Grosman A.H.,University of Amsterdam |
Grosman A.H.,Bio Bee Sde Eliyahu LTD |
Holtz A.M.,Federal University of Viçosa |
Holtz A.M.,Federal University of Espirito Santo |
And 3 more authors.
Entomologia Experimentalis et Applicata | Year: 2017
The ‘enemy-free space’ hypothesis predicts that herbivorous insects can escape their natural enemies by switching to a novel host plant, with consequences for the evolution of host plant specialisation. However, if natural enemies follow herbivores to their novel host plants, enemy-free space may only be temporary. We tested this by studying the colonisation of the introduced tree Eucalyptus grandis (Hill) Maiden (Myrtaceae) by insects in Brazil, where various species of herbivores have added eucalyptus to their host plant range, which consists of native myrtaceous species such as guava. Some herbivores, for example, Thyrinteina leucoceraea Ringe (Lepidoptera: Geometridae), cause outbreaks in eucalyptus plantations but not on guava, possibly because eucalyptus offers enemy-free space. We sampled herbivores (mainly Lepidoptera species) and natural enemies on eucalyptus and guava and assessed parasitism of Lepidoptera larvae on both host plant species during ca. 2 years. Overall, predators were encountered more frequently on guava than on eucalyptus. In contrast, parasitoids were encountered equally and parasitism rates of Lepidoptera larvae were similar on both host plants. This indicates that herbivores may escape some enemies by moving to a novel host plant. However, this escape may be temporary and may vary with time. We argue that studying temporal and spatial patterns of enemy-free space and the response of natural enemies to host use changes of their herbivorous prey is essential for understanding the role of natural enemies in the evolution of host plant use by herbivorous arthropods. © 2017 The Netherlands Entomological Society
Zisovich A.H.,Galilee Technology Center |
Goldway M.,Galilee Technology Center |
Goldway M.,Galilée College |
Schneider D.,Galilee Technology Center |
And 4 more authors.
Journal of Horticultural Science and Biotechnology | Year: 2012
The European pear (Pyrus communis) cultivars 'Spadona' and 'Coscia' exhibit full self-incompatibility, and therefore fruit production depends entirely on cross-pollination, which is carried out mainly by honeybees (HB), the ultimate pollinators of pear. To increase the efficiency of HB pollination, colony numbers are doubled or introduced sequentially; nevertheless, yields remain relatively low and fruit are small due to the low number of seeds per fruit. In the present research, we studied the effect of adding bumblebees (BB) to the HB colonies. Adding BB hives to pear orchards 10 d before bloom, at a density of ten hives ha-1, improved the percentage fruit-set, fruit size, and also sometimes, fruit yield. These positive results were due to a large increase in seed numbers per fruit, especially in 'Spadona' which had only one-to-three seeds per fruit when pollinated only by HB,compared to four-to-six seeds after pollination with HB + BB. There was a strong positive correlation between the number of BB visits tree-1 min-1 and the number of seeds fruit-1, and a similar correlation between seed number and fruit size.
Caspi-Fluger A.,Newe Ya'ar Research Center |
Caspi-Fluger A.,Haifa University |
Inbar M.,Haifa University |
Steinberg S.,BioBee Sde Eliyahu Ltd |
And 4 more authors.
Bulletin of Entomological Research | Year: 2014
Nesidiocoris tenuis (Reuter) (Heteroptera: Miridae) is an omnivorous insect used for biological control. Augmentative release and conservation of N. tenuis have been used for pest control in tomato crops. Intracellular bacterial symbionts of arthropods are common in nature and have diverse effects on their hosts; in some cases they can dramatically affect biological control. Fingerprinting methods showed that the symbiotic complex associated with N. tenuis includes Wolbachia and Rickettsia. Rickettsia of N. tenuis was further characterized by sequencing the 16S rRNA and gltA bacterial genes, measuring its amount in different developmental stages of the insect by real-time polymerase chain reaction, and localizing the bacteria in the insect's body by fluorescence in situ hybridization. The Rickettsia in N. tenuis exhibited 99 and 96% similarity of both sequenced genes to Rickettsia bellii and Rickettsia reported from Bemisia tabaci, respectively. The highest amount of Rickettsia was measured in the 5th instar and adult, and the symbionts could be detected in the host gut and ovaries. Although the role played by Rickettsia in the biology of N. tenuis is currently unknown, their high amount in the adults and localization in the gut suggest that they may have a nutritional role in this insect. Copyright © Cambridge University Press 2014 .
Bio Bee Sde Eliyahu Ltd | Date: 2012-05-10
A Biological Control Agent (BCA) system comprising processed parasitized mealybug mummies is disclosed. The processed and modified parasitized mealybug mummies are essentially devoid of their limbs and waxy covering. In the novel BCA system the modified parasitized mealybug mummies are processed in a manner that strips off their waxy covering and detaches their limbs without impacting on their viability as a host for parasitoid pupae. The modified parasitized mealybug mummies of the BCA system are encased in specially adapted packaging for delivering and distributing the modified parasitized mealybug mummies to plants with mealybug infestations. A method of preparing and storing the modified parasitized mealybug mummies as a BCA is also presented.