Joop C. van Lenteren

Do new Access and Benefit Sharing procedures under the Convention on Biological Diversity threaten the future of biological control

Under the Convention on Biological Diversity (CBD) countries have sovereign rights over their genetic resources. Agreements governing the access to these resources and the sharing of the benefits arising from their use need to be established between involved parties [i.e. Access and Benefit Sharing (ABS)]. This also applies to species collected for potential use in biological control. Recent applications of CBD principles have already made it difficult or impossible to collect and export natural enemies for biological control research in several countries. If such an approach is widely applied it would impede this very successful and environmentally safe pest management method based on the use of biological diversity. The CBD is required to agree a comprehensive Access and Benefit Sharing process in 2010, in preparation for which the IOBC (International Organization for Biological Control of Noxious Animals and Plants) Global Commission on Biological Control and Access and Benefit Sharing has prepared this position paper. Here, we first describe the practice of biological control in relation to the principles of ABS, illustrated extensively by case studies and successes obtained with biological control. Next, we emphasise the very limited monetary benefits generated in biological control when compared to other fields of ABS such as the collection of germplasm for development of human drugs, chemical pesticides or crop cultivars. Subsequently, we inform the biological control community of good ABS practice and challenges, and we hope to make clear to the community involved in ABS under the CBD the special situation with regard to biological control. Finally, based on the non-commercial academic research model, we make recommendations which would facilitate the practice of collection and exchange of biological control agents, propose a workable framework to assist policy makers and biological control practitioners, and urge biological control leaders in each country to get involved in the discussions with their national ABS contact point to take their needs into consideration.

Foraging Behaviour of Rhagoletis pomonella, a Parasite of Hawthorn (Crataegus viridis), in Nature

(4) Flies never or rarely oviposited in non-host and marked fruit respectively, and in both cases emigrated from trees harbouring those fruit soon after examining the fruit. (5) Flies exhibited success-motivated search following discovery of and oviposition in uninfested, unmarked fruit. (6) Flies visited more fruit, oviposited more often and remained longer in trees harbouring high v. low densities of fruit clusters. (7) Flies emigrated sooner after the last egg they laid on trees harbouring high, v. low, densities of fruit clusters (Giving Up Time shorter). (8) Rhagoletis pomonella foraging behaviour is discussed in relation to current foraging theory.

Plutella xylostella (diamondback moth) and its parasitoid Diadegma semiclausum show different gustatory and longevity responses to a range of nectar and honeydew sugars

Parasitoids as well as many of their herbivorous hosts, depend on carbohydrate‐rich food during the adult stage. Different types of nectar and honeydew vary with regard to their sugar composition. In order to successfully exploit a food source, the insect must show a positive gustatory response to its component sugars and be able to digest and metabolise them. Here we tested the herbivore Plutella xylostella L. (Lepidoptera: Plutellidae) and its parasitoid Diadegma semiclausum (Hellén) (Ichneumonidae: Campopleginae) with respect to their feeding response and longevity when provided with one of nine sugars (fructose, glucose, lactose, maltose, melibiose, melezitose, raffinose, sucrose, or trehalose). Both species responded to and showed a prolonged life span on a broad range of sugars. The impact of food supply on life span was about sixfold higher for the parasitoid than for the herbivore. In general, there was a good fit between gustatory response and achieved longevity, with some outliers. Both species showed only weak responses to melibiose, which significantly prolonged life span. The parasitoid showed a gustatory response to melezitose, which did not prolong its life span. The parasitoid and its herbivorous host responded differently to trehalose. These differences in gustatory response and longevity show the potential for application of selective sugar sources in conservation biological control. At the same time it also reveals a risk that the indiscriminate application of sugar sources may stimulate herbivory.

Biological control using invertebrates and microorganisms: plenty of new opportunities

Abstract In augmentative biological control (ABC), invertebrate and microbial organisms are seasonally released in large numbers to reduce pests. Today it is applied on more than 30 million ha worldwide. Europe is the largest commercial market for invertebrate biological control agents, while North America has the largest sales of microbials. A strong growth in use of ABC, particularly of microbial agents, is taking place in Latin America, followed by Asia. The current popularity of ABC is due to (1) its inherent positive characteristics (healthier for farm workers and persons living in farming communities, no harvesting interval or waiting period after release of agents, sustainable as there is no development of resistance against arthropod natural enemies, no phytotoxic damage to plants, better yields and a healthier product, reduced pesticide residues [well below the legal Maximum Residue Levels (MRLs)], (2) professionalism of the biological control industry (inexpensive large scale mass production, proper quality control, efficient packaging, distribution and release methods, and availability of many (>440 species) control agents for numerous pests), (3) a number of recent successes showing how biological control can save agricultural production when pesticides fail or are not available, (4) several non-governmental organizations (NGOs), consumers, and retailers demanding pesticide residues far below the legal MRLs, and (5) policy developments in several regions of the world aimed at reduction and replacement of synthetic pesticides by more sustainable methods of pest management. We are convinced, however, that ABC can be applied on a much larger area than it is today. We plead in the short term for a pragmatic form of agriculture that is adaptable, non-dogmatic and combines the sustainability gain from all types of agriculture and pest management methods. We then propose to move to “conscious agriculture”, which involves participation of all stakeholders in the production and consumer chain, and respects the environment and resource availability for future generations. Were “conscious agriculture” to be considered a serious alternative to conventional farming, ABC would face an even brighter future.

Lessons from agriculture for the sustainable management of malaria vectors.

Willem Takken and colleagues argue for the expansion of insecticide monotherapy in malaria control by taking lessons from agriculture and including more sustainable integrated vector management strategies.

Persistence of the fungal whitefly pathogen, Aschersonia aleyrodis, on three different plant species

Persistence of Aschersonia aleyrodis, a fungal pathogen of whitefly, was studied on cucumber, gerbera and poinsettia. Germination capacity and infectivity of conidia, which stayed on the plants for up to 1 month, were assessed. Average germination of conidia on the leaves was low (

Importance of host feeding for parasitoids that attack honeydew-producing hosts

Insect parasitoids lay their eggs in arthropods. Some parasitoid species not only use their arthropod host for oviposition but also for feeding. Host feeding provides nutrients to the adult female parasitoid. However, in many species, host feeding destroys an opportunity to oviposit. For parasitoids that attack Homoptera, honeydew is a nutrient‐rich alternative that can be directly imbibed from the host anus without injuring the host. A recent study showed that feeding on host‐derived honeydew can be an advantageous alternative in terms of egg quantity and longevity. Here we explore the conditions under which destructive host feeding can provide an advantage over feeding on honeydew. For 5 days, Encarsia formosa Gahan (Hymenoptera: Aphelinidae) parasitoids were allowed daily up to 3 h to oviposit until host feeding was attempted. Host feedings were either prevented or allowed and parasitoids had ad libitum access to honeydew between foraging bouts. Even in the presence of honeydew, parasitoids allowed to host feed laid more eggs per hour of foraging per host‐feeding attempt than parasitoids that were prevented from host feeding. The higher egg‐laying rate was not compromised by survival or by change in egg volume over time. In conclusion, host feeding can provide an advantage over feeding on honeydew. This applies most likely under conditions of high host density or low extrinsic mortality of adult parasitoids, when alternative food sources cannot supply enough nutrients to prevent egg limitation. We discuss how to integrate ecological and physiological studies on host‐feeding behavior

Intraguild predation behaviour of ladybirds in semi-field experiments explains invasion success of Harmonia axyridis.

Harmonia axyridis has been introduced as a biological control agent in Europe and the USA. Since its introduction, it has established and spread, and it is now regarded as an invasive alien species. It has been suggested that intraguild predation is especially important for the invasion success of H. axyridis. The aim of this study was to compare the intraguild predation behaviour of three ladybird species (Coccinella septempunctata, Adalia bipunctata, and H. axyridis). Predation behaviour was investigated in semi-field experiments on small lime trees (Tilia platyphyllos). Two fourth-instar larvae placed on a tree rarely made contact during 3-hour observations. When placed together on a single leaf in 23%–43% of the observations at least one contact was made. Of those contacts 0%–27% resulted in an attack. Harmonia axyridis attacked mostly heterospecifics, while A. bipunctata and C. septempunctata attacked heterospecifics as often as conspecifics. In comparison with A. bipunctata and C. septempunctata, H. axyridis was the most successful intraguild predator as it won 86% and 44% of heterospecific battles against A. bipunctata and C. septempunctata respectively, whilst A. bipunctata won none of the heterospecific battles and C. septempunctata won only the heterospecific battles against A. bipunctata. Coccinella septempunctata dropped from a leaf earlier and more often than the other two species but was in some cases able to return to the tree, especially under cloudy conditions. The frequency with which a species dropped did not depend on the species the larva was paired with. The results of these semi-field experiments confirm that H. axyridis is a strong intraguild predator as a consequence of its aggressiveness and good defence against predation from heterospecific species. The fact that H. axyridis is such a strong intraguild predator helps to explain its successful establishment as invasive alien species in Europe and the USA.

Functional anatomy of the ovipositor clip in the parasitoid Leptopilina heterotoma (Thompson) (Hymenoptera: Eucoilidae): a structure to grip escaping host larvae.

Abstract Observations on the host attack behaviour of the parasitoid Leptopilina heterotoma (Hymenoptera : Eucoilidae) led to the supposition that this wasp should possess a structure on its ovipositor by which it can hold a host larvae in a fixed position until the larva is paralyzed. The ovipositor was studied by light, scanning and transmission electron microscopy and appeared to have a clip with teeth on the unpaired valve of the ovipositor, about 50 μm from the tip. Based on the structure of this ovipositor clip and the oviposition behaviour, the functioning of the ovipositor clip is discussed.

Response of the zoophytophagous predators Macrolophus pygmaeus and Nesidiocoris tenuis to volatiles of uninfested plants and to plants infested by prey or conspecifics

Knowledge about the orientation mechanisms used by two important predaceous mirids (Macrolophus pygmaeus Rambour and Nesidiocoris tenuis (Reuter)) in finding their prey (whitefly Bemisia tabaci (Gennadius) and the tomato borer Tuta absoluta (Meyrick)) is limited. In a Y-tube olfactometer, we tested the behavioral responses of naïve and experienced predators to uninfested plants, herbivore-induced plant volatiles (HIPVs) from plants infested with T. absoluta and/or B. tabaci, the sex pheromone of T. absoluta, and volatiles produced by plants injured by the predators. Nesidiocoris tenuis responds to volatiles produced by uninfested plants only after experience with the plant, whereas naïve and experienced M. pygmaeus show positive chemotaxis. Both predators are attracted to volatiles from prey-infested plants, and we provide the first evidence that experience affects this response in M. pygmaeus. Infestation of the same plant by both prey species elicited similar responses by the two predators as plants infested by either herbivore singly. Neither predator responded to sex pheromones of T. absoluta. Macrolophus pygmaeus avoided plants injured by conspecifics, while N. tenuis females were attracted by such plants. The implications of these results for augmentative biological control are discussed.