Life Table of Tamarixia radiata (Hymenoptera: Eulophidae) on Diaphorina citri (Hemiptera: Psyllidae) at Different Temperatures Author(s): Mariuxi Lorena Gómez-Torres, Dori Edson Nava, and José Roberto Postali Parra Source: Journal of Economic Entomology, 105(2):338-343. 2012. Published By: Entomological Society of America DOI: http://dx.doi.org/10.1603/EC11280 URL: http://www.bioone.org/doi/full/10.1603/EC11280 BioOne (www.bioone.org) is a nonprofit, online aggregation of core research in the biological, ecological, and environmental sciences. BioOne provides a sustainable online platform for over 170 journals and books published by nonprofit societies, associations, museums, institutions, and presses. Your use of this PDF, the BioOne Web site, and all posted and associated content indicates your acceptance of BioOne’s Terms of Use, available at www.bioone.org/page/terms_of_use. Usage of BioOne content is strictly limited to personal, educational, and non-commercial use. Commercial inquiries or rights and permissions requests should be directed to the individual publisher as copyright holder. BioOne sees sustainable scholarly publishing as an inherently collaborative enterprise connecting authors, nonprofit publishers, academic institutions, research libraries, and research funders in the common goal of maximizing access to critical research. BIOLOGICAL AND MICROBIAL CONTROL Life Table of Tamarixia radiata (Hymenoptera: Eulophidae) on Diaphorina citri (Hemiptera: Psyllidae) at Different Temperatures MARIUXI LORENA GO´ MEZ-TORRES,1 DORI EDSON NAVA,2 1 AND JOSE´ ROBERTO POSTALI PARRA J. Econ. Entomol. 105(2): 338Ð343 (2012); DOI: http://dx.doi.org/10.1603/EC11280 ABSTRACT Tamarixia radiata (Waterston, 1922) is the main parasitoid of Diaphorina citri (Ku- wayama, 1907), and has been used in classical biological control programs in several countries. The current study investigated the biology and determined the fertility life table of T. radiata in different temperatures, to obtain information to support the establishment of a biological control program for D. citri in Brazil. Fifth-instar nymphs of D. citri were offered to females of T. radiata for parasitism, for 24 h. Then, the parasitoid was removed and the nymphs were placed in incubators at 15, 20, 25, 30, or 35 Ϯ 1ЊC, 70 Ϯ 10% RH, and a 14-h photophase. The percentages of parasitism and emergence, the sex ratio, and the preimaginal period of T. radiata were determined. The fertility life table was developed from the biological data. The highest parasitism rate (77.24%) was obtained at a temper- ature of 26.3ЊC, and the lowest parasitism rates occurred at 15 and 35ЊC (23.1 and 40.2%, respectively). The highest percentages of emergence of the parasitoid occurred at 25, 30, and 35ЊC (86.7, 88.3, and 78.8%, respectively), with the calculated peak at 30.8ЊC (89.90%). The duration of the preimaginal developmental period for both females and males of T. radiata was inversely proportional to tem- perature in the thermal range of 15Ð35ЊC. The development of T. radiata occurred at all temperatures studied, and the highest viability of the preimaginal period occurred at 25ЊC. The highest values of net reproductive rate and Þnite growth ratio (␭) were observed at 25ЊC, so that in each generation the population of T. radiata increased 126.79 times, higher than the values obtained at the other temperatures. KEY WORDS citrus, parasitism, life cycle, net reproductive rate Diaphorina citri (Kuwayama, 1907) (Hemiptera: Psyl- which had been kept below the economic threshold lidae) has been associated with citrus in Brazil since level through biological control, in accordance with the 1940s (Costa Lima 1942) and now occurs in most the principles of integrated pest management (IPM) of the country. In Brazil until 2004, insecticide control (Yamamoto and Parra 2005). The wide geographical of D. citri was carried out sporadically, that is, only distribution of D. citrus in Brazil and its potential as a when population outbreaks occurred. The only inju- vector of HLB may negatively affect citrus crops, as ries caused by the pest had been leaf curling and shoot has been reported in other countries (Fundecitrus deformation, which prevented normal growth. These 2004, Parra et al. 2010). injuries were caused by a toxin released by D. citri as Alternatives for management of D. citri are cur- it feeds on sap (Fundecitrus 2004). In 2004, Huang- rently being studied, and include biological control longbing (HLB), also known as citrus greening patho- with Tamarixia radiata (Waterston, 1922) (Hymenop- gen, was Þrst detected in Brazil, speciÞcally in citrus tera: Eulophidae). T. radiata is an idiobiont ectopara- groves in the state of Sa˜o Paulo, and D. citri was sitoid that has been used in classical biological control identiÞed as the vector of the disease (Teixeira et al. programs, signiÞcantly reducing D. citri populations in 2005). several parts of the world (Aubert and Quilici 1984, Insecticide control of D. citri became the principal Chien and Chu 1996, E´ tienne et al. 2001, Hoy and strategy for HLB management in orchards in Brazil. Nguyen 2000, Skelley and Hoy 2004). The consequent frequent use of insecticides has In Brazil, T. radiata was Þrst identiÞed in 2006 in the caused a series of problems, including the destruction state of Sa˜o Paulo (Go´mez Torres et al. 2006). How- of the natural enemies of other major citrus pests, ever, T. radiata is not found in all regions of Brazil, and the parasitism rate is highly variable. 1 Departamento de Entomologia e Acarologia, Escola Superior de The success of a biological control program depends Agricultura “Luiz de Queiroz”, Universidade de Sa˜o Paulo, 13418-900, on factors that affect the Þeld efÞciency of organisms Piracicaba, Sa˜o Paulo, Brazil. raised under laboratory conditions (Bigler 1986). Cli- 2 Corresponding author: Laborato´rio de Entomologia, Embrapa Clima Temperado, 96001-970, Pelotas, Rio Grande do Sul, Brazil mate is probably the most important of these factors, (e-mail: [email protected]). given that a complex set of meteorological variables 0022-0493/12/0338Ð0343$04.00/0 ᭧ 2012 Entomological Society of America April 2012 GO´ MEZ-TORRES ET AL.: LIFE TABLE OF T. radiata 339 affects the development, emergence, survival, activity, Development of T. radiata on D. citri at Different and fecundity of the parasitoids released; temperature Temperatures. Recently emerged females and males and relative humidity are the most inßuential factors of T. radiata were left for 24 h in cages measuring 60 ϫ (King et al. 1985, Fauvergue and Quilici 1991). A life 50 ϫ 50 ϫ 52 cm, to mate. During this period the table is extremely useful for understanding the pop- insects were fed with a mixture of pure honey and ulation dynamics of the target species, because it pollen (Chien et al. 1994), provided on small plates in provides an integrated view of the biological charac- the upper part of the cage, which was made of glass. teristics of a given population under deÞned environ- Afterwards, the females were placed in individual mental conditions, as well as showing the develop- cages consisting of plastic cylinders (15.5 ϫ 5.5 cm), ment rate, longevity, and fecundity, all of which are with their openings covered with voile for ventilation. expressed in terms of population means (Coppel and Each female T. radiata was offered a myrtle plant with Mertins 1977, Silveira Neto et al. 1976). 30 Þfth-instar nymphs of D. citri, according to Chu and The objective of the current study was to investigate Chien (1991) (Gomez-Torres, 2009). Parasitism was the biology of T. radiata and to construct life tables at allowed for 24 h, in incubators at temperatures of 15, Ϯ Њ Ϯ different temperatures, to determine the possible im- 20, 25, 30, and 35 1 C, RH 70 10%, and a 14-h pacts of this factor on parasitism, emergence, devel- photophase. After, the female was removed from the ϫ opment, and the growth potential of the population of cage with the use of a glass tube (12 75 mm), and this parasitoid, envisaging its mass production. This the parasitized nymphs of D. citri were maintained in study will contribute to the establishment of a biolog- the same temperatures until the adults emerged. ical control program for D. citri, as a component of For each of the temperatures (treatment), four rep- IPM in different citrus-growing regions of Brazil. licates were used, each consisting of Þve myrtle plants with 30 nymphs, totaling 150 nymphs/replicate and 600 nymphs/treatment. The following biological pa- rameters were evaluated: percentage of parasitism, Materials and Methods duration of the preimaginal (egg-adult) period, per- We collected adults of D. citri and T. radiata from centage of emergence, and sex ratio. The percentage of parasitism was determined on the Þfth day after the citrus groves in the state of Sa˜o Paulo. The insect populations were maintained at the Insect Biology nymphs were offered to the parasitoids, evaluating the formation of mummies. The sex ratio was deÞned as Laboratory of the Department of Entomology and the number of females divided by the total number of Acarology of the Luiz de Queiroz School of Agricul- individuals. ture, University of Sa˜o Paulo, Piracicaba. Life Table of T. radiata at Different Temperatures. Rearing D. citri. D. citri was reared by a technique Ten pairs of 24-h-old individuals, fed with pure honey adapted from those proposed by Skelley and Hoy and pollen (Chien et al. 1994), were placed in indi- (2004) and Nava et al. (2007). We used seedlings of vidual cylindrical plastic cages (15.5 ϫ 5.5 cm) with the orange jasmine Murraya paniculata (L.) Jack, the openings covered with voile (for ventilation). To 25Ð30 cm in height. The plants were grown in a sub- each female parasitoid, 30 Þfth-instar nymphs of D.