Questions: To what extent does species‐specific variation in gut passage time (GPT), habitat use and mobility of three key avian frugivores synergistically affect the distribution of Xymalos monospora seeds within and among isolated forest fragments? Location: Three fragments of a severely fragmented cloud forest, Taita Hills, southeast Kenya. Methods: We experimentally determined GPTs of X. monospora seeds and recorded movements and habitat use by Turdus helleri, Andropadus milanjensis and Tauraco hartlaubi through radiotelemetry, and combined these data to generate species‐specific seed dispersal patterns. Results: Differences in mobility and habitat use among the three frugivores caused significant complementarity in seed dispersal, despite the fact that gut transit times were highly comparable. While the most sedentary and forest‐dependent species mainly led to short‐distance dispersal away from parent trees, two more mobile species dispersed seeds further away from the source trees, both within indigenous forest patches and towards exotic plantations and isolated fruiting trees in the landscape matrix. A. milanjensis inhabiting a very small forest fragment spent significantly more time in the landscape matrix than conspecifics residing in the two larger fragments. Conclusions: By varying distances over which seeds are carried away from parent trees and the habitat types in which they are ultimately deposited, avian frugivores affect the spatial distribution of seeds and early plant recruits in a distinct and complementary manner. Because landscape properties are expected to lead to different constraints on avian mobility for habitat specialists and for generalists, ecosystem processes such as avian seed dispersal are shaped by complex interactions between disperser behaviour and the environment.

The granary weevil Sitophilus granarius is a stored product pest found worldwide. Environmental damages, human health issues and the emergence of resistance are driving scientists to seeks alternatives to synthetic insecticides for its control. With low mammal toxicity and low persistence, essential oils are more and more being considered a potential alternative. In this study, we compare the toxicity of 25 essential oils, representing a large array of chemical compositions, on adult granary weevils. Bioassays indicated that Allium sativum was the most toxic essential oil, with the lowest calculated lethal concentration 90 (LC90) both after 24 h and 7 days. Gaultheria procumbens, Mentha arvensis and Eucalyptus dives oils appeared to have a good potential in terms of toxicity/cost ratio for further development of a plant-derived biocide. Low influence of exposure time was observed for most of essential oils. The methodology developed here offers the possibility to test a large array of essential oils in the same experimental bioassay and in a standardized way. It is a first step to the development of new biocide for alternative management strategies of stored product pests.

Pear cultivation accounts for a large proportion of worldwide orchards, but its sustainability is controversial because it relies on intensive use of pesticides. It is therefore crucial and timely to find alternative methods to chemical control in pear orchards. The psyllids Cacopsylla pyri and Cacopsylla pyricola are the most important pests of pear trees in Europe and North America, respectively, because they infest all commercial varieties, causing damage directly through sap consumption or indirectly through the spread of diseases. A set of natural enemies exists, ranging from generalist predators to specialist parasitoids. Trechnites insidiosus (Crawford) is undoubtedly the most abundant specialist parasitoid of psyllids. In our literature review, we highlight the potential of this encyrtid species as a biological control agent of psyllid pests by first reviewing its biology and ecology, and then considering its potential at regulating psyllids. We show that the parasitoid can express fairly high parasitism rates in orchards, and almost perfectly matches the phenology of its host and is present early in the host infestation season, which is an advantage for controlling immature stages of psyllids. We propose new research directions and innovative approaches that would improve the use of T. insidiosus in integrated pest management strategies in the future, regarding both augmentative and conservation biocontrol. We conclude that T. insidiosus has many advantages and should be included as part of integrated biological control strategies of pear psyllids, along with predators, in‐field habitat conservation, and the rational use of compatible chemicals. © 2021 Society of Chemical Industry.

Although synthetic pesticides are still used to control insect pests, greater efforts have been made to develop healthier and more environmentally friendly pesticides. Because of their insecticidal properties, botanical essential oils (EOs) are considered as promising alternatives to the use of synthetic insecticides. However, little is known about mechanisms underlying the insecticidal activity of most these natural compounds. In the present study, we evaluated the contact toxicity and the modes of action of the EO from Mentha arvensis against the granary weevil, Sitophilus granarius L. (Coleoptera: Curculionidae), a cosmopolitan insect pest that causes extensive damage to stored cereals. M. arvensis EO caused high contact toxicity in S. granarius adults, resulting in a rapid paralysis and rapid alteration of walking behavior. Our label-free quantitative proteomics approach revealed that M. arvensis EO induced dramatic physiological changes in exposed insects. The majority of the differentially expressed proteins (DEPs) were upregulated and are related to the development and functioning of the muscular and nervous systems, cellular respiration, protein synthesis, and detoxification. These results suggest that M. arvensis essential oil is capable of affecting a variety of biological processes, and shed light on the repair mechanisms put in place in surviving insects to counter the damage inflicted. This work opens new perspectives on the proposed mechanisms of insecticidal activity of a promising EO for controlling pests of stored cereals and may represent a first step in the development of novel bio-rational insecticides.