Population dynamics of Thecodiplosis japonensis (Diptera: Cecidomyiidae) under influence of parasitism by Inostemma matsutama and Inostemma seoulis (Hymenoptera: Platygastridae)

Jeon, Mun-Jang,Choi, Won-Il,Choi, Kwang-Sik,Chung, Yeong-Jin,Shin, Sang-Chul Korean Society of Applied Entomology 2006 Journal of Asia-Pacific Entomology Vol.9 No.3

To understand influence of two species of parasitoids on host population dynamics, adult population dynamics of pine needle gall midge (PNGM), Thecodiplosis japonensis and two species of parasitoids, Inostemma matsutama and Inostemma seoulis were observed using emergence traps from 1986 to 2005. Density of PNGM decreased after outbreaks in 1986 and 1987 and showed density-dependent regulation. Relationships between density of PNGM and its parasitoids were linear except the period of outbreak regardless of parasitoids species. Relationships between host density and parasitism of I. matsutama and I. seoulis were density-independent and inverse density-dependent, respectively. I. seoulis was the dominant parasitoid against PNGM. Interspecific competition between two parasitoids was not strong and temporal niche segregation between two parasitoids was a possible mechanism for coexistence of two parasitoids. The parasitoid complex responded to changes in host density more sensitively than single parasitoid species. These results suggested that two parasitoid can stabilize PNGM population density without strong negative effects on each species of parasitoids.

Impact of maternal crowd on the reproductive performance of an ecto-pupal parasitoid Nesolynx thymus (Hymenoptera: Eulophidae)

Siddaiah, Aruna Ambadahalli,Danagoudra, Manjunath Korean Society of Sericultural Science 2014 International Journal of Industrial Entomology Vol.29 No.1

Nesolynx thymus Girault (Hymenoptera: Eulophidae) is one among 20 hymenopteran parasitoids reported to attack the uzi fly, Exorista bombycis, which in turn infests the silkworm, Bombyx mori accounting a cocoon yield loss of 10-20%. A host of factors viz., age and size of host, age and size of parasitoid, availability of host, temperature and quality of host are reported to influence the reproductive efficiency of the parasitoids. In the present study an attempt was made to record the influence of foraging parasitoid density on their reproductive performance. Three day-old uzi pupae were offered to varying numbers (1 - 10) of 2 day old Nesolynx thymus adults for parasitization. The progeny production per pupa (84.44 - 132.77) increased significantly with increase in the number of foraging parasitoid adults (1 - 10) however, progeny production per female decreased. The sex ratio (M : F) (1:25.49 - 1:1.53) decreased significantly with increase in foraging parasitoid adults. The morphometric parameters except female abdomen width of first generation parasitoid showed significant negative correlation with number of foraging adults. However, correlation between the parasitoid size in first generation and their reproductive performance was nonsignificant.

Impact of maternal crowd on the reproductive performance of an ecto-pupal parasitoid Nesolynx thymus (Hymenoptera: Eulophidae)

( Aruna Ambadahalli Siddaiah ),( Manjunath Danagoudra ) 한국잠사학회 2014 International Journal of Industrial Entomology Vol.29 No.1

Nesolynx thymus Girault (Hymenoptera: Eulophidae) is one among 20 hymenopteran parasitoids reported to attack the uzi fly, Exorista bombycis, which in turn infests the silkworm, Bombyx mori accounting a cocoon yield loss of 10-20%. A host of factors viz., age and size of host, age and size of parasitoid, availability of host, temperature and quality of host are reported to influence the reproductive efficiency of the parasitoids. In the present study an attempt was made to record the influence of foraging parasitoid density on their reproductive performance. Three day-old uzi pupae were offered to varying numbers (1 - 10) of 2 day old Nesolynx thymus adults for parasitization. The progeny production per pupa (84.44 - 132.77) increased significantly with increase in the number of foraging parasitoid adults (1 - 10) however, progeny production per female decreased. The sex ratio (M : F) (1:25.49 - 1:1.53) decreased significantly with increase in foraging parasitoid adults. The morphometric parameters except female abdomen width of first generation parasitoid showed significant negative correlation with number of foraging adults. However, correlation between the parasitoid size in first generation and their reproductive performance was nonsignificant.

Wolbachia infection in six species of gall wasps and their parasitoids

Zhao Gao-Zhi,Zhu Teng-Ran,Zeng Yang,Zhu Dao-Hong 한국응용곤충학회 2021 Journal of Asia-Pacific Entomology Vol.24 No.1

Wolbachia are endosymbiotic bacteria that are widely present in nematodes and arthropods and sometimes have a significant impact on the evolution, ecology, and biology of their hosts. The co-occurrence of Wolbachia within both Cynipid gall wasps and their parasitoids has rarely been studied. In this study, we report the occurrence of six species of gall wasps and 10 species of their parasitoids in central China. Wolbachia detection using the wsp gene showed that Wolbachia infected two species of gall wasps as well as their parasitoids, indicating that horizontal transmission of Wolbachia occurs between gall wasps and their parasitoids. Given that parasitoids will kill their hosts, Wolbachia may be horizontally transferred from gall wasps to their parasitoids. Using multilocus sequence typing (MLST) analysis, five new strains of Wolbachia were identified, all of which belonged to su pergroup A. The strains of Wolbachia that infected gall wasps were not the same as those that infected their parasitoids. This result indicated that Wolbachia may evolve independently in parasitoids after they have been transferred from the host gall wasps.

Bionomics of Diadromus sp. (Hymenoptera: Ichneumonidae), an internal and solitary pupal parasitoid, and the characteristics of its parasitism on diamondback moth, Plutella xylostella (L.)

Min Kwon,Ju-Il Kim,June-Yeol Choi,Seung-Hwan Lee 한국응용곤충학회 2010 한국응용곤충학회 학술대회논문집 Vol.2010 No.05

Diamondback moth (DBM, Plutella xylostella L.), the most destructive pest of cruciferous crops, is well-known as typical subtropical insect pest. A number of biological agents such as diseases, parasites and predators can affect populations of DBM in the fields negatively. In previous reports, we suggested Cotesia glomerata, Diadegma semiclusum, and Microplitis plutellae as promising natural enemies to DBM control at highland areas, but these species are larval parasitoids. In 2004~2009, we searched highland fields cultivating various cruciferous crops for PUPAL parasitoids which can supplement the unsatisfactory parasitism in the augmentative release of larval parasitoids. We obtained adults of hymenopteran parasitoid from DBM pupae in early July at Hoengseong region (asl 540 m), and then identified as Diadromus sp., although being a critical species so far. This parasitoid showed high rate of parasitism, about 13.2%, in mid October at the same region. Development period from oviposition to emergence of Diadromus sp. ranged from 14 to 18 days under 23℃ condition. Adult longevity, > three weeks, was longer when it was provided with 10% sugar solution as food than with water only or without food. Male adults mated as soon as emerging from parasitized DBM pupae, and laid eggs into DBM pupae for a week. Parasitism by Diadromus sp. was highest on 7th day after emergence. In contrast, lethality of DBM pupae which were not parasitized by wasps showed 60% on average for seven days. Parasitized DBM pupae could be stored at 10℃ for two weeks. The simultaneous augmentative release of larval parasitoids and pupal parasitoids can be an important component to integrated DBM management program in the future.

Biological Control Strategy of Uzi Fly in Sericulture

Singh, R.N.,Saratchandra, Beera Korean Society of Sericultural Science 2003 International Journal of Industrial Entomology Vol.6 No.2

Uzi fly (Exorista bombycis Louis) is one of the major larval endo-parasitoid of silkworm (Bombyx mori). It causes extensive damage to sericulture industry. The application of synthetic organic pesticides has tremendous impact on minimizing pest population but their overuse and frequent misuse and high sensitivity towards the silkworms, has forced the entomologists to search for alternatives to chemical control, which is safe to silkworm, environment and farm workers. Biological control continues to offer exciting possibilities for the control of fly pest population. It is environmentally safe alternative to chemical control and offering a long-term protection. Several potential hymenopteran parasitoids have been screened. Among successful natural enemies, Nesolynx thymus, Trichomalopsis apanteloctena, Trichopria sp., Brachymeria lasus, Pediobius sp., Spalangia sp., Spilomicrus karnatakensis and Dhirhinus sp. are important. It is essential to predict accurately the efficacy of these natural enemies in a new habitat prior to its introduction. The important desirable attributes of these potential parasitoids viz., host searching capacity, specificity, power of increase and fitness and adaptability of the parasitoid in new environment has been recorded. Results of the host parasitoid interaction indicate that the aging of the host function as a factor that influence the host finding efficiency of the parasitoid. It is highly scored with 15-20 hrs old pupa of the host. However, aging of the parasitoid does not significantly affect it. The sex ratio is female biased which is advantageous from biological control point of view, Biological suppression methods involving conservation and utilization of natural enemies have been discussed in detail.

Efficacy of the parasitoid, Diaeretiella rapae (McIntosh) (Hymenoptera: Braconidae) against Myzus persicae (Sulzer) (Hemiptera: Aphididae) infesting rapeseed-mustard

Soni Saurbh,Kumar Surjeet 한국응용곤충학회 2021 Journal of Asia-Pacific Entomology Vol.24 No.3

Efficacy of Diaeretiella rapae (McIntosh) (Hymenoptera: Braconidae) was determined by studying its biological and behavioural attributes on the aphid, Myzus persicae (Sulzer) (Hemiptera: Aphididae). Total developmental duration of the parasitoid was longer in younger instars compared to that in older instars of aphid. Host age negatively affected the oviposition period and fecundity of the ovipositing parasitoid. Survival of the immatures was higher in older than the younger instars of the aphid. Sex ratio for the parasitoid was female-biased. Longevity of female parasitoid was higher while parasitizing aphid nymphs of younger age groups (1–2 days old) compared to that of older age groups (4–5 days old). Parasitoid showed a higher preference towards second instar of M. persicae both in choice and no-choice tests. Results on mutual interference revealed that per capita searching efficiency decreased from 0.91 to 0.07 as parasitoid densities increased from 1 to 8. Logistic regression exhibited a type II functional response for D. rapae. The estimated values of search-efficiency (a) and handling time (T h ) were 0.038 h − 1 and 1.59 h, respectively. The maximum parasitization rate was 15.08. This investi gation suggests that D. rapae could be an effective candidate for augmentative biological control of M. persicae which infests several plant species of economic importance.

The Larval Parasitoid, Bracon hebetor, Could Have Positive Influence on its Host, Indianmeal Moth, Population

Jaehyub Shin,Youngwoo Nam,Yong Shik Chun,Mun Il Ryoo 한국응용곤충학회 2010 한국응용곤충학회 학술대회논문집 Vol.2010 No.10

The larval parasitoid, Bracon hebetor, attacks third or older larvae of indianmeal moth (Plodia interpunctella), which results in laying eggs or simply paralyzing the larvae. We studied the influence of the parasitoid’s attack on the larval development of indianmeal moth. The third larval instars of the same age were collected from the experimental colonies and each larva introduced in an acrylic cube (2 x 2 x 2 cm) treated with: 1) empty, 2) three rice grains, 3) three rice grains and a female parasitoid without ovipositor (by removing) and 4) three rice grains and a paralyzed larva. The larval activity in the experimental cube was photographed every five minutes until the larva died or pupated. Only the larvae in the cube with paralyzed larvae could pupate and emerge. The other larvae in the three treatments died before pupating, although the survival time was significantly different in relation to the treatment (F=5.27; df=2,14; P=0.019); the larvae in the empty cube had a shorter survival time than those in the rest of treatments. The results indicated that the paralyzed larvae could be fed by the health larvae and contribute to prevent population crush in the situation of food shortage with the presence of the parasitoids. The host parasitoid interaction between indianmeal moth and Bracon hebetor might not always be negative to the indianmeal moth population.

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

( Ken Okwae Fening ),( Esther Ndaisi Kioko ),( Suresh Kumar Raina ) 한국잠사학회 2009 International Journal of Industrial Entomology Vol.19 No.2

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.

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 Korean Society of Sericultural Science 2009 International Journal of Industrial Entomology Vol.19 No.2

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.