Citrus leafminer Phyllocnistis citrella and its parasitoids in Sargodha region of Pakistan

In order to identify the parasitoids of Phyllocnistis citrella, an important pest of Citrus, the larvae and pupae of this pest were collected from Citrus reticulata Blanco orchards in the Sargodha region of Pakistan. The parasitoid species were identified, and their abundance was recorded. A total of two species were identified: Citrostichus phyllocnistoides (Narayan) (Hymenoptera: Eulophidae) and Cirrospilus ingenuus Gahan (Hymenoptera: Eulophidae). Out of a total of 409 P. citrella larvae and pupae collected, 73 C. phyllocnistoides and 39 C. ingenuus adults emerged. This paper documents the species and the abundance of the parasitoids associated with P. citrella in the Sargodha region of Pakistan.     

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.

     

The role of Tetrastichus giffardianus Silvestri (Eulophidae: Hymenoptera) in natural control of Bactrocera zonata (Saunders) (Tephritidae: Diptera) and its temporal abundance in Sudan

Bactrocera zonata is an alien fruit fly which was introduced into Sudan in 2012 and spread throughout the country, severely hampering the production and export of fruit and vegetable crops. Cataloguing indigenous natural enemies of pests, especially parasitoids, is key to successful biological control programmes, to mitigate damage and decrease reliance on insecticides. This study was conducted to determine the parasitoids of B. zonata in two orchards in Gezira State, Sudan from November 2015 to May 2016 and from February to December, 2016 and to determine their role in natural control of the pest. Three parasitoids emerged from puparia of B. zonata, these were: Tetrastichus giffardianus Silvestri (Eulophidae), an Aganaspis sp. (Figitidae: Eucoilinae) and a Psyttalia sp. (Braconidae Opiinae). Tetrastichus giffardianus was the most numerous parasitoid throughout the study period. The mean percentages of B. zonata from guava fruits that were parasitized by T. giffardianus for the whole study period were 13.7% and 13.2% with 3.1 ± 0.3 and 2.8 ± 2.4 parasitoids per puparium at Fadasi and Gazirat Elfil sites respectively. Data on the temporal abundance of T. giffardianus is presented. Strenuous efforts should be considered to involve the reported natural enemies of B. zonata in integrated management programmes for fruit flies in Sudan.     

Using new egg parasitoids (Trichogramma spp.) to improve integrated management against Tuta absoluta

This study is the first step of the TutaPI program (2011–13) to decrease the costs of Integrated Pest Management (IPM) strategies against Tuta absoluta in France by investigating new beneficial insects. Currently, the association of predator/egg parasitoid (Macrolophus pygmaeus and Trichogramma achaeae, respectively) in IPM strategies are quite effective, but expensive. Sixty‐four new potential strains from 19 Trichogramma species originating from different regions of the world (from the collection of Trichogramma at INRA Provence Alpes Côte d'Azur (PACA), France) were studied in this work. A screening study was performed on T. absoluta eggs on isolated tomato leaves (for 24 h at 25 ± 1°C, RH 75 ± 5% and 16 h light : 8 h dark). The proportion of parasitized T. absoluta eggs varied greatly (between 0 and 73%) depending on the different strains used. Levels of parasitism by females, equal to or higher than that of T. achaeae, were observed in 14 of the strains tested among eight species (four from France, four from elsewhere in Europe). The proportion of females that parasitized T. absoluta eggs was significantly different between strains (from 0 to 100%). Experimental results allowed about half of the 64 initial strains to be eliminated before the next steps: tests on a larger scale (mesocosm, and then in the greenhouse and field).     

Effect of temperature on predation of Chilocorus bipustulatus L. (Col.: Coccinellidae) feeding on Agonoscena pistaciae (Hem.: Psyllidae)

Chilocorus bipustulatus L. (Col.: Coccinellidae) is a predatory coccinellid with a wide geographical distribution. Biological control programs should have a good understanding of the capacity of a predator to kill the target prey. Therefore, the age-stage specific predation rate and functional response of C. bipustulatus feeding on Agonoscena pistaciae (Hem.: Psyllidae) were studied at 18, 25, and 32 °C (65?±?5%RH and 16 L: 8D) to confirm its potential as a biological control agent of common pistachio psylla. The functional response at 18 and 25 °C were described by type II and type III at 32 °C. The estimated maximum attack rate (T/Th) was at 25 °C. Moreover, the highest net feeding (C₀) was observed at 25 °C (3271.5 psyllids). This laboratory study, thus, suggested that the predatory coccinellid C. bipustulatus reacted to the rise of temperature by enhancing the predation rate on A. pistaciae.

     

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.     

Temperature-dependent parasitism and development in Aenasius arizonensis Girault (Hymenoptera: Encyrtidae), a solitary endoparasitoid of Phenacoccus solenopsis (Hemiptera: Pseudococcidae)

Ophmella communa (Coleoptera: Chrysomelidae) is a biological control agent of Ambrosia artemisiifolia (Asterales: Asteraceae). To reveal its climate adaptation, the effect of temperature on life traits of Aenasius arizonensis, a parasitoid of Phenacoccus solenopsis was studied. The results showed that both the highest parasitism and emergence rates of A. arizonensis were observed at 31 °C. The parasitism and emergence rates of the parasitoid significantly increased with the increasing temperature from 19 °C to 31 °C, but dropped when the temperature exceeded 31 °C. Female ratio reached a higher value at 19, 22, 31, 34 or 37 °C. The minimum threshold temperatures for female and male parasitoids were 11.5 and 11.2 °C, respectively. The effective accumulative temperatures for the parasitoid to develop from eggs to both female and male adults were 222.2 day-degrees. Since the highest parasitism rate, the highest emergence rate and a higher female ratio were observed at 31 °C, we conclude that the optimum temperature for mass rearing of A. arizonensis is 31 °C in the insectary based on the results of our study.     

Two new species of egg parasitoids (hymenoptera: Encyrtidae) of wood-boring beetle pests from China

Oobius agrili sp.n. andAvetianella xystrocerae sp.n. (Hymenoptera: Encyrtidae) are described from China. Morphological characters of the new species are illustrated.O. agrili is an egg parasitoid of the emerald ash borerAgrilus planipennis Fairmaire (Coleoptera: Buprestidae) andA. xystrocerae is an egg parasitoid of the wood borerXystrocera globosa (Olivier) (Coleoptera: Cerambycidae). The two new species are potential biocontrol agents of economically important pest insects. The type specimens are deposited in the Institute of Zoology, Chinese Academy of Sciences, Beijing (IZCAS). http://www.phytoparasitica.org posting May 17, 2005.     

Introduction into Italy of Gryon pennsylvanicum (Ashmead), an egg parasitoid of the alien invasive bug Leptoglossus occidentalis Heidemann

Leptoglossus occidentalis (Heteroptera, Coreidae), a Nearctic species, was accidentally introduced into Northern Italy in the late 1990s, from where it has spread throughout Europe. The bug causes abortion of immature cones of Pinus pinea L., with economic impact on the pine‐nut industry. As part of a pest control research program, the egg parasitoid Gryon pennsylvanicum Ashmead (Hymenoptera, Platygastridae) was collected from British Columbia, Canada, and legally introduced to a quarantine climatic chamber in Florence, Italy. The egg parasitoid will be tested against native non‐target heteropterans, an environmental impact assessment will be conducted, and a mass rearing method will be developed if appropriate. The ultimate goal is to release G. pennsylvanicum into Italian P. pinea forests for classical biological control of L. occidentalis.     

两种蚜小蜂对烟粉虱MED隐种的田间笼罩控效评价

为明确烟粉虱Bemisia tabaci MED隐种优势寄生蜂海氏桨角蚜小蜂Eretmocerus hayati ZolnerowichRose与浅黄恩蚜小蜂Encarsia sophia GiraultDodd对其控制效果的影响,在棉田尼龙纱网笼罩中释放烟粉虱之后,再分别单独释放海氏桨角蚜小蜂、浅黄恩蚜小蜂以及二者以不同比例组合(1∶1、1∶3、3∶1)释放,定期调查统计2种蚜小蜂对烟粉虱的寄生量和烟粉虱的种群动态。结果表明,相对于不放蜂对照,自首次放蜂后40 d开始,所有放蜂处理均能显著降低烟粉虱若虫种群密度,每100 cm~2叶片上均少于1.00头,但各处理间的烟粉虱种群密度无显著差异;海氏桨角蚜小蜂和浅黄恩蚜小蜂以3∶1比例组合释放的处理中对烟粉虱的寄生量最高,每100 cm~2棉花叶片上能达到4.25头。表明在棉田中对烟粉虱进行生物防治时,以初级寄生蜂海氏桨角蚜小蜂与复寄生蜂浅黄恩蚜小蜂为3∶1的比例释放,可以到达较好的控制效果。     

Parasitoid community of the loreyi leaf wormMythimna (Acantholeucania) loreyi: Novel host-parasitoid associations and their efficiency in the eastern mediterranean region of Turkey

The loreyi leaf worm,Mythimna (Acantholeucania) loreyi Duponchel (Lepidoptera, Noctuidae), is a pest of gramineous crops and causes significant economic damage to maize. In field surveys on maize to determine the parasitoid community and its impact on the pest in the eastern Mediterranean region of Turkey, nine parasitoid species were found associated with immature stages ofM. loreyi: The hymenopteran (Braconidae and Ichneumonidae) parasitoidsCotesia (=Apanteles) ruficrus (Haliday),Chelonus oculator Panzer,Meteorus ictericus Nees,Hyposoter didymator (Thunberg),Sinophorus sp.; and the dipteran (Tachinidae) parasitoidsPseudogonia rufifrons Wiedeman,Exorista rossica Mesnil,Gonia picea (Robineau-Desvoidy) andLinnaemya vulpina (Fallen) — the last three recorded for the first time as parasitoids ofM. loreyi in Turkey.C. ruficrus was the dominant parasitoid species, being recovered from 38.5% of the larvae collected and was also the most prevalent species, existing in 91.0% of the fields in whichM. loreyi was found. Total parasitism levels achieved by braconid species was 41.4%, by ichneumonid parasitoids 4.8%, and by tachinid parasitoids 1.9%. In a separate field experiment, seasonal population fluctuations and natural efficiency ofC. ruficrus onM. loreyi were found to be 35.1% and 42.4%, respectively. Population levels ofC. ruficrus were closely related to fluctuations in the population ofM. loreyi, with parasitism ranging between 0 and 77.3% during the study. http://www.phytoparasitica.org posting Aug. 28, 2005.     

The tomato leafminer Tuta absoluta (Meyrick) in Tunisia: current status and management strategies

The tomato leafminer Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) was first identified in the region of Akkouda in October 2008 before it spread to all tomato‐producing areas in Tunisia. The introduction of this pest disturbed existing pest control programmes in greenhouses and open fields, forcing Tunisian growers to use more chemicals to reduce its impact on their crops. A national programme was adopted to control T. absoluta, including cultural practices, the use of pheromones, the installation of insect‐proof screens in greenhouses, and the use of organic insecticides including Bacillus thuringiensis Kurstaki (Bt) and plant extract‐based products. In addition, a few experiments in biological control, using the predatory Mirid Nesidiocoris tenuis Reuter (Heteroptera: Miridae) and the parasitoid wasp Trichogramma cacoeciae Marchal (Hymenoptera: Trichogrammatidae), were conducted in greenhouses and open‐field crops (producing tomatoes for fresh consumption as well as for processing). This paper describes the status of T. absoluta in Tunisia, including data collected from sex pheromone traps installed in six tomato‐producing areas (Takelssa, Korba, Teboulba, Bekalta, Sousse and Kairouan) between 2009 and 2011, and control strategies in greenhouses and open fields.     

Aphid aqueous-extract as a source of host searching kairomones for the aphidophagous predatorCoccinella septempunctata L. (Col., Coccinellidae)

AdultCoccinella septempunctata, a coccinellid predator of the bean aphidAphis fabae Scop., responded to aqueous extract containing kairomones of the prey. The crude aphidextract was topically dropped onto either clean leaves ofVicia faba or clean Petri-dishes. After application of aqueous-extract at different aphid densities, the predator showed variations in the attractivity and searching behaviour in comparisons with control. The variations are summarized as follows: (1) the aqueous-extract of aphids attract or directC. septempunctata adults to the treated vials at all aphid densities. The number of attracted or directed coccinellid adults was directly proportional with aphid concentrations; (2) the predatorC. septempunctata adult intensified its searching behaviour by increasing the total path length walked; (3) the number of turns exhibited is significantly higher as compared with those of control; and (4) the arrested time spent by coccinellid adults with treated plant is much more than that with clean plant at all aphid densities. The present results show that the aphid aqueous-extract contains the active ingredients (kairomone) which induce considerable changes in the searching pattern of the predator coccinellid adults.     

Aphid aqueous-extract as a source of host searching kairomones for the aphidophagous predatorCoccinella septempunctata L. (Col., Coccinellidae)

AdultCoccinella septempunctata, a coccinellid predator of the bean aphidAphis fabae Scop., responded to aqueous extract containing kairomones of the prey. The crude aphidextract was topically dropped onto either clean leaves ofVicia faba or clean Petri-dishes. After application of aqueous-extract at different aphid densities, the predator showed variations in the attractivity and searching behaviour in comparisons with control. The variations are summarized as follows: (1) the aqueous-extract of aphids attract or directC. septempunctata adults to the treated vials at all aphid densities. The number of attracted or directed coccinellid adults was directly proportional with aphid concentrations; (2) the predatorC. septempunctata adult intensified its searching behaviour by increasing the total path length walked; (3) the number of turns exhibited is significantly higher as compared with those of control; and (4) the arrested time spent by coccinellid adults with treated plant is much more than that with clean plant at all aphid densities. The present results show that the aphid aqueous-extract contains the active ingredients (kairomone) which induce considerable changes in the searching pattern of the predator coccinellid adults.     

Baeoentedon balios (Hymenoptera: Eulophidae): a parasitoid of ficus whitefly,Singhiella simplex (Singh) (Hemiptera: Aleyrodidae), new to the United States

A new host and distribution record is provided for the whitefly parasitoid Baeoentedon balios Wang, Huang, & Polaszek (Hymenoptera: Eulophidae). Specimens were reared from ficus whitefly, Singhiella simplex (Singh) (Hemiptera: Aleyrodidae), in St. Petersburg, FL, USA, representing the second confirmed host for B. balios, as well as the first record of Baeoentedon Girault from the Western Hemisphere.     

Biological control of the prickly pear cochineal Dactylopius opuntiae Cockerell (Hemiptera: Dactylopiidae)

The prickly pear cochineal Dactylopius opuntiae Cockerell (Hemiptera: Dactylopiidae) is a serious pest that causes severe damage to prickly pear cactus species of the genus Opuntia. Before its introduction to Morocco no control methods were available for use against this pest. The current paper presents the results of the use for the first time of the mealybug destroyer Cryptolaemus montrouzieri Mulsant (Coleoptera: Coccinellidae) and the biopesticide d ‐limonene to control D. opuntiae. The efficacy of the biopesticide was evaluated under field conditions. Corrected female mortality rates were >82% 6 days after application of d ‐limonene at 60 ppm. The greatest mortality rates 6 days after treatment were 98% and 99% at 120 and 150 ppm, respectively. The data analysis showed that there was no significant difference between the different doses 6 or 13 days after treatment. The LD₅₀ recorded was 33 ppm. In terms of biological control, the use of Cryptolaemus montrouzieri significantly reduced the cochineal scale population by 92% 77 days after release. This effect was maintained until 99 days after release of C. montrouzieri, and then the rate of population reduction declined to the level observed 64 days after release (66%). These results suggest that C. montrouzieri has the potential to suppress D. opuntiae populations to an acceptable level and reduce the damage caused by this cochineal.     

Presence of the <Emphasis Type="Italic">Eucalyptus</Emphasis> gall wasp <Emphasis Type="Italic">Ophelimus maskelli</Emphasis> and its parasitoid <Emphasis Type="Italic">Closterocerus chamaeleon</Emphasis> in Portugal: First record,geographic distribution and host preference

The Eucalyptus gall wasp Ophelimus maskelli (Hymenoptera: Eulophidae) and its parasitoid Closterocerus chamaeleon (Hymenoptera: Eulophidae) were observed for the first time in Portugal, in 2006 and 2007, respectively. Data on the distribution of O. maskelli in Portugal, differences in the susceptibility of two host species, Eucalyptus globulus and Eucalyptus camaldulensis, and parasitism by C. chamaeleon are given.     

Effect of the acylurea insect growth regulator teflubenzuron on the endo-larval stages of the hymenopteran parasitoids Cotesia plutellae and Diadegma semiclausum in a susceptible and an acylurea-resistant strain of Plutella xylostella

The toxicity of the acylurea, teflubenzuron, was assessed against larval stages of the hymenopteran parasitoids, Cotesia plutellae Kurdjumov and Diadegma semiclausum Hellén in a susceptible laboratory strain and a teflubenzuron-resistant field strain of the diamondback moth, Plutella xylostella L. In fourth-instar hosts (L4), when both parasitoid species were in their final larval instar, teflubenzuron significantly (P < 0.05) reduced emergence of adult D. semiclausum but had no significant (P > 0.05) effect on C. plutellae, although a small proportion of the latter were unable to reproduce. Treatment of L4 hosts with teflubenzuron ( > LD₅₀) had no significant (P > 0.05) effect on the fecundity of surviving females of D. semiclausum. Similar differential toxicity with teflubenzuron was observed in L2 hosts, when parasitoids were at the egg or early larval instar stage. There was no apparent increased effect of teflubenzuron on either species of parasitoid when highly resistant (c. 4000-fold) L2 hosts (field strain) were treated with concentrations of teflubenzuron two to three orders of magnitude greater than in equivalent experiments with the susceptible host strain. This suggests that host resistance to teflubenzuron confers some protection to both species of parasitoid. Uptake experiments with [¹⁴C]teflubenzuron showed that accumulation of radioactivity was much greater in D. semiclausum than in C. plutellae and this may account for the differential toxicity observed. The results are discussed in relation to the field status of these parasitoid species. The influence of insecticide resistance in the host on endo-larval parasitoids is also considered.     

Phenacoccus madeirensis Green, 1923 (Homoptera: Pseudococcidae) on Ocimum basilicum: a new geographical record for Greece

In Greece, Phenacoccus madeirensis Green, 1923 (Homoptera: Pseudococcidae) was identified for the first time in June 2010 in the regions of Thessaloniki, Xanthi and Kavala (Northern Greece). This mealybug was found on sweet basil (Ocimum basilicum). The highest population densities were observed on basil stems rather than on the leaves. Phenacoccus madeirensis is a serious pest of horticultural crops and this is its first record on O. basilicum in Greece.     

New Ichneumonidae (Hymenoptera) parasitoids of forest insect pests in Bulgaria

During the period 1989–1998 investigations were carried out on the parasitoids of some forest insect pests in Bulgaria. Twenty-one ichneumonid species are reported for the first time in Bulgaria as parasitoids of different coleopteran, lepidopteran, and hymenopteran hosts. From these, 6 parasitoids are new records for the parasitoid complexes of the hosts:Exochus decoratus Holmgr. onEudemis profundana (Den. & Schiff.) andGelechia turpella (Den. & Schiff.);Lissonota culiciformis Grav.—onParanthrene tabaniformis (Rott.);Lissonota unicincta Holmgr.—onG. turpella; Xorides gracilicornis (Grav.)—onXylotrechus sp.; andEriborus terebrator Aubert—onClostera anastomosis (L.). Most parasitoids developed as primary parasitoids in the hosts.Itoplectis alternans (Grav.) is a primary parasitoid ofNycteola asiatica (Krul.) and a hyperparasitoid ofE. terebrator: Acropimpla pictipes (Grav.) is secondary parasitoid onAnacampsis populella (Cl.). With the exception of two species ofOlesicampes genus, which destroyed over 50% ofStauronematus compressicornis (F.) andPristophora conjugata (Dahlm.) larvae, andE. terebrator which killed 15.4% ofC. anastomosis population, the rest of the parasitoids occurred in low densities, and did not play an important role in reducing the number of their hosts.