Mealybug Species Research Articles

First report of mealybug, Crisicoccus hirsutus (Newstead) on cocoa (Hemiptera, Peudococcidae) from India

During the survey, five species of mealybugs viz., Pseudococcus longispinus (Targioni Tozzetti), Planococcus citri (Risso), Rastrococcus sp., Planococcus lilacinus Cockerell and Crisicoccus hirsutus Newstead) were found damaging cocoa crop. Among these, C. hirsutus, collected from cocoa plantation of Sagara taluk of Shivamogga District, Karnataka, is a new record from India.

Description of Peliococcus schmuttereri Caballero and Kaydan sp. n. from specimens of an invalid species, Spinococcus kozari Schmutterer, 2002 (Hemiptera: Pseudococcidae)

ABSTRACT The description of a mealybug species found in Germany, Spinococcus kozari Schmutterer, 2002 (Hemiptera: Coccomorpha), is considered invalid because no type material or depository were specified in the original literature. Here a valid description of the same species is provided under the name Peliococcus schmuttereri Caballero and Kaydan sp. n. following the International Code of Zoological Nomenclature. The species is redescribed, with a taxonomic illustration and microphotographs, an updated taxonomic key is provided, and type material and a depository are designated. With this record, the number of species of Peliococcus Borchsenius, 1948 is increased to 37 worldwide and the number of Peliococcus species present in Germany is increased to two, the second species being Peliococcus calluneti (Lindinger, 1912). http://www.zoobank.org/urn:lsid:zoobank.org:pub:875561CB-E514-4084-8F7A-AF36A3C24D53

Chromosome-level genome assembly of the invasive pest Pseudococcus jackbeardsleyi (Hemiptera: Pseudococcidae)

Among over 2,000 species of mealybugs (Hemiptera: Pseudococcidae), only 13 genomes have been published so far, seriously limiting the researches on the phylogeny and adaptive evolution of this group. The continuous publication of mealybug genomes will significantly facilitate our exploration of the biological characteristics, detrimental attributes, and control strategies of the Pseudococcidae family. Jack Beardsley mealybug (Pseudococcus jackbeardsleyi) as one of the hazardous invasive pests, it could cause enormous losses to the fruit and vegetable industries worldwide. Herein, we combined Nanopore long-read, short-read Illumina and Hi-C sequencing, generating a high-quality chromosome-level genome assembly of P. jackbeardsleyi. The genome size was determined to be 334.818 Mb, which was assembled into 5 linkage groups with a N50 of 67.233 Mb. The BUSCO analysis demonstrated the completeness of the genome assembly and annotation are 95.7% and 92.8%, respectively. The developed high-quality genome will serve as an asset for delving into the genetic mechanisms underlying the invasiveness of P. jackbeardsleyi, thereby offering a crucial theoretical foundation for the prevention and management of Pseudococcidae pests.

Mealybug Population Dynamics: A Comparative Analysis of Sampling Methods for Saccharicoccus sacchari and Heliococcus summervillei in Sugarcane (Saccharum sp. Hybrids).

This research is focused on a comparative field-based study of the population dynamics and sampling methods of two mealybug species, Saccharicoccus sacchari (Cockerell, 1895) (Hemiptera: Coccomorpha, Pseudococcidae) and Heliococcus summervillei (Brookes, 1978) (Hemiptera: Coccomorpha, Pseudococcidae), in sugarcane (Saccharum sp. hybrids) (f. Poaceae) over consecutive growing seasons. The research monitored and compared the above- and belowground populations and seasonal abundance of these two mealybug species in sugarcane fields in Far North Queensland, with non-destructive sampling techniques of yellow sticky traps, pan traps, and stem traps, and destructive sampling of the whole leaf and whole plant. The results indicated that S. sacchari (n = 29,137) was more abundant and detected throughout the growing season, with population peaks in the mid-season, while H. summervillei (n = 2706) showed peaks of the early-season activity. S. sacchari is primarily located on sugarcane stems and roots, compared to H. summervillei, which is located on leaves and roots. The whole-leaf collection and stem trap were the most effective sampling techniques for quantification of H. summervillei and S. sacchari, respectively. This study enhanced the understanding of S. sacchari and the first-ever record of H. summervillei on sugarcane in Australia and will contribute to the development of more effective pest management strategies.

The Determination Mealybug Species and Natural Enemies in Pitaya Greenhouses in the Mediterranean Region

Pitaya, Hylocereus spp. (Caryophyllales: Cactaceae) has been one of the new species cultivated in Türkiye in recent years. There are many limiting factors, including pests, diseases and weeds, to decrease the yield and fruit quality in pitaya (dragon fruit) areas in Türkiye. In addition, the pests of pitaya is not fully studied therefore this research has been conducted to determine mealybug species in pitaya greenhouses in Türkiye. The present study aimed to determine mealybug species and its natural enemies (parasitoids, and predator insects) in pitaya greenhouses in Adana, Mersin, and Antalya between 2021 and 2022. According to results of this study, 2 different mealybug species was determined; Phenacoccus solenopsis Tinsley 1898, Phenacoccus madeirensis Green, 1923 (Hemiptera: Pseudococcidae) in pitaya greenhouses. Moreover one parasitoid (Aenasius arizonensis Girault (Hymenoptera: Encyrtidae), and two different predatory insects from 2 different orders and 2 different families (Chrysoperla carnea Stephens (Neuroptera: Chrysopidae), Nephus includens Kirsch (Coleoptera: Coccinellidae) were detected within this research. These two invasive mealybug species have wide spectrum host plants and may cause economically important damages to pitaya, if natural enemies cannot work successfully or control strategies do not applied properly in pitaya greenhouses.

Development of recombinase polymerase amplification-based colorimetric detection assay for rapid identification of invasive cassava mealybug, Phenacoccus manihoti Matile-Ferrero

Phenacoccus manihoti Matile-Ferrero (Hemiptera: Pseudococcidae), is an economically important invasive cassava pest responsible for the massive devastation of cassava in Asia and African continent. Initially, identifying this invasive pest posed challenges because it closely resembled native mealybug species. Additionally, the traditional morphological identification process is labor-intensive and time-consuming. Detecting invasive pests at an early stage is crucial, hence development of a rapid detection assay is essential. In the current study, we have developed a simple, rapid, sensitive, and efficient molecular detection assay for P. manihoti based on Recombinase Polymerase Amplification (RPA). The primers for the RPA assay were designed using unique nucleic acid sequences of P. manihoti, and the protocol was standardized. Specificity test demonstrated that the RPA assay could amplify DNA of P. manihoti only, and no amplification was observed in six other mealybug species. The specificity of assay was confirmed using SYBR green-based colorimetric detection and gel electrophoresis where positive samples showed 195 bp amplicon size in P. manihoti samples. The assay successfully amplified P. manihoti DNA in thirty minutes at an annealing temperature of 41° C in a water bath and displayed a sensitivity of 72.5 picograms per microliter. The assay's simplicity, rapidity, and high sensitivity make it a valuable tool for detecting and monitoring P. manihoti in quarantine stations and facilitating in development of a portable diagnostic kit.

A new species of Paraputo Laing 1929 (Hemiptera: Coccomorpha: Pseudococcidae) from India

A new mealybug species, Paraputo blackmani Joshi, sp. n. (Hemiptera: Coccomorpha: Pseudococcidae) is described and illustrated based on adult females collected from Butea monosperma (Fabaceae), in Bengaluru Rural district, Karnataka, southern India. The new mealybug is most similar morphologically to P. mazoensis (Hall). Ants belonging to the genus Nylanderia were found tending the mealybugs; notes on the ecological associates of the mealybug and a key to adult females of all the species of Paraputo recorded from India are provided.

Three new species of Puto giant mealybugs (Hemiptera: Coccomorpha: Putoidae) from Mexico and Guatemala, with keys to New World adult females and World adult males

Three new species of Puto Signoret, 1876 are described and illustrated from material intercepted at US plant quarantine inspection, including the adult females, all available immature stages, and for two species, the adult male. Puto philo Powell & Miller, sp. n. and Puto brom Powell & Miller, sp. n. are described from Mexico, and Puto spath Powell & Miller, sp. n. is described from Guatemala. Three keys are included to: the instars of Puto, the New World species of Puto based on adult females, and a world key to the adult males of Puto.

Two new species of the mealybug genus Paracoccus from Jiangxi, South China (Hemiptera, Coccomorpha, Pseudococcidae).

Two new mealybug species, Paracoccusgillianwatsonae Zhang, sp. nov. and P.wui Zhang, sp. nov., collected from Jiangxi, South China, are described and illustrated based on the morphology of adult females. Paracoccusgillianwatsonae is similar to P.burnerae (Brain, 1915), but it differs in having fewer pairs of cerarii, and in lacking both ventral oral collar tubular ducts on the margins of the head and translucent pores on the hind femur. Paracoccuswui resembles P.keralae Williams, 2004 and P.neocarens (Lit, 1992), but it differs in lacking ventral oral collar tubular ducts on the margins of the head and in having multilocular disc-pores usually in double rows at the posterior edges of abdominal segments V and VI. A key to the Paracoccus species found in China is provided.

Rapid identification of Ripersiella (= Rhizoecus) hibisci (Kawai & Takagi, 1971) (Hemiptera: Rhizoecidae) with TaqMan probe‐based real‐time PCR

AbstractRipersiella hibisci (Kawai & Takagi, 1971) is a root mealybug included in the EPPO A1 list of pests recommended for regulation and an EU A1 Quarantine pest list (Annex IIA). This pest causes damage to several species of monocotyledonous and dicotyledonous ornamental and foliage potted plants, especially bonsais. The underground location of R. hibisci makes its detection difficult during phytosanitary controls, and moreover, it can be confused with other non‐regulated species of mealybugs (e.g. Planococcus citri, P. ficus, Rhizoecus falcifer, Rhizoecus dianthi). Thus, a molecular test based on real‐time PCR was designed for rapid and unambiguous identification of this mealybug. Analytical sensitivity, analytical specificity, repeatability and reproducibility of the test were assessed as part of the validation. The test showed 100% analytical specificity (exclusivity and inclusivity), allowing the target to be distinguished from all non‐target species tested (exclusivity); the inclusivity was demonstrated, validating the test on different populations of the pest. The molecular test is an efficient tool for the identification of the root mealybug R. hibisci (in its various life stages), which is particularly useful when a rapid screening of samples is needed to limit or avoid the introduction of the pest.

Coccinellid predators of mealybugs infesting banana in South India, including a new species and a new record of Scymnus Kugelann (Coleoptera: Coccinellidae), with notes on other natural enemies.

Several species of mealybugs infest various parts of bananas and plantains including foliage, fruits, rhizome and roots in all the major banana growing regions of India and cause moderate to occasionally serious damage but systematic attempts at documenting the mealybug pests of banana and their natural enemies are lacking in India. In this study, mealybugs infesting bananas and plantains in Tamil Nadu, South India, are documented along with their coccinellid predators and other natural enemies. The exotic Jack Beardsley mealybug, Pseudococcus jackbeardsleyi Gimpel & Miller, was found to be a major pest of banana bunches in all localities surveyed in Tamil Nadu and the grey pineapple mealybug, Dysmicoccus neobrevipes Beardsley, was a serious pest in some isolated pockets. Three coccinellids, Scymnus (Pullus) coccivora Ramakrishna Ayyar, Nephus regularis Sicard and Slipinskiscymnus saciformis (Motschulsky) were found to be the major predators of all species of mealybugs. Brumoides suturalis (Fabricius) was predatory on solenopsis mealybug (Phenacoccus solenopsis Tinsley) only and Hyperaspis maindroni Sicard was associated with solenopsis mealybug and pink pineapple mealybug (Dysmicoccus brevipes (Cockerell)). One new species, Scymnus (Pullus) spicatus sp. n., is described as a predator of Jack Beardsley mealybug and striped mealybug (Ferrisia virgata (Cockerell)). Scymnus (Pullus) syoitii Sasaji, 1971, a Japanese species, is recorded for the first time from India as a predator of banana root mealybugs in Tamil Nadu and on Planococcus citri (Risso) in Karnataka. Brief notes on the other natural enemies of banana mealybugs are also given with illustrations.

Cacao sustainability: The case of cacao swollen-shoot virus co-infection.

The cacao swollen shoot virus disease (CSSVD) is among the most economically damaging diseases of cacao trees and accounts for almost 15-50% of harvest losses in Ghana. This virus is transmitted by several species of mealybugs (Pseudococcidae, Homoptera) when they feed on cacao plants. One of the mitigation strategies for CSSVD investigated at the Cocoa Research Institute of Ghana (CRIG) is the use of mild-strain cross-protection of cacao trees against the effects of severe strains. In this study, simple deterministic, delay, and stochastic ordinary differential equation-based models to describe the dynamic of the disease and spread of the virus are suggested. Model parameters are estimated using detailed empirical data from CRIG. The modeling outcomes demonstrate a remarkable resemblance between real and simulated dynamics. We have found that models with delay approximate the data better and this agrees with the knowledge that CSSVD epidemics develop slowly. Also, since there are large variations in the data, stochastic models lead to better results. We show that these models can be used to gain useful informative insights about the nature of disease spread.

Identification and characterization of novel resistant genotypes of Gymnema sylvestre (Retz.) R. Br. ex Sm. against invasive mealybug species, Phenacoccus solenopsis Tinsley and Paracoccus marginatus Williams and Granara de Willink for sustainable pest management

Madhunashini, Gymnema sylvestre R. Br. ex Sm. (F: Asclepiadaceae) is an important industrial medicinal plant that has various pharmacological properties like antidiabetic, antiobesity, anticarcinogenic and neuroprotective. The invasive mealybugs, i.e., Phenacoccus solenopsis and Paracoccus marginatus, are causing significant yield losses to G. sylvestre in India. The identity of the mealybug species, P. solenopsis and P. marginatus, were confirmed both morphologically and molecularly by using Cytochrome c oxidase subunit I (COI) gene with (GenBank Accession No. OQ349395 and OQ358124). The pest incidence occurs throughout the year, but its peak activity was observed during the summer months (April to August). In the current investigation, 30 genotypes were examined for their resistance against mealybugs in their natural field environment for three consecutive years from 2019 to 2021 in the geographical region of Anand, Gujarat, India. The pooled analysis showed that the severity of infestation ranged between 0.41 and 3.57. Our study results revealed that 10% of the genotypes i.e. DGS-18, DGS-26, and DGS-28, were highly resistant. Furthermore, 16.66% of the genotypes, i.e. DGS-13, DGS-15, DGS-22, DGS-30, and DGS-33 were categorized as resistant. The novel resistant genotypes identified in the present study will be helpful for the management of P. solenopsis and P. marginatus, in G. sylvestre. The resistant genotypes have excellent scope for reducing the use of pesticide usage as well as help in mitigating pesticide residue.

Transmission of areca palm velarivirus 1 (APV1) by Pseudococcus cryptus

Betel palm is one of the most economically important crops in Southeast Asia. The occurrence and expansion of yellow leaf disease (YLD) have significantly impacted betel palm plantations. Our previous research demonstrated that areca palm velarivirus 1 (APV1) was associated with YLD and transmitted by Ferrisia virgata (striped mealybug), causing YLD in betel palms. This finding provides strong etiological evidence of the role played by APV1 in YLD. Controlling YLD is a pressing issue with significant challenges. One viable approach is to prevent the virus from spreading by disrupting the transmission vectors. Therefore, it is imperative to identify potential vectors of APV1. In this study, we detected APV1 in the stylet, foregut, midgut, and hindgut of Pseudococcus cryptus (cryptic mealybug) using immunocapture RT-PCR and in situ immunofluorescence localization. P. cryptus transmitted APV1 in a non-circulative, semi-persistent manner. The retention time of APV1 in P. cryptus was notably longer than that in F. virgata. Additionally, field investigations revealed that three other insects infesting betel palms also carried APV1. In summary, APV1 may also be transmitted by other mealybug species, and the lower specificity of transmission vectors makes it challenging to control the spread of this devastating disease. This work provides timely knowledge for the prevention and management of YLD.

A new species of Paraputo Laing (Hemiptera: Coccomorpha: Pseudococcidae) on Fagaceae from southern China.

A new species of mealybug (Hemiptera: Coccomorpha: Pseudococcidae), Paraputo nanlingensis Li & Wu, sp. n., is recorded on Fagaceae from Guangdong Province, China. The adult female is described and illustrated, and an identification key is provided to separate the adult females of Paraputo species known from China.

Potential Global Distribution of Paracoccus marginatus, under Climate Change Conditions, Using MaxEnt.

The papaya mealybug, Paracoccus marginatus, is an invasive pest species found all over the world. It is native to Mexico and Central America, but is now present in more than 50 countries and regions, seriously threatening the economic viability of the agricultural and forestry industry. In the current study, the global potential distribution of P. marginatus was predicted under current and future climatic conditions using MaxEnt. The results of the model assessment indicated that the area under the curve of the receiver operating characteristic ( ROC-AUC) was 0.949, while the TSS value was 0.820. The results also showed that the three variables with the greatest impact on the model were min temperature of coldest month (bio6), precipitation of wettest month (bio13), and precipitation of coldest quarter (bio19), with corresponding contributions of 46.8%, 31.1%, and 13.1%, respectively. The results indicated that the highly suitable areas were mainly located in tropical and subtropical regions, including South America, southern North America, Central America, Central Africa, Australia, the Indian subcontinent, and Southeast Asia. Under four climate scenarios in the 2050s and 2070s, the area of suitability will change very little. Moreover, the results showed that the area of suitable areas in 2070s increased under all four climate scenarios compared to the current climate. In contrast, the area of suitable habitat increases from the current to the 2050s under the SSP370 and SSP585 climate scenarios. The current study could provide a reference framework for the future control and management of papaya mealybug and other invasive species.

Habitat heterogeneity reduces abundance of invasive mealybugs in subtropical fruit crops

Abstract The simplification of agricultural landscapes has been associated with an increase in pest pressure. While monocultures increase the resources available for pests and may facilitate their dispersion, the lack of non‐crop habitats may reduce the resources available for pest natural enemies. Herein, we tested which of these hypotheses, namely ‘resource concentration’ and ‘natural enemies’, can better explain the abundance of invasive mealybug pests in two subtropical fruit crops. For this aim, 17 persimmon orchards and 16 citrus orchards were sampled during three different seasons across two consecutive years. Using a model selection approach, we assessed the effects of the surrounding landscape (proportion of focal crops and semi‐natural habitats at different distances) and inter‐row ground cover vegetation on the abundance of mealybugs and their natural enemies. The proportion of focal crop in the landscape increased the abundance of mealybugs attacking both crops. This effect was found at closer distances (up to ~600 m) in citrus and at both closer and further distances (up to 1250 m) in persimmon. Non‐crop habitats, both surrounding semi‐natural habitats and ground cover vegetation, decreased the abundance of mealybugs by increasing the activity of their parasitoids in persimmon. Conversely, non‐crop habitats did not decrease the abundance of the main mealybug species attacking citrus, likely because this mealybug species was not attacked by native or naturalized parasitoids. Synthesis and applications. Our models show that the increase in habitat heterogeneity at local and landscape scales can reduce the abundance of invasive mealybugs in subtropical crops via ‘resource concentration’ and ‘natural enemies’ mechanisms. Therefore, habitat diversification strategies should be considered in the conservation biological control of invasive mealybugs. Importantly, our findings also show that the presence of efficient natural enemies is critical to maximize their control through habitat diversification strategies.

GRAPEVINE VEIN-CLEARING VIRUS IS MEALYBUG-BORNE BUT NOT MEALYBUG-TRANSMITTED

This article investigates the ability of two types of mealybugs, citrus (Planococcus citri) and longtailed (Pseudococcus longispinus) mealybugs, of acquiring and transmitting Grapevine vein-clearing virus (GVCV) in a greenhouse setting. Mealybugs are the primary vectors for most Badnaviruses, and only a few species have been shown to be aphid-transmitted. In this study, we tested the acquisition and transmission ability of two mealybug species using GVCV-infected and healthy grapevines in a greenhouse setting for three consecutive seasons. This study determined that acquisition time by the mealybugs could be as low as three days, yet the transmission of GVCV from infected grapevines to healthy grapevines by these two mealybug species was unsuccessful. Additionally, with the use of previously-developed species-specific primers, this study determined that those mealybugs captured in the greenhouse facilities at the University of Missouri could not be identified using these primers, and required primers that were specific to their regional diversity. This study contributes to the wider understanding of the acquisition and transmission of GVCV by certain mealybug species.

Chitosan-Delivered Chlorantraniliprole for Pest Control: Preparation Optimization, Deposition Behavior, and Application Potential.

Chitosan has emerged as a promising biopolymer carrier for the sustained release of pesticides owing to its good biocompatibility, biodegradability, and bioactivity. In this work, a controlled-release formulation of insecticide chlorantraniliprole was fabricated through coprecipitation-based synchronous encapsulation with chitosan, where the optimum preparation conditions, storage stability, deposition behavior, and application potential were investigated. Preparation of optimization data from response surface methodology showed high correlation coefficient (R2) of 0.9875 and adjusted coefficient (Radj2) of 0.9715. The resulting formulation displayed good loading content of 28.39%, high encapsulation efficiency of 75.71%, and good storage stability. Compared with the commercial suspension concentrate, the formulation exhibited better wettability and retention behaviors on plant leaves. Excitingly, effective control against one species of mealybug genus Paraputo Laing (outside the killing spectrum) on the Hippeastrum reticulatum plant was successfully achieved by spraying the controlled-release formulation at different time intervals. This work indicates the good potential of the developed formulation in expanding the application scope of chlorantraniliprole, which shows a new strategy for sustainable pest management.

Interações entre formigas e cochonilhas em cana-de-açúcar: espécies e efeitos sobre os insetos pragas

ABSTRACT The objective of this work was to evaluate ant species interacting with mealybugs in sugarcane plantations, the frequency of occurrence, and the effects of the interaction with ants on mealybug population size. The data was collected in a sugarcane plantation area in Seropedica, Rio de Janeiro, Brazil. The insect species were collected from 70 thoroughly inspected sugarcane plants and the nature and frequency of the interactions were evaluated. The effect of the interaction with ants on mealybug abundance was evaluated by counting the number of adult females of each mealybug species on ten plants isolated and ten plants not isolated from ants. Two mealybug species were collected: Aclerda takahashii (Kuwana, 1932) and Saccharicoccus sacchari (Cockerell, 1895). Ten and seven ant species were found interacting with A. takahashii and S. sacchari, respectively, which were distributed among six genera; the most frequent genera were Crematogaster and Camponotus. Three ant species interacted exclusively with A. takahashii, whereas the others interacted with both mealybug species. The abundance of A. takahashii females was significantly higher on non-isolated than on isolated plants (Paired t-test; t = 2.34; p = 0.04). However, no significant difference in S. sacchari abundance was found between isolated and non-isolated plants (t = 0.27; p = 0.8), nor for the two species combined (t = 1.9; p = 0.09). Thus, ant species that interact with mealybugs in sugarcane plantations cause increases in A. takahashii populations which, at a larger scale, can reduce crop yield.