蝇蛆寄生对家蚕血细胞和酚氧化酶活性的影响

为了探明蝇蛆寄生对家蚕免疫因子的影响,对家蚕追寄蝇(Exorista sorbillansW iedem ann)幼虫寄生的5龄家蚕血淋巴中血细胞数量的变化以及血淋巴酚氧化酶活性的变化进行了研究。结果表明:蝇蛆寄生家蚕后,家蚕血淋巴中颗粒细胞和浆细胞的数量急剧上升,在寄生后16~24 h,蝇蛆蚕血淋巴颗粒细胞和浆细胞数达到6.81×106/mL,比对照增加了4.76×106/mL;蝇蛆寄生导致血淋巴黑化反应加快,黑色素增加;蝇蛆蚕血淋巴酚氧化酶活性升高,在6 d内由7 U/mg上升到34 U/mg。     

康氏木霉的寄生性及其在防治棉花立枯病中的应用

研究结果显示,康氏木霉(Trichoderma koningii)以菌丝缠绕、博贴等形式寄生于病例菌的菌丝上,吸取其营养,并产生抑菌物质,致使病茵丝的断裂,原生质凝固,直至死亡.大田小区实验和大面积防治示范部表明,康氏木霉可有效防治棉立枯病(Rhizoclonia solani)等土传病害,降低其发病率和发病程度.     

Phenological and ecological aspects of <Emphasis Type="Italic">Protopulvinaria pyriformis</Emphasis> (Cockerell) (Hemiptera: Coccidae) in Greece

The ecology of the coccid Protopulvinaria pyriformis infesting the laurel Laurus nobilis was studied from October 2003 to September 2005 in SW Greece. The coccid is parthenogenetic and oviparous, producing increased amounts of honeydew throughout the year. It settles mainly on the lower leaf surface. The scale overwinters as egg, 1st and 2nd instar nymph and adult and completes several overlapping generations every year. The life cycle was estimated to last in nature ~52 days during winter and 29–33 days during summer. Infestation density ranged between 0.3 and 2.8 live scales per cm² of leaf surface. Metaphycus helvolus was the only wasp found to parasitize P. pyriformis. Parasitism rate reached 31.2% during the second year of the study. The scale was able to resist parasitization by encapsulating the parasitoid’s eggs. Maximum encapsulation rate was estimated up to 23% of the adult scales. Encapsulated eggs ranged from 1 to 5 eggs per adult scale. Predation rate reached 7% and it was attributed to the coccinellid Chilocorus bipustulatus. The above information could be important for planning a sustainable control strategy for this new pest in Greece.     

Parasitoid complex of Phyllonorycter robiniella (Clemens, 1859) (Lepidoptera, Gracillariidae) in Serbia

In a study of the parasitoid complex of the locust leaf miner Phyllonorycter robiniella (Clemens, 1859), 23 species of its parasitoids were recorded at 18 localities in Serbia. The parasitoid species included 2 species of the family Braconidae, 1 of the family Eupelmidae, and 20 of the family Eulophidae. The recorded species of parasitoids are polyphagous; in addition to Ph. robiniella, they also develop on other species of leaf miners as primary; primary and secondary; or primary, secondary, and tertiary parasitoids. Among the recorded species of parasitoids, the most significant were the species Pholetesor bicolor, Pholetesor nanus, Sympiesis sericeicornis, Sympiesis acalle, Minotetrastichus frontalis, Pediobius saulius, and Baryscapus nigroviolaceus. The parasitoids were found to have a strong effect on the abundance of Ph. robiniella because they reduced more than 50% of its larvae and pupae in the majority of study samples.