9 Abstract As an effective generalist predator of aphids and other hemipteran pests 10 H. axyridis has been a successful biological control agent. However, the very functional 11 traits that have contributed to its success in this regard also implicate it as an intraguild 12 predator that poses a significant risk not only to the diversity of other natural enemies of 13 Hemiptera (and their associated ecosystem services), but to biodiversity more widely. In 14 this paper we will specifically review the existing data on intraguild predation involving 15 H. axyridis, and consider the strength and symmetry of such interactions both within its 16 native guild and within exotic guilds where it has established as an invasive alien. We will 17 use these studies to interpret the observed population declines in predator diversity in the 18 field, predict species at risk in regions not yet invaded and consider implications for 19 resulting ecosystem services. We will also indicate gaps in our knowledge that require 20 further study in order to identify opportunities for mitigation.21 Keywords Coccinellidae Á Harmonia axyridis Á Aphidophagous guild Á 22 Intraguild predation Á Predators Á Parasitoids Á Pathogens Á Ecosystem services 23 Introduction 24 Terrestrial ecosystems support a diversity of species that are directly and indirectly linked 25 to each other within food webs that span multiple trophic levels. Natural enemy species (in 26 the context of this paper we will collectively call these 'predators' as they all have a trophic 27 relationship with their hosts/prey) contribute to the population regulation of species in both

9 Abstract As an effective generalist predator of aphids and other hemipteran pests 10 H. axyridis has been a successful biological control agent. However, the very functional 11 traits that have contributed to its success in this regard also implicate it as an intraguild 12 predator that poses a significant risk not only to the diversity of other natural enemies of 13 Hemiptera (and their associated ecosystem services), but to biodiversity more widely. In 14 this paper we will specifically review the existing data on intraguild predation involving 15 H. axyridis, and consider the strength and symmetry of such interactions both within its 16 native guild and within exotic guilds where it has established as an invasive alien. We will 17 use these studies to interpret the observed population declines in predator diversity in the 18 field, predict species at risk in regions not yet invaded and consider implications for 19 resulting ecosystem services. We will also indicate gaps in our knowledge that require 20 further study in order to identify opportunities for mitigation.21 Keywords Coccinellidae Á Harmonia axyridis Á Aphidophagous guild Á 22 Intraguild predation Á Predators Á Parasitoids Á Pathogens Á Ecosystem services 23 Introduction 24 Terrestrial ecosystems support a diversity of species that are directly and indirectly linked 25 to each other within food webs that span multiple trophic levels. Natural enemy species (in 26 the context of this paper we will collectively call these 'predators' as they all have a trophic 27 relationship with their hosts/prey) contribute to the population regulation of species in both

The behavioural response of an insect to a fungal pathogen will have a direct effect on the efficacy of the fungus as a biological control agent. In this paper we describe two processes that have a significant effect on the interactions between insects and entomopathogenic fungi: (a) the ability of target insects to detect and avoid fungal pathogens and (b) the transmission of fungal pathogens between host insects. The behavioural interactions between insects and entomopathogenic fungi are described for a variety of fungal pathogens ranging from commercially available bio-pesticides to non-formulated naturally occurring pathogens. The artificial manipulation of insect behaviour using dissemination devices to contaminate insects with entomopathogenic fungi is then described. The implications of insect behaviour on the use of fungal pathogens as biological control agents are discussed.

Reproductive success and response to alarm pheromone, both potentially important components of fitness, were assessed using clones of Myzus persicae (Sulzer) to establish associations with insecticide resistance conferred by insensitive modified acetylcholinesterase (MACE). Both traits showed significant trends that were apparently related to this mechanism. MACE forms appeared to reproduce at slower rates than non-MACE forms expressing moderate (R1) levels of another resistance mechanism based on elevated carboxylesterase. However, MACE forms were more responsive to alarm pheromone than their non-MACE counterparts. The potential implications for parasitoid performance were tested using two clones showing clear differences in alarm response. The level of parasitism of M persicae by the parasitoid Aphidius colemani (Viereck) was significantly lower in MACE forms on pepper crops compared to non-MACE forms. In addition, the distribution of MACE and non-MACE forms differed on the pepper plants, with more MACE forms being found on the growing points. The presence of the parasitoid A colemani did not alter this change in distribution.

1. The ladybird Harmonia axyridis is an invasive alien species in many countries and is predicted to have a negative impact on native biodiversity. However, little is known on the status of this aphidophage as an intraguild predator of natural enemies of aphids such as insect‐pathogenic fungi.2. The study assessed the predation of the aphid‐specific pathogenic fungus Pandora neoaphidis by adult and larval H. axyridis collected from the U.K. (an invasive population) and Japan (a native population) relative to that of the ladybird Coccinella septempunctata (native to the U.K.) and the non‐U.K. C. septempunctata subspecies brucki that were either starved or unstarved.3. Overall, predation of uninfected aphids was greater than infected aphids and, when given a choice, a preference for aphids was shown. However, the extent of this preference was dependent on the species and origin of the coccinellid. Harmonia axyridis (U.K.) consumed the greatest quantity of fungal cadavers and showed little preference for uninfected aphids over infected aphids. In contrast, C. septempunctata rarely consumed infected aphids. Life stage had no direct effects on predation but starved coccinellids consumed more uninfected aphids than infected aphids.4. Harmonia axyridis (U.K.) is a stronger intraguild predator of P. neoaphidis cadavers than the native species C. septempunctata and, therefore, may have an impact on the occurrence and persistence of P. neoaphidis. The differences in intraguild predation by H. axyridis collected in the U.K. and those from Japan suggests that individuals that invaded the U.K. could have a different genetic profile to those in its native range.