Gross Pathology of SpliNPVs and Alterations in Spodoptera littoralis Boisd. Lepidoptera:Noctuidae Morphology Due to Baculoviral Infection

Abstract

Baculoviruses are invertebrate-specific pathogens and baculoviral infections cause alterations in the physiology, metabolism and morphology of insects. It is important to recognize these physiological and symptomatologic changes to understand baculovirus infection cycle and biology. For this reason, in our study Spodoptera littoralis Boisd. Lepidoptera: Noctuidae larvae were inoculated with the SpliNPV to doses of 3000 and 20,000 OBs for third instars and to concentrations of 106 and 3x 106 OBs/ml for neonates and the alterations due to NPV infection in larvae were then examined. Bioassays carried out with the third instar S. littoralis larvae revealed that no symptoms were detected during the first three days post-inoculation due to SpliNPV infection. Approximately, in the 4th day, infected larvae began to respond much more slowly than healthy larvae. This symptom was followed by whitening and slimming of cuticula, failure in molting, swelling of the body, diarrhoea, climbing to high places and hanging, liquefaction of the body and death. Infected neonates exhibited limited symptoms of distension and the failure of molting. The larvae died in approximately 8-8.5 days for third instars and in approximately 3-3.5 days for neonates due to baculoviral infection for the both doses and concentrations. On the other hand, different doses or concentrations did not cause an alteration in the occurence time of symptoms.To associate the NPV biology with the genes involved in baculovirus genome and understand their life cycle will improve their efficacy as biopesticides and help to the effective use of baculoviruses

Keywords

• Spodoptera littoralis,NPV,baculovirus,gross pathology,morphology

SpliNPV’lerin Genel Patolojisi ve Bakulovirüs Enfeksiyonundan Dolayı Spodoptera littoralis Boisd. Lepidoptera:Noctuidae Morfolojisindeki Değişimler

Abstract

Bakulovirüsler omurgasızlara spesifik patojenler olup bakuloviral enfeksiyonlar böceklerin fizyolojisi, metabolizması ve morfolojisinde değişimlere neden olmaktadır. Bu fizyolojik ve simptomatolojik değişikliklerin farkına varmak, bakulovirüs enfeksiyon döngüsünü ve biyolojisini anlamak için önemlidir. Bu amaçla, çalışmamızda Spodoptera littoralis Boisd. Lepidoptera:Noctuidae larvaları 3. dönemler için 3000 ve 20,000 OBs dozlarında, birinci dönemler için ise 106 and 3x 106 OBs/ml konsantrasyonlarında SpliNPV ile inokule edilmiş ve daha sonra larvalarda NPV enfeksiyonundan kaynaklanan değişimler irdelenmiştir. Üçüncü dönem S. littoralis larvalarıyla yapılan denemelerde inokulasyonu takip eden ilk üç gün boyunca SpliNPV enfeksiyonundan kaynaklı simptom görülmediği saptanmıştır. Yaklaşık olarak dördüncü günle birlikte hastalıklı larvalar sağlıklı larvalara göre daha yavaş tepkiler vermiştir. Bu simptomu, kutikulanın beyazlaşması ve incelmesi, deri değiştirememe, vücudun şişmesi, ishal durumu, yüksek yerlere tırmanma ve asma, vücudun sıvılaşması ve ölüm takip etmiştir. Enfekteli birinci dönem larvalar ise şişme ve deri değiştirememeyi içeren kısıtlı simptomlar vermiştir. Bakulovirüs enfeksiyonundan dolayı 3. dönem larvalar 8-8.5 günde, 1. dönem larvalar ise 3-3.5 günde her iki doz ve konsantrasyonda ölmüştür. Diğer taraftan farklı doz ya da konsantrasyonlar, simptomların ortaya çıkış zamanında bir değişikliğe neden olmamıştır. NPV bioyolojisini bakulovirus genomunda yer alan genlerle ilişkilendirmek ve hayat döngülerini anlamak bunların birer biyopestisit olarak etkinliğini artıracak ve daha etkin kullanımlarına yardımcı olacaktır

Keywords

• Spodoptera littoralis,NPV,bakulovirüs,genel patoloji,morfoloji

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