Effects of Wolbachia-targeted tetracycline on a host-parasitoid-symbiont interaction

Abstract

Abstract. The uzifly, Exorista sorbillans (Diptera: Tachinidae), a parasite of the silkworm, Bombyx mori L. (Lepidoptera: Bombycidae), causes heavy losses to the silk industry. This parasitoid harbours a Wolbachia endosymbiont, which controls the fly's reproduction. In the present study a method for curtailing this notorious pest by administering Wolbachia-targeted tetracycline via its silkworm host's diet is investigated. Tetracycline not only influenced the larval growth of the silkworms' by decreasing larval duration, increased silk production and fecundity, without affecting hatchability, it also decreased the reproductive fitness of the uzifly endoparasite by killing the Wolbachia. The antibiotic exerts a beneficial influence by affecting the intestinal flora of silkworm larvae. On the other hand the reproductive fitness of uzifly was greatly reduced in terms of different reproductive abnormalities. When male and female flies that emerged from treated host silkworms were crossed and males from untreated hosts and females from treated hosts were crossed, approximately 72% and 97% of the eggs failed to hatch, respectively. However, of the eggs from crosses between male and female flies that emerged from untreated hosts and between males from treated hosts with females from untreated hosts, an average of 30% failed to hatch and the Wolbachia infection enhanced the fecundity of uziflies. These results demonstrate that the Wolbachia may be essential for uzifly reproduction and that Wolbachia-targeted antibiotics have a beneficial influence on silkworm growth while decreasing the reproductive fitness of the uzifly, E. sorbillans.

Frequency of infection with A and B supergroup Wolbachia in insects and pests associated with mulberry and silkworm

“…Though there are a number of curative measures, the loss of agro-products continues to be 25-30%. Our earlier work showed that some insects and pests of sericulture harbour Wolbachia (Madhu and Puttaraju 2001;Puttaraju and Madhu 2002;Prakash and Puttaraju 2006a) and suggested a novel method for the management of uzifl y, a parasitoid of silkworn (Puttaraju and Prakash 2005a;Puttaraju and Prakash 2005b;Puttaraju and Prakash 2005c;Prakash and Puttaraju 2006b). In the present paper we demonstrate the frequency of double versus single infection of Wolbachia using ftsZ A-and B-specifi c primers (Prakash 2006) in some insects and pests associated with mulberry and silkworn.…”

Effects of elimination ofWolbachiaon oogenesis of the uziflyExorista sorbillans, a parasitoid of the silkwormBombyx mori

“…Exorista sorbillans is a larval endoparasitoid of silkworm Bombyx mori (Jolly 1981; Srikanth et al. 1991), which harbors Wolbachia (Madhu & Puttaraju 2001; Puttaraju & Madhu 2002; Puttaraju & Prakash 2005a,b,c; Prakash & Puttaraju 2006a). The female uzifly lays an average of 500 eggs (Puttaraju & Prakash 2005a) on the body of third to fifth instar silkworm larvae, within which parasitic maggots subsequently feed and develop.…”

“…The assay was carried out with a PTC 200 Thermalcycler (MJ Research, Walthman, USA). The thermal conditions were followed as described elsewhere (Puttaraju & Prakash 2005a,c). The amplified PCR products were separated through 1.3% agarose gel electrophoresis run in 1 × TBE (89.2 mM Tris‐HCl, 88.9 mM boric acid, 2.0 mM disodium‐ethylenediaminetetra‐acetic acid) buffer for a length of 5–6 cm at a constant of 65 V from a power supply unit, (EP S200V/400 mA, Amersham Pharmacia Biotech, Uppsala, Sweden).…”

“…The present paper focuses on the involvement of Wolbachia in the growth and proliferation of oocytes in uzifly Exorista sorbillans (Diptera: Tachinidae), a serious parasitoid of silkworm Bombyx mori . Earlier we reported that the elimination of Wolbachia causes cytoplasmic incompatibility, male biased sex ratio, nucleo‐cytoplasmic conflict and reduction of fecundity up to 20% (Puttaraju & Prakash 2005a,b,c; Prakash & Puttaraju 2006b, c). Curing of Wolbachia with antibiotics had no effect on host longevity, locomotor activity and behavior, and these effects were not due to the toxic effect of tetracycline on uzifly but due to the removal of Wolbachia (Puttaraju & Prakash 2005c).…”

“…2000; Bourtzis & Miller 2003; Huigens & Stouthamer 2003; Kageyama et al. 2003; Puttaraju & Prakash 2005a,b,c; Prakash & Puttaraju 2006b). It also affects fecundity in a number of insect species including Drosophila (Hoffmann et al.…”