Predatory Ladybird Research Articles

Integrated biological control of Diaspis echinocacti (Bouché) on Opuntia ficus-indica (L.) Mill (Cactaceae) using predatory ladybirds and fungal pathogens

Diaspis echinocacti (Bouché) (Hemiptera: Diaspididae) causes severe damage to Opuntia spp. (Cactaceae) worldwide, necessitating effective control measures. In this study, we tested the single and combined use of predatory ladybirds and a fungal pathogen on D. echinocacti infesting Opuntia ficus-indica (L.) Mill. Plants under screenhouse conditions (mean 26.32 °C, 55.1% RH.). The treatments were: untreated control, 0.003% Tween 80 (TW), Chilocorus bipustulatus (Coleoptera: Coccinellidae) (CB) alone, Exochomus nigripennis (Coleoptera: Coccinellidae) (EN) alone, entomopathogenic fungi Alternaria murispora (AM) alone, AM + CB, AM + EN, and mineral oil (MO) (positive control). Treatment efficacy was evaluated weekly for five weeks. AM + EN and AM + CB treatments significantly reduced egg counts to 4.89 and 2.44 by week 5, respectively. For motile stages, the AM + CB and AM + EN treatments were most effective, reducing counts to 6.89 and 9.56 by week 5. AM alone resulted in the highest number of mummies (D. echinocacti killed by A. murispora) (29.67) by week 5. For predator densities, C. bipustulatus peaked at 36.11 individuals per cladode by week 3 in the CB-only treatment, while E. nigripennis peaked at 32.33 individuals per cladode by week 3 in the EN-only treatment. Both CB and EN densities were higher in single treatments compared to the combined treatments throughout the study. Combining A. murispora with C. bipustulatus or E. nigripennis significantly reduced D. echinocacti infestations on O. ficus-indica without affecting plant quality (visual score >9 by week 5). Prolonged exposure enhanced efficacy, showing promise for effective non-chemical pest management.

Exploration of Developmental Variants of Predatory Ladybird, Coccinella septumpunctata L. (Coleoptera: Coccinellidae) on an Artificial Diet.

This study aimed to focus on the identification, rearing, and exploration of developmental variants of the predatory ladybird, Coccinella septempunctata L., renowned for its efficacy as a biological control agent and its predation on agricultural pests. However, comprehensive knowledge concerning the occurrence and characteristics of developmental variants in this species remains limited. In this study, through meticulous monitoring and exploration, we identified developmental variants exhibiting distinct sexual attributes, as well as survival rates. The research outcomes enhance our understanding of the developmental variations within an egg batch of C. septempunctata. Moreover, the findings hold practical implications for the implementation of biological control strategies in agriculture, as specific variants may possess unique characteristics that enhance their effectiveness as natural enemies against pests.

Population genomics and demographic modeling enhance our understanding of trophic level interactions in biological control

In this paper, we focus on the application of population genomics, including next-generation sequencing and demographic modeling, to enhance the understanding of historical and contemporary trophic level interactions that are a fundamental basis of biological control. We outline how the integration of ecological approaches with population genomics and demographic modeling can provide additional insights into existing trophic interactions and how natural enemies, their parasitoids, and pest species evolve through these interactions, potentially affecting future levels of biological control. We briefly review and summarize our recent population genomic studies of predatory ladybird beetles and discuss how our results provide guidelines for the use of population genomics techniques and population demographic modeling to enhance our understanding of trophic level interactions. Our intent is to demonstrate as a proof of concept, how these methods can supplement currently used techniques and add a complementary genomic aspect to ecological understandings of trophic level interactions, including estimates of effective population sizes of natural enemies and pest species, examination of correlations between these effective population sizes, and evolutionary changes in natural enemies and pest species which may influence levels of biological control. This in combination with experiments and simulations provide a well-rounded framework for using population genomics to inform multi-tier trophic level interactions.

Interaction of Predatory Ladybird Beetle, Micraspis discolor with Nilaparvata lugens throughout Paddy Growing Seasons

Coccinellidae is a high-interest family that has performed well and is widely distributed. It is valuable in economic service because it acts as an agricultural biological control agent. The Micraspis discolor (Syn=Verania) (Coleoptera: Coccinellidae) is a successful omnivorous predator in rice ecosystem and functions well as a general biological control for maintaining the population of brown planthopper (BPH) (Nilaparvata lugens), the major rice pest worldwide. Studies of natural enemies’ abundance are necessary to increase the practical use of biological control in agriculture. This study investigated the abundance correlation of M. discolor (prey) and rice pest N. lugens (prey) from two different geographical areas of rice fields in west and south Peninsular Malaysia. The cyclone lightrap and sweep net method succeeded in collecting 185 individuals of M. discolor and N. lugens. The study indicated that M. discolor, and the N. lugens collected from Selangor were more numerous than Johor in the ripening phase than in the reproductive and vegetative phases. M. discolor can be found in all stages of rice growth. There are positive correlations between M. discolor and N. lugens in both localities throughout the rice growing season. The positive correlation highlighted that the number of pests has increased parallel to the number of predators and vice versa. The use of M. discolor as a predator is essential in agriculture, along with the treatment of a healthy ecosystem landscape of diverse vegetation combinations, which helps to reduce the use of pesticides.

Effects of Two Prey Species Combinations on Larval Development of the Predatory Ladybird Cheilomenes propinqua.

Feeding on mixed, alternating, or changing diets often favor insect development. With the aim to optimize mass rearing and use for the biological control of insect pests, we investigated the effects of various combinations of high-quality (the green peach aphid Myzus persicae) and low-quality (eggs of the grain moth Sitotroga cerealella) foods on the larval development of a predatory ladybird Cheilomenes propinqua. In the first experiment, eggs and aphids were mixed in different proportions; in the second experiment, larvae switched from feeding on aphids to feeding on eggs. Although the beneficial additive effect of mixed foods was detected in some treatments with limited diets, feeding on various combinations of eggs with aphids never resulted in higher survival, faster development, or a larger size of emerging adults than those observed for feeding on unlimited amounts of aphids. For the practice of biological control, we conclude that, if necessary (for example, in the case of temporary shortage or a lack of aphids in mass rearing facilities or in the case of preventing release of C. propinqua adults in greenhouses), C. propinqua larvae can be fed with grain moth eggs by replacing, mixing, or alternating with aphids, although this will inevitably result in a proportional decrease in pre-adult survival, rate of development, weight, and size of the emerging adults. On the other hand, even a minimal addition of aphids can have a substantial positive effect on larvae fed with grain moth eggs.

Population Growth Parameters of Scymnus nubilus Fed Single-Aphid Diets of Aphis fabae or Myzus persicae.

Life tables are an important tool to forecast the performance of biological control agents used in pest management programs, and they are often assessed in terms of population growth. In the present study, the suitability of the aphids Aphis fabae Scopoli and Myzus persicae (Sulzer) for the ladybird predator Scymnus nubilus Mulsant was assessed for the first time. For this, we evaluated and compared the life history traits of immature individuals and adults of the predator fed single-aphid diets and the consequences of the single-aphid diets for the demographic parameters. Scymnus nubilus that were fed A. fabae were significantly more fecund and presented a shorter immature development time than those fed M. persicae. The predators fed A. fabae had a significantly higher net reproductive rate, an intrinsic and finite rate of increase, while their doubling time was significantly lower than that of those fed M. persicae. The aphid species used in this study are new additions to the essential prey list of the ladybird, with the predator presenting a better biological performance than that found on the previously known essential prey species.

Ladybird predators in natural and agricultural landscapes in Mexico: diversity and parasitism

Ladybirds (Coleoptera: Coccinellidae) are a significant predator group that plays a role in agricultural contexts. They serve as important biocontrol agents against several agricultural pests. However, there is limited information available about how ladybirds’ populations are regulated by their natural enemies and habitat perturbation. In this study, we evaluated ladybird communities associated with natural and managed areas during the agricultural cycle of 2018 (June–September). We identified seven ladybird species; the most abundant species were Hippodamia convergens (70% individuals) and Cycloneda sanguinea (20% individuals), followed by the exotic species Harmonia axyridis (3.33% individuals), while Paranaemia vittigera, Coleomegilla maculata, Brachiacantha sp., and Olla v-nigrum represented less than 3% each. Ladybirds were more abundant in agricultural fields than in natural habitats. We identified several natural enemies associated with the collected ladybirds, including parasitoids (Dinocampus coccinellae, Hymenoptera: Braconidae), ectoparasitic Acari (Coccipolipus sp., Podapolipidae), and nematodes (Mermithidae). However, none of the natural enemies affected more than 10% of the ladybirds, so natural enemies do not appear to be exerting substantial control over their populations. Our results corroborated that ladybirds can efficiently thrive in anthropogenic habitats in Mexico and therefore may represent good biocontrol agents for agriculture. It is important to consider the ecology of agriculturally important ladybirds in programs for integrated pest management. This includes factors contributing to the mortality of ladybirds, including their natural enemies.

Harmonia axyridis (Boyer de Fonscolombe) (Hemiptera: Coccoidea) as a potential biological control agent of the invasive soft scale, Sphaerolecanium prunastri (Boyer de Fonscolombe) (Hemiptera: Coccoidea) in native wild apricot forests

BackgroundThe globose scale (GS), Sphaerolecanium prunastri (Boyer de Fonscolombe) (Hemiptera: Coccoidea), has invaded wild apricot forests in their native range in Central Eurasia threatening the ancestral germplasm resource. Biological control efficacy of the harlequin ladybird, Harmonia axyridis (Pallas, 1773) (Coleoptera: Coccinellidae) against the globose scale was assessed in laboratory and field experiments.ResultsIn the laboratory, Harmonia axyridis has a high feeding capacity on GS with numbers consumed daily increasing with temperature (15, 20, 25, 30, 35 °C), reaching an upper asymptote of 160–200 scales per day. In field cage experiments, efficacy of biological control (EBC) against first instar (49–99%) and second instar nymphs (20–80%) increased with GS density. When ants were present, control efficiency was reduced by 10–15%. In open-field experiments without cages, EBC was comparatively lower regardless of duration and how H. axyridis were released whether as adults, eggs cards or a mixture of adults and eggs cards.ConclusionsIn the long term, biological control with this ladybird predator could be considered as part of an IPM program package that includes banning or delaying mowing grass and understory plants in the forests that offer pollen and nectar for natural enemies.

Shared patterns of population genomic variation and phenotypic response across rapid range expansions in two invasive lady beetle species

Non-native lady beetle species have often been introduced, with variable success, into North America for biological control of aphids, scales, whiteflies, and other agricultural pests. Two predatory lady beetle species, Propylea quatuordecimpunctata and Hippodamia variegata, both originating from Eurasia, were first discovered near Montreal, Quebec, in North America in 1968 and 1984, respectively, and have since expanded into northeastern North America and the midwestern United States. In this study, we estimate the range-wide population structure, establishment and range-expansion, and recent evolutionary history of these lady beetle species using reduced-representation genotyping-by-sequencing via ddRADseq. In addition, we quantified the responses to a key abiotic factor, photoperiod, that regulates adult reproductive diapause in these two species and may influence their geographical range in North America. Our analyses detect: (1) non-significant genetic differentiation and divergence among North American populations that likely originated from a single accidental introduction, (2) evidence of reduced contemporary gene flow within the continental US, and (3) minor phenotypic differences in diapause induction between populations of the two species from the same location.

Artificial diets can manipulate the reproductive development status of predatory ladybird beetles and hold promise for their shelf-life management

With the development of biological control methods, the predatory ladybird beetle Harmonia axyridis Pallas (Coleoptera: Coccinellidae) has been widely used for pest control in agricultural production. Appropriate shelf-life management strategies could synchronize H. axyridis production with pest outbreaks, finally improving the effectiveness of biological control. Herein, we preliminarily explored whether an artificial diet could optimize the shelf-life management of H. axyridis. We compared the survival rate, nutrition accumulation, reproductive development, juvenile hormone (JH) related-gene expression levels, and stress resistance gene expression levels between aphid-fed and artificial diet-fed H. axyridis females. The results revealed that H. axyridis females maintained a high survival rate after being fed an artificial diet for 60 days, whereas the survival rate of aphid-fed females decreased. Continuous feeding of the artificial diet caused H. axyridis females to enter a diapause-like state, which was characterized by low JH levels, high triglycerides and trehalose accumulation, ovarian development inhibition, decreased Vgs expression levels, and increased stress resistance gene expression levels. This diapause-like state could be promptly recovered upon transferring to an aphid diet. These results indicate that the artificial diet could manipulate the reproductive development status of H. axyridis and lay the foundation for its shelf-life management.

Canola bee pollen is an effective artificial diet additive for improving larval development of predatory coccinellids: a lesson from Harmonia axyridis.

Pollen is a common plant-derived food source for predatory ladybird beetles under field conditions, yet the potential for pollen to improve the quality of artificial diets remains largely unexplored. In this study, we developed three pollen diets by incorporating varying proportions of canola bee pollen (7.5%, 15.0% and 22.5% with 2.5%, 5.0%, and 7.5% of water, respectively) into a conventional diet. The feeding efficiency of Harmonia axyridis, an omnivorous predator, was evaluated and compared on three pollen diets, a conventional nonpollen diet and pea aphids. The larvae fed a medium or high pollen diet exhibited significantly higher survival in the 4th instar, pupa and adult stages than those fed a nonpollen diet. These larvae also developed into significantly heavier adults, and their survival rates in adulthood were comparable to those fed pea aphids. Specifically, we revealed the underlying mechanisms through which a high pollen diet enhances pupal development. Consumption of high pollen diet versus nonpollen diet resulted not only in a significant decrease in pupal glycogen content, but also an increase in adult lipid content. Both diet treatments induced similar changes in carbohydrate and glycogen content compared to the aphid diet while exhibiting different alterations in pupal protein content and adult lipid content. Furthermore, the transcriptome analysis revealed that the nutrient metabolism, immune response, and cuticle development pathways were predominantly enriched among the differentially expressed genes (DEGs). Canola bee pollen offers diverse advantages in terms of rearing H. axyridis larvae with an artificial diet, which will advance the development of effective diets for predaceous coccinellids. © 2024 Society of Chemical Industry.

Go west: Population genomics reveals unexpected population fluctuations and little gene flow in Western hemisphere populations of the predatory lady beetle, Hippodamia convergens.

Hippodamia convergens-the convergent lady beetle, has been used extensively in augmentative biological control of aphids, thrips, and whiteflies across its native range in North America, and was introduced into South America in the 1950s. Overwintering H. convergens populations from its native western range in the United States are commercially collected and released across its current range in the eastern USA, with little knowledge of the effectiveness of its augmentative biological control. Here we use a novel ddRADseq-based SNP/haplotype discovery approach to estimate its range-wide population diversity, differentiation, and recent evolutionary history. Our results indicate (1) significant population differentiation among eastern USA, western USA, and South American populations of H. convergens, with (2) little to no detectable recent admixture between them, despite repeated population augmentation, and (3) continued recent population size expansion across its range. These results contradict previous findings using microsatellite markers. In light of these new findings, the implications for the effectiveness of augmentative biological control using H. convergens are discussed. Additionally, because quantifying the non-target effects of augmentative biological control is a difficult problem in migratory beetles, our results could serve as a cornerstone in improving and predicting the efficacy of future releases of H. convergens across its range.

Effects of vector‐borne plant pathogen on the interactions between Diaphorina citri and its natural enemy, Harmonia axyridis

AbstractThe Asian citrus psyllid, Diaphorina citri, is a vector of the bacterial pathogen, Candidatus Liberibacter asiaticus (CLas) that is believed to cause huanglongbing (HLB), also known as citrus greening disease. This phytopathogen can manipulate its vectors directly by modifying behaviour and altering fitness and indirectly by reducing host plant quality, which may affect the predation efficiency of natural enemies. Little is known about how this phytopathogen may affect third tropic level predators. The purpose of this investigation was to determine if the CLas pathogen modifies interactions between D. citri and its predators. We tested whether CLas infection of psyllids indirectly affects fitness of a key predator, the lady beetle Harmonia axyridis. We provided ladybeetles with 10 infected or uninfected adult psyllids in choice bioassays and measured the consumption rate over 24 h. Similarly, 15 infected or uninfected adult psyllids were provided to ladybeetles in no‐choice bioassays and feeding rates and net weight gain of male and female beetles were measured over 5 consecutive days. Fecundity and fertility of lady beetles feeding on CLas‐infected D. citri was reduced compared with those feeding on uninfected D. citri, and oocyte development appeared diminished in those beetles feeding on infected compared with uninfected psyllids. However, in choice assays, beetles did not distinguish between CLas‐infected and uninfected psyllids. We postulate that CLas may reduce the nutritional quality of psyllids diminishing fecundity and fertility of their predatory beetles. Our results lead us to speculate that under conditions of near 100% HLB infection, as occurs endemically in Florida, effectiveness of biological control for D. citri may benefit from provisioning ladybeetle predators with alternative hosts of higher nutritional quality or augmentative releases of laboratory‐reared predators.

Footprints of predatory lady beetles stimulate increased dispersal of aphid prey, but do not alter feeding behavior or spread of a non-persistently transmitted plant virus

Predators impact prey directly, through consumption, and indirectly, through non-consumptive effects that modify prey physiology and behavior in ways that affect survival and reproduction. Non-consumptive effects (NCEs) are well documented across prey taxa in response to different predator cues. However, for most prey species, both the mechanisms underlying NCEs and the impacts of NCEs on broader ecological processes are poorly understood. We addressed these knowledge gaps for an aphid prey species (Myzus persicae) by studying dispersal, in-leaf feeding behavior, and plant virus transmission in response to chemical cues deposited by a walking predator (Hippodamia convergens), a non-predator, non-competitor (Drosophila melanogaster), and an artificial feeding deterrent (2% mineral oil). We used this approach to better understand the specificity of M. persicae responses to chemical footprints of threatening and non-threatening organisms, as well as the magnitude of behavioral responses relative to a known deterrent. We found that chemical footprints deposited by H. convergens stimulated M. persicae to disperse from a suitable host (Brassica napus) at a rate equivalent to the 2% mineral oil positive control, while footprints of D. melanogaster did not modify M. persicae dispersal. Through electrical penetration graphing (EPG) recordings, we found that mineral oil stimulated aphids to make more probes, but footprint treatments did not significantly modify feeding behavior. In mesocosm-based virus transmission assays, H. convergens footprints and 2% mineral oil also stimulated increased dispersal, but this did not translate into increased transmission of turnip mosaic virus. We identified components of H. convergens and D. melanogaster footprints using gas chromatography and mass spectrometry and found that H. convergens footprints are chemically similar to footprints of related Coccinellidae, but distinct from D. melanogaster footprints. Our results provide evidence of specificity in M. persicae responses to predator footprints, which may help this prey species avoid costly dispersal behavior in response to cues from non-predators. We also provide ecological context by demonstrating that increased dispersal in response to predator cues does not always lead to increased virus transmission, as previously assumed, particularly when in-leaf feeding behaviors underlying virus acquisition do not change in response to predator cues.

Correlation between the Seasonal Incidence of Aphids and Coccinellids on the Indian Mustard in Different Varieties and Sowing Dates

Ecological engineering plays an important role in Integrated Pest Management. Considering this, a field experiment was conducted at the Students’ Instructional Farm (SIF), Chandra Shekhar Azad University of Agriculture and Technology, Kanpur during the rabi season of 2020-21. The severity of the mustard aphid, Lipaphis erysimi (Kalt.) in mustard (Brussica juncea L.) crop and its period of occurrence were not uniform in two successive crop seasons. The highest aphid intensities of 120.8 aphids per plant, 138.0 aphids per plant, 148.7 aphids per plant, and 176.1 aphids per plant were recorded on mustard varieties Varuna, Varuna, Azad Mahak, and Ashirwad, respectively, during mid-February (6th MSW) when the mustard was planted on 13th November, 23rd November, 25th November, and 10th December 2020. A negative correlation was established between the average temperature (r = -0.3599) and the actual intensity of aphids, as well as the weekly increase of aphids (r = -0.5838). On the other hand, average relative humidity had a positive influence on aphid incidence. The potentiality of predatory beetles (coccinellids) in the mustard ecosystem was found to be weather-dependent. The weather factors favourable for aphid multiplication did not support the enhancement of the population of predatory ladybird beetles.

Discovery of a novel circulation route of free-living Serratia symbiotica mediated by predatory ladybird beetles.

Horizontal transmission of bacteria to varied hosts can maintain and even expand microbial niches. We previously found that the aphid gut bacterium Serratia symbiotica strain SsMj can be transmitted to ladybird beetles via predation, but whether the predator is a new host, a reservoir or a dead end of this bacterium is unknown. This study aims to provide a clear picture of SsMj circulation from aphids to plants and predators. We first found that SsMj in aphids and ladybirds was abundantly distributed not only in digestive tracts but also in droppings. We found no evidence for vertical transmission of SsMj to aphid offspring. Instead, we showed that it could be transmitted to conspecific aphids by sharing the same plant or contacting honeydews. The key finding of this study is that SsMj was transmitted from aphids to ladybirds through predation, while ladybirds could also transfer SsMj back to aphids, possibly through feces. Together, this evidence suggests that SsMj is able to survive in the digestive tracts and droppings of insects and to expand its host range with plants and predators as reservoirs.

Emergence of the aphid Hysteroneura setariae (Thomas, 1878) and ladybird predators Coccinella septempunctata L., 1758 (Coleoptera: Coccinellidae) on the grass Muhlenbergia capillaris (Lamark) Trinius in central Japan

Pink muhly grass Muhlenbergia capillaris (Lamark) Trinius is a perennial, tussock-forming grass that is native to North and Central America. The reddish-purple coloration of the spikes of this species has resulted in this grass becoming popular as an ornamental plant around the world. Interestingly, very few insects have been reported to be associated with this grass. I therefore examined arthropod assemblages on M. capillaris in two urban parks in central Japan in autumn and found that the aphid Hysteroneura setariae (Thomas, 1878) (Hemiptera: Aphididae) and its natural ladybird predator Coccinella septempunctata L., 1758 (Coleoptera: Coccinellidae) occurred at high densities at one of the parks (ca. 9000 vs 3.4 individuals/m2). Other insect pests, such as the moth Helicoverpa armigera (Hübner, 1808) (Lepidoptera: Noctuidae) and mirid bugs were also present, but at markedly lower densities. Since H. setariae is not a pest in Japan and C. septempunctata is a beneficial predator, M. capillaris could be used as a banker plant in agricultural fields as well as in urban green spaces.

Generalist Predators Shape Biotic Resistance along a Tropical Island Chain.

Islands offer exclusive prisms for an experimental investigation of biodiversity x ecosystem function interplay. Given that species in upper trophic layers, e.g., arthropod predators, experience a comparative disadvantage on small, isolated islands, such settings can help to clarify how predation features within biotic resistance equations. Here, we use observational and manipulative studies on a chain of nine Indonesian islands to quantify predator-mediated biotic resistance against the cassava mealybug Phenacoccus manihoti (Homoptera: Pseudococcidae) and the fall armyworm Spodoptera frugiperda (Lepidoptera: Noctuidae). Across island settings, a diverse set of generalist lacewing, spider and ladybeetle predators aggregates on P. manihoti infested plants, attaining max. (field-level) abundance levels of 1.0, 8.0 and 3.2 individuals per plant, respectively. Though biotic resistance-as imperfectly defined by a predator/prey ratio index-exhibits no inter-island differences, P. manihoti population regulation is primarily provided through an introduced monophagous parasitoid. Meanwhile, resident predators, such as soil-dwelling ants, inflict apparent mortality rates up to 100% for various S. frugiperda life stages, which translates into a 13- to 800-fold lower S. frugiperda survivorship on small versus large islands. While biotic resistance against S. frugiperda is ubiquitous along the island chain, its magnitude differs between island contexts, seasons and ecological realms, i.e., plant canopy vs. soil surface. Hence, under our experimental context, generalist predators determine biotic resistance and exert important levels of mortality even in biodiversity-poor settings. Given the rapid pace of biodiversity loss and alien species accumulation globally, their active conservation in farmland settings (e.g., through pesticide phasedown) is pivotal to ensuring the overall resilience of production ecosystems.

Individual variability and modifi cations of day and night movement activity in Cheilomenes propinqua (Mulsant) (Coleoptera, Coccinellidae) adults

Laboratory experiments revealed individual variability in the intensity of day and night movement activity of starved and fed adults of a predatory ladybird Cheilomenes propinqua . Statistical analysis of the experimental data showed that (1) individual variability of day and night movement activity is determined by di erent parameters of Ch. propinqua adults, (2) environmental factors also have di erent impacts on the rate of individual variability of day and night movement activity, and (3) e ects of temperature and starvation on modi cations of day and night movement activity are also di erent. These results suggest that day and night movement activities of Ch. propinqua adults are determined by di erent physiological mechanisms.

FIRST DATA ON ESTABLISHMENT AND POPULATION TREND OF THE NEOTROPICAL DELPHASTUS CATALINAE (HORN, 1895) (COLEOPTERA COCCINELLIDAE) IN ITALY

After the first record in 2018 in southern Italy and in Sicily, the Neotropical ladybird Delphastus catalinae (Horn, 1895) (Coleoptera: Coccinellidae, Sticholotidinae) has been rediscovered and monitored in Sicily. The population of this non-indegenous species was observed in an experimental citrus orchard with organic management in eastern Sicily. D. catalinae is the only Italian and Sicilian allochthonous ladybird species with Neotropical origin. It was abundant in the study area and active all year, especially in autumn-winter. Overall, a total of 971 specimens of D. catalinae were collected during the three years field surveys on twenty sampled trees. Over the years the population of D. catalinae increased, as increased the percentage of D. catalinae specimens on the total number of ladybirds collected. More studies will be needed for monitoring the spread of D. catalinae in Sicily and the effective interaction with other indigenous ladybird predators of Aleyrodidae like Clitostethus arcuatus (Rossi, 1794). Key Words: Ladybeetles; Delphastus catalinae; Delphastus pusillus; Clitostethus arcuatus; Italy; Biological invaders.