphyas sp. n., the latter species being described in full.     

Mass-rearing biology of Fopius vandenboschi (Hym., Braconidae)

Abstract:   Basic biological information concerning the reproductive activities of Fopius ( Biosteres ) vandenboschi (Fullaway) (Hym., Braconidae, Opiinae) were determined to facilitate insectary mass production. Mean (±SE) progeny production per generation (yield) of 200 ♀♀ F. vandenboschi was 6835.8 ± 433.2 and 3755.8 ± 112.4 parasitoids, with 24-h exposure to second instar Bactrocera dorsalis (Hendel), and Ceratitis capitata (Wiedemann), respectively. Ceratitis capitata as a factitious host was more sensitive to parasitism, producing a significantly higher percentage of uneclosed host puparia frequently containing parasitoid cadavers (22.5 ± 0.8%), than B. dorsalis (3.4 ± 0.2%). The overall mean production of female offspring was ≥50%♀♀ in both host species. Unlike several other opiine parasitoids, young (5-day-old) females of F. vandenboschi produced low proportion of daughters (26–37%♀♀) and significantly shifted production to female-biased offspring (53–71%♀♀) at older age intervals (16–30 days). Based on the parasitoid yield data with a 24-h exposure period to second instar host larvae of B. dorsalis , about 150 cage replicates (of 200 ♀♀ each) may be sufficient to mass produce about 1 million parasitoids of F. vandenboschi during the reproductive period of 5–30 days, with an average of 56% female offspring. A short oviposition exposure period of 6 h was not optimal for mass production of F. vandenboschi . Total yield at 6 h exposure was one-fifth the production at 24-h exposure, using B. dorsalis hosts.     

Suitability of Bemisia tabaci (Hemiptera: Aleyrodidae) instars for the parasitization by Encarsia bimaculata and Eretmocerus sp. nr. furuhashii (Hymenoptera: Aphelinidae) on glabrous and hirsute host plants

The host instar preferences of Encarsia bimaculata and Eretmocerus sp. nr. furuhashii parasitizing Bemisia tabaci and their development on four host plants, collard, eggplant, cucumber and tomato, were studied in the laboratory. Both of the parasitoids accepted all nymphal stages of B. tabaci, but E. bimaculata preferred third and fourth instars while Er. sp. nr. furuhashii preferred second and third instars under both choice and no choice conditions. Regardless of host stage parasitized, adults of parasitoids emerged only from fourth instars. When given the simultaneous choice of all instars, E. bimaculata reduced parasitization of first and second instars (3.73 and 4.76%, respectively) while increasing parasitization of third and fourth instars (5.44 and 6.93%, respectively), in contrast Er. sp. nr. furuhashii increased its parasitization of second and third instar nymphs (1.27 and 3.17%, respectively) and decreased that of first and fourth instars (7.0 and 3.06%, respectively). Host plants did not significantly influence instar preference for either parasitoid. Developmental periods of both the parasitoids from egg to adult emergence were longest when first instars were parasitized and shortest when fourth instars were selected. Parasitoid developmental time was generally shorter on glabrous plants than on hirsute plants.     

Parasitism-induced effects of Glyptapanteles liparidis (Hym., Braconidae) on the juvenile hormone titer of its host, Lymantria dispar: the role of the parasitoid larvae

Parasitization by the gregarious larval endoparasitoid Glyptapantles liparidis induces a dramatic increase in the hemolymph juvenile hormone (JH) titer (especially JH III) of its host larva, Lymantria dispar. Here, we investigated the role of the parasitoid larvae in JH synthesis and release by in vitro and in vivo experiments. GC-MS analyses confirmed that the rising hemolymph JH titer coincided with the time at which the parasitoids molt to the second larval instar. Peak values in host hemolymph titers were observed prior to parasitoid emergence, and titers dropped to negligible levels within 24 h after parasitoid emergence. Whole body extracts from excised second instar parasitoids yielded JH III and trace amounts of JH II. The in vitro secretory activity of the corpora allata (CA) of L. dispar larvae was not enhanced by parasitization. When the host's CA were separated by neck ligation, we found elevated JH III titers, but no JH II in the hemolymph of the posterior section, which contained the parasitoids. Parasitoids that were kept in in vitro culture produced and released only JH III. The parasitoids’ ability to secrete JH and to molt independently from their host's molting cycles indicates that at least second instar parasitoids are hormonally self-reliant.     

Indigenous parasitoids (Hym., Chalcidoidea) of Phyllocnistis citrella Stainton (Lep., Gracillariidae) in Jaguariúna, São Paulo State, Brazil: preliminary results

Abstract: The citrus leafminer, Phyllocnistis citrella Stainton, is native to Asia and was detected for the first time in Brazil in 1996. The objectives of this study were to conduct a survey of parasitoids attacking citrus leafminer in Jaguariúna, one of the citrus production regions of São Paulo State, Brazil, and to determine whether indigenous species were providing effective control of this pest species. The collections of new leaves were made weekly at citrus groves in Jaguariúna from October 1996 to October 1997. Of the six indigenous parasitoids which were found, Galeopsomyia fausta LaSalle was the most abundant parasitoid of P. citrella in this region, accounting for more than 90% of the specimens collected. Thus, this species is a serious candidate for biological control of the citrus leafminer in this region of Brazil. Other species collected were Horismenus sp., Cirrospilus 'sp. C', Elasmus sp., Eupelmus sp. and Conura (Ceratosmicra) sp. The mean percentage of parasitism was 39.28% (6.19−86.21%) in unsprayed orchards and 21.38% (1.33−56.63%) in orchards that were occasionally treated with fungicides, acaricides and insecticides Temik and Dipterex.     

Differences in egg parasitism of Chrysophtharta agricola (Chapuis) (Coleoptera: Chrysomelidae) by Enoggera nassaui Girault (Hymenoptera: Pteromalidae) in relation to host and parasitoid origin

Abstract The first instances of egg parasitism of Chrysophtharta agricola , a pest of eucalypt plantations, are recorded. Enoggera nassaui was found parasitising C. agricola egg batches in Tasmania, the Australian Capital Territory (ACT), New South Wales and Victoria: this is the first record of this parasitoid species from Victoria. One instance of Neopolycystus sp. parasitising C. agricola eggs in Victoria was also recorded. Parasitism of egg batches by E. nassaui ranged from 0 to 55% between five geographical populations collected in mainland Australia ( n  = 45), and from 0 to 2% between two populations collected in Tasmania ( n  = 300). For mainland sites at which parasitism was recorded, parasitism rates within sites differed significantly from either population in Tasmania. Reciprocal exposure experiments using one Tasmanian (Florentine Valley) and one parasitised mainland (Picadilly Circus, ACT) population were conducted in the laboratory to examine whether these different parasitism rates were attributable to egg or parasitoid origin. Parasitoids from the ACT parasitised C. agricola eggs of both origins more successfully than parasitoids from Tasmania, with up to 65% wasp emergence compared with 33% from Tasmania. Parasitoid origin significantly affected the number of wasps that emerged from exposed batches, but not the total loss from parasitism.     

Parasitoids of Paratachardina lobata (Hem., Kerriidae): surveys for biological control of the invasive lobate lac scale

Paratachardina lobata is an invasive pest in southern Florida, threatening a great number of economically important and native plants. The lobate lac scale does not cause problems in its area of origin, India and Sri Lanka, presumably due to various parasitoid wasps. In an attempt to discover promising parasitoids for biological control against the invasive pest in Florida, P. lobata infesting Pongamia pinnata (Fabaceae) was collected bimonthly from August 2005 to June 2006 at 14 sites in southern India. Four parasitoids were demonstrably associated with P. lobata: a eulophid Aprostocetus bangaloricus Narendran, an encyrtid Ooencyrtus kerriae Hayat and two aphelinids, Marietta leopardina Motschulsky and an undescribed Coccophagus Westwood sp. These chalcidoid wasps were found regularly at all heavily infested sites with an average emergence number per collection period of 62.8, 31.7, 11.9 and 90.5 respectively. The mean number emerged 20–28 days after the collection date, excluding the Coccophagus sp., which occurred significantly later, on average 41 days after collection. Species emergence was examined and parasitized scales dissected. Parasitoid remains were interpreted to understand the mode of parasitism. The Coccophagus sp. was found to be a secondary parasitoid. Marietta leopardina occurred as a primary parasitoid, but only in low number and this species is also known to be hyperparasitic on chalcidoid wasps. Aprostocetus bangaloricus and O. kerriae are promising candidates for the lobate lac scale control in Florida. They are primary parasitoids of P. lobata and occurred at almost every collection site, especially where P. lobata was very abundant.     

BIONOMICS OF MICROPLITIS MEDIATOR (HYM: BRACONIDAE) PARASITIZING PSEUDALETIA SEPARATA (LEP: NOCTUIDAE)*

Abstract This paper deals with the bionomics of Microplitis mediator parasitizing Pseudaletia separata. There were some stings (ca. 3. 1%) in which female wasps oviposited more than one eggs and about 4. 6% stings that there was no egg laid into a host. A negative correlation existed between the host age and percentage of parasitization. When the host suffered more stings by the parasitoid wasps, the percentage of parasitization was higher. But there was no correlation between the parasitoid sex ratio and the host age or the frequency of stings by the parasitoids. The host age is not the major factor affecting the offspring sex ratio of the parasitoid. Some putative sex determinant factors in the parasitoid are discussed and the 2nd instar of the host is recommended as a suitable host age in which parasitization could be performed for the purpose of the parasitoid mass culture.     

Limited protection of the parasitoid Pachycrepoideus vindemiae from Drosophila suzukii host‐directed spinosad suppression

Laboratory trials were conducted to determine whether the spotted wing drosophila, Drosophila suzukii (Matsumura) (Diptera: Drosophilidae), puparium can provide an effective physical barrier to protect immature stages of the pupal parasitoid Pachycrepoideus vindemiae (Rondani) (Hymenoptera: Pteromalidae) from spinosad treatments. Spinosad insecticides are currently an important suppression strategy for D. suzukii in organically managed fruit orchards although they are well known to cause mortality in hymenopteran parasitoids. High adult P. vindemiae female mortality (83%) occurred within 24 h of exposure to D. suzukii pupae treated with 10 mg a.i. l^?1 spinosad and female parasitoids did not avoid the pupae treated with similar low levels of spinosad in choice tests that included untreated pupae. Pachycrepoideus vindemiae develops as an idiobiont ectoparasitoid on host fly pupa within the sclerotized host puparium. Significant P. vindemiae survival and emergence was recorded when parasitized D. suzukii puparia were exposed to field treatment levels of spinosad; however, the parasitoid survival was dependent on the time of the spinosad treatment of the host post‐parasitization. Significant parasitoid survival occurred when the host puparia were treated at 2 weeks when the parasitoid was in the pupal stage but did not occur when the host puparia were treated at 1 week post‐parasitization, when the parasitoids were still in a larval stage. The parasitoid adults consumed or otherwise came in contact with residual degrading spinosad when they exited the treated host, and consequently high and low adult parasitoid mortality occurred when the adults emerged from puparia treated at 2 and 1 week(s), respectively. Our study indicates that generally the integration of P. vindemiae parasitism into a sustainable D. suzukii management program is not compatible with spinosad treatments, although P. vindemiae in the pupal stage inside sclerotized host puparia appear to be minimally impacted by spinosad treatments, provided that the spinosad degrades before parasitoid emergence.     

Structure of egg-batches of Thaumetopoea pityocampa (Den. and Schiff.) (Lep., Thaumetopoeidae), egg parasitoids and rate of egg parasitism on the Iberian Peninsula

In four regions of the Iberian Peninsula 273 egg-batches of the pine processionary moth were collected after hatching of the caterpillars in 1991 and 1992. After collection, the batches were stored singly in test tubes closed with foam stoppers under laboratory conditions at 20–25°C. The number of eggs in each egg-batch varied between 37 and 312 and the length of the batches between 0.6 and 4.2 cm. Independently of the pine species infested, seven to nine rows of eggs were counted, wrapped around one pair of needles. A correlation was found between number of eggs and the product of number of egg rows and length of egg-batches (82% <  r ²  < 97%). Oviposition almost always started from the base towards the tip of the needles. The egg parasitoids that emerged were counted daily, removed and identified. Later in the year of oviposition, after the end of the period of emergence of the parasitoids, the scale cover of the egg-batches were removed. One year later, all eggs were opened and the contents, such as parasitoid meconia and remains of caterpillars, were determined. The hatching rate of the caterpillars varied from 47.2 to 79.7%. The rate of parasitism fluctuated between 11.3 and 31.7%, but 44% of parasitoids died before successful emergence. Four species of Chalcidoidea were identified: Baryscapus servadeii (Dom.), Ooencyrtus pityocampae (Mercet), Anastatus bifasciatus (Fonsc.) and Trichogramma sp. Baryscapus servadeii and O. pityocampae were the most abundant species, followed by Trichogramma sp. Baryscapus servadeii emerged mainly in June and O. pityocampae in April or June, depending on the region. For A. bifasciatus only males, and for B. servadeii females emerged except one male. In O. pityocampae , a relatively high percentage of males (5.4–10.4%) was found.     

Biology and Seasonal Abundance of Parasitoids of the Banded Sunflower Moth (Lepidoptera: Tortricidae) in Sunflower

Mortality, parasitization, and overwintering development through pupation of the banded sunflower moth, Cochylis hospes Walsingham, larvae and two of its endoparasitoids, Glypta prognatha Dasch and Chelonus phaloniae Mason, were followed over a 2-year period (1987 to 1989). Development of parasitoids in the field was determined for each species by examination of moth eggs and larvae during the 1989 season. Parasitoids of C. hospes, recovered from cultivated sunflower, Helianthus annuus L., from North and South Dakota and Minnesota in 1994 and 1995, parasitized 24 and 17% of larvae, respectively. Species of Hymenoptera collected included G. prognatha and Trathala sp. (Ichneumonidae), C. phaloniae and Macrocentrus ancylivorus Rohwer (Braconidae), and Perilampus robertsoni Crawford (Pteromalidae). The most abundant parasitoid was G. prognatha. In 1994 and 1995, C. phaloniae, an egg-larval parasitoid, emerged earlier but was less abundant than the later occurring larval parasitoid G. prognatha. Species of parasitoids collected from cultivated sunflower and five species of native sunflowers were similar. An additional parasitoid, Mastrus sp. (Ichneumonidae), was recovered only from the native sunflowers H. annuus and H. tuberosus L. Results from 1994 and 1995 showed that parasitization rates for the total season by the two most abundant parasitoids were similar in fields using three planting dates. These results suggest that altering planting date could be successfully used as a pest management strategy without disrupting the biological control of the banded sunflower moth. Conservation of these parasitoids in the sunflower agroecosystem is needed since they play an important role in the management of C. hospes.