Selection for and Analysis of UV-Resistant Cryptophlebia Leucotreta Granulovirus-SA as a Biopesticide for Thaumatotibia leucotreta

Cryptophlebia leucotreta granulovirus-SA (CrleGV-SA) is used as a commercial biopesticide for the false codling moth, Thaumatotibia leucotreta, in citrus and other crops. The virus is sensitive to UV irradiation from sunlight, which reduces its efficacy as a biopesticide in the field. We selected a UV-resistant CrleGV-SA isolate, with more than a thousand-fold improved virulence compared to the wild-type isolate, measured by comparing LC50 values. CrleGV-SA purified from infected T. leucotreta larvae was exposed to UV irradiation under controlled laboratory conditions in a climate chamber mimicking field conditions. Five cycles of UV exposure, followed by propagating the virus that retained infectivity in vivo with re-exposure to UV, were conducted to isolate and select for UV-resistant virus. Serial dilution bioassays were conducted against neonates after each UV exposure cycle. The concentration-responses of the infectious UV-exposed virus populations were compared by probit analysis with those from previous cycles and from the original CrleGV-SA virus population. NGS sequences of CrleGV-SA samples from UV exposure cycle 1 and cycle 5 were compared with the GenBank CrleGV-SA sequence. Changes in the genomes of infective virus from cycles 1 and 5 generated SNPs thought to be responsible for establishing UV tolerance. Additional SNPs, detected only in the cycle 5 sequence, may enhance UV tolerance and improve the virulence of the UV-tolerant population.

HAMA TANAMAN BELIMBING DI WILAYAH KABUPATEN BLITAR JAWA TIMUR

Pests of star fruit in Blitar District, East Java. Pest attack causes the production of star fruit decreases. This study aim was to identify the pests of star fruit in Blitar District which could provide an information about pest species, damage symptoms and damage intensity. The research was conducted during August – September 2014 in Gogodeso, Karangsonoand Pojok Villages at Blitar District, East Java. Observations of the pests ware done by determining the four locations of plantation on each villages randomly. Three plants sample were choosen in each plantation location diagonally. Each plant was divided into four quadrant according to wind directions. One branch in the bottom was choosen in each quadrant. Nine species were recorded as pests of starfruit in Blitar district. Pest was identified on the leaf was Pteroma plagiophleps, on the branch was Zeuzera coffeae, on the flower were Toxoptera aurantii and Maconellicoccus hirsutus, whereas those on the fruit were Toxoptera aurantii, Maconellicoccus hirsutus, Thrips javanicus, Helopeltis bradyi, Cryptophlebia leucotreta, Bactrocera dorsalis, and Bactrocera carambolae. The population density of M. hirsutus was higher in Karangsono than in other villages. The highest damage intensity was caused by Bactrocera spp., C. leucotreta and H. bradyi (occured in Gogodeso), whereas the highest damage intensity of T. javanicus occurred in Pojok.