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This book contains 20 chapters, divided into 6 sections. The first section discusses the development of quality control for natural enemies. The second section consists of chapters dealing with background information on sources of variation in foraging behaviour that are regularly encountered, but not understood and often misinterpreted in mass rearing. The third section focuses on how to cope with this variation. The fourth section gives an overview of the species of natural enemies that are mass produced worldwide. The fifth section contains chapters that describe developments towards quality control testing of natural enemies. The sixth and the final section deals with actual quality control tests. This section provides a description of the guidelines that are currently used for quality control of commercially produced natural enemies, and discusses future improvements of these guidelines.

There is increasing interest in the use of fungi for the control of pests, weeds and diseases. This book brings together perspectives from pathology, ecology, genetics, physiology, production technology, to address the use of fungi as biological control agents.

Interest in biological control of plant pathogens has been stimulated in recent years by trends in agriculture towards greater sustainability and public concern about the use of hazardous pesticides. There is now unequivocal evidence that antibiotics play a key role in the suppression of various soilborne plant pathogens by antagonistic microorganisms. The significance of antibiotics in biocontrol, and more generally in microbial interactions, often has been questioned because of the indirect nature of the supporting evidence and the perceived constraints to antibiotic production in rhizosphere environments. Reporter gene systems and bio-analytical techniques have clearly demonstrated that antibiotics are produced in the spermosphere and rhizosphere of a variety of host plants. Several abiotic factors such as oxygen, temperature, specific carbon and nitrogen sources, and microelements have been identified to influence antibiotic production by bacteria biocontrol agents. Among the biotic factors that may play a determinative role in antibiotic production are the plant host, the pathogen, the indigenous microflora, and the cell density of the producing strain. This review presents recent advances in our understanding of antibiotic production by bacterial biocontrol agents and their role in microbial interactions.

Nesidiocoris tenuis (Reuter) (Hemiptera: Miridae) is an effective predator of pests of tomato crops and a promising biocontrol agent of Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) in the Mediterranean area. The aim of this study was to determine the numerical response of N. tenuis to different levels of abundance of T. absoluta and its potential for controlling it when infesting tomato crops. The effects of infesting plants with either 0.2 or 2 larvae of T. absoluta and releasing either 2 or 0 adults of N. tenuis per plant were assayed in a complete factorial randomised-block design with 3 repeats in 12 greenhouse compartments in southern Spain. The population dynamics of the moth was similar in all compartments, with and without N. tenuis, but T. absoluta reached a lower absolute peak density in compartments with N. tenuis (29.1 +/- 8.2 larvae per leaf) than in those without them (44.5 +/- 19.4 larvae per leaf). The peak numbers of larvae of T. absoluta did not differ on the plants initially infested with 0.2 or 2 larvae. Nesidiocoris tenuis reached a maximum of 1.9 +/- 0.43 and 3.0 +/- 0.4 individuals per leaf in compartments in which low and high numbers of T. absoluta were initially introduced, respectively. The yield of tomatoes was higher in the treatments with N. tenuis than in those without, but the percentage of damaged fruit (more than 50%) was similar. The slow numerical response of N. tenuis might have been due, among other things, to the poor establishment of this mirid due to the scarcity of prey. N. tenuis densities of about 0.2 individuals per leaf during the linear population growth phase of T. absoluta (0.5 to 3 larvae per leaf) did not prevent outbreaks.

The efficacy of natural enemies in controlling pests under field conditions is largely correlated with their capacity to spread within infested crops. In this study the spatial dispersal of the California red scale parasitoid Aphytis melinus was evaluated in the field after augmentative releases. The experiment was conducted in 2007 in six 1-ha plots in a Sicilian citrus orchard under integrated pest management. A total of 180,000 A. melinus adults was released in each of three plots and the other plots were left as untreated control. The flight range of the parasitoid was evaluated, for 35 days after the release, on 16 trees per each plot, located at 20 and 40 m from the central release point using yellow sticky traps activated with Aonidiella aurantii sexual pheromone and by monitoring the percentage parasitism of the scale on fruits and twigs. The effects of the distance from the release point and density of susceptible stages of host on parasitoid dispersal were evaluated. The number of wasps captured during the whole trial was greater in the traps located 20 m from the release point than in those at 40 m and in the control plots. Aphytis melinus dispersed over distances less than 40 m based on both the lower percentage parasitism and numbers captured recorded at distances of 40 m. The results are discussed in the context of the biological control of California red scale in citrus orchards by means of wasp releases. In particular, the release points should be no more than 40 m apart for a quick and homogeneous colonization of the area treated.

In the present study, the predatory interactions between two locally abundant large lady beetles, Coccinella septempunctata L. (C7) and Coccinella transversalis F. (Ct) provided with either an extremely scarce, scarce, sub-optimal, optimal or abundant supply of the pea aphid, Acyrthosiphon pisum (Harris) were investigated. For this, three 2-predator combinations (conspecific C7 + C7 and Ct + Ct, and heterospecific C7 + Ct) of 10-day-old unmated adult females were used. The relationships between the proportion of prey consumed by the predators in the conspecific and heterospecific combinations when provided with five different abundances of prey were similar in consisting of a decelerating (type II) functional response when provided with an extremely scarce to optimal supply of prey, followed by an accelerating (type III) functional response when provided with an optimal to abundant supply of prey. It is likely that the modified type II functional response recorded in the present study was a consequence of using a small experimental arena (Petri dish). The multiplicative risk model analysis revealed that the predators interacted antagonistically except in the C7 + C7 combination provided with an extremely scarce supply of prey where the predators had an additive effect. The predators in the heterospecific C7 + Ct combination consumed fewer aphids when provided with an extremely scarce, scarce, sub-optimal or optimal supply of prey prey than the predators in conspecific C7 + C7 combination but a similarly high number when provided with an abundant supply of prey. In addition, the efficiency of converting prey biomass into their own biomass was higher in the heterospecific C7 + Ct than in the conspecific C7 + C7 or Ct + Ct combinations at all prey densities. Although the conversion efficiency of the predators in the conspecific and heterospecific combinations provided with an extremely scarce supply of prey was the highest recorded, their growth rate was the lowest. In contrast, both the conversion efficiency and growth rate of the predators in the three combinations were highest when provided with an abundant supply of prey. It may, therefore, be concluded that when the predators in the combinations occupy similar ecological niches, they will probably consume less prey than they require when prey is both scarce and abundant because the predators interact antagonistically.

The predatory bug Orius sauteri (Poppius) (Hemiptera: Anthocoridae) is an important biological control agent in Asia that is often released on field crops and in greenhouses to control pests on vegetable and ornamental plants. This study compared the developmental and reproductive performance of O. sauteri on monotypic diets of four aphid species, western flower thrips, and two-spotted spider mite. Thrips emerged as the optimal prey type, consistent with findings for many other Orius spp. A diet of Frankliniella occidentalis (Pergande) yielded the fastest development, largest adult body size, shortest pre-oviposition period, and highest fecundity and longevity. Tetranychus urticae (Koch) was the next most suitable prey by most performance measures. Among aphids, Myzus persicae (Sulzer) was the most suitable and Aphis gossypii Glover the least suitable, with Aphis craccivora Koch and Megoura japonica (Matsumura) intermediate. Female O. sauteri were larger than males and female body mass varied more with prey type than did that of males. Despite the variation in performance among prey, all prey species yielded equally good juvenile survival and none would be expected to negatively impact the numerical response of O. sauteri in biological control applications where these arthropods form part of the prey complex.

The effects of condensed tannins (CTs) extracted from pine bark on egg hatching, larval development and the viability of infective L3 larvae of Trichostrongylus colubriformis and Teladorsagia circumcincta (syn. Ostertagia circumcincta) were evaluated using in vitro bioassays. Significant inhibitory effects of CTs were obtained on the viability of the infective larvae, egg hatching and larval development of both nematodes. In all bioassays, the larval stages of Te. circumcincta were significantly (P less than 0.05) more susceptible to the inhibitory effects of CT than those of Tr. colubriformis. At 1 000 microg/ml, CTs from pine bark inhibited 48% and 69% of the infective larvae of Tr. colubriformis and Te. circumcincta, respectively, from passing through the sieve relative to the control incubations (no CT added; P less than 0.0001). At the same concentration, CTs were able to inhibit 36% and 47% of the eggs of the two parasites, respectively, from hatching relative to the control incubations without CTs. Moreover, at 150 microg/ml, the CTs were able to inhibit 88% and 95% (P less than 0.0001 relative to control incubation) of L1 larvae of the two nematodes, respectively, from attaining the full development to L3 larvae in comparison with the control incubations without CTs. At 200 microg/ml, CTs were able to inhibit completely the larval development in both nematodes. Addition of 2 microg polyethylene glycol (PEG; tannin inhibitor) per microg CT eliminated up to 87% of the CT activity (P less than 0.0001) compared to incubations without PEG. In conclusion, this study shows that CTs are able to disrupt the life cycle of nematodes and their effects varied according to the parasite species and stage.

Predator searching efficiency increases in response to a variety of environmental cues associated with its prey. The sugary excretion of aphids (honeydew) has been found to act as a prey-associated cue for many aphid natural enemies. In the present study, the honeydew excreted by Acyrthosiphon pisum (Harris) was identified as an arrestant and a contact kairomone for young larvae and adults of a common predatory hoverfly, Episyrphus balteatus (De Geer) (Diptera: Syrphidae). First and second instar larvae increased their foraging behaviour in the honeydew-treated area. When plants were sprayed with crude honeydew, the speed of movement of female E. balteatus was significantly higher than in controls, resulting in a longer period of time spent on treated plants and laying eggs. We conclude that the honeydew excreted by A. pisum induces searching behaviour and acts as and arrestant not only for adults but also for young E. balteatus larvae.

The activity of Rhizobium japonicum against the soilborne pathogens Fusarium solani and Macrophomina phaseolina as causative agents of soybean root rot disease in both culture medium and soil was evaluated. Rhizobial culture filtrate caused an inhibition of the radial growth of Fusarium solani and Macrophomina phaseolina on potato dextrose agar medium amended with the filtrate compared with control. The addition of rhizobial culture suspension to the soil contaminated by the two pathogens, Fusarium solani and Macrophomina phaseolina and their interaction, in pots improved seed germination percentages and reduced the root rot disease index significantly. The sowing of rhizobial coated seeds in soil contaminated by Fusarium solani and Macrophomina phaseolina (separately and in combination) in the field increased seed germination significantly and induced a high reduction in disease severity. These results indicate that rhizobia could be an important element in root rot disease management.