Island and Mountain Ecosystems as Testbeds for Biological Control in the Anthropocene

For centuries, islands and mountains have incited the interest of naturalists, evolutionary biologists and ecologists. Islands have been the cradle for biogeography and speciation theories, while mountain ranges have informed how population adaptation to thermal floors shapes the distribution of species globally. Islands of varying size and mountains’ altitudinal ranges constitute unique “natural laboratories” where one can investigate the effects of species loss or global warming on ecosystem service delivery. Although invertebrate pollination or seed dispersal processes are steadily being examined, biological control research is lagging. While observations of a wider niche breadth among insect pollinators in small (i.e., species-poor) islands or at high (i.e., colder) altitudes likely also hold for biological control agents, such remains to be examined. In this Perspective piece, we draw on published datasets to show that island size alone does not explain biological control outcomes. Instead, one needs to account for species’ functional traits, habitat heterogeneity, host community make-up, phenology, site history or even anthropogenic forces. Meanwhile, data from mountain ranges show how parasitism rates of Noctuid moths and Tephritid fruit flies exhibit species- and context-dependent shifts with altitude. Nevertheless, future empirical work in mountain settings could clarify the thermal niche space of individual natural enemy taxa and overall thermal resilience of biological control. We further discuss how global databases can be screened, while ecological theories can be tested, and simulation models defined based upon observational or manipulative assays in either system. Doing so can yield unprecedented insights into the fate of biological control in the Anthropocene and inform ways to reinforce this vital ecosystem service under global environmental change scenarios.The development of this manuscript was funded by the Food and Agriculture Organization FAO through LOA/RAP/2021/57, executed by The University of Queensland. AS was supported by the "Ramon y Cajal" program (RYC2020029407-I), financed by the Spanish "Ministerio de Ciencia e Innovacion".info:eu-repo/semantics/publishedVersio

EFFECT OF Melia azedarach ON APHID (Brevcorinae brassicae) OF ORGANIC CABBAGE FARMING

In order to assess the effectiveness of botanical plant material use in reducing cabbage aphid population (Brevicoryne brassicae), an experiment was conducted in the research command area of Ecological Service Centre at Devghat-9, Gaight, Tanahun during the winter of 2001/2002. Two levels of concentration, 1:5 and 1:10, from the fresh green leaves of Bakaino (Melia azedarach L.), were applied to the aphid population in cabbage at five and ten days intervals. The result indicated that the 1:5 concentrated solution of Bakaino (Melia azedarach L.) extract at five day intervals was most effective in lowering the aphid population and scale of leaf damage as compared to other treatments. Even the 1:10 concentration sprayed at the shorter period of interval was found to be effective. Similarly, the research indicated that both concentration of plant extract and spraying interval are equally important for effective pest management, indicating the possibility of using botanical plant materials in the development of organic insect pest management methods in vegetables

Abundance and diversity of Scarabaeid beetles (Coleoptera: Scarabaeidae) in different farming areas in Nepal.

The abundance and diversity of scarabaeid beetles was examined at fivedifferent farming areas in Nepal. Light traps were used to monitor the beetlesfor 12 months. A total of 4708 scarabaeid beetles of 29 genera and 77 specieswere trapped during the one year duration of this study. The five most commonscarabaeid species in the study areas were Adoretus coronatus Burmeister,Maladera thomsoni (Brenske), Anomola bilobata Arrow, Holotrichia nigricollisBrenske and Anomola dimidiata (Hope). They accounted for 58.81% of allindividuals collected. An inventory of scarabaeid beetles associated with thefive different farming areas in Nepal was developed. This data creates a basefor further studies of beetles and for the developement of conservation andmanagement strategies in Nepal

Generalist Predators Shape Biotic Resistance along a Tropical Island Chain

Islands offer exclusive prisms for an experimental investigation of biodiversity x ecosystem function interplay. Given that species in upper trophic layers, e.g., arthropod predators, experience a comparative disadvantage on small, isolated islands, such settings can help to clarify how predation features within biotic resistance equations. Here, we use observational and manipulative studies on a chain of nine Indonesian islands to quantify predator-mediated biotic resistance against the cassava mealybug Phenacoccus manihoti (Homoptera: Pseudococcidae) and the fall armyworm Spodoptera frugiperda (Lepidoptera: Noctuidae). Across island settings, a diverse set of generalist lacewing, spider and ladybeetle predators aggregates on P. manihoti infested plants, attaining max. (field-level) abundance levels of 1.0, 8.0 and 3.2 individuals per plant, respectively. Though biotic resistance—as imperfectly defined by a predator/prey ratio index—exhibits no inter-island differences, P. manihoti population regulation is primarily provided through an introduced monophagous parasitoid. Meanwhile, resident predators, such as soil-dwelling ants, inflict apparent mortality rates up to 100% for various S. frugiperda life stages, which translates into a 13- to 800-fold lower S. frugiperda survivorship on small versus large islands. While biotic resistance against S. frugiperda is ubiquitous along the island chain, its magnitude differs between island contexts, seasons and ecological realms, i.e., plant canopy vs. soil surface. Hence, under our experimental context, generalist predators determine biotic resistance and exert important levels of mortality even in biodiversity-poor settings. Given the rapid pace of biodiversity loss and alien species accumulation globally, their active conservation in farmland settings (e.g., through pesticide phasedown) is pivotal to ensuring the overall resilience of production ecosystems