Natural enemies of the invasive mealybug Phenacoccus peruvianus (Hemiptera: Pseudococcidae): first report of some parasitoids in Italy

The bougainvillea mealybug, Phenacoccus peruvianus Granara de Willink (Hemiptera: Pseudococcidae), was first detected in Sicily in 2002 at high population levels on Bougainvillea glabra Choisy (Nyctaginaceae). In 2016, during a recent monitoring activity, natural enemies of this pest were detected for the first time. This report represents the first identification of P. peruvianus parasitoids in Italy and some information on the recovered entomophagous species is provided.     

Valuation of gamma irradiation for proficient production of parasitoids (Hymenoptera: Chalcididae & Eucoilidae) in the management of the peach fruit-fly,Bactrocera zonata (Saunders)

Recognizing the potential significance of using nuclear techniques in biological control, investigations were conducted on the rearing of parasitoids of the peach fruit-fly, Bactrocera zonata (Saunders) (Diptera: Tephritidae) to lead to a greater flexibility in the use of irradiated hosts. For improving mass production of the biological control agents, the use of irradiated fruit-fly larvae at the dose of 15 Gy proved useful for enhancing the parasitism and adult emergence of the larval parasitoid, Trybliographa daci (Weld) (Hymenoptera: Eucoilidae) due to no negative repercussions on parasitoid development. Overall, parasitism by the parasitoid increased with age of the host larvae; however, significantly higher parasitism occurred on 4 d-old irradiated larvae of B. zonata compared to those aged 5 d. The female parasitoids preferred the irradiated larvae, and significantly higher numbers of larvae were parasitized compared with non-irradiated larvae. There was no significant difference in adult parasitoid emergence with respect to the sex of the host. A radiation level of 80 Gy was the best dose for rearing of the pupal parasitoid, Dirhinus giffardii (Silvestri) (Hymenoptera: Chalcididae) owing to broad tolerances in the use of irradiation for the rearing of fruit-fly's parasitoids. Percentage parasitism by D. giffardii varied with host pupal age, and the preference of the female parasitoid was lower on 48 h old host pharate pupae due to optimum size and mass of host. Present findings further revealed that the 24 h old host pupae of B. zonata were relatively more suitable for the maximum parasitism and progeny production of D. giffardii. Parasitisms by D. giffardii and T. daci were significantly higher on B. zonata host when parasitoids were released at a density of 3000 individuals per acre (7500 per hectares) than the other release rates of parasitoids for the management of fruit-flies in mango orchards. The implementation of these findings ought to help improve the mass production of parasitoids and the effectiveness of releases of biocontrol agents for control of B. zonata in mango plantations.     

Survey on Bactrocera spp. (Tephritidae,Diptera) in Austria

Fruit fly species (Diptera: Tephritidae) of the genus Bactrocera are among the most serious orchard pests worldwide but are not native to Austria. The unexpected finding of one Bactrocera zonata adult in Vienna in 2011 initiated increasing survey efforts in Austria since 2012. Traps with male attracting lures were employed at several sites during the fruiting periods and catches were analysed. At sites in Vienna (urban area) Bactrocera specimens were trapped between 2012 and 2018, whereas no Bactrocera specimens were caught in agricultural areas or commercial orchards outside the city. Twelve specimens were identified as B. zonata and nine specimens as B. dorsalis sensu lato, though for the latter it was not possible to distinguish between B. dorsalis s.l. and B. carambolae using molecular analysis (ITS1). Molecular sequencing showed that the specimens caught were genetically different (with only a few exceptions), indicating genetically different origins. It is evident that the repeated findings of Bactrocera specimens in Vienna, where winter temperatures do not allow the establishment of tropical fruit flies, are linked to repeated entries of juveniles with infested fruits (in luggage or consignments). The results of our study reveal the need to strengthen phytosanitary import requirements for fruit commodities and travellers’ luggage in order to protect fruit production in Austria and probably in other countries.     

Biologie et complexe des ennemis naturels de Tuta absoluta à Mostaganem (Algérie)

Following the appearance of Tuta absoluta (Meyrick) in Algeria the agricultural and scientific sectors have undertaken research work aiming to control this pest using a variety of methods. This paper focuses on the biology of T. absoluta and of its predator Nesidiocoris tenuis and on an inventory of the natural enemies of T. absoluta in the region of Mostaganem. The life cycle of T. absoluta is 21.1 ± 0.4 days at 26 ± 1.6°C, RH 87 ± 6.4% and 29.4 ± 2 days to 23.4 ± 2°C, RH of 75 ± 3%. N. tenuis had a life cycle of 17.1 ± 0.5 days at 26 ± 1.6°C, and a longevity of adults of 16 ± 1.6 days for individuals fed with larvae of T. absoluta and 9 ± 2.2 days for those not fed. The inventory revealed the presence of three species of predators of T. absoluta: Nesidiocoris tenuis Reuter, Macrolophus pygmaeus ‘caliginosus’ Wagner and Dicyphus errans Wolff, and six parasitoids: Necremnus artynes Walker, Neochrysocharis sp., Sympiesis sp., Diglyphus isaea Walker, a Braconidae and Ichneumonidae paarasitoid. Necremnus artynes was the most frequent and most abundant parasitoid.     

The scale Nemolecanium graniformis (Wunn) (Homoptera: Coccidae) in Greece

The phenology and natural enemies of Nemolecanium graniformis (Wunn) (Homoptera: Coccidae) in infesting Abies cephalonica, were studied in Greece during 1998–1999. This oviparous species develops one generation per year in Central Greece (Attica) and overwinters as 2^nd instar nymph. Young adult females appear by the end of July, and the first instar nymphs by the middle of August. By the middle of October, the whole population of the scale is recorded as 2^nd instar nymphs. The parasitoids Coccophagus lycimnia (Walker), Coccophagus Westwood sp., Aphycoides Mercet sp. and the predator Exochomus quadripustulatus L. (Coleoptera: Coccinellidae), were observed as natural enemies of the scale. The average fecundity of N. graniformis was 188.4 eggs.     

The scale Nemolecanium graniformis (Wunn) (Homoptera: Coccidae) in Greece

The phenology and natural enemies of Nemolecanium graniformis (Wunn) (Homoptera: Coccidae) in infesting Abies cephalonica, were studied in Greece during 1998–1999. This oviparous species develops one generation per year in Central Greece (Attica) and overwinters as 2^nd instar nymph. Young adult females appear by the end of July, and the first instar nymphs by the middle of August. By the middle of October, the whole population of the scale is recorded as 2^nd instar nymphs. The parasitoids Coccophagus lycimnia (Walker), Coccophagus Westwood sp., Aphycoides Mercet sp. and the predator Exochomus quadripustulatus L. (Coleoptera: Coccinellidae), were observed as natural enemies of the scale. The average fecundity of N. graniformis was 188.4 eggs.     

Contribution of Biological Control to Integrated Pest Management of Tephritid Fruit Flies in the Tropics and Subtropics

The biological control of pest tephritid flies using parasitoids has been successful in relatively few subtropical and tropical regions. The best documented successes were in Hawaii and Florida, USA, Fiji and southern Europe. There were relatively limited successes in Australia, Costa Rica and Mexico. With the accidental establishment of new pest tephritids, such as Bactrocera latifrons (Hendel) in Hawaii or Bactrocera papayae Drew and Hancock in Australia, foreign exploration for new parasitoids is essential. A renewal of interest in classical biological control has recently occurred, although not at the same level as in the 1940s and 1950s. New parasitoid species are currently being obtained for several tephritids, such as Ceratitis capitata (Weidemann), B. latifrons and Anastrepha suspensa (Loew). The advances in mass rearing and quality control technology for parasitoids has enabled researchers to perform large-scale field testing of these parasitoids to determine the potential of augmentative releases. Numerous studies on the augmentative release of parasitoids have been done. Historically, the larval—pupal parasitoid Diachasmimorpha longicaudata (Ashmead) has been the most frequently studied parasitoid, due to the ease of rearing this species. However, recent successes in rearing other species with different biologies, e.g. the egg—pupal parasitoid Biosteres arisanus (Sonan), the gregarious eulophid, Tetrastichus giffardianus (Silvestri) and the pupal parasitoid, Coptera sp., will enable researchers to broaden the repertoire of parasitoid species for the future. Both successes and failures in augmentative releases have occurred. Without knowledge of the behavioural ecology of parasitoids, the reasons for success or failure can only be surmised. Recent research on the dispersal and host habitat finding of tephritid parasitoids will provide insights into improving augmentation and conservation strategies. The integrated pest management (IPM) of tephritid flies in the tropics has been less well-developed than research and programmes for tephritids in temperate zones. Significant emphasis is now being placed on the development of quarantine treatment methods that are environmentally sound; thus IPM will take a larger role. Several existing pest management strategies are reviewed which show the potential for compatibility with the activities of tephritid parasitoids. These include trap cropping, insecticides with selective toxicity to the target pests, mass trapping with parapheromones, the sterile insect technique and field sanitation.     

宁波地区小菜蛾幼虫期和蛹期寄生蜂调查

小菜蛾Plutella xylostella是十字花科蔬菜最重要的世界性害虫,保护和利用寄生性天敌是控制小菜蛾的重要手段。为有效控制小菜蛾在蔬菜上的为害,减少农药用量,作者于2007年4月至2009年1月对宁波地区小菜蛾幼虫期和蛹期主要寄生性天敌种类及其田间自然被寄生率进行了调查。结果表明,宁波地区十字花科蔬菜上小菜蛾幼虫期和蛹期共有8种原寄生蜂（菜蛾盘绒茧蜂Cotesia vestalis、螟蛉盘绒茧蜂Cotesia ruficrus、颈双缘姬蜂Diadromus col-laris、东方长颊姬蜂Macromalon orientale、棉铃虫齿唇姬蜂Campoletis chlorideae、无脊大腿小蜂Brachymeria excarinata、齿唇姬蜂Campoletissp.、弯尾姬蜂Diadegmasp.）、1种兼性寄生蜂（菜蛾啮小蜂Oomyzus sokolowskii）和5种重寄生蜂（盘背菱室姬蜂Mesochorus discitergus、粘虫广肩小蜂Eurytoma verticillata、稻灿金小蜂Trichomalopsis oryzae、绒茧灿金小蜂Trichomalopsis apanteloctena和啮小蜂Tetrastichussp.）,其中优势种为菜蛾啮小蜂和菜蛾盘绒茧蜂,分别占62.23%和31.19%,同时,小菜蛾幼虫期田间自然被寄生率普遍高于蛹期。另外,菜地蔬菜品种的多样性有利于寄生蜂的保护和利用。     

Native and introduced parasitoids in the biocontrol of Dryocosmus kuriphilus in Veneto (Italy)

The invasive gallmaker Dryocosmus kuriphilus is a threat to chestnut stands and it is necessary to control it in order to maintain a satisfactory nut yield. A preliminary evaluation of the native natural enemies emerging from the galls, mainly parasitoids associated with native cynipid gallmakers, revealed that they were not able to contain the pest. Consequently, a classical biological control programme using Torymus sinensis started in 2010, with almost 500 releases being made in 6 years. The parasitoid achieved a satisfactory level of control of the pest over a period of time shorter than expected based on literature related to other countries. The success in the study area might be explained by specific traits intrinsic to T. sinensis, such as its high spread capability via stratified dispersal (i.e. a combination of short‐ and long‐distance flights), together with a large availability of host galls and limited competition with other parasitoids.     

Data on ecology of the purple scale Lepidosaphes beckii (Newman) on citrus in Greece

The ecology of the purple scale Lepidosaphes beckii (Newman) (Hemiptera: Diaspididae) was studied on citrus, in the area of Kalamata (Messinia ‐ Peloponnese) from May 2009 to May 2011. Observations on infested citrus branches were conducted to study the phenology of the scale. Yellow sticky traps were hung in infested trees and examined to monitor the flights of male L. beckii as well as the flights of adults of parasitoids and predators of this pest. Lepidosaphes beckii mainly infested the leaves and fruits and to a lesser extent the shoots and stems. During the period of the study all developmental stages of L. beckii were found. Sticky transparent band traps were also placed on shoots and were examined to monitor the fluctuation in the population of crawlers. From the crawlers caught in the traps three population peaks were recorded in June, August and October. Natural enemies of the scale consisted of the parasitoids Aphytis lepidosaphes Compère and Encarsia sp. (Hymenoptera: Aphelinidae), which together parasitized up to 32% of L. beckii as well as the predators Chilocorus bipustulatus (L.) and Rhyzobius lophanthae Blaisdell (Coleoptera: Coccinellidae).     

Distribution and tephritid hosts (Diptera) of braconid parasitoids (hymenoptera) in Brazil

Tephritid parasitoids reared from 26 different host fruit species showed remarkably little diversity across 21 Brazilian counties. The majority of the parasitoids (81.4%) belonged to the braconid subfamily Opiinae, with Doryctobracon areolatus (Szépligeti) the most commonly encountered species. Four other opiines, namely D. brasiliensis (Szépligeti), Opius bellus Gahan, Optus sp. and Utetes (Bracanastrepha) anastrephae (Viereck) were also reared, but in much smaller numbers. Asobara anastrephae (Muesebeck), an alysiine braconid parasitoid of tephritids, accounted for an additional 18–6% of the individuals reared from tephritids. The hosts and distribution patterns of the braconid parasitoids of Brazilian fruit‐infesting Tephritidae are summarized.     

Populations of predators and parasitoids of Bemisia tabaci (Hemiptera: Aleyrodidae) after the application of eight biorational insecticides in vegetable crops

BACKGROUND: The sweetpotato whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), is an important pest of vegetables and many other crops worldwide. Eight biorational insecticides (based on oil, plant derivatives, insect growth regulator and fungus) were evaluated in the field for their influence on populations of six natural enemies of B. tabaci. Natural populations of two predators [Chrysoperla carnea Stephen (Neuroptera: Chrysopidae) and Orius spp. (Hemiptera: Anthocoridae)] and two genera of parasitoids [Encarsia spp. and Eretmocerus spp. (Hymenoptera: Aphelinidae)] were evaluated in eggplant (Solanum melongena L.). Also, augmented field populations of three predators [C. carnea, Coccinella undecimpunctata L. (Coleoptera: Coccinellidae) and Macrolophus caliginosus (Wagner) (Hemiptera: Miridae)] were evaluated in cabbage (Brassica oleracea var. capitata L.), cucumber (Cucumis sativus L.) and squash (Cucurbita pepo L.). RESULTS: Regardless of natural enemy or crop, jojoba oil, Biovar and Neemix had the least effect on abundance of the natural enemies in comparison with the other insecticides during a 14 day evaluation period. Conversely, Admiral, KZ oil, Mesrona oil, Mesrona oil + sulfur and natural oil had a high detrimental effect on abundance of the natural enemies. CONCLUSION: These results demonstrate the differential effects of biorational insecticides for whitefly control on predators and parasitoids in the field. Published 2011 by John Wiley & Sons, Ltd.     

First report of Encarsia cubensis Gahan (Hymenoptera: Aphelinidae) an exotic parasitoid on the Neotropical Whitefly Aleurotrachelus atratus Hempel (Hemiptera: Aleyrodidae) in India

The Neotropical palm infesting whitefly, Aleurotrachelus atratus Hempel (Hemiptera: Aleyrodidae) is a highly invasive pest that was reported during 2019 on coconut in India. In a short span of time, it spread rapidly across states of Karnataka, Tamil Nadu, Kerala and Andhra Pradesh on coconut, oil palm and many other ornamental palm plants. During the recent survey, the immature stages of A. atratus were found parasitized by an aphelinid parasitoid, Encarsia cubensis Gahan (Hymenoptera: Aphelinidae). These parasitoids were identified by their morphological characteristics and also characterized by DNA barcoding of adult parasitoids using partial (658 bp) mitochondrial cytochrome oxidase 1 (CO1) gene (GenBank accession number ON881119). This is the first report on occurrence of Encarsia cubensis as primary parasitoids on A. atratus in India and its natural parasitism ranged from (46–68%) on coconut across the different locations in Karnataka. It is believed that the parasitoid likely entered India along with A. atratus in India and constitutes a potential biological agent against A. atratus. It is expected that the E. cubensis population will become fully established, increase, spread and exert a significant impact on A. atratus population in India. Therefore, efforts may be made by growers and other stakeholders to increase the rate of natural parasitism through inundative, conservation and classical biological control approaches to reduce the pest population, crop damage and yield loss.

     

Phenology and impact of natural enemies associated with the hop looper (Hypena humuli) in Washington State,USA

The hop looper, Hypena humuli Harris (Lepidoptera: Noctuidae), is becoming an increasingly important pest of hops (Humulus lupulus L.) (Rosales: Cannabaceae) in western USA. Currently, control of this pest usually involves broad-spectrum pesticides that kill natural enemies and disrupt biological control of other hop pests. In order to develop better management strategies for H. humuli, field and laboratory studies were conducted over a four-year period to identify the pest's natural enemies and to investigate their phenologies and to assess their impact. Nine parasitoid species and assorted species of invertebrate predator were found to attack different life-stages of H. humuli. Levels of parasitism were consistently low throughout the study period and none of the parasitoids found was a specialist natural enemy of the pests. Exclusion cage studies showed, however, that the complex of natural enemies as a whole can significantly reduce larval densities of the pest, and laboratory studies confirmed successful predation of H. humuli larvae by several generalist predators including the European earwig (Forficula auricularia L.), the damsel bug Nabis alternatus Parshley and two species of the geocorid bug genus Geocoris.     

Survey of the genus Bursaphelenchus Fuchs, 1937 (Nematoda: Aphelenchoididae) in Romania

An overview of the occurrence of species of the genus Bursaphelenchus in Romania is presented. The data is based on recent surveys conducted for the first time throughout the country, to monitor and evaluate the potential entry of the pine wood nematode, Bursaphelenchus xylophilus. Wood samples were collected from declining trees, wood‐processing companies and imported wood packaging material. Of the 895 wood samples examined, 11 contained Bursaphelenchus specimens. Morphological and molecular analyses were carried out to characterize the species detected. With respect to the possible presence of B. xylophilus, all samples were negative, confirming the absence of this quarantine pest in Romania. Nevertheless, five Bursaphelenchus species were found: B. hofmanni, B. poligraphi, B. vallesianus, B. willibaldi, and one putative new species belonging to the sexdentati group, classified here as Bursaphelenchus sp. NR512. These results constitute the first report of the genus Bursaphelenchus in Romania.     

Spinosad bait sprays against the olive fruit fly (Bactrocera oleae (Rossi)): effect on the canopy non-target arthropod fauna

Abundance and diversity of arthropods were compared in olive trees treated against the olive fruit fly with spinosad bait sprays and an untreated control, paying special attention to predators and parasitoids. Spinosad bait sprays did not reduce the abundance and diversity of arthropods as a whole in the canopy. However, principal response curve analysis revealed a significant deleterious effect of the treatments on natural enemies in the last of the three years of study. The most affected taxa were Anthocoridae (especially Orius spp.) and Aphelinidae.     

Biological control of Tuta absoluta in Argentina and Italy: evaluation of indigenous insects as natural enemies

By means of an international project, Argentinian and Italian researchers are carrying out joint research to study biological and ecological aspects of Tuta absoluta biological control. This paper lists indigenous natural enemies reported for T. absoluta, as well as the current results on T. absoluta egg and larval parasitoids in both countries. Parasitoid species that conformed to different guilds are shown to coexist in cropping conditions, and some show positive characteristics as potential biocontrol agents against T. absoluta by means of augmentative releases. Future laboratory and field evaluations of the efficacy of biological control programmes in Argentina and Italy are proposed.     

First record of Oomyzus scaposus (Hymenoptera: Eulophidae), as a parasitoid of Coccinella septempunctata (Coleoptera: Coccinellidae) in Pakistan

Coccinella septempunctata L. (Coleoptera: Coccinellidae) is a natural enemy of several important pests. This biocontrol agent is also a host for different parasitoids. Little is known about the parasitoid complex of C. septempunctata in Pakistan. The authors identified Oomyzus scaposus (Thomson, 1878) (Hymenoptera: Eulophidae) as a larval-pupal parasitoid of C. septempunctata in the district of Sargodha, Punjab, Pakistan. Out of 36 C. septempunctata pupae collected, 58.3% were parasitized by O. scaposus. This study documents the first record of O. scaposus parasitizing C. septempunctata in Pakistan.     

Hymenopteran Parasitoids on Fruit-infesting Tephritidae (Diptera) in Latin America and the Southern United States: Diversity, Distribution, Taxonomic Status and their use in Fruit Fly Biological Control

We first discuss the diversity of fruit fly (Diptera: Tephritidae) parasitoids (Hymenoptera) of the Neotropics. Even though the emphasis is on Anastrepha parasitoids, we also review all the information available on parasitoids attacking flies in the genera Ceratitis, Rhagoletis, Rhagoletotrypeta, Toxotrypana and Zonosemata. We center our analysis in parasitoid guilds, parasitoid assemblage size and fly host profiles. We also discuss distribution patterns and the taxonomic status of all known Anastrepha parasitoids. We follow by providing a historical overview of biological control of pestiferous tephritids in Latin American and Florida (U.S.A.) and by analyzing the success or failure of classical and augmentative biological control programs implemented to date in these regions. We also discuss the lack of success of introductions of exotic fruit fly parasitoids in various Latin American countries. We finish by discussing the most pressing needs related to fruit fly biological control (classical, augmentative, and conservation modalities) in areas of the Neotropics where fruit fly populations severely restrict the development of commercial fruit growing. We also address the need for much more intensive research on the bioecology of native fruit fly parasitoids.     

Note:Capparimyia savastani (Martelli, 1911): A new record of tephritidae of economic significance for Spain

During a trial in Majorca (Balearic Islands) conducted in 2007 for the detection of parasitoids of the olive flyBactrocera oleae by using yellow sticky traps, a single female of the tephritidaeCapparimyia savastani (Martelli, 1911) was captured. This species had never been recorded previously either in the Balearics or mainland Spain. The larvae of this species feed on the edible flower buds of the common caper (Capparis sp.), thus being a potential pest of this crop. There has not been any previous study of the response of this diptera to the traps and attractants most commonly used in the area for the monitoring of other tephritidae of economic importance, such asB. oleae and the Mediterranean fruit flyCeratitis capitata. http://www.phytoparasitica.org posting May 30, 2008.