Insectary Plants Research Articles

ORGANIC LYCHEE, RAMBUTAN, STAR APPLE, MANGOSTEEN AND DURIAN PRODUCTION

Lychees (Litchi chinensis Sonn.), rambutans (Nephelium lappaceum L.), star apple (Chrysophyllum caimito), mangosteen (Garcinia mangostana) and durian (Durio zibethinus) are grown organically in Australia. Organic soil nutrition, weed, pest and disease management allows the farm to produce high yields of quality fruit. The use of insectary plants and other organic control methods has resulted in a significant reduction in insect pests and diseases. IPM scouting surveys show that the organic farm has the least number of insect pest species. Soil tests show that soil fertility is constantly increasing.

Relative Frequencies of Visits to Selected Insectary Plants by Predatory Hoverflies (Diptera: Syrphidae), Other Beneficial Insects, and Herbivores

Abstract The use of insectary plants in agroecosystems to provide floral resources for enhancing natural enemy activity is an increasingly used practice, but candidate flowering plant species are not always screened for their attractiveness to key arthropods in the system being studied. In the work presented here, the relative attractiveness of four species of insectary plants to beneficial and pest insect species was assessed by observing the relative frequencies of flower visits to replicated blocks of the insectary flowers in two Oregon broccoli fields. The four plant species tested were alyssum (Lobularia maritima L. Desv.), coriander (Coriandrum sativa L.), buckwheat (Fagopyrum esculentum Moench), and phacelia (Phacelia tanacetifolia Benth.). Predatory hoverflies (Syrphidae) were identified to species, where possible, because of their previously observed importance as aphid predators in broccoli fields in the study area. The other beneficial insect groups observed were in the families Apidae, Coccine...

Multiple parasitoid visitors to the extrafloral nectaries of Solanum adherens. Is S. adherens an insectary plant?

Abstract Extrafloral nectary plants are generally thought of as ant plants despite the fact that they are visited by many other predatory and parasitoid insects. All the conditions for facultative mutualisms between EFN plants and parasitoids are present and there is some evidence showing that these mutualisms exist. EFN plants that benefit from multiple taxa of natural enemies are known as insectary plants. The goal of this study was to determine if Solanum adherens is an insectary plant. Visitation rates of parasitoids, amount of parasitism on several shared lepidopteran species, and overall herbivore load and diversity were compared between S. adherens and two congeners. Significantly more parasitoids and parasitism of its lepidopteran pests were found on S. adherens , while more species and significantly more herbivores overall were found on the congeners without EFNs. These results suggest that S. adherens is an insectary plant with facultative mutualist parasitoid visitors. Although no one parasitoid species could act as a general protector like an ant species could, parasitoids in the aggregate were able to aid the EFN plant. Pflanzen mit extrafloralen Nektarien (EFN) Betriebe werden im Allgemeinen als Ameisenpflanzen betrachtet, trotz der Tatsache, dass sie von vielen anderen rauberischen und parasitoiden Insekten besucht werden. Alle Voraussetzungen fur fakulative Mutualismen zwischen den EFN-Pflanzen und Parasitoiden sind vorhanden, und es gibt einige Hinweise, dass diese Mutualismen bestehen. EFN-Pflanzen, die von einer Vielzahl von Taxa naturlicher Gegenspieler profitieren, werden als Insektenpflanzen bezeichnet. Das Ziel dieser Studie war zu bestimmen, ob Solanum adherens eine Insektenpflanze ist. Dazu wurden die Besucherraten der Parasitoide, das Ausmas des Parasitismus bei einigen, allen unersuchten Pflanzen gemeinsamen Lepidoptera-Arten sowie die gesamte Herbivorenbelastung und -diversitat zwischen S. adherens und zwei Arten der gleichen Gattung verglichen. Auf S. adherens wurden deutlich mehr Parasitoide und eine starkere Parasitierung der Lepidoptera-Schadlinge gefunden, wahrend auf den Arten ohne EFN mehr Arten und insgesamt signifikant mehr Herbivore gefunden wurden. Die Ergebnisse lassen vermuten, dass S. adherens eine Insektenpflanze mit fakultativen, mutualistischen Parasitoiden ist. obwohl keine Parasitoidenart in gleicher Weise wie eine Ameisenart als allgemeiner Schutz wirken kann, waren die Parasitoide in ihrer Gesamtheit in der Lage, die EFN-Pflanze zu schutzen.

Plant Defense Guilds

Optimal plant defense should incorporate any mechanisms that influence the feeding behavior of potential pests. From a diverse collection of examples suggesting that the defense of a plant may be improved in the company of specific neighbors, we discuss a framework of operational mechanisms that begin to clarify some aspects of the recognized influence of species diversity on herbivory. Neighbors serve as insectary plants for herbivore predators and parasites, and influence herbivore feeding behavior by repelling, masking, attracting, and decoying. Insectary plants lower the numerical response of herbivores by increasing the efficiency of their predators and parasites. Repellent plants primarily lower functional response by causing the predator to fail to locate or reject its normal prey. Attractant-decoy plants dilute herbivore impact by drawing off herbivores, either increasing or decreasing their numerical and functional response (or either). The concept of gene conservation guilds adds diversionary and delaying tactics to the adaptation-counteradaptation view of plant-herbivore coevolution. The useful life of a given gene for resistance may best be extended by mechanisms that disrupt genetic tracking (specialization) by herbivores. Some plants may remain inedible not because their chemistry or morphology represents an evolutionary impasse, but because they live in an environment that provides acceptable options of variable quality. Feeding environments that provide little or no choice promote specialization by forcing physiological adaptation. Conversely, the evolutionary momentum of specializing herbivores may be lowered by enhancing their susceptibility, either by selection against virulent individuals, or by decreasing the exposure frequency of susceptible genotypes. The latter mechanism of conserving susceptible individuals takes advantage of herbivore behavioral sensitivity to variable plant quality. Direct selection against virulent genotypes requires temporal cycling of the herbivore population between resistant and nonresistant hosts. Both events may occur within defense guilds that provide acceptable feeding options of similar but distinctive quality.