Changes in Numbers in the Parasitoid Complex Associated With the Diamond-Back Moth, Plutella Xylostella (L.) (Lepidoptera), in Victoria.

1979 ◽  
Vol 27 (6) ◽  
pp. 981 ◽  
Author(s):  
S Goodwin

Between 1972 and 1974, a study was made of parasitoids of P. xylostella naturally infesting four successive crops of cabbages which had not received any pesticide treatment. Parasitism fluctuated in each crop, averaging 49% during the study. The major parasitoid species were Diadegma cerophaga, Thyraeella collaris and Diadegma rapi, which averaged 93% of parasitism over the study period. Six minor primary parasitoid and one hyperparasite species were also recorded. Parasitoid activity was high during spring and summer, although extremely high temperatures during summer reduced numbers of both the host and its parasitoids. Drought conditions accentuated this. Parasitism in autumn depended upon the severity of this depletion and on the ensuing rate of recovery. The more important larval parasitoids were closely synchronized with host numbers, with a distinct lag during the winter period.

1984 ◽  
Vol 35 (3) ◽  
pp. 486-496 ◽  
Author(s):  
Louise E.M. Vet

Larval parasitoids of frugivorous Drosophila as well as related parasitoid species that attack Drosophila or Fannia species in mushrooms use water soluble larval kairomones in host location. Parasitoids of fungivorous flies allocate more searching time to patches containing a filtrate of mushrooms infested with host larvae compared to patches with a filtrate of uninfested mushrooms. Filtrates of mushrooms infested with a non-host species do not increase their searching time. Studies with parasitoids of frugivorous Drosophila showed that the ability to recognize kairomone is acquired through learning. Females without oviposition experience do not respond differently to patches with and without kairomone. Parasitoids that had learned the kairomone of one drosophilid host species also recognized the kairomone of another host species, which suggests that kairomones from Drosophilidae may be similar.


2014 ◽  
Vol 105 (1) ◽  
pp. 70-81 ◽  
Author(s):  
M.T. Martínez-Ferrer ◽  
J.M. Campos-Rivela ◽  
M.J. Verdú

AbstractSeasonal trends and the parasitoid complex of Chinese wax scale (Ceroplastes sinensis) was studied from July 2010 to February 2013. Six commercial citrus groves located in northeastern Spain were sampled fortnightly. Chinese wax scale completed a single annual generation. Egg oviposition started in May and continued until mid-July. Egg hatching began in mid-June, and in the first quarter of August, the maximum percentage of hatched eggs was reached. In the same groves, the parasitoid species of C. sinensis were determined together with their seasonal trends, relative abundance and occurrence on C. sinensis. Four hymenoptera were found parasitizing C. sinensis, mainly on third instars and females: Coccophagus ceroplastae (Aphelinidae), Metaphycus helvolus (Encyrtidae), Scutellista caerulea (Pteromalidae) and Aprostocetus ceroplastae (Eulophidae). The most abundant species was A. ceroplastae, corresponding to 54% of the parasitoids emerged. Coccophagus ceroplastae and M. helvolus represented 19%, whereas S. caerulea comprised 8% of the total. This study is the first published record of C. ceroplastae in Spain and the first record of M. helvolus on C. sinensis in Spain. Concerning the economical thresholds normally used, sampling plans developed for the management of C. sinensis in citrus groves should target population densities of around 12–20% of invaded twigs, equivalent to 0.2–0.5 females per twig. The sample size necessary to achieve the desired integrated pest management precision is 90–160 twigs per grove for the enumerative plan and about 160–245 twigs per grove for the binomial plan.


AGRICA ◽  
2020 ◽  
Vol 7 (2) ◽  
pp. 111-121
Author(s):  
Yustina Maria Silvia Wonga Puu

This study aims at exploring and identifying parasitoid Plutella xylostella pest on cabbage plants Brassica oleracea in Nduaria Village and finding out the most dominant parasitoid associated with Plutella xylostella pest. Observation variables used included identification of parasitoid species being parasitic in each stage of Plutella xylostella pest life found in the field, parasitoid species abundance and domination of parasitoid. The result of exploration in three sub-villages of NduariaVillage indicated that there were three species of the parasitoid, namely eggof parasitoid Trichogrammatoidae cojuangcoi, the larva of parasitoid Diadegma semiclausum and Cotesia Plutellae. The dominant parasitoid is Diadegma semiclausumwith the value of 0,11. The most abundance in parasitoid larva Diadegma semiclausum is 5,7%. Damage intensity caused by Plutella xylostella was categorized as medium damage intensity of>25-?50%, and this kept rising along with the age of larva and population as well as supporting environment condition due to Plutella xylostella resistance to the pesticide.


2015 ◽  
Vol 11 (2) ◽  
pp. 91-98 ◽  
Author(s):  
Levente Szőcs ◽  
George Melika ◽  
Csaba Thuróczy ◽  
György Csóka

Abstract Between 2011 and 2014, 1,154 mines of Phyllonorycter comparella (Duponchel) were collected at 12 locations in Hungary and were put into single-mine rearing containers. A total of 574 parasitoid specimens belonging to 29 parasitoid species (26 Chalcididae, 2 Encyrtidae and 1 Braconidae) emerged. Of these species, 13 have not yet been mentioned in either international or in Hungarian literature as a parasitoid of the P. comparella. The species assemblages of the parasitoid complexes varied greatly among the sample sites. The primary dominant species of the total samples was found to be Sympiesis sericeicornis (Nees), an abundant idiobiont solitary ectoparasitoid. Among the species reared, we have found specialist parasitoids such as Achrysocharoides scaposa (Erdős) and even species never recorded from Populus (Zagrammosoma variegatum (Masi)) according to the Universal Chalcidoidea Database.


2014 ◽  
Vol 97 (4) ◽  
pp. 1825-1828 ◽  
Author(s):  
Mark S. Hoddle ◽  
Christina D. Hoddle ◽  
Serguei V. Triapitsyn ◽  
Shouket Z. Khan ◽  
Muhammad J. Arif

Author(s):  
Eliza TEODORESCU ◽  
Neculai MUNTEANU ◽  
Costel VáŽNÄ‚TORU

The study presents the main characteristics of 10 local bean population (Phaseolus vulgaris L. convar. nanus). Considering the total opposite weather conditions in 2011 and 2012, growing bean allowed their evaluation in drought conditions. High temperatures and relative low air humidity determined a 76.61% yield diminuation at V7 in 2012 comparative to 2011. The 13.52% yield diminuation from an year to another registered at V1 corroborated with a 0.25 drought susceptibility index (DSI), recommands using this provenience in drought breeding works for this species.


2019 ◽  
pp. 133-138
Author(s):  
Vladimir Stamatidi ◽  
Vladimir Volynkin

Приведены результаты мониторинга водных потенциалов листьев (ВП) шести сортов винограда в условиях юго-западной Предгорно-приморской зоны Крыма. Измерения ВП проводили по Сколандеру при помощи камеры давления. Установлено, что значения ВП за все годы мониторинга в течение вегетации постепенно увеличивались по модулю вплоть до начала созревания. Наиболее резкое увеличение ВП по модулю наблюдалось в начале созревания ягод, с последующим небольшим снижением в сентябре. В июне каждого года предутренние значения водных потенциалов составляли порядка -0.1 МПа, в июле около - 0.3 МПа, в августе - 0.6 МПа, в сентябре -0.5 МПа. Аналогичные изменения имеют место и у послеполуденных значений водных потенциалов: в июне они составляют порядка -1.0 МПа, в июле - 1.3 МПа, в августе - 1.5 МПа, в сентябре -1.4 МПа. Установлена достоверная разница в послеполуденных значениях ВП между сортами Мускат белый - Цитронный Магарача, Мускат черный - Альминский. Сортовые различия были статистически достоверными в 75% случаев (три года из четырех лет исследований). Сделан вывод, что в условиях высоких температур и засухи растения сортов Цитронный Магарача и Альминский испытывают меньший водный стресс, чем Мускат белый и Мускат черный. Результаты исследований не выявили разницу между предутренними и послеполуденными водными потенциалами у сортов Рислинг рейнский - Рислинг Магарача.The article summarizes monitoring data on leaf water potential (WP) of six grapevine cultivars in the south-western piedmont-coastal zone of Crimea. WP has been measured in a pressure chamber using Scolander method. It was established that WP values over all the years of monitoring during the vegetation season gradually increased in absolute value until veraison. The most dramatic WP increase in absolute value was observed at veraison, followed by a slight decrease in September. In June of each year, the pre-dawn water potential values were around -0.1 MPa, in July around - 0.3 MPa, in August - 0.6 MPa, in September -0.5 MPa. The afternoon water potential values demonstrated similar changes: in June they were around -1.0 MPa, in July - 1.3 MPa, in August - 1.5 MPa, in September - 1.4 MPa. A significant difference was established in the afternoon WP values between varieties “Muscat Belyi’ - “Tsitronny Magaracha”, “Muscat Chernyi’ - ‘Alminsky’. Varietal differences were statistically significant in 75% of cases (three years out of four years of research). It was found that under high temperatures and drought conditions, plants of the cultivars ‘Tsitronny Magaracha’ and ‘Alminsky’ undergo less water stress as compared to ‘Muscat Belyi’ and ‘Muscat Chernyi’. The study results did not reveal any difference between the predawn and afternoon water potentials of ‘Riesling of the Rhine’ - ‘Riesling Magaracha’ cultivars.


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