• Title, Summary, Keyword: parasitoids

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Effect of Parasitoids' Exit and Predators' Ingress Holes on Silk Yield of the African Wild Silkmoth, Gonometa Postica Walker (Lepidoptera: Lasiocampidae)

  • Fening, Ken Okwae;Kioko, Esther Ndaisi;Raina, Suresh Kumar
    • International Journal of Industrial Entomology
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    • v.19 no.2
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    • pp.265-268
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    • 2009
  • Wild silkmoths can be utilised sustainably in the production of silk as an income for resource-poor rural communities. However, attack by parasitoids and predators affect the quality of cocoons and quantity of raw silk produced. A laboratory experiment was undertaken to quantify the effect of parasitoids' (dipteran and hymenopteran) and predators' (ants) exit and ingress holes, respectively, on silk production. The mean number of shells required to produce fifty grams of raw silk was highest with cocoons parasitised by a dipteran and lowest with unattacked cocoons (but with moths already emerged). Degumming loss was highest in parasitised and lowest in unttacked cocoons, but both were not different from cocoons predated by ants. Shell weight was highest in unattacked cocoons, followed by hymenopteran-parasitised and predated cocoons, with the dipteran parasitized ones being the least. Single cocoon weight was greater in hymenopteran-parasitised and predated cocoons than the dipteran-parasitised and unattacked cocoons. Shell ratio or raw silk, floss and yarn weights were higher in unattacked than parasitised and predated cocoons. The total loss in raw silk attributable to attack by parasitoids and predators ranged between 17.4~31.2%. The results offer baseline information for assessment of economic losses in wild silk farming due to parasitoids and predators in the field.

Natural parasitism of parasitoids on Phyllocnistis citrella (Lepidoptera: Gracillaridae) in Jeju citrus orchards in Korea (제주 감귤원에서 귤굴나방에 대한 포식 기생자 천적의 자연 기생율)

  • Hyun, Seung Young;Lim, Un Taek;Kim, Dong-Soon
    • Korean journal of applied entomology
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    • v.58 no.4
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    • pp.299-303
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    • 2019
  • This study was conducted to investigate the species of native parasitoids attacking Phyllocnistis citrella and their parasitism in citrus orchards in Jeju, Korea. During the survey period from 2013 to 2014, seven parasitoids belonging to Chalcidoidea were found: majority of the parasitoids were Sympiesis striatipes with 73% and Quadrastichus sp. with 22% in Eulophidae. The others were Neochrysocharis sp., Pnigalio sp., Holcopelte sp., Ageniaspis sp. (Encyrtidae) and Trichomalopsis sp. (Pteromalidae). Average parasitism rate reached 10.7% in orchards with spraying insecticide, and 32.2% in environmental-friendly managed orchards.

Primary Parasitoids and Hyperparasitoids of the Soybean Aphid, Aphis glyciner (Homoptera: Aphididae) (콩진딧물에 기생하는 진디벌과 이의 중기생벌에 관한 연구)

  • 장영덕;이재영;윤영남
    • Korean journal of applied entomology
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    • v.33 no.2
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    • pp.51-55
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    • 1994
  • Mummification, host selection and biological characteristics of primary parasitoids and hyperparasitoids in the soybean aphid, Aphis glycines, were studied. The soybean aphid mummies which were infected by primary parasitoids or hyherparasitoids were collected at Taejon area from May to September in 1987 Primary parasitoids and hyperparasitoids were emerged 27.1% and 50.3%, from 177 collected mummies. respectively Aphidius cingulatus, Ephedrus persicae and Ephedres plagiator could be effective primary parasitoids against the soybean aphid. Among the hyperparasitoids, Asaphes unlgaris and Ardilea conuexa might be dominant species to primary parasitoids of the soybean aphid. Charips brasicae was recorded for the first time in Korea E.plagiator was less parasitized than any other primary parasitoid by hyperparasitoids. E. plagiator might be higher than A. cingulatus in the ability of prarsitism. Life span of hyperparasitoid and primary parasitoid was estimated to be 3~29 days and 1~4 days, respectively.

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Studies on the Parasitoids of Chestnut Gall Wasp, Dryocosmus kuriphilus Yasumatsu (Hymenoptera : Cynipidae) in Korea (밤나무혹벌의 기생천적(寄生天敵)에 관(關)한 연구(硏究))

  • Kim, Jong Kuk
    • Journal of Korean Society of Forest Science
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    • v.87 no.3
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    • pp.475-482
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    • 1998
  • 9 species of parasitoids emerged from chestnut gall samples collected at Chunchon, Kangwon in June to July 1995 - 1997, and 8 species emerged from gall samples at the 5 investigation sites in December 1997. The primary parasitoids among them were Torymus sinensis, Torymus geranii, Sycophila variegata, Megastigmus nipponicus, Megastigmus maculipennis, Eurytoma brunniventris, Ormyrus flavitibialis, Ormyrus punctiger, Eupelmus urozonus, while the secondary parasitoids were Torymus geranii, Sycophila variegata, Eupelmus urozonus, Eupelmus sp., Eurytoma setigera, Ormyrus punctiger. Torymus sp.. Some of secondary parasitoids were facultative hyperparasitoids, parasitizing the gall wasp as well as primary parasitoids, Among these natural enemies, Torymus sinensis was dominant at all sites. At Chunchon, the rate of gall formation showed decreasing tendency as the function of generation and the parasitism rate of Torymus sinensis showed increasing tendency gradually. But the rate of parasitization of the secondary parasitoids(Sycophila variegata, Eupelmus urozonus, Torymus geranii, Ormyrus puntiger) ranged from 4.0% to 10.5%. The mortality was high during June to October which was immature stage of Torymus sinensis, and mainly caused by secondary parasitoids. Torymus sinensis emerged from April to May and the estimated dates of 50% emergence was 21st April. The estimated dates of 50% emergence for the other, Sycophila variegata, Eupelmus urozonus, Torymus geranii, and Ormyrus puntiger were 25th April, 30th April, 4th May, and 22nd May, respectively.

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Parasitism of Liriomyza trifolii (Diptera: Agromyzidae) by Hemiptarsenus zilahisebessi(Hymenoptera: Eulophidae) on Tomato (토마토에서 Hemiptarsenus zilahisebessi에 의한 아메리카잎굴파리 기생율)

  • 문형철;최정식;황창연
    • Korean journal of applied entomology
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    • v.41 no.1
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    • pp.61-65
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    • 2002
  • This study was conducted to investigate percentage of parasitism and control effect of Liriomyza trifolii by Hemiptarsenus zilahisebessi on tomato. Percentages of parasitism on L. trifolii larva by ectopatasitoids war e 26∼45% Among them the parasitism by H. zilahisebessi was highest as 47∼75% in tomato. The parasitoids preferred 1 st to 3rd instar of host larvae. In laboratory test, the parasitoids showed high parasitism on 3rd instar larvae of host by 89.8∼93.1% when the female parasitoids were introduced by the ratios of 1 : 10, 1 : 20, and 1 : 30. In field test, 3 or 5 female parasitoids were introduced per plant. In the case, the parasitism increased to 80% 4 weeks after introduction of the parasitoids. This increased parasitism was resulted from density reduction of the host larvae There were no significant differences in parasitism, density of alive host, and percentage of damaged leaf between inoculation density.

Biological Control of Pests of Non-Mulberry Silkworms and Its Host Plants in India

  • Singh, R.N.;Maheshwari, M.
    • International Journal of Industrial Entomology
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    • v.4 no.2
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    • pp.83-91
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    • 2002
  • The protection of silkworm and its host plants from various kinds of pests parasite and predator is a chronic problem in sericulture. Silkworms and its primary food plants are heavily damaged by large number of pest. The major pests of primary tasar food plants (Terminalia arjuna and Terminalia tomentosa) are the gall insect (Trioza fletcheri minor). Various species of aphids (Eutrichosiphum sp.) have been recorded to damage oak tasar food plants whereas muga silkworm host plants (Machilus bombycina and Litsaea polyantha) are generally attacked by stem bores (Zeuzera multistrigata). Castor (Ricinus communis) is one of the primary host plant of eri silkworm and extensive damage is caused by the castor white fly (Trialeurodes ricini). Insects pests are major enemies of silkworms. Parasites (Blepharipa zebina, Exorista bombycis, Apateles glomeratus), predators (Canthecona furcellata, Sycanus collaris, Hierodulla bipapilla), wasps (Vespa orientalix) and ants (Oecophylla smargdina) continues to cause damage to silk industry. It is estimated that the losses due to parasites and predators are to an extent of 15-20 percent and varies from crop to crop. The complexities in the behaviour and life cycle of pest population existing in semi ecosystem warrant a special attention for their effective management specially in changing scenario for our modern sericulture. Though use of synthetic insecticides has provided us with effective control of almost all major pests and predators, yet their undesirable side effects limit their continued use. Biological control is one of the most important method which can be used to control the pests, parasites and predators population in sericulture. Various potential parasitoids, which can be utilized as an agent of biological control in sericulture have been screened. The natural enemies of the uzi fly (E. bombycis and B. zebina ) are already present in the nature. Nesolynx thymus, Trichria sp., Splangia endius, Dirhinus sp., Trichopria sp., Trichomalopsis apanteloctena and Pediobius sp. are the major parasitoids effective against uzi fly pupa. The scelionid Psix striaticeps and Trissolcus sp. are the Potential egg Parasitoids against stink bug (Canthecona furcellata). Various other native natural potential parasitoids have been screened and suitable strategies have been developed to check the population of pest insect in sericulture.

Studies on the Natural Enemies of Protopulvinaria mangiferae(Green) (Homoptera : Coccidae) (담팔수깍지벌레의 천적에 관한 연구)

  • Kim, Jong-Kuk;Morimoto, Katsura
    • Journal of Forest and Environmental Science
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    • v.14 no.1
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    • pp.128-137
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    • 1998
  • In Fukuoka, the natural enemies of Protopulvinaria mangiferae were confirmed as six primary parasitoids, three hyperparasitoids, and six predators. Among the primary parasitoids, Aneristus ceroplastae, Microterys flavus, and Coccophagus yoshidae were relatively abundant in Fukuoka. Aneristus ceroplastae and Coccophagus yoshidae were solitary endoparasitoid, whereas Microterys flavus was a gregarious endoparasitoid. Tetrastichus sp. was a hyperparasitoid and solitarily ectoparasitic to the pupae of Aneristus ceroplastae and Microterys flavus. The seasonal fluctuation of parasitisim and adult emergence of the important parasitoids was investigated in Fukuoka. Among the predatorys, Rhyzobius forestieri and Chilocorus kuwanae were relatively abundant, and seasonal fluctuation of adult emergence and consumption of the host were studied. As the first record from Japan, Rhyzobius forestieri was collected on leaves of Elaeocarpus sylvestris with heavy infestation of Protopulvinaria mangiferae.

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Interactions between Pine Needle Gall Midge, Thecodiplosis japonensis (Diptera: Cecidomyiidae), and its Parasitoids in Newly Invaded Areas (솔잎혹파리 확산지역에서 솔잎혹파리와 기생봉의 상호작용)

  • 박영석;정여진;전태수;이범영;이준호
    • Korean journal of applied entomology
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    • v.40 no.4
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    • pp.301-307
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    • 2001
  • The pine needle gall midge (PNGM), Thecodiplosis japonensis Uchida et Inouye, is a serious pest in pine forests in Korea. Since the first report of PNGM infestation in Korea in 1929, the infestation area has been expanded gradually. In 1975 the distribution of PNGM and its parasitoids were surveyed throughout several infested areas in Korea. Annual survey has been made for the rates of gall formation by PNGM and parasitism by its parasitoids at the monitoring sites including newly infested area in 1975 since 1980. These data were used to examine the relationship between PNGM and its parasitoids for newly invaded areas. The gall forming rate of PNGM and the parasitism by the parasitoid were 34.8 and 1.9% in 1975, respectively, while the gall forming rate and the parasitism were 20.7 and 8.9% in 1985, respectively. The relationships of densities between PNGM and its parsitoid were weak in the early stage of dispersion, but the density of parasitoid was with an asymptotic increase along with PNGMs density increase during the observation period for 10 years.

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Parasitoid Complex of the Gypsy Moth (Lymantria dispar) in the Increase-phase Populations in Korea

  • Lee, Jang-Hoon;Pemberton, Robert W.
    • Journal of Ecology and Environment
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    • v.32 no.2
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    • pp.75-81
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    • 2009
  • The species composition of the parasitoid complex and the degree of parasitism by each species were analyzed for gypsy moth (Lymantria dispar) populations in the increasing phase. Total of 7,826 mid-late instar larvae and pupae were collected and reared from two collection sites in Gangwon Province, Korea. Two tachinid flies (Blepharipa schineri and Parasetigena silvestris), and the ichneumonid wasp (Coccygomimus disparis) were the most abundant parasitoids, in the order of decreasing importance. Other parasitoids occurring included Coteisa melanoscelus, Cotesia scheaferi, Glyptapanteles liparidis, Brachymeria lasus, and Exorista spp. The low incidence of the NPVirus is hypothesized to be an important factor in determining degree of parasitism rate by P. silvestris and B. schineri, and their relative dominance in the parasitoid complex.