Establishment of Citrostichus phyllocnistoides (Hymenoptera: Eulophidae) as a biological control agent for the citrus leafminer Phyllocnistis citrella (Lepidoptera: … (original) (raw)
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A survey of parasitoids of the Citrus leaf miner Phyllocnistis citrella Stainton (Lepidoptera: Gracillariidae), was carried out in more than 100 citrus orchards located within 60 km of Valencia. Orchards were sampled all along the citrus growing season from 1995 to 2001. Ten different species were found. The two main species, Pnigalio sp and Cirrospilus brevis Zhu, LaSalle and Huang represented more than 90% of the adults identified. The parasitoids originated from native leafminers living mostly on woody plants. The preferred stages for parasitism were third (27-38% of parasitism rate) and fourth instars (30-53%). Second instar and pupae were less parasitized (10 and 5%, respectively). A program of introduction of exotic parasitoids was carried out between 1996 and 1999. Through a total of 37 shipments coming from nine countries, six species were released in the field. Ageniaspis citricola (Logvinosvskaya) established temporarily but was unable to overwinter. Between 1999 and 2001 Citrostichus phyllocnistoides (Narayanan) expanded to all citrus orchards grown in continental Spain and the Balear Islands, becoming the most abundant parasitoid and displacing native and other introduced parasitoids. Parasitism on second instars increased to 65% and foliar surface damage by the citrus leafminer decreased by 56%.
Biological Control, 2010
The citrus leafminer, Phyllocnistis citrella, is a pest native to Southeast Asia which threatened the citrus industry in the Mediterranean region upon its introduction in 1993. Immediately afterward, a classical biological control program was implemented in Spain. The exotic parasitoid Citrostichus phyllocnistoides was the only introduced parasitoid to become established. In 2006, data on both the incidence of P. citrella and the impact of its natural enemies were collected following the same protocols used in 1997-1999 when C. phyllocnistoides was not yet present. C. phyllocnistoides constituted 99.4% of the parasitoids collected in 2006 corresponding to a decrease in the incidence of P. citrella from 3.2-5.1 to 1.8-2.4 mines per leaf in 1997-1999 and 2006, respectively. Mortality caused by natural enemies on P. citrella in 2006 was 93.3% (18.0% parasitism, 40.8% feeding punctures and 34.5% predation). C. phyllocnistoides, which preferentially parasitizes P. citrella second instar larvae, has displaced most of the indigenous parasitoids that moved onto P. citrella mainly parasitizing third instar larvae, upon its introduction. Because C. phyllocnistoides is an idiobiont parasitoid and preferentially parasitizes P. citrella second instars, this stage has become dominant in the orchards. The shift in the relative abundance of P. citrella larvae has prompted generalist predators to prey mostly on second instars and has contributed to the displacement of the native non-specific parasitoids, which principally utilize third instars, from the system. Both indigenous predators and the introduced parasitoid are key players in the natural regulation of P. citrella.
Biological Control, 2004
The parasitoid assemblage associated with the citrus leafminer Phyllocnistis citrella Stainton (Lepidoptera: Gracillariidae) was studied in citrus orchards in eastern Spain over a 7-yr period (1995Ð2001) after the leafminerÕs introduction in 1994. In total, 11,587 adult native parasitoids were collected. To evaluate parasitism, 93,846 live immature stages of the citrus leafminer were observed, of which 21,460 (22.9%) were found to be parasitized. The parasitoid complex recruited around P. citrella was typical for invader hosts: lower species richness, generalized habits, idiobiont strategy, and low to moderate rates of parasitism. Two of the 10 species reared from the citrus leafminer, Pnigalio sp. and Cirrospilus brevis Zhu, LaSalle and Huang, accounted for Ͼ90% of the parasitoids. Native parasitoids moved onto the invading host rapidly, except for C. brevis, which required 3 yr to become common and widespread. In other leafminer species from plants in the vicinity of citrus orchards, the proportion of P. citrella parasitoids was higher in woody (69.7%) than in herbaceous plants (22.2%). The high population levels reached by the new pest, associated with a negative density dependence response of the parasitoids at these high population levels, suggest that the native parasitoid assemblage exerted only a limited role in regulating the population of the new host.
Phyllocnistis citrella and its parasitoids in three citrus species in Greece
Phytoparasitica, 2013
The relative abundance as well as the percentage of parasitism of Phyllocnistis citrella Stainton (Lepidoptera: Gracillariidae) and its parasitoids were studied in a citrus orchard with orange, mandarin and lemon trees in Greece. Infestation of P. citrella on each citrus host, as expressed by the number of mines per leaf, was significantly higher on lemon than on mandarin. The P. citrella parasitoid complex included the native species Neochrysocharis formosa and Pnigalio pectinicornis, as well as the introduced Citrostichus phyllocnistoides. The most abundant of those was N. formosa in all of the citrus species. The average percentage of parasitism was 13.1%, 13.8% and 11.7% on orange, mandarin and lemon, respectively. No significant differences in parasitism rate by each of the three parasitoid species separately were recorded among the three citrus species.
Environmental Entomology, 2005
The parasitoid assemblage associated with the citrus leafminer Phyllocnistis citrella Stainton (Lepidoptera: Gracillariidae) was studied in citrus orchards in eastern Spain over a 7-yr period (1995Ð2001) after the leafminerÕs introduction in 1994. In total, 11,587 adult native parasitoids were collected. To evaluate parasitism, 93,846 live immature stages of the citrus leafminer were observed, of which 21,460 (22.9%) were found to be parasitized. The parasitoid complex recruited around P. citrella was typical for invader hosts: lower species richness, generalized habits, idiobiont strategy, and low to moderate rates of parasitism. Two of the 10 species reared from the citrus leafminer, Pnigalio sp. and Cirrospilus brevis Zhu, LaSalle and Huang, accounted for Ͼ90% of the parasitoids. Native parasitoids moved onto the invading host rapidly, except for C. brevis, which required 3 yr to become common and widespread. In other leafminer species from plants in the vicinity of citrus orchards, the proportion of P. citrella parasitoids was higher in woody (69.7%) than in herbaceous plants (22.2%). The high population levels reached by the new pest, associated with a negative density dependence response of the parasitoids at these high population levels, suggest that the native parasitoid assemblage exerted only a limited role in regulating the population of the new host.
Environmental Entomology, 2005
The parasitoid assemblage associated with the citrus leafminer Phyllocnistis citrella Stainton (Lepidoptera: Gracillariidae) was studied in citrus orchards in eastern Spain over a 7-yr period (1995Ð2001) after the leafminerÕs introduction in 1994. In total, 11,587 adult native parasitoids were collected. To evaluate parasitism, 93,846 live immature stages of the citrus leafminer were observed, of which 21,460 (22.9%) were found to be parasitized. The parasitoid complex recruited around P. citrella was typical for invader hosts: lower species richness, generalized habits, idiobiont strategy, and low to moderate rates of parasitism. Two of the 10 species reared from the citrus leafminer, Pnigalio sp. and Cirrospilus brevis Zhu, LaSalle and Huang, accounted for Ͼ90% of the parasitoids. Native parasitoids moved onto the invading host rapidly, except for C. brevis, which required 3 yr to become common and widespread. In other leafminer species from plants in the vicinity of citrus orchards, the proportion of P. citrella parasitoids was higher in woody (69.7%) than in herbaceous plants (22.2%). The high population levels reached by the new pest, associated with a negative density dependence response of the parasitoids at these high population levels, suggest that the native parasitoid assemblage exerted only a limited role in regulating the population of the new host.
2006
A survey of parasitoids of the citrus leafminer, Phyllocnistis citrella Stainton (Lepidoptera: Gracillariidae), was carried out in the citrus orchards in the east Mediterranean region of Turkey during 1995-2001. Their relative abundance and rate of parasitism were also determined. Ten species of parasitoids were identified: Cirrospilus sp. nr. lyncus (Walker), C. pictus (Nees), C. variegatus (Masi), C. vittatus Walker, C. ingenuus Gahan, Ratzeburgiola incompleta (Boucek), Diglyphus isaea (Walker), Semielacher petiolatus (Girault), Citrostichus phyllocnistoides (Narayanan), Neochrysocharis formosa (Westwood) (Hymenoptera: Eulophidae). Neochrysocharis sp., Chrysocharis sp., Barycapus sp., Pnigalio sp. (Hymenoptera: Eulophidae) and the Pteromalus sp. (Hym.: Pteromalidae) were also identified. Among these species, R. incompleta in 1995-1996 and C. sp. nr. lyncus in 1997 were the most dominant of all encountered species. In 1998, a new parasitoid species, C. phyllocnistoides, expanded to...
Brazilian Journal of Biology, 2008
Many species of microhymenopterous parasitoids have been registered on Phyllocnistis citrella, the citrus leafminer. The present study aimed to identify the spatial distribution pattern of the native and introduced parasitoids of P. citrella in two citrus orchards in Montenegro, RS. The new shoots from 24 randomly selected trees in each orchard were inspected at the bottom (0-1.5 m) and top (1.5-2.5 m) stratum and had their position relative to the quadrants (North, South, East and West) registered at every 15 days from July/2002 to June/2003. The leaves with pupae were collected and kept isolated until the emergence of parasitoids or of the leaf miner; so, the sampling was biased towards parasitoids that emerge in the host pupal phase. The horizontal spatial distribution was evaluated testing the fitness of data to the Poisson and negative binomial distributions. In Montenegrina, there was no significant difference in the number of parasitoids and in the mean number of pupae found in the top and bottom strata (χ 2 = 0.66; df = 1; P > 0.05) (χ 2 = 0.27; df =1; P > 0.05), respectively. In relation to the quadrants, the highest average numbers of the leafminer pupae and of parasitoids were registered at the East quadrant (χ 2 = 11.81; df = 3; P < 0.05), (χ 2 = 10.36; df = 3; P < 0.05). In the Murcott orchard, a higher number of parasitoids was found at the top stratum (63.5%) (χ 2 = 7.24; df =1 P < 0.05), the same occurring with the average number of P. citrella pupae (62.9%) (χ 2 = 6.66; df = 1; P < 0.05). The highest number of parasitoids and of miners was registered at the North quadrant (χ 2 = 19. 29; df = 3; P < 0.05), (χ 2 = 4.39; df = 3; P < 0.05). In both orchards, there was no difference between the numbers of shoots either relative to the strata as well as to the quadrants. As the number of shoots did not varied much relative to the quadrants, it is possible that the higher number of miners and parasitoids in the East and West quadrants would be influenced by the higher solar exposure of these quadrants. The data of the horizontal spatial distribution of the parasitism fit to the negative binomial distribution in all sampling occasions, indicating an aggregated pattern.