Tenebrio molitor (Coleoptera: Tenebrionidae) as an alternative host for the parasitoid Trichospilus diatraeae (Hymenoptera: Eulophidae)
Tenebrio molitor (Coleoptera: Tenebrionidae) como un huésped alternativo para la cría de Trichospilus diatraeae (Hymenoptera: Eulophidae)
KELLEN FAVERO1, FABRICIO FAGUNDES PEREIRA2, HARLEY NONATO DE OLIVEIRA3 and JOSÉ COLA ZANUNCIO4
1 M. Sc. Faculdade de Ciências Biológicas e Ambientais, Universidade Federal da Grande Dourados, 79804-970, Dourados, Mato Grosso do Sul, Brasil. fabriciofagundes@ufgd.edu.br.
2 Ph. D. Professor Faculdade de Ciências Biológicas e Ambientais, Universidade Federal da Grande Dourados, 79804-970, Dourados, Mato Grosso do Sul, Brasil. fabriciofagundes@ufgd.edu.br.
3 Ph. D. Researcher Embrapa Agropecuária Oeste, Caixa Postal 449, CEP 79804-970 Dourados, MS, Brazil. harley.oliveira@embrapa.br. Corresponding author.
4 Ph. D. Professor Universidade Federal de Viçosa, 36571-900, Viçosa, Minas Gerais, Brasil. zanuncio@ufv.br.
Received: 10-May-2012 - Accepted: 22-Apr-2013
Abstract: The aim of this work was to verify if Trichospilus diatraeae (Hymenoptera: Eulophidae) was able to parasitize and develop in pupae of Tenebrio molitor (Coleoptera: Tenebrionidae). The parasitism rate and emergence of T. diatraeae on pupae of T. molitor was 80% and 50%, respectively. The total number of individuals emerged per pupae on this host was 97.06 ± 17.50 with a sex ratio of 0.94 ± 0.02. The longevity (in days) of females and males of this natural enemy was 18.15 ± 0.99 and 11.67 ± 0.62, respectively. The high reproductive performance of T. diatraeae shows the adequacy of T. molitor pupae for this parasitoid. This is the first report of T. molitor pupae as an alternative host for rearing T. diatraeae.
]]> Key words: Biological control. Parasitism. Pupae parasitoid. Reproductive potential.Resumen: El objetivo de este trabajo fue verificar la capacidad de Trichospilus diatraeae (Hymenoptera: Eulophidae) de parasitar y desarrollarse en pupas de Tenebrio molitor (Coleoptera: Tenebrionidae). Los porcentajes de parasitismo y emergencia de T. diatraeae sobre pupas de T. molitor fue de 80% y 50%, respectivamente. El número total de individuos emergidos por pupa de este huésped fue 97,06 ± 17,50, con una proporción sexual de 0,94 ± 0,02. La longevidad (días) de hembras y machos de este enemigo natural fue de 18,15 ± 0,99 y 11,67 ± 0,62, respectivamente. El alto rendimiento reproductivo de T. diatraeae muestra la adecuación de las pupas de T. molitor para este parasitoide. Este es el primer registro de pupas de T. molitor como un huésped alternativo para la cría de T. diatraeae.
Palabras clave: Control biológico. Parasitismo. Pupas parasitoide. Potencial reproductivo.
Introduction
Trichospilus diatraeae Cherianand Margabandhu, 1942 (Hymenoptera: Eulophidae) is a gregariousendoparasitoid that preferentially attacks Lepidoptera pupae. It was first reported on Diatraea venosata Walker, 1863 (Lepidoptera: Crambidae) and dates from 1942 (Bouček 1976). In Brazil, the first occurrence was on pupae of Arctiidae (Paron and Berti-Filho 2000), but recently it was also reported attacking species of Oecophoridae (Oliveira et al. 2001), Geometridae (Pereira et al. 2008; Zaché et al. 2010) and Pyralidae (Melo et al. 2011).
One the most important issues in a program of biological control of insect is to find an adequate alternative host to rear the natural enemy. This host should be reared with low production costs and without affecting the efficiency of natural enemy in the field (Zanuncio et al. 2008). Tenebrio molitor Linnaeus, 1758 (Coleoptera: Tenebrionidae) is easy and inexpensive to rear in mass (Otuka et al. 2006) and shows very good results to rear pupae parasitoids (Zanuncio et al. 2008). For this reason, the parasitism of T. diatraeae on T. molitor pupae was studied.
The experiment was carried out in an acclimatized room, under the following conditions: mean maximum temperature of 25.88 ± 0.18 ºC and minimum of 24.12 ± 0.16 °C, maximum relative humidity of 62.33% ± 1.15 and a minimum of 55.63% ± 1.00 and photophase of 12 hours. Forty pupae of T. molitor 24 hours old and weighing between 0.11 g and 0.14 g were individualized in glass tubes (2.5 x 8.5 cm) and exposed to parasitism by 20 T. diatraeae females with age between 48 and 72 hours. The experiment was set up in a completely randomized design. There were evaluated the duration of the life cycle (egg to adult), the percentage of parasitism discounting host natural mortality (Abbott 1925), the percentage of parasitoid emergence, the number of parasitoids per pupa of T. molitor, the longevity of males and females and sex ratio (rs= number of females/number of females + males).
The life cycle (egg to adult) of T. diatraeae in pupae of T. molitor took 26.14 ± 0.99 days, being longer than on Diatraea saccharalis (Fabricius, 1794) (Lepidoptera: Crambidae) 19.8 ± 0.7 days, at 25 °C, RH of 70 ± 10% and 14 hours photophase (Paron 1999). This may be due to a better adaptation of this parasitoid to pupae of the host. Although important, it is not the only factor responsible for variations on the development of this parasitoid. Also, it is affected by temperature, humidity and photoperiod (Zago et al. 2006).
The percentages of parasitism and emergence of T. diatraeae were 80 and 50%, respectively from pupae of T. molitor. The total number of individuals emerged per pupa of this host was 97.06 ± 17.50 and with 4.62 ± 0.87 females produced per female of this parasitoid with a sex ratio of 0.94 ± 0.02. The longevity (days) of females and males of this natural enemy was 18.15 ± 0.99 and 11.67 ± 0.62, respectively. Paron and Berti Filho (2000) also reported high parasitism of T. diatraeae on pupae of D. saccharalis and some Noctuidae (Lepidoptera) such as Spodoptera frugiperda Smith, 1797, Anticarsia gemmatalis Hübner, 1818, Heliothis virescens (Fabricius, 1781). These authors used one and several females, without mentioning clearly the number of parasitoids used. Trichospilus diatraeae is a gregarious parasitoid, which makes necessary to determine the ideal density of its females per pupa to increase the efficiency of production techniques in the laboratory. The progeny of T. diatraeae per pupa of T. molitor was higher than that reported for Palmistichus elaeisis Delvare and LaSalle, 1993 (Hymenoptera: Eulophidae) (70.07 ± 2.50) with this host (Zanuncio et al. 2008), but this latter parasitoid has greater body size than the first. However, the number of individuals of this parasitoid emerged per pupa of S. frugiperda (208.3 ± 4.5), D. saccharalis (194.7 ± 6.8), A. gemmatalis (186.7 ± 2.8) and H. virescens (170.5 ± 1.3) (Paron and Berti-Filho 2000) was higher than that of this work. These variations can be attributed to host size (bigger pupae can support the development of more immature), hardness of pupae integument (Godfray 1994) and the methodologies used.
The sex ratio of T. diatraeae produced per pupae of T. molitor was similar to that of P. elaeisis on this host (0.94 ± 0.01) (Zanuncio et al. 2008) what shows the high reproductive capacity and great potential of both parasitoids. The higher number of females is an important issue, especially in a system of mass rearing and in the selection of individuals to release in the field, because the predominance of females can increase the number of individuals produced in the following generation (Pereira et al. 2009). The high sex ratio of T. diatraeae from T. molitor pupae, also, indicates that this host is adequate for this parasitoid. The survival of females and males of T. diatraeae from T. molitor pupae in the laboratory may be sufficient for this parasitoid to copulate, find and parasitize hosts in the field. The longevity of T. diatraeae was lower in pupae of T. molitor than that of P. elaeisis with this host (Zanuncio et al. 2008). This may be due to food competition between immature because T. diatraeae produced more offspring per pupa of T. molitor than P. elaeisis. The temperature also affects the longevity but its impact differs between parasitoids species. The longevity of insects is also related to factors such as diet, environment conditions and energy spent during copulation and oviposition (Kapranas and Luck 2008).
]]> The high reproductive performance of T. diatraeae shows the adequacy of T. molitor pupae for this parasitoid. This is the first report of T. molitor pupae as an alternative host to rearing T. diatraeae. As this natural enemy preferentially attacks Lepidoptera pupae; the qualitative and quantitative biological characteristics of this parasitoid may increase with the number of generations due to a better conditioning in this Coleoptera pupa. This can be explained by the fact that the experiment was developed with T. diatraeae reared with pupae of T. molitor between the second and third generation in the laboratory. The low cost of producing T. molitor allows the use of this host to mass rearing T. diatraeae for biological control programs of lepidopterous.Acknowledgements
To "Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)" and "Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)".
Literature cited
ABBOTT, W. S. 1925. A method of computing the effectiveness of an insecticide. Journal of Economic Entomology 18 (1): 265-267. [ Links ]
BOUČEK, Z. 1976. The African and Asiatic species of Trichospilus and Cotterellia (Hymenoptera: Eulophidae). Bulletin of Entomological Research 65 (4): 669-681. [ Links ]
GODFRAY, H. C. J. 1994. Parasitoids, behavioral and evolutionary ecology. New Jersey, Princeton University Press. 473 p. [ Links ]
]]>KAPRANAS, A.; LUCK, R. F. 2008. Egg maturation, host feeding, and longevity in two Metaphycus parasitoids of soft scale insects. Biological Control 47 (2): 147-153. [ Links ]
MELO, R. L.; PRATISSOLI, D.; POLANCZYK, R. A.; TAVARES, M.; MILANEZ, A. M.; MELO, D. F. 2011. Ocorrência de Trichospilus diatraeae (Hym.: Eulophidae) em broca-das-cucurbitáceas, no Brasil. Horticultura Brasileira 29 (2): 228-230. [ Links ]
OLIVEIRA, M. A. S.; JUNQUEIRA, N. T. V.; ICUMA, I. M.; ALVES, R. T.; OLIVEIRA, J. N. S.; ANDRADE, G. A. 2001. Incidência de danos da broca do fruto da graviola no Distrito Federal. Comunicado Técnico-Embrapa Cerrados, Planaltina 51: 1-5. [ Links ]
OTUKA, A. K.; VACARI, A. M.; MARTINS, M. I. E. G.; DE BORTOLI, S. A. 2006. Custo de produção de Podisus nigrispinus (Dallas, 1851) (Hemiptera: Pentatomidae) criado com diferentes presas. O Biológico 68 (1/2): 224-227. [ Links ]
PARON, M. R. 1999. Bioecologia de Trichospilus diatraeae Cherian & Maragabandhu, 1942 (Hymenoptera: Eulophidae), endoparasitóide de Lepidoptera. Tese (Doutorado em Entomologia) Piracicaba, SP. Escola Superior "Luis de Queiroz, Universidade de São Paulo. [ Links ]
]]>PARON, M. R.; BERTI-FILHO, E. 2000. Capacidade reprodutiva de Trichospilus diatraeae (Hymenoptera: Eulophidae) em pupas de diferentes hospedeiros (Lepidoptera). Scientia Agrícola 57 (2): 355-358. [ Links ]
PEREIRA, F. F.; ZANUNCIO, J. C.; TAVARES, M. T.; PASTORI, P. L.; JACQUES, G. C.; VILELA, E. F. 2008. New Record of Trichospilus diatraeae as a parasitoid of the eucalypt defoliator Thyrinteina arnobia in Brazil. Phytoparasitica 36 (3): 304-306. [ Links ]
PEREIRA, F. F.; ZANUNCIO, J. C.; SERRÃO, J. E.; PASTORI, P. L.; RAMALHO, F. S. 2009. Reproductive performance of Palmistichus elaeisis (Hymenoptera; Eulophidae) with previously refrigerated pupae of Bombyx mori (Lepidoptera; Bombycidae). Brazilian Journal of Biology 69 (3): 865-869. [ Links ]
ZACHÉ, B.; WILCKEN, C. F.; DACOSTA, R. R.; SOLIMAN, E. P. 2010. Trichospilus diatraeae Cherian & Margabandhu, 1942 (Hymenoptera: Eulophidae), a new parasitoid of Melanolophia consimilaria (Lepidoptera: Geometridae). Phytoparasitica 38 (4): 355-357. [ Links ]
ZAGO, H. B.; PRATISSOLI, D.; BARROS, R.; GONDIM JUNIOR, M. G. C. 2006. Biologia e exigências térmicas de Trichogramma pratissolii Querino & Zucchi (Hymenoptera: Trichogrammatidae) em hospedeiros alternativos. Neotropical Entomology 35 (3): 377-381. [ Links ]
]]>ZANUNCIO, J. C.; PEREIRA, F. F.; JACQUES, G. C.; TAVARES, M. T.; SERRÃO, J. E. 2008. Tenebrio molitor Linnaeus (Coleoptera: Tenebrionidae), a new alternative host to rear the pupae parasitoid Palmistichus elaeisis Delvare & LaSalle (Hymenoptera: Eulophidae). The Coleopterist Bulletin 62 (1): 64-66. [ Links ]
]]>