Dysmicoccus Neobrevipes Research Articles

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.

A new species of Apertochrysa Tjeder, 1966 and new record of Plesiochrysa ramburi (Schneider, 1851) (Neuroptera: Chrysopidae) from China, with potential biocontrol significance.

A new green lacewing species Apertochrysa roseusfrontata sp. nov. and a newly recorded Plesiochrysa ramburi (Schneider, 1851) (Neuroptera: Chrysopidae: Chrysopinae) from South China are described based on the morphological characters of both adults and larvae. Both species were found predating Dysmicoccus neobrevipes Beardsley, 1959 (Hemiptera: Pseudococcidae) on sisal (Agave sisalana Perrine, 1838) in Guangdong Province.

The Impact of Cryptolaemus montrouzieri Mulsant (Coleoptera: Coccinellidae) on Control of Dysmicoccus neobrevipes Beardsley (Hemiptera: Pseudococcidae).

Cryptolaemus montrouzieri (Coleoptera: Coccinellidae) is an important predator of the mealybug Dysmicoccus neobrevipes (Hemiptera: Pseudococcidae), a major pest of Agave sisalana in China. Limited reports on the efficacy of C. montrouzieri against D. neobrevipes are available. This study reports the predatory efficacy and functional response of C. montrouzieri against D. neobrevipes under laboratory conditions. The prey consumption rate per day of 4th instar larvae of C. montrouzieri feeding on 1st instar D. neobrevipes nymphs (241.3 mealybugs) was the highest among the different larval life stages of the beetle. For C. montrouzieri, the prey consumption per day of adult females (19.8 mealybugs) was significantly higher compared to males (15.2 mealybugs) when feeding on 3rd instar D. neobrevipes nymphs. The functional responses of C. montrouzieri on 1st and 2nd instar D. neobrevipes nymphs were determined as Holling type II. The search rates of C. montrouzieri 4th instar larvae towards the 1st and 2nd instar nymphs of D. neobrevipes were higher than those of the other beetle life stages. In addition, the handling times of 4th instar larvae were shorter than those of the other beetle life stages. The results from this study indicate that C. montrouzieri can be used as a predator of D. neobrevipes and, therefore, it should be evaluated further for use as a biocontrol agent in D. neobrevipes management programs.

Heavy metals transported through a multi-trophic food chain influence the energy metabolism and immune responses of Cryptolaemus montrouzieri.

Contamination of environment with heavy metals is increasingly becoming an issue of major concern across the globe. Heavy metals are highly toxic to humans as well as other organisms of the ecosystem. The translocation of heavy metals from soil to predatory insects via multi-tophic food chains can influence the growth, reproduction, metabolism and innate immune systems of the predators. This study was performed to observe the changes in energy metabolism and immune responses of Cryptolaemus montrouzieri feeding on heavy metal (Cd, Pb, Ni and Zn) contaminated pink hibiscus mealybug (Dysmicoccus neobrevipes). The average concentrations of Cd, Pb, Ni and Zn in mealybugs used for feeding assays were 30.57, 32.64, 31.47 and 33.19 mg/kg, respectively. The results showed a significant increase in total protein, glycogen, cholesterol and triglycerides content of C. montrouzieri feeding on heavy metals contaminated mealybugs compared with control groups. The activities of endogenous enzymes (acid phosphatase and alkaline phosphatase) as well as antioxidant enzymes (SOD, POD and CAT) were significantly higher in beetles feeding on heavy metals contaminated mealybugs. Our results provide basic insight into the influences of heavy metals (Cd, Pb and Ni) on energy metabolism and the innate immune system of the insect predator (C. montrouzieri) in a multi-trophic food chain. Further research on genetic processes involved in the regulation of metabolism and innate immune system of C. montrouzieri is still needed.

Phylogenetic analyses and characteristics of the microbiomes from five mealybugs (Hemiptera: Pseudococcidae).

Associations between Sternorrhyncha insects and intracellular bacteria are common in nature. Mealybugs are destructive pests that seriously threaten the production of agriculture and forestry. Mealybugs have evolved intimate endosymbiotic relationships with bacteria, which provide them with essential amino acids, vitamins, and other nutrients. In this study, the divergence of five mealybugs was analyzed based up the sequences of the mitochondrial cytochrome oxidase I (mtCOI). Meanwhile, the distinct regions of the 16S rRNA gene of primary symbionts in the mealybugs were sequenced. Finally, high‐throughput sequencing (HTS) techniques were used to study the microbial abundance and diversity in mealybugs. Molecular phylogenetic analyses revealed that these five mealybugs were subdivided into two different clusters. One cluster of mealybugs (Dysmicoccus neobrevipes, Pseudococcus comstocki, and Planococcus minor) harbored the primary endosymbiont “Candidatus Tremblaya princeps,” and another cluster (Phenacoccus solenopsis and Phenacoccus solani) harbored “Ca. Tremblaya phenacola.” The mtCOI sequence divergence between the two clusters was similar to the 16S rRNA sequence divergence between T. princeps and T. phenacola. Thus, we concluded that the symbiont phylogeny was largely concordant with the host phylogeny. The HTS showed that the microbial abundance and diversity within P. solani and P. solenopsis were highly similar, and there was lower overall species richness compared to the other mealybugs. Among the five mealybugs, we also found significant differences in Shannon diversity and observed species. These results provide a theoretical basis for further research on the coevolution of mealybugs and their symbiotic microorganisms. These findings are also useful for research on the effect of symbiont diversity on the pest status of mealybugs in agricultural systems.

Developmental responses of Cryptolaemus montrouzieri to heavy metals transferred across multi-trophic food chain

The current studies were carried out to observe the variations in development, biology and life table parameters of ladybird beetle, Cryptolaemus montrouzieri, feeding on pink hibiscus mealybug (Dysmicoccus neobrevipes) contaminated with heavy metals (cadmium, lead, and nickel) bio-transferred across a multi-trophic chain. The developmental time required for immature life stages (1st, 2nd, 3rd, 4th instar nymphs, pupae) and total developmental period (egg-adult) differed significantly among different heavy metal treatments and control. The accumulated survival rate of C. montrouzieri immature life stages also differed significantly among different heavy metal treatments and control. Different parameters of adult female biology (Pre-oviposition period, fecundity, female longevity) were adversely affected by different heavy metals. Life table analysis revealed that all the heavy metals caused significant reduction in net reproduction rate (R0) and intrinsic rate of increase (r) while the mean generation time (T) and doubling time (Dt) were significantly higher than control. The results obtained provide possible insight into the implications of heavy metals on the population dynamics of insect predator (C. montrouzieri) in a multi-trophic food chain. However, further research is required on genetic as well as physiological processes involved in the regulation of growth and development of C. montrouzieri.

Transfer of lead (Pb) in the soil-plant-mealybug-ladybird beetle food chain, a comparison between two host plants

Contamination of soil with heavy metals has become an issue of concern on global scale. This study investigates the translocation of lead (Pb) along the soil - plant (eggplant and tomato) - mealybug (Dysmicoccus neobrevipes) - ladybird beetle (Cryptolaemus montrouzieri) food chain. Soil amendments used for this study were adjusted to 0, 25, 50 and 100mg/kg of Pb (w/w). The results revealed significantly higher transfer of Pb in tomato when compared to eggplant. Bio-magnification of Pb (2–4 times) was observed for soil - root transfer whereas Pb was bio-minimized in later part of food chain (shoot – mealybug - ladybird transfer). A dose dependent increase in transfer of Pb across the multi-trophic food chain was observed for both host plants. A decrease in coefficients of Pb transfer (from root - shoot and shoot - mealybug) was observed with increase in Pb concentrations. Our results also showed removal of Pb from the bodies of ladybird beetle during metamorphosis. Further studies are required to explain the mechanisms or physiological pathways involved in the bio-minimization of Pb across the food chain.

Effects of temperature on the growth, development and reproduction of Dysmicoccus neobrevipes Beardsley (Hemiptera: Pseudococcidae).

In recent years, Dysmicoccus neobrevipes Beardsley (Hemiptera: Pseudococcidae) is found as one of important alien species in China. For the alien pest, temperature always is a crucial factor on constructing stable population. In this study, the development and reproduction of D. neobrevipes population of pumpkin under different temperatures were investigated. The developmental duration, developmental rate, survival rate and fecundity of D. neobrevipes were compared in the laboratory under the conditions of 17, 20, 23, 26, 29 and 32 ℃, photoperiod 14L:10D, RH (75±5)%, and the life table of the laboratory population was constructed. The results showed that in 20-29 ℃, the developmental durations of every stage of D. neobrevipes all decreased with the increasing temperature; under 20 ℃, both female and male nymph D. neobrevipes had the longest duration, being 46.95 and 50.26 d, respectively. The female and male nymph D. neobrevipes grew most fast under 29 ℃ (20.28 d) and 32 ℃ (20.70 d). The relationship between the developmental rate and temperature for each stage could be simulated by the quadratic regression. In addition, we found that the temperature could impact the survival rate of D. neobrevipes. The highest survival rate of D. neobrevipes was recorded at 29 ℃ for both female (70.3%) and male (69.3%) nymphs. The developmental threshold temperature of female and male was 13.80 ℃ and 11.61 ℃, and the accumulated temperature of female and male was 491.50 and 388.85 day-degrees, respectively. Both pre-oviposition duration and adult longevity decreased with increasing temperature, and the highest fecundity per female was 442.2 eggs at 29 ℃, and the lowest 111.8 eggs at 20 ℃. The population trend indexes under 20 ℃ and 29 ℃ were 19.1 and 168.2, respectively. At 17 ℃ and 32 ℃, D. neobrevipes of the 1st instar nymphs and 3rd instar nymphs were found to stop growth, suggesting that excessively high or low temperature was unfavorable to the growth of D. neobrevipes. In conclusion, temperature could significantly affect the growth and development, survivorship, reproduction and population increasing of D. neobrevipes, and the most suitable temperature range for this pest is from 23 ℃ to 29 ℃.

Biotransfer of Cd along a soil-plant- mealybug-ladybird food chain: A comparison with host plants

Agro-ecosystem contamination by the heavy metals present in different agricultural products is a serious challenge faced by the living organisms. This study explains the cadmium (Cd) transfer from soils contaminated with different cadmium concentrations through a plant (eggplant and tomato) - mealybug (Dysmicoccus neobrevipes) - predator (Cryptolaemus-montrouzieri) food chain. The soils were amended with Cd at the rates of 0, 12.5, 25 and 50 mg/kg (w/w). Our findings showed that considerably higher Cd transfer through tomato plant. Cadmium was biomagnified during soil-root transfer while bio-minimization of Cd was observed for shoot-mealybug – ladybird transfer. Our results further showed sequestration of Cd during the metamorphosis of ladybird beetle whilst transfer of Cd through soil-plant-mealybug-ladybird multi-trophic food chain increased in a dose dependent manner. Our results emphasize the need of further studies to elaborate possible mechanisms of Cd bio-minimization by plants, mealybugs and ladybirds observed during this study.

Faunistic Study of the Family Pseudococcidae (Hemiptera) from Cambodia and Laos

The family Pseudococcidae or mealybugs (Hemiptera) are common pests on ornamental plants and fruit trees in tropical regions of the world. Previously, the mealybug fauna of Cambodia and Laos comprised 22 species and 12 species, respectively. Recently, we collected 13 mealybug species in Cambodia and Laos. Among these, eight species were found in these countries for the first time: Phenacoccus solani (Ferris, 1918) and Rastrococcus iceryoides (Green, 1908) in Cambodia; Dysmicoccus neobrevipes (Beardsley, 1959) in both countries; Paracoccus invectus (Williams, 2004), Phenacoccus solenopsis (Tinsley, 1898), Planococcus litchi (Cox, 1989), Planococcus minor (Maskell, 1897) and Pseudococcus jackbeardsleyi (Gimpel & Miller, 1996) in Laos.

Enantioselective synthesis of the sex pheromone of the grey pineapple mealybug, Dysmicoccus neobrevipes (Hemiptera: Pseudococcidae), for determination of the absolute configuration

The grey pineapple mealybug, Dysmicoccus neobrevipes Beardsley, originally found on Hawaii and on Australasian islands, was recently discovered on a southwestern island (Ishigaki Island) of Japan. Because D. neobrevipes is known to attack many fruits and other crops, it is essential to establish a strategy to prevent the spread of this potential pest. Detection and monitoring by use of pheromone traps would provide important information about its distribution. The sex pheromone of D. neobrevipes has been isolated and identified as (E)-2-isopropyl-5-methylhexa-3,5-dien-1-yl acetate, although its absolute configuration was unknown. In this study, we achieved enantioselective synthesis of this compound by use of porcine pancreas lipase (PPL)-catalyzed acylation. Acetyl transfer from vinyl acetate to prochiral 2-isopropyl-1,3-propanediol in the presence of PPL in an organic solvent predominantly produced the (R) enantiomer of the monohydroxy acetate (86 % ee). In contrast, PPL-catalyzed hydrolysis of 2-isopropyl-1,3-diacetoxypropane in phosphate buffer yielded the (S) enantiomer of the monohydroxy acetate (75 % ee). Each enantiomer of the monohydroxy acetate was oxidized to a formyl acetate then coupled with a Wittig reagent, to produce the (R)-(−) and (S)-(+) pheromones. Analysis by gas chromatography with a chiral column and by polarimetry revealed the natural pheromone to be the (S)-(+) enantiomer. In a field trap experiment, the attractiveness of the pheromone produced by this route was equivalent to that of the pure (+) enantiomer (>99 % ee).

A new lavandulol-related monoterpene in the sex pheromone of the grey pineapple mealybug, Dysmicoccus neobrevipes.

The grey pineapple mealybug, Dysmicoccus neobrevipes, is a serious pest that attacks a variety of crops in tropical regions. Recently, it was recorded on an island in southwestern Japan, suggesting that its distribution is expanding. As a measure against this expansion, a monitoring tool is urgently needed. In this study we determined the structure of the sex pheromone of D. neobrevipes in order to develop an efficient lure for monitoring traps. Volatiles collected from virgin adult females were fractionated by high performance liquid chromatography (HPLC) and gas chromatography, and fractions were tested for attractiveness to males in a laboratory bioassay. A single compound was isolated which was as attractive to males as the crude collections, and this was proposed to be the main, if not the only, component of the female-produced sex pheromone. The structure of this was determined to be (E)-2-isopropyl-5-methylhexa-3,5-dienyl acetate by gas chromatography/mass spectrometry and nuclear magnetic resonance analyses. This compound was synthesized through four steps, and the synthetic chemical was as attractive as the natural product in a greenhouse bioassay. The enantiomers of the synthetic acetate were obtained by enantioselective HPLC fractionation of the corresponding alcohols, and the natural pheromone was shown to be the (+)-isomer. The carbon skeleton of this novel compound is related to lavandulol, a monoterpene with an unusual non-head-to-tail connection of isoprene units that is often found in mealybug pheromones.

Effects of three mealybug species on the development, survivorship and reproduction of the predatory lady beetle Cryptolaemus montrouzieri Mulsant

The lady beetle Cryptolaemus montrouzieri Mulsant (Coleoptera: Coccinellidae) is an important predator of mealybugs. The development, survivorship, longevity and reproduction of C. montrouzieri feeding on three different mealybug species [Dysmicoccus neobrevipes Beardsley, Ferrisia virgata Cockerell and Planococcus minor (Maskell)] were investigated in the laboratory at 26 ± 1°C, 75-–90% RH and 14:10 (L:D) h photoperiod. Results indicated that, when feeding on different mealybugs, no significant differences were observed between developmental periods and survivorship of C. montrouzieri (from egg to adult), but differences were recorded between the sex ratios, preovipositional periods, adult longevities and reproduction of the differently treated lady beetle populations. The highest sex ratio (0.56), the longest preovipositional period (6.6 days) and adult longevity (84.8 days for females and 93.9 days for males), and the maximum fecundity (659.0 eggs/female) of C. montrouzieri were recorded when feeding on F. virgata. Moreover, C. montrouzieri had a high net reproductive rate (313.66), intrinsic rate of increase (0.0816) and finite rate of increase (1.085) when feeding on F. virgata. Results indicated that the population growth of C. montrouzieri may increase faster when feeding on F. virgata than feeding on either of the other two mealybugs.

The occurrence of two species of pineapple mealybugs (Dysmicoccusspp.) (Hemiptera: Pseudococcidae) in China and their genetic relationship based on rDNA ITS sequences

To explore the composition, distribution and interrelation of the pineapple mealybugs in China, samples were collec from 14 counties of five provinces. The genetic variations of pineapple mealybugs from China, Brazil and Hawaii of USA have been analyzed. The whole ribosomal internal transcribed spacer 1 (ITS1), 5.8S and ribosomal internal transcribed spacer 2 (ITS2) were sequenced for all samples. Pink pineapple mealybug (PPM), Dysmicoccus brevipes (Cockerell) and gray pineapple mealybug (GPM), Dysmicoccus neobrevipes Beardsley are found causing damage on Ananas comosus (L.) Merr. PPM is a predominant species of mealybug on A. comosus in China. Though GPM has wider host range in China, PPM has larger distribution area than GPM. The results showed that two pineapple mealybug species belong to two different clades based on the sequences of ITS. PPM from China was found to have four haplotypes, and GPM had two haplotypes. The genetic variation of PPM is greater than that of GPM, though both of them had one p...

Effect of temperature on the life history of Dysmicoccus neobrevipes (Hemiptera: Pseudoccocidae): An invasive species of gray pineapple mealybug in South China

The gray pineapple mealybug, Dysmicoccus neobrevipes Beardsley, is an invasive pest that during recent years has caused serious damage on Sisal (Agave sisalana Perrine) crops in South China. The biology of D. neobrevipes including its development, survivorship, longevity and reproduction was investigated at six constant temperatures (17, 20, 23, 26, 29 and 32 °C) under laboratory conditions. Results indicated that the developmental periods of D. neobrevipes females (from the first instar nymph to adult) shortened from 55.4 days at 17 °C to 16.9 days at 29 °C, while the males' decreased from 54.0 days at 17 °C to 15.8 days at 32 °C. The highest survivorship of D. neobrevipes from the first instar nymph to adult was recorded at 29 °C; 88.8% for females and 89.2% for males. The average longevity of females was 95.0 days at 17 °C, but decreased to 30.0 days at 26 °C. This was still significantly longer than those of males; 5.6 days at 17 °C and 2.3 days at 32 °C. The average number of nymphs laid per female increased with increasing temperature and reached a maximum of 409.4 nymphs at 23 °C. The intrinsic rates of increase (rm) of D. neobrevipes at the range of temperatures between 17 and 32 °C were 0.0287, 0.0613, 0.0941, 0.1131, 0.1202 and 0.0485, respectively. The lower temperature thresholds for females and males of D. neobrevipes from the 1st instar nymph to adult estimated using the linear model were 8.7 and 10.3 °C, respectively. The thermal constants for females and males were 370.4 and 312.5DD, respectively. The results indicate that temperature has significant effects on the biology of D. neobrevipes and that the optimum temperature range for its population growth is 23–29 °C.

Pineapple bacilliform CO virus: Diversity, Detection, Distribution, and Transmission.

Members of the genus Badnavirus (family Caulimovirdae) have been identified in dicots and monocots worldwide. The genome of a pineapple badnavirus, designated Pineapple bacilliform CO virus-HI1 (PBCOV-HI1), and nine genomic variants (A through H) were isolated and sequenced from pineapple, Ananas comosus, in Hawaii. The 7,451-nucleotide genome of PBCOV-HI1 possesses three open reading frames (ORFs) encoding putative proteins of 20 (ORF1), 15 (ORF2), and 211 (ORF3) kDa. ORF3 encodes a polyprotein that includes a putative movement protein and viral aspartyl proteinase, reverse transcriptase, and RNase H regions. Three distinct groups of putative endogenous pineapple pararetroviral sequences and Metaviridae-like retrotransposons encoding long terminal repeat, reverse-transcriptase, RNase H, and integrase regions were also identified from the pineapple genome. Detection assays were developed to distinguish PBCOV-HI1 and genomic variants, putative endogenous pararetrovirus sequences, and Ananas Metaviridae sequences also identified in pineapple. PBCOV-HI1 incidences in two commercially grown pineapple hybrids, PRI 73-114 and PRI 73-50, was 34 to 68%. PBCOV-HI1 was transmitted by gray pineapple mealybugs, Dysmicoccus neobrevipes, to pineapple.

New records of some potential pest mealybugs (Hemiptera: Coccoidea: Pseudococcidae) in Japan

Four species of mealybugs, Dysmicoccus neobrevipes, Phenacoccus defectus, Ph. parvus, and Ph. solenopsis (Hemiptera: Coccoidea: Pseudococcidae) are recorded for the first time from Japan in the Ryukyu (Ryukyu) Archipelago, with brief biological notes. We discuss some features of these species compared with those of related species, D. brevipes and Ph. solani, and we consider their potential risks to Japanese agriculture and/or horticulture.

Effects of gamma irradiation on different stages of mealybug Dysmicoccus neobrevipes (Hemiptera: Pseudococcidae)

Utilization of phytosanitary irradiation as a potential treatment to disinfest agricultural commodities in trade has expanded rapidly in the recent years. Cobalt-60 gamma ray target doses of 100, 150, 200 and 250 Gy were used to irradiate immatures and adults of Dysmicoccus neobrevipes (Beardsley) (Hemiptera: Pseudococcidae) infesting dragon fruits to find the most tolerant stage and the most optimal dose range for quarantine treatment. In general, irradiation affected significantly all life stages of D. neobrevipes mortality and adult reproduction. The pattern of tolerance to irradiation in D. neobrevipes was 1st instars<2nd instars<3rd instars<adults, in which the adult is the most tolerant stage. Based on obtained results after 21 days of irradiation, predicted doses for 100% mortality of each different development stage in the above mentioned pattern were 224.6, 241.3, 330.9 and 581.5 Gy, respectively. No survived female adult produced offspring at 200 and 250 Gy. Dose range between 200 and 250 Gy could be efficient to prevent the reproduction of this mealybug.

TRANSMISSION CHARACTERISTICS OF PINEAPPLE MEALYBUG WILT ASSOCIATED VIRUS-2 BY THE GREY PINEAPPLE MEALYBUGS DYSMICOCCUS NEOBREVIPES IN HAWAII

Pineapple mealybug wilt associated virus-2 (PMWaV-2) is a mealybug transmitted ampelovirus associated with mealybug wilt disease of pineapple (MWP) in Hawaii. The characteristics of PMWaV-2 acquisition and persistence of grey pineapple mealybugs (GPM), Dysmicoccus neobrevipes Beardsley, were measured. Some GPM were able to acquire the virus within 36 hours. Transmission efficiency of GPM in groups of 25 was 100% following a 72-hour acquisition access period (AAP). GPM remained viruliferous for up to three days after a 3-day AAP when serially transferred to virus-free pineapple plants at 24-hour intervals over a 7-day period. Access to a kabocha squash, a non-host of the virus, reduced the transmission efficiency and persistence of the virus. These data show that PMWaV-2 is transmitted by the grey pineapple mealybug in a semi-persistent manner. A potential management strategy based on these findings is discussed.

Effects of host plant on the development, survivorship and reproduction of Dysmicoccus neobrevipes Beardsley (Hemiptera: Pseudoccocidae)

The effects of four host plants ( Agave sisalana, Ag. americana var. marginata, Ananas comosus Baili and An. comosus Smooth Cayenne) on the biology of the mealybug Dysmicoccus neobrevipes Beardsley were studied in the laboratory at 26 ± 1 °C, 75–90% RH and 14:10 (L:D) photoperiod. The development, survivorship, longevity, reproduction and life table parameters of D. neobrevipes differed among the host plants. The shortest developmental period (from the first instar nymph to adult) was recorded on An. comosus Smooth Cayenne (22.4 days for females and 21.3 days for males), whereas the longest was recorded on An. comosus Baili (25.6 days for females and 24.7 days for males). The highest survivorship was found on An. comosus Baili (98% for both females and males) and the lowest was on Ag. americana var. marginata (39.6% for females and 50% for males). Meanwhile the sex ratio and fecundity were highest and the pre-lay period was shortest on Ag. sisalana. The longest longevity of females was 62.5 days on An. comosus Baili, whereas the other host plants did not differ significantly with grand mean longevities of 51.0 days for females, while the longest and shortest longevities of males were 4.6 days and 2.3 days on Ag. americana var. marginata and Ag. sisalana, respectively. Values for net reproductive rate, intrinsic rate of increase and finite rate of increase were highest on Ag. sisalana, whereas the mean generation time was shortest on An. comosus Smooth Cayenne. The results indicated that Ag. sisalana is the most suitable host for D. neobrevipes among the four tested plants. When reared on Ag. sisalana, D. neobrevipes had a short developmental period (females 22.7 days and males 23.8 days), high reproduction (418 nymphs/female) and a high intrinsic rate of increase (0.106). Results of this study indicated that host plant can largely influence the population dynamics of D. neobrevipes, and our findings are useful in understanding the roles of host plants in integrated management of this pest, including exploitation of these host plants in push-pull control.