A highly effective nucleopolyhedrovirus against Malacosoma spp. (Lepidoptera: Lasiocampidae) from Turkey: isolation, characterization, phylogeny, and virulence

Abstract

IntroductionMalacosoma species are very common in Turkey and cause extensive economic losses in a number of plants (Doğanlar, 1975). One of these species, Malacosoma americanum (Fabricius, 1793) (Lepidoptera: Lasiocampidae), the eastern tent caterpillar, is a pest native to North America (Stene, 1914). The presence of M. americanum has not been reported in Turkey until now, when we detected it in Gümüşhane, Turkey. However, with the great importation of indoor plants to Turkey, it is possible that this insect was introduced in this way.M. americanum is particularly injurious to apple, cherry, and other fruit trees but can also be destructive to other deciduous trees (Leathers and Gupta, 1993). Furthermore, its caterpillars induce mare reproductive loss syndrome, which causes early fetal losses and late-term abortion in horses (Webb et al., 2004). Control of this pest is difficult, largely because of its congregation behavior. Larvae spend the day inside their protective tents where they are largely shielded from exposure to insecticides. At night and in rainy weather, they emerge to forage, at which time a widely disseminated control agent would be necessary.Another species, Malacosoma neustria (Linnaeus, 1758) (Lepidoptera: Lasiocampidae), known as the European tent caterpillar, is an important defoliator of various fruit trees and ornamental trees, particularly in eastern and central Turkey (Özbek and Çalmasur, 2005; Özbek and Çoruh, 2010). The caterpillars first feed on the buds and then on the leaves of the trees. Within a few years, they become so widespread that they leave the trees completely bare. Since 1970, outbreaks have been observed at about 3-to 7-year intervals in the province of Erzurum (Özbek and Çoruh, 2010).Nucleopolyhedroviruses (NPVs), members of the family Baculoviridae, are one of the most promising biological and biotechnological control agents of insects to date (Demir et al., 2008). They are enveloped viruses that have double-stranded, circular DNA genomes ranging in size from 80 to 180 kbp (Theilmann et al., 2005). These viruses have been used as biopesticides to control the population of insect pests in agriculture, forestry, and pastures (Moscardi, 1999;Lacey et al., 2001;Szewczyk et al., 2006). The susceptibility of M. americanum and M. neustria to nucleopolyhedroviruses has been noted on Abstract: A nucleopolyhedrovirus (NPV) was isolated from diseased larvae of the eastern tent caterpillar, Malacosoma americanum (Fabricius), collected from the northeastern part of Turkey. Light and electron microscopic observations showed that this virus is a multiple nucleopolyhedrovirus (MNPV). The dimensions of the polyhedral inclusion bodies varied from 1.0 to 2.1 µm, and the sizes of the virions were also measured to be approximately 194.5 nm. Restriction analysis of the new isolate and ManeNPV-T2 (previously isolated from M. neustria larvae) showed that the new virus is closely related to ManeNPV-T2. Furthermore, sequence and phylogenetic analysis of polh and lef-8 also revealed a high degre...

Characterization of a novel baculovirus isolate from Malacosoma neustria (Linnaeus, 1758) (Lepidoptera: Lasiocampidae) in Samsun and its pathogenicity in different hosts

“…Scanning electron microscopy observations showed that the OBs of ManeNPV-T4 are irregularly shaped and about 1.5-2.17 µm in diameter. The OB dimension of ManeNPV-T4 was compared to those of other ManeNPVs, and ManeNPV-T4 OBs was found to be larger than the Latvian isolates (Jankevica et al, 1998), which have OBs of 0.85-1.4 µm, and also larger than previous Turkish isolates, which have OBs of 0.87-1.75 µm (Demir et al, 2013) and 1.0-2.1 µm (Demir et al, 2014). However, ManeNPV-T4 OBs are smaller than the other Turkish ManeNPV isolates (Yaman, 2003), Polish isolate (Lipa et al, 1968) and the isolate used by Ponsen et al (1964) which have OB of 0.76-3.85, 0.9-2.0 and 1-3.5 µm, respectively.…”

“…The mortality with 10 7 OBs/ml reached 100% in M. neustria larvae after 14 d. Whereas 10 6 OBs/ml of ManeNPV-T2 was enough to cause 100% mortality on M. neustria larvae after 10 d (Demir et al, 2013). Furthermore, in another study, 10 6 OBs/ml concentration of ManeNPV-T3 caused 100% mortality in M. neustria larvae within 10 d (Demir et al, 2014). Additionally, ManeNPV-T4, at 10 7 OBs/mln, caused mortality between 28 and 42% in H. armigera, H. cunea, S. exigua and L. dispar larvae within 14 d. Hyphantria cunea is the most resistant to these baculovirus isolates and M. neustria is most susceptible of the species tested.…”

“…Moreover, the presence of baculoviruses in various Malacosoma spp. populations had been previously reported in Turkey (Yaman, 2003;Demir et al, 2013Demir et al, , 2014.…”

“…Additionally, the pathogenicity of this isolate was determined in five species of lepidopteran insect larvae. This new isolate was designated ManeNPV-T4 to indicate its difference from previous Turkish isolates (Yaman, 2003;Demir et al, 2013Demir et al, , 2014. Scanning electron microscopy observations showed that the OBs of ManeNPV-T4 are irregularly shaped and about 1.5-2.17 µm in diameter.…”

“…Genes, lef-8, lef-9 and polh, of ManeNPV-T4 were amplified using the degenerate primers of De Moraes and Maruniak (1997), Herniou et al (2003) and Jehle et al (2006). PCR reactions were performed as previously described (Demir et al, 2014). Amplified fragments were cloned into a pJET1.2 (Thermo Fisher Scientific, Waltham, MA, USA) vector and subsequently sequenced by Macrogen Inc. (Amsterdam, The Netherlands).…”