Adalia Bipunctata Research Articles

Distribution, host range and host preferences of Dinocampus coccinellae (Hymenoptera: Braconidae): A worldwide database

Dinocampus coccinellae (Schrank) is a braconid parasitoid of ladybird beetles (Coleoptera: Coccinellidae) and has exceptionally wide geographical and host ranges. Based on published and unpublished sources Dinocampus coccinellae probably occurs throughout the temperate, subtropical and tropical climatic zones, but some regions, such as sub-Saharan Africa (except its southernmost part) and the Malay Archipelago, have not so far been surveyed for this wasp. In most of its extensive range D. coccinellae was present before the widespread use of classical biological control. It is likely, however, to have reached some oceanic islands and archipelagos at a later date, along with ladybirds used as biocontrol agents. At least 72 species of Coccinellidae are hosts of D. coccinellae. Three of them, Vibidia duodecimguttata (Poda), Calvia decemguttata (L.) and Coccinella miranda Wollaston, are reported here for the first time as hosts of this parasitoid. The most often reported host of D. coccinellae worldwide is Coccinella septempunctata L. followed by Harmonia axyridis (Pallas), Coleomegilla maculata (De Geer) and Hippodamia convergens Guerin.

Adalia decempunctata (Coleoptera: Coccinellidae), a Palaearctic species now established in North America

Abstract The Palaearctic ten-spotted lady beetle, Adalia decempunctata (Linnaeus), has been confirmed as established in North America, based on morphological characters and DNA barcodes. Its distribution currently appears limited to the Avalon Peninsula of the island of Newfoundland, Canada. Several characters, including the colour of the mesepimera, frons, labrum, antennal club, mouthparts, and legs, are reliable for discriminating among this species and the native, Holarctic two-spotted lady beetle, Adalia bipunctata (Linnaeus), in Newfoundland. An identification key to the two species is provided.

The genome sequence of the two-spot ladybird, Adalia bipunctata (Linnaeus, 1758).

We present a genome assembly from an individual male Adalia bipunctata (the two-spot ladybird; Arthropoda; Insecta; Coleoptera; Coccinellidae). The genome sequence is 475 megabases in span. Most of the assembly (94.87%) is scaffolded into 11 chromosomal pseudomolecules, with the X and Y sex chromosomes assembled. The complete mitochondrial genome was also assembled and is 21.2 kilobases in length. Gene annotation of this assembly in Ensembl identified 13,611 protein coding genes.

Evaluation of manuka honey on the microsporidian pathogen Vairimorpha (Nosema) adaliae and its host, the two-spotted lady beetle, Adalia bipunctata L. (Coleoptera: Coccinellidae)

Honey is known for its antibacterial and antifungal properties. Manuka honey was examined for its potential to manage the microsporidium Vairimorpha (Nosema) adaliae infecting Adalia bipunctata larvae. Development time for uninfected larvae fed aphids and water was 13.0 ± 0.2 days, which did not differ significantly from larvae fed aphids and manuka honey. Development of V. adaliae-infected larvae fed aphids and water was 16.3 ± 0.5 days, compared to 15.0 ± 0.2, 15.2 ± 0.3, and 15.6 ± 0.2 days for larvae fed aphids and 5 %, 10 %, or 15 % manuka honey, respectively. Development time was shorter for all honey treatments, but only those fed 5 % manuka differed significantly from the control. Control adults had 19.4 ± 3.0 spores/120 µm2, compared to 19.0 ± 2.0, 19.1 ± 2.1, and 14.3 ± 2.2, for adults provided with 5 %, 10 %, and 15 % honey, respectively. Although spore loads did not differ significantly (p > 0.05), lighter infections were observed in the group fed 15 % manuka.

(-)-Adaline from the Adalia Genus of Ladybirds Is a Potent Antagonist of Insect and Specific Mammalian Nicotinic Acetylcholine Receptors.

Ladybird beetles (Coleoptera: Coccinellidae) possess strong chemical defences that are secreted in response to stress and are also found on the coating of eggs, which are rich in alkaloids that are responsible for their toxicity to other species. Recent studies have shown that alkaloids from several species of ladybird beetle can target nicotinic acetylcholine receptors (nAChRs) acting as receptor antagonists. Here, we have explored the actions of (−)-adaline, found in the 2-spot (Adalia bipunctata) and 10-spot (Adalia decempunctata) ladybirds, on both mammalian (α1β1γδ, α7, α4β2, α3β4) and insect nAChRs using patch-clamp of TE671 cells and locust brain neurons natively expressing nAChRs, as well as two-electrode voltage clamp of Xenopus laevis oocytes recombinantly expressing nAChRs. All nAChR subtypes were antagonised by (−)-adaline in a time-dependent, voltage-dependent and non-competitive manner with the lowest IC50s at rat α3β4 (0.10 μM) and locust neuron (1.28 μM) nAChRs, at a holding potential of −75 mV. The data imply that (−)-adaline acts as an open channel blocker of nAChRs.

A roadmap for ladybird conservation and recovery.

Ladybirds (Coleoptera: Coccinellidae) provide services that are critical to food production, and they fulfill an ecological role as a food source for predators. The richness, abundance, and distribution of ladybirds, however, are compromised by many anthropogenic threats. Meanwhile, a lack of knowledge of the conservation status of most species and the factors driving their population dynamics hinders the development and implementation of conservation strategies for ladybirds. We conducted a review of the literature on the ecology, diversity, and conservation of ladybirds to identify their key ecological threats. Ladybird populations are most affected by climate factors, landscape composition, and biological invasions. We suggest mitigating actions for ladybird conservation and recovery. Short-term actions include citizen science programs and education, protective measures for habitat recovery and threatened species, prevention of the introduction of non-native species, and the maintenance and restoration of natural areas and landscape heterogeneity. Mid-term actions involve the analysis of data from monitoring programs and insect collections to disentangle the effect of different threats to ladybird populations, understand habitat use by taxa on which there is limited knowledge, and quantify temporal trends of abundance, diversity, and biomass along a management-intensity gradient. Long-term actions include the development of a worldwide monitoring program based on standardized sampling to fill data gaps, increase explanatory power, streamline analyses, and facilitate global collaborations.

Erzurum İlinde Karaağaçlarda (Ulmus glabra Hudson) Zararlı Tinocallis (Sappocallis) saltans (Nevsky, 1929) (Hemiptera: Aphididae)’ın Popülasyon Değişimi ve Predatörleri

Bu çalışma, Erzurum (Atatürk Üniversitesi Kampüsü)’da 2016 ve 2017 yıllarının mayıs-eylül ayları arasında Karaağaç (Ulmus glabra Hudson) bitkisinde yoğun olarak zararına rastlanan Tinocallis (sappocallis) saltans (Nevsky, 1929) (Hemiptera: Aphididae)’ın popülasyon değişimi ve predatörlerini tespit etmek amacıyla yürütülmüştür. Türkiye’de bu karaağaç türü üzerinde T. saltans ilk kez bu çalışma ile belirlenmiştir. Çalışmada, araziden 4 gün aralıklarla karaağaç sürgünleri alınarak laboratuvar ortamına getirilmiş, ergin ve nimf sayımları yapılmıştır. Ayrıca, predatör türler atrap, japon şemsiyesi, aspiratör ve direk elle yakalama yöntemleriyle toplanmışlardır. Predatör türlerin ergin öncesi dönemleri de bulunduğu sürgünlerle laboratuvara getirilmiş ve kültüre alınarak ergin çıkışları sağlanmıştır. Çalışma sonunda, T. saltans’ın 2016 yılında 27 Temmuz (56.83 ergin+nimf), 4 Ağustos (52.32 ergin+nimf) ve 24 Ağustos (47.66 ergin+nimf), 2017 yılında ise 12 Ağustos (39.36 ergin+nimf) tarihinde yaprak başına en fazla birey sayısına ulaştığı tespit edilmiştir. Çalışmada, Coccinellidae (Coleoptera)’den 4 (Adalia bipunctata (L.), Adalia fasciatopunctata revelieri Mulsant; Coccinella septempunctata (L.), Harmonia quadripunctata (Pontoppidan); Anthocoridae (Hemiptera)’den 1 (Orius horvathi Reut.), Nabidae (Hemiptera)’den 1 (Nabis pseudoferus Rem.); Syrphidae (Diptera)’den 5 (Episyrphus balteatus (De Geer), Eristalis pratorum (Meigen), Sphaerophoria rueppelli (Wiedemann), Sphaerophoria scripta (L.), Syritta pipiens (L.)) ve Chrysopidae (Neuroptera)’den 1 (Chrysoperla carnea (Stephens)) tür olmak üzere toplamda 12 predatör tür saptanmıştır. Bu türlerden sırasıyla A. f. revelieri (39 birey), H. quadripunctata (21 birey), C. punctata ve Ch. carnea (16 birey) ve E. balteatus (14 birey) en fazla bireyi elde edilen türler olmuşlardır. Bu predatör türlerin hepsi için T. saltans, Türkiye’de ilk kez bu çalışmada yeni av olarak kaydedilmiş durumdadırlar. Bu türe karşı yapılacak mücadele çalışmalarında özellikle predatörlerinin dikkate alınması büyük önem taşımaktadır.

Influence of Hamiltonella defensa infection and predator type on anti‐predator behaviours in pea (Acyrthosiphon pisum) and potato aphids (Macrosiphum euphorbiae)

AbstractFacultative endosymbionts can induce benefits and costs to their aphid hosts. In the pea aphid, Acyrthosiphon pisum (Harris) (Hemiptera: Aphididae), infection with the γ‐proteobacterium Hamiltonella defensa Moran et al. can confer resistance against parasitoids, but may also reduce the frequency of aggressive and escape behaviours exhibited in response to predators. In potato aphids, Macrosiphum euphorbiae (Thomas) (Hemiptera: Aphididae), H. defensa does not appear to influence susceptibility to parasitism, but its impact on anti‐predator behaviours remains unexplored. Here we investigated defensive behaviours in two pea aphid lines (differing in H. defensa‐infection status) and four potato aphid lines (that additionally differed in genotype‐associated parasitism susceptibility) when faced with foraging ladybirds – Adalia bipunctata (L.) (Coleoptera: Coccinellidae) – and lacewings – Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae). In response to ladybirds, symbiont‐infected pea aphids exhibited proportionately fewer evasive defences (dropping and walking away) than non‐infected (cured) pea aphids, but more frequent aggressive kicking. Ladybirds provoked more evasive, aggressive, and total defensive behaviours than lacewings. For potato aphids, symbiont status, predator type, and aphid genotype (i.e., assumed parasitism susceptibility) all influenced behavioural repertoires. Overall, infected lines showed greater differentiation in behaviours in response to the two predators than the uninfected lines. The presence of the symbiont H. defensa may be a key determinant of aphid anti‐predator behaviours, but the fitness consequences of this are unresolved. In our study, neither symbiont infection status nor aphid genotype affected the number of aphids consumed by predators.

Establishment and Expansion of Harmonia axyridis Pallas (Coleoptera: Coccinellidae) in Urban Green Areas in the Iberian Peninsula: From 2015 to 2021.

Simple SummaryHarmonia axyridis (Coleoptera: Coccinellidae) is a widespread invasive ladybird. In this study, we determine its occurrence and expansion in urban areas of the Iberian Peninsula after 2014. We also define the aphidophagous ladybird species complex in urban areas of the northeastern Iberian Peninsula and track any changes between 2015 and 2021. The expansion of the species mainly occurred in Catalonia (northeast Iberian Peninsula), where spring and summer populations on trees and shrubs and overwintering aggregations were recorded. The records of H. axyridis populations allow us to distinguish between two areas: one that has already been invaded and another that has not yet been invaded. The relative abundance of the ladybird species in each area is determined on a yearly basis. In the invaded area, H. axyridis became dominant two years after its detection, replacing Adalia bipunctata. This change in species prevalence is more pronounced in trees highly infested with aphids. In the not yet invaded area, changes in species dominance also occurred, and A. bipunctata replaced Oenopia conglobata from 2020 onwards. The yearly release of this ladybird in urban green areas for aphid control purposes could explain this shift. This study defines the current situation of H. axyridis in the Iberian Peninsula, and determines the main changes in ladybird species assemblages during the last few years.In the Western Palearctic region, Harmonia axyridis (Coleoptera: Coccinellidae) is mainly established in urban areas. In this study, we update its occurrence in urban areas of the Iberian Peninsula and determine its expansion after 2014. Changes in the ladybird species assemblage are also evaluated. We compile information about the records of H. axyridis in Spain from 2015 to 2021. In addition, we sample different locations to determine the relative abundances of the species composing the aphidophagous ladybird complex. The expansion of H. axyridis mainly occurred in Catalonia (Iberian Peninsula), where it is possible to identify two clear areas: one that has already been invaded and another that has not yet been invaded. Harmonia axyridis became the dominant species in the invaded area two years after it was first identified. This dominance is clearly shown on Liriodendron tulipifera and Tilia platyphyllos, where it accounted for more than 75% of the total collected individuals in the last year of the study. In the not-yet invaded area, Adalia bipunctata overcame Oenopia conglobata and became the prevalent species from 2020 onwards, likely due to its regular releases for aphid biocontrol. This study reveals that changes in ladybird species assemblages may not only be caused by invasive species, but also by biological control practices.

Temporal and climatic variation in the colour forms of Adalia bipunctata and Harmonia axyridis (Coleoptera: Coccinellidae) populations in the United Kingdom

Colour form polymorphism in Adalia bipunctata (Linnaeus, 1785) and Harmonia axyridis (Pallas, 1773) has been extensively studied in the past. Climate, season, and region are known to influence the colour form frequencies of these species, however, this effect is region specific, and the response of populations has changed over time. Here, 5862 photographic records from the UK Ladybird Survey from 2013-2017 were used to assess the geographic variation in colour form frequency (melanic versus non-melanic) of A. bipunctata and H. axyridis across the United Kingdom (UK) in relation to climate and season. Climate data from the UK Met Office were used to determine the effect of climate on melanic form. Seasonal variation in melanic form was observed in H. axyridis but not A. bipunctata. For H. axyridis, the probability of being melanic decreased in areas with higher annual sunlight hours. In A. bipunctata, there was an interaction between sunlight hours and rainfall. In areas with low rainfall, the probability of being melanic was negatively correlated with sunlight hours. Where rainfall was high, the probability of being melanic was positively correlated with sunlight hours. These findings highlight the role of climate in determining the proportion of colour forms in UK populations of A. bipunctata and H. axyridis. Furthermore, the results support the hypothesis that seasonal variation in melanism does not occur in A. bipunctata populations with a low overall proportion of melanics.

Combined effects of insecticide and IGP on native and invasive ladybeetles in apple orchard

AbstractThe Asian ladybeetle Harmonia axyridis Pallas is an invasive species commonly found in Canadian apple orchards. It threatens native ladybeetles through exploitative competition and intraguild predation (IGP), including the 12 spotted ladybeetle Coleomegilla maculata DeGeer (Gagnon, Heimpel and Brodeur, 2011). Both species are exposed to novaluron, a reduced risk insecticide used against the codling moth Cydia pomonella (L.), the primary pest in apple orchards. Previous research showed that novaluron is highly toxic for the invasive H. axyridis, but it is less toxic for the indigenous C. maculata. Novaluron reduces the adaptive value of IGP for H. axyridis but not for C. maculata. However, there is a lack of knowledge on the combined effect of novaluron and IGP outside laboratory conditions. This study explores under semi‐field conditions the effect of novaluron residues and IGP on the survival of H. axyridis and C. maculata larvae. IGP was assessed considering third instar larvae as predators. Results showed that novaluron was toxic for first instar larvae of both species after 10 days of exposure. When H. axyridis was the intraguild predator, novaluron increased the survival of the intraguild preys. Novaluron did not change the outcome of the IGP when C. maculata was the intraguild predator. These results indicate that novaluron can change the competition outcome between the invasive H. axyridis and a native ladybeetle species. This is the first demonstration that intraguild predation and competition may be greatly altered in the presence of pesticides.

The Effects of an Arbuscular Mycorrhizal Fungus and Rhizobium Symbioses on Soybean Aphid Mostly Fail to Propagate to the Third Trophic Level.

The cascading effects of microbe–plant symbioses on the second trophic level, such as phytophagous insects, have been most studied. However, few studies have examined the higher third trophic level, i.e., their natural enemies. We investigated the effects of the symbiotic associations between an arbuscular mycorrhizal (AM) fungus, Rhizophagus irregularis (Glomerales: Glomeraceae), a nitrogen-fixing bacterium, Bradyrhizobium japonicum (Rhizobiales: Bradyrhizobiaceae), and soybean, Glycine max (L.) Merr. (Fabaceae) on two natural enemies of the soybean aphid, Aphis glycines Matsumura (Hemiptera: Aphididae), the ladybird beetle Coleomegilla maculata (De Geer) (Coleoptera: Coccinellidae), and the parasitoid Aphelinus certus Yasnosh (Hymenoptera: Aphelinidae). We measured the growth and survival in the predator and parasitoid reared on aphids feeding on soybean inoculated seedlings. The rhizobium symbiosis alone was affected with a decreased rate of parasitoid emergence, presumably due to decreased host quality. However, number of mummies, sex-ratio, development time, and parasitoid size were all unaffected by inoculation. AM fungus alone or co-inoculated with the rhizobium was unaffected with any of the parameters of the parasitoid. For the predator, none of the measured parameters was affected with any inoculant. Here, it appears that whatever benefits the microbe–plant symbioses confer on the second trophic level are little transferred up to the third.

<i>HARMONIA AXYRIDIS</i> (PALLAS, 1773) (COLEOPTERA: COCCINELLIDAE) IN MOSCOW CITY AND YALTA CITY: ITS COMPETITION WITH NATIVE SPECIES OF COCCINELLIDS AND THE INFLUENCE OF PARASITOIDS ON ITS NUMBER

The Asian ladybird Harmonia axyridis is an invasive species that is rapidly spreading around the world. Occupying new territories, H. axyridis often causes a decrease in the biodiversity of native species of coccinellids, competing with them for food resources. A comparison of H. axyridis with six species of ladybirds was made in terms of the ratio of the number of individuals and the degree of infestation with parasitoids. In Moscow city, the most widespread species of ladybirds was Adalia bipunctata (67.1%), H. axyridis ranks second (16.5%). The total infestation of H. axyridis pupae with parasitoids is 1.8% in Moscow city and 12.2% in Yalta city. Infestation with parasitoids of other ladybird species in Moscow city is much higher: from 11.0% to 36.4%. Thus, parasitoids effectively regulate the number of native ladybird species, but have an insignificant effect on the number of the invasive species H. axyridis .

How Diet Leads to Defensive Dynamism: Effect of the Dietary Quality on Autogenous Alkaloid Recovery Rate in a Chemically Defended Beetle.

The impact of different diets on chemical defense has been extensively studied in animals that sequester defensive chemicals from food. However, there are fewer studies of diet-mediated variation in autogenously produced defenses. Ladybird beetles, which use autogenously synthesized defensive alkaloids, are used as models in a wide diversity of studies of chemical defense, specifically in studies of intraspecific variation in color pattern and chemical defense. Many aphidophagous ladybirds consume a wide diversity of aphid prey, which vary in quality and thus could affect the synthesis of chemical defense. We measured alkaloid recovery rate after reflex bleeding by the ladybird Adalia bipunctata on two different aphid diets, the high quality Acyrthosiphon pisum and the lower quality Aphis fabae. Alkaloids reaccumulated in ladybirds more slowly when they were fed A. fabae than when they were fed A. pisum and females generally had more alkaloid than males, but reaccumulated alkaloid more slowly. Recovery times were more than 12days. There appeared to be a weak positive relationship between alkaloid level and time since reflex bleeding for eggs of A. pisum- but not A. fabae-fed females. Our findings on diet and alkaloid synthesis in ladybirds suggest that chemical defense levels are very dynamic, indicating that studies conducted at a single point in time, such as those focused on ladybird color pattern, fail to consider a wide diversity of temporal variation that occurs in the field. This is likely true for many autogenously produced chemical defense systems in a diversity of other organisms.

EVALUATION OF CHRYSOPERLA CARNEA COMPLEX AND COCCINELLID PREDATORS AS BIOCONTROL AGENTS OF RICANIA SPECULUM (WALKER, 1851) (HEMIPTERA RICANIIDAE)

Ricania speculum is an alien insect feeding on several host plants belonging to several families, including important vegetables, crops, ornamental plants, wild plants as well as trees. For the first time, recently, Chrysoperla sp. and coccinellid beetles have been observed preying on this species in the field on Citrus sp. and Laurus nobilis plants. The main purposes of this work were to evaluate the possible predation capability of these groups of insects and determine their prey preference in laboratory trials. In the choice trials, R. speculum nymphs were paired in a confined space and exposed for 24h to single predators: Ch. carnea complex and to the coccinellids Cryptolaemus montrouzieri, Adalia bipunctata, Coccinella septempunctata, and Propylea quatuordecimpunctata. Specimens of Aphis rumicis, an aphid frequently found on her baceous plants, were used as a control prey. In the cage trials, a single Ch. carnea complex second-instar larva was placed into a jar containing a tomato plant with ten R. speculum nymphs. In the choice trials, a high mortality percentage of both preys was observed with the Ch. carnea complex, while in those with Coccinellids only high A. rumicis mortality was reported. In the cage trials, 13% mortality of R. speculm was recorded after 24h while after 72h and 168h prey mortalities reached 18% and 25%, respectively. The results of the study showed that larvae of the Ch. carnea complex could be potential predators of R. speculum, while coccinellids do not seem promising predators of this alien species.

Declining Abundance of Coccinellidae (Coleoptera) Among Crop and Prairie Habitats of Eastern South Dakota, USA

Lady (= ladybird) beetles (Coleoptera: Coccinellidae) provide agroecosystem services as major predators of aphids and other pests of field crops. Several native coccinellids in North America have declined in association with the introduction of invasive species of lady beetles. In particular, populations of three native species declined drastically (Coccinella transversoguttata richardsoni) or effectively disappeared (Coccinella novemnotata, Adalia bipunctata) from agricultural landscapes in eastern South Dakota, U.S.A., following establishment of an invasive coccinellid (Coccinella septempunctata) in the 1980s. Since then, two other non-native coccinellids (Harmonia axyridisandHippodamia variegata) have established in eastern South Dakota, but long-term analysis of their impact on the aphidophagous coccinellid guild is lacking. This paper summarizes long-term results from 14 years (2007–2020) of sampling coccinellids by sweepnet and timed searches in five field crops and restored prairie in eastern South Dakota. In all, 17,338 aphidophagous coccinellids comprising 10 species were sampled. Two invasive species (Coc. septempunctata, Har. axyridis) were the third- and fourth-most abundant species, respectively. The seven most abundant species constituted 99% of all coccinellids sampled and were recorded from all six habitats. However, coccinellid species ranged considerably in their evenness of habitat use, resulting in differences in rank abundance among habitats. Coccinellid assemblages were similar for alfalfa and winter wheat, but not for other habitats, which possessed distinct coccinellid assemblages based on rank abundance. Annual abundance of coccinellids varied considerably within habitats, but declining trends were evident from significant negative regressions in annual abundance for adult and immature coccinellids in corn and adults in soybean. As a group, native adult coccinellids showed a significant declining trend in corn but not in other habitats, whereas trends for non-native adult coccinellids were non-significant in all habitats. Sample rates of coccinellids in alfalfa, spring grains, and corn in this study were 74, 26, and 6%, respectively, compared to that of a previous study from the region, further indicating substantial decreases in coccinellid abundance. Possible explanations and implications for observed patterns in coccinellid diversity and individual species abundances in field crops and restored prairie of eastern South Dakota are discussed with respect to prey, agronomic trends, and landscape factors.

The diversity of Wolbachia and its effects on host reproduction in a single Adalia bipunctata (Coleoptera: Coccinellidae) population

The diversity of Wolbachia and its effects on host reproduction in a single Adalia bipunctata (Coleoptera: Coccinellidae) population

Does the non-native Harlequin ladybird disrupt the feeding behaviour of the native two-spot ladybird?

Since its arrival in 2004, the non-native Harlequin ladybird Harmonia axyridis (Coleoptera: Coccinellidae) has rapidly spread throughout Britain, and it is now the most common coccinellid in England. There have since been concerns about the detrimental effects it may have on native coccinellids because there is a strong correlation between the arrival of H. axyridis and the decline in native species, including the two-spot ladybird, Adalia bipunctata. However, there have been few studies of the behavioural interactions between these two species, which occupy a high-niche overlap. This study investigated if the presence of H. axyridis impacts the feeding behaviour of A. bipunctata through direct competition for aphid prey. Foraging and interactive behaviour of A. bipunctata and H. axyridis were investigated within microcosms. Adalia bipuncata exhibited a similar consumption rate and time in the presence of H. axridis, yet H. axyridis consumed 3.5 times more prey items and were seven times faster compared to A. bipuncata. Observations showed that H. axyridis does not directly disrupt the feeding behaviour of A. bipunctata, but rather indirectly excludes the native species through being a superior competitor for prey items. Results indicate that the decline in native coccinellid species may be a consequence of H. axyridis competitive advantage, but that the concept of coexistence should not be dismissed.

Efficacy and biosafety assessment of neuropeptide CAPA analogues against the peach-potato aphid (Myzus persicae).

Insect CAPA neuropeptidesare considered to affect water and ion balance by mediating the physiological metabolism activities of the Malpighian tubules. In previous studies, the CAPA-PK analogue 1895 (2Abf-Suc-FGPRLamide) was reported to decrease aphid fitness when administered through microinjection or via topical application. However, a further statistically significant decrease in the fitness of aphids and an increased mortality could not be established with pairwise combinations of 1895 with other CAPA analogue. In this study, we assessed the topical application of new combinations of 1895 with five CAPA-PVK analogues on the fitness of aphids. We found that 1895 and CAPA-PVK analogue 2315 (ASG-[β3 L]-VAFPRVamide) was statistically the most effective combination to control the peach potato aphid Myzus persicae nymphs via topical application, leading to 72% mortality. Additionally, the combination (1895+2315) was evaluated against a selection of beneficial insects, that is, a pollinator (Bombus terrestris) and three natural enemies (Chrysoperla carnea, Nasonia vitripennis, and Adalia bipunctata). We found no significant influence on food intake, weight increase, and survival for the pollinator and the three representative natural enemies. These results could facilitate to further establish and generate CAPA analogues as alternatives to broad spectrum and less friendly insecticides.

Post-Dropping Behavior of Potato Aphids (Macrosiphum euphorbiae)

Dropping behavior is an effective antipredator defense utilized by many insects including aphids, which drop from plants to lower plant parts or underlying substrates to avoid attack from predatory invertebrates. While research commonly focusses on triggers of dropping, less attention is given to what happens to prey individuals following escape drops. In this study, the duration of tonic immobility, recovery rates, and cases of “instant recovery” (re-clinging to lower plant parts) exhibited by potato aphids (Macrosiphum euphorbiae) that dropped from potted seedlings in response to introduced ladybird (Adalia bipunctata) adults, lacewing (Chrysoperla carnea) larvae, and a standardized tactile stimulus were investigated in relation to a range of environmental factors. Air temperature had a negative correlation with the duration of post-dropping tonic immobility; as temperature increased, time spent motionless decreased. Aphids also showed a pattern of increased recovery rate at higher temperatures. Aphids may be selected to move off the substrate quicker to avoid risks of overheating/desiccation at higher temperatures; and/or higher body temperature facilitates locomotion. Stimulus type also influenced recovery rate back to the original seedling, with aphids generally recovering after the standardized stimulus quicker than after dropping triggered by a real predator. Considering cases of instant recovery onto lower-reaches of the host seedling, seedling height influenced the likelihood of re-clinging, with aphids that managed to instantly recover dropping from, on average, taller seedlings than aphids that dropped to the substrate. Plant architecture could mitigate the costs of dropping for aphids, but further studies quantifying understory foliage cover are needed.