Oligonychus Punicae Research Articles

Interspecific interaction network of mites associated with mango trees.

Direct and indirect ecological interactions, environmental factors, and the phenology of host plants can shape the way mites interact. These relationships interfere with species occurrence and consequently alter the structure and stability of the intraplant community. As predatory mites act as regulators of herbivorous mites, we hypothesized that these mites may occupy a central position in a network of interactions among mite species associated with mango trees, and the occurrence of these species is mediated by environmental variables and the phenological stage of the host plant. We evaluated the global structure of the interaction network of mites associated with individual Mangifera indica plants and analyzed the interspecific relationships of the species using an undirected Bayesian network approach. Additionally, we observed a correlation between mite population density and plant phenological stage. Environmental variables, such as average monthly temperature, monthly precipitation, and average monthly relative humidity at different sampling date were used in the correlation analysis. The modularity at the mite-plant network level showed a low specialization index H2 = 0.073 (generalist) and high robustness (R = 0.93). Network analysis revealed that Amblyseius largoensis, Bdella ueckermanni, Parapronematus acaciae, and Tuckerella ornata occupied central positions in the assembly of mites occurring on mango trees. Environmental variables, average monthly temperature, and monthly precipitation were correlated with the occurrence of Brachytydeus formosa, Cisaberoptus kenyae, Oligonychus punicae, T. ornata, and Vilaia pamithus. We also observed a correlation between the plant phenological stage and population densities of Neoseiulus houstoni, O. punicae, P. acaciae, and V. pamithus.

Ovicidal Effect of the Ethanolic Extract of Moringa oleifera Leaf on Oligonychus punicae (Trombidiformes: Tetranychidae) Eggs1

Abstract Mexico is the leader in avocado (Persea americana Miller [Lauraceae]) production, with the United States being the principal consumer of avocados produced there. The avocado crop is susceptible to attacks by insect and mite pests, including the avocado brown mite, Oligonychus punicae (Hirst) (Acari: Tetranychidae), which is a serious economic pest of the crop in Mexico. This study evaluated the effects of different concentrations (0.1, 0.5, 1, 5, 10, 15, and 20% [v/v]) of the ethanolic extract from Moringa oleifera Lamarck (Moringaceae) leaves against O. punicae eggs and its residual effect on the density of larvae and nymphs emerging from treated eggs. Egg mortality ranged from 0.0 at the 0.1% concentration to 70.48% at the 20% concentration, compared with the control group. Egg mortality increased as extract concentrations increased. The density of larvae and nymphs that emerged from the treated eggs was significantly lower than the density in the control, indicating that both the number of living larvae and nymphs responded to extract concentration. Our results support the suggestion that the ethanolic extract of M. oleifera leaf has ovicidal and residual activity against O. punicae and can be incorporated into an integrated mite management program to control avocado brown mite populations. Further studies are needed to assess the efficiency and efficacy of M. oleifera extract against arthropod pests and natural enemies under greenhouse and field conditions.

Evaluation of Ethanolic Powdered Extract of Magnolia tamaulipana Vazquez against Oligonychus punicae Hirst (Trombidiformes: Tetranychidae).

Avocado bronze mite (ABM), Oligonychus punicae Hirst (Trombidiformes: Tetranychidae) has potential for development in several plant species of agricultural importance. ABM is one of the most economically important pests in avocado cultivars, causing major damage to fruit and defoliation. At present, the control of ABM depends mainly on agrochemicals. Therefore, it is necessary to find alternatives to agrochemicals that can help minimize environmental impact and health risks for humans and mammals. The aim of this research was to assess the effect of different concentrations (5, 10, 50, 100, 250, 500, 1000 µg/mL) of ethanolic powdered extract of M. tamaulipana leaves against adult ABM females. The different concentrations of M. tamaulipana extract did not cause mortality of O. punicae. Females treated with 5 and 1000 µg/mL of the extract showed a decrease in the number of eggs laid per female at 24 (5.17 and 1.27), 48 (5.07 and 1.17), and 72 h (4.97 and 0.80), compared to the control treatment (5.20, 6.60 and 6.87), respectively, which led to a reduction in the growth rate. Percentage of feeding damage decreased with the increasing concentration of the extract. The ethanolic powdered extract of M. tamaulipana leaf has potential to control O. punicae.

Evaluation of Ethanol Extract of Moringa oleifera Lam. as Acaricide against Oligonychus punicae Hirst (Trombidiformes: Tetranychidae).

Simple SummaryAvocado bronze mite (ABM), Oligonychus punicae Hirst (Acari: Tetranychidae) is one of the most economically important pests in avocado cultivars. Its feeding causes major damage, defoliation and fruit abortion. Control measures of ABM are performed mainly through the use of synthetic acaricides. Alternative control strategies for ABM with a low environmental impact are necessary. The aim of this research was to assess the effect of different concentrations (0.1, 0.5, 1, 5, 10, 15 and 20% (v/v)) of ethanolic extract from Moringa oleifera leaves against adult ABM females. Mites treated with 0.1 and 20% (v/v) of the extract showed mortality of 0.00% and 46.67%, 6.67% and 86.67%, 13.70% and 96.67%, at 24, 48 and 72 h, respectively, compared to the control group. The oviposition and eggs hatch, as well as ABM feeding rates, depended on the extract concentration, which led to a reduction in the growth rate. The M. oleifera leaves ethanolic extract has potential to control O. punicae.Tetranychidae family is a major group of mites causing serious damage in agricultural, vegetable and ornamental crops. Avocado bronze mite (ABM), Oligonychus punicae Hirst (Acari: Tetranychidae) causes major crop damage, defoliation and fruit abortion. At present, the control of this mite depends mainly on agrochemicals. Therefore it is necessary to find alternatives to synthetic pesticides that can help minimize environmental impact and health risks for the consumers. The aim of this research was to assess the effect of different concentrations (0.1, 0.5, 1, 5, 10, 15 and 20% (v/v)) of ethanolic extract of Moringa oleifera leaves against adult ABM females. Mites treated with 0.1 and 20% (v/v) of the extract showed mortality of 0.00% and 46.67%, 6.67% and 86.67%, 13.70% and 96.67%, at 24, 48 and 72 h, as compared to the control treatment, respectively. The number of eggs laid and hatch, as well as ABM feeding rates, depended on the extract concentration, which led to a reduction in the growth rate. M. oleifera leaf ethanolic extract has potential to control O. punicae.

<p><strong>Temperature-dependent development and reproduction of </strong><strong><em>Oligonychus punicae</em></strong><strong> (Acari: Tetranychidae) on Eucalyptus</strong></p>

Temperature plays an important role in the development and reproduction of mites. The present study assesses how temperature affects the biology (development and survival of immatures) and life table parameters of Oligonychus punicae. This study also determines the mite thermal requirements (thermal requirement and development base temperature). The experiments were conducted in an air-conditioned chamber under different temperatures (21, 25, 29, 33, and 37ºC). The period of each stage (egg to adult) of O. punicae at different temperatures was used to determine the thermal constant and the lower thermal limit of development. The duration of the periods of pre-oviposition, oviposition, post-oviposition, fecundity, and longevity was recorded. The life table at different temperatures was created using data from the biological cycle. There was an inverse relationship between the development time of O. punicae and temperatures. However, there was no hatching of eggs at 37ºC. All O. punicae eggs resulted in females. The survival analysis for the immature and adult (female) stages of O. punicae showed a decreased life span with increasing temperatures. For the egg-adult period, the lower thermal threshold and the thermal constant for females of O. punicae were 10.34ºC and 163.93 degree-days, respectively. Temperature affected the periods of pre-oviposition, oviposition, and fecundity of adult females of O. punicae, tending to decrease with increasing temperatures. Specific fecundity varied over the oviposition period, decreasing with increasing temperatures. The net reproduction rate decreased significantly following temperatures 21°C to 33°C. The increase in temperature results in a significantly shorter average generation time. The intrinsic rate of increase ranged from 0.15 to 0.20. The finite rates of increase were all greater than 1.00. The effects of temperature on the development of O. punicae varies according to the stage of development. The optimum temperature for O. punicae is between 25 and 29ºC.

Two new life types and assessment of web-associated behavioral characteristics of some Oligonychus species on various host plants.

The webbing life type of three spider mite species of the genus Oligonychus was studied based on web-associated behavioral characteristics. All tested Oligonychus species-viz., avocado brown mite, Oligonychus punicae (Hirst), date palm mite, Oligonychus afrasiaticus (McGregor), and banks grass mite, Oligonychus pratensis (Banks)-exhibited a complicated-web (CW) life type on various host plants. A new life type, 'CW-c,' was documented for O. punicae on the adaxial leaf side of Conocarpus erectus L. (Combretaceae). The weaving pattern with guy ropes is spun by the O. punicae female and is associated with stalked eggs; it appeared as a unique character in the CW-life type. Oligonychus afrasiaticus, also showed a new life type, 'CW-d,' when reared on the abaxial side of leaves of four host plants, viz., desert fan palm, maize, sorghum, and sugarcane. Oligonychus afrasiaticus showed a site for quiescence and a site for oviposition as variables, whereas the site for defecation (SD) was a persistent characteristic on all four tested host plants. Oligonychus pratensis showed the characteristics of the sub-type 'CW-u' on the abaxial leaf side of Washingtonia filifera (Lindl.) H. Wendl. (Arecaceae). The SD was a distinguishing behavioral characteristic used to separate O. afrasiaticus from O. pratensis when inhabiting the same host plant, W. filifera.

Arthropod pests of pomegranate (Punica granatum L.) and their management

There are ninety one insects, six mites and one snail pest have been found feeding on pomegranate crop in India. Pomegranate pests cause severe damage to flowers, fruits, twigs and leaves by de sapping, biting and boring, which result in loss of quality of fruits and reduction in yield. In addition, the abuse of insecticides has led to secondary pests outbreak like pomegranate whitefly, (Siphoninus phillyreae Haliday), spiralling whitefly, (Aleurodicus dispersus Russell), mealy bug (Pseudococcus lilacinus Cockerell), thrips (Rhipiphorothrips cruentatus Hood, Scirtothrips dorsalis Hood, Anaphothrips oligochaetus Karny), aphid (Aphis punicae Passerini) and mites (Aceria granati Can. and Massal, Oligonychus punicae). The above reports confirmed that the commercially growing pomegranate farmers are facing a number of pest problems in their field, with no practical ecofriendly solutions. Further, in order to increase the production and productivity, farmers are growing pomegranate under high density planting. Since the introduction of high density planting in pomegranate is new, systematic study on the occurrence of pests is wanting. Hence, to address the problem of pests with ecosafe management practices was discussed in this review.

<p class="Body"><strong>Host preference, population dynamics, distribution, and injuries of <em>Oligonychus punicae</em> (Acari: Tetranychidae) in an eucalyptus clonal minigarden</strong></p>

Oligonychus punicae has potential for development in several species of eucalyptus. In this study was evaluated the preference for permanence and oviposition of O. punicae in different eucalyptus species. Additionally, we evaluated its dynamics and population distribution, as well as injuries in strains of Eucalyptus urophylla in a clonal minigarden. The preference for permanence and oviposition of O. punicae was evaluated using a test with and without choice in six species of Eucalyptus. We also analyzed the dynamics, population distribution and injury levels by O. punicae on E. urophylla in a clonal minigarden. We collected samples for 24 months and counted the number of eggs, immature and adult individuals. We calculated the Morisita dispersion index. We estimated injuries on leaves of E. urophylla using visual notes. In the test with choice, Eucalyptus urophylla was the preferred host of O. punicae for permanence and oviposition. In the test without choice, the oviposition of O. punicae in eucalyptus species did not differ statistically until 24 hours of evaluation. However, there was a significant difference after 48 hours, with greater oviposition on Eucalyptus brassiana, Eucalyptus tereticornis and Eucalyptus grandis. In the population survey, we collected 3,293 mites. The population peak of O. punicae occurred in March and April 2018 and April 2019. Oligonychus punicae presented an aggregate distribution and caused injuries of 20% on average in leaves. These results are important to guide management strategies in specific infestation foci and optimizing the use of phytosanitary products.

<p class="Body"><strong>Host preference, population dynamics, distribution, and injuries of <em>Oligonychus punicae</em> (Acari: Tetranychidae) in an eucalyptus clonal minigarden</strong></p>

Oligonychus punicae has potential for development in several species of eucalyptus. In this study was evaluated the preference for permanence and oviposition of O. punicae in different eucalyptus species. Additionally, we evaluated its dynamics and population distribution, as well as injuries in strains of Eucalyptus urophylla in a clonal minigarden. The preference for permanence and oviposition of O. punicae was evaluated using a test with and without choice in six species of Eucalyptus. We also analyzed the dynamics, population distribution and injury levels by O. punicae on E. urophylla in a clonal minigarden. We collected samples for 24 months and counted the number of eggs, immature and adult individuals. We calculated the Morisita dispersion index. We estimated injuries on leaves of E. urophylla using visual notes. In the test with choice, Eucalyptus urophylla was the preferred host of O. punicae for permanence and oviposition. In the test without choice, the oviposition of O. punicae in eucalyptus species did not differ statistically until 24 hours of evaluation. However, there was a significant difference after 48 hours, with greater oviposition on Eucalyptus brassiana, Eucalyptus tereticornis and Eucalyptus grandis. In the population survey, we collected 3,293 mites. The population peak of O. punicae occurred in March and April 2018 and April 2019. Oligonychus punicae presented an aggregate distribution and caused injuries of 20% on average in leaves. These results are important to guide management strategies in specific infestation foci and optimizing the use of phytosanitary products.

<p class="Body"><strong>Biology and fertility life table of <em>Oligonychus punicae</em> Hirst (Acari: Tetranychidae) associated with eucalyptus in a clonal minigarden</strong></p>

The mite Oligonychus punicae has potential for development in Eucalyptus spp. in clonal minigardens. However, there is no information on its biological and reproductive parameters on eucalyptus species. The objective of this study is to evaluate the biological and reproductive performance of O. punicae on different species of eucalyptus cultivated in a clonal minigarden. Development time, survival, longevity, fecundity and life table parameters of O. punicae were determined on six species of eucalyptus (Eucalyptus urophylla, Eucalyptus brassiana, Eucalyptus grandis, Eucalyptus tereticorinis, Eucalyptus pellita and Corymbia citriodora). All eggs of O. punicae originated females and completed the cycle in all hosts. Differences were observed in development, longevity, pre-oviposition, oviposition and post-oviposition, and fecundity of females of O. punicae when different eucalyptus species were used as hosts for O. punicae. The best performance of O. punicae was observed on E. tereticornis, while the worst performance was observed on C. citriodora, on which the net reproductive rates (R0) ranged from 5.09 to 44.85, the intrinsic rate of population increase (rm) ranged from 0.09 to 0.19, the finite rate of population increase (λ) ranged from 1.10 to 1.21, and the mean generation time (T) ranged from 0.09 to 0.19. These results suggest that E. tereticornis is an excellent host for O. punicae.

Oligonychus punicae as a pest of Eucalyptus urophylla in cultivation and potential new host species in Brazil

ABSTRACTThis study identified a mite species associated with Eucalyptus urophylla in clonal mini-garden of nursery seedling production and determined its instantaneous growth rate on several species of eucalypts. Mites were collected on the leaves of E. urophylla strains grown in clonal mini-garden and mounted on microscopy slides to species identification, while other were kept rearing on arenas. To determine the instantaneous growth rate of mites on Eucalyptus brassiana, E. urophylla, E. grandis, E. tereticornis, E. pellita and Corymbia citriodora grown on pots, arenas were assembled with Petri dishes containing foam, filter paper and leaf discs of each species of eucalypt and five adult mite females from the breeding colony. The “arenas” were kept in climatic chambers under controlled conditions. After 10 days the instantaneous growth rate was determined. The experiment was conducted in a completely randomized design with six treatments and six replicates. Data were submitted to Kruskal Wallis non-parametric test. The mite was identified as Oligonychus punicae. This is the first record of O. punicae associated with E. urophylla plants in clonal mini-garden of nursery seedling production. The instantaneous growth rate of O. punicae was positive in the six species of eucalypts suggesting the mite might damage clonal mini-gardens.

Respuesta funcional de Phytoseiulus persimilis sobre Oligonychus punicae (Acari: Phytoseiidae, Tetranychidae) en hojas de aguacate

Se evaluó la respuesta funcional de Phytoseiulus persimilis (Athias-Henriot, 1957) sobre diferentes densidades y estados de desarrollo del ácaro del aguacate Oligonychus punicae (Hirst, 1926) bajo condiciones de laboratorio. Los resultados muestran nula depredación en el estado de huevo, mientras que para el resto de los estados, el depredador exhibió una respuesta funcional tipo II. El máximo consumo de P. persimilis sobre O. punicae fue en promedio de 23.4 y 14.67 para larvas y ninfas respectivamente a una densidad de 64 presas ofrecidas, mientras que el máximo promedio de consumo en hembras adultas de O. punicae fue de 6.07 adultos a una densidad de 16 adultos hembra ofrecidos. Los resultados de la depredación muestran que P. persimilis puede ser utilizado como un agente de control biológico.

STATUS OF POMEGRANATE PESTS AND THEIR MANAGEMENT STRATEGIES IN INDIA

Pomegranate (Punica granatum L.) is one of the important fruit crops in India and is being cultivated in Gujarat, Maharashtra, Karnataka, Uttar Pradesh, Andhra Pradesh and Tamil Nadu. Thorough scanning of literature revealed a total of 91 insects, 6 mites and 1 snail pest feeding on pomegranate crop in India. The most obnoxious enemy is pomegranate butterfly, Deudorix (=Virachola) isocrates Fab. which may destroy more than 50% of fruits. Next in the order are the three species of fruit sucking moths (Eudocima (=Othreis) fullonia (Clerk); Eudocima (=Othreis) materna (Linn.); Eudocima (=Othreis) homaena Hub.) and two species of bark eating caterpillars (Indarbela tetraonis (Moore); Indarbela quadrinotata (Walker)). In the recent past two species of pomegranate shot hole borers (Xyleborus fornicatus E.; X. perforans Wollastan) have become major pests infesting in the collar region of the plant by making innumerable pin or shot holes causing discontinuity in the conducting vessels affecting conduction of water to the upper portion of the plant. Consequently, the drying of the twigs became imminent. The drying progressed from the tip towards the base and in severe cases the entire plant dried up. Overuse and improper use of insecticides has led to many serious problems like whiteflies (Pomegranate whitefly, Siphoninus phillyreae (Haliday); Spiralling whitefly, Aleurodicus dispersus Russell) mealy bug (Pseudococcus lilacinus (Cockerell)) Thrips (Rhipiphorothrips cruentatus Hood; Scirtothrips dorsalis Hood; Anaphothrips oligochaetus Karny), aphid (Aphis punicae (Passerini)) and mites, Aceria granati Can. & Massal; Oligonychus punicae (Hirst.)). These sucking pests occur during the flowering and fruiting stage of the crop and thereby reduce the vigour of the plant in addition to excretion of honeydew on the leaves and develop-ment of sooty mould on leaves and fruits. Besides, termites, Odontotermes obesus (Rambur) and root grubs (Anomala dimidiata (Hope); Holotrichia spp.) attack roots, defoliators feed on foliage and few bugs, borers, moths and fruit flies damage the fruits. The nature of damage and management options of a few key pests are discussed in this paper.

Biological studies of Oligonychus punicae (Acari: Tetranychidae) on grapevine cultivars

Life cycle, fecundity and longevity of the avocado brown mite, Oligonychus punicae (Hirst), were studied on six grapevine cultivars (Tucupita, Villanueva, Red Globe, Sirah, Sauvignon and Chenin Blanc), under laboratory conditions at 27 +/- 2 degrees C, 80 +/- 10% RH, and L12:D12 photoperiod. Mite-infested leaves were collected from vineyards, placed in paper bags and taken to the laboratory. A laboratory mite culture was established using the grape cultivar Criolla Negra as host plant. To elucidate potential effects on avocado brown mite parameters, we assessed levels of secondary metabolites, such as alkaloids, flavonoids, tannins and polyphenols, of leaves of the six grape cultivars, as well as the thickness of the adaxial cuticle-epidermis. The life cycle of O. punicae differed among cultivars with average values ranging between 8.2 days on Tucupita leaves and 9.1 days on Sirah. Relatively high fecundity was found on Tucupita leaves (2.8 eggs/female/day) during 11.4 oviposition days, while low fecundity values occurred on Sirah and Villanueva leaves, with 0.9 and 1.8 eggs/female/day during 7.9 and 6.7 days, respectively. Average longevity of O. punicae females ranged from 8.1 to 17.5 days on Sirah and Sauvignon leaves, respectively. Intrinsic rate of increase (r (m)) was highest on Sauvignon (0.292) and Tucupita (0.261), and lowest on Sirah (0.146) and Villanueva (0.135). Although significant differences in cuticle-epidermis thickness were detected among the six cultivars, it seemed not to affect mite parameters. Secondary metabolite content also varied between the cultivars. Generally, increasing flavonoid content coincided with decreasing reproductive parameters. The natural plant resistance observed in this study could be useful in the development of an integrated pest management program for mite pests in grape production.

Additions and corrections toMites of Australia:A Checklist and Bibliography

Some corrections and additions to the recently published Mites of Australia: A Checklist and Bibliography are briefly summarised. The most important name changes are in the spider mite family Tetranychidae. The species previously identified in Australia as Allonychus braziliensis (McGregor) is shown to be Tetranychus gloveri Banks. Bryobia cristata (Dugès) is a junior synonym of Bryobia graminum (Schrank). Bryobia repensi Manson is a junior synonym of Bryobia vasiljevi Rekk. Oligonychus biharensis (Hirst) has been recorded from Queensland and Oligonychus punicae (Hirst) and Schizotetranychus asparagi (Oudemans) are now believed to occur in Australia on the basis of unconfirmed records.

Effect of different foods on development, reproduction and survival ofPhytoseiulus longipes [Acarina: Phytoseiidae

The effect of different prey mite species on development of the immature stages and on survival and oviposition of adult predator femalePhytoseiulus longipes Evans was studied.P. longipes completed its development onTetranychus pacificus McGregor,Oligonychus punicae (Hirst), andPanonychus citri (McGregor), but not onPetrobia harti (Ewing). Females oviposited while feeding onT. pacificus andO. punicae, but not onP. citri orP. harti. The highest percent survival was observed onT. pacificus, followed byO. punicae andP. citri. The longevity ofP. longipes onP. harti (vial arenas) and on pollen (leaf arenas) was the same as that on leaves with no food. The provision of 10% sucrose solution and clover honey doubled the longevity ofP. longipes females compared with no food.

Physiological Responses of Avocado Leaves to Avocado Brown Mite 1 Feeding Injury

Effects of various levels of feeding injury caused by the avocado brown mite, Oligonychus punicae (Hirst) (Acari: Tetranychidae), on avocado leaves were examined. Mite feeding from the upper leaf surface reduced chlorophyll content of the upper mesophyll layer of avocado leaves, whereas chlorophyll content remained unchanged in the lower spongy parenchyma layer. Stomatal and mesophyll conductance values, photosynthesis, and transpiration were found to be negatively correlated with increasing levels of spider mite injury. Avocado photosynthesis rates were reduced 56% when 100% feeding injury was sustained on the upper leaf surface.

Spider Mites of El Salvador, Central America (Acari: Tetranychidae)

Nineteen species representing 6 genera of spider mites (Acarina: Tetranychidae) are reported from cultivated and wild host plants in El Salvador. Many of these species can cause noticeable and probably economically important damage to a number of the most important crops of the country. Eutetranychus banksi was by far the most ubiquitous and important species. Other economically important species are Oligonychus punicae, O. mcgregori, and Tetranychus ludeni.

The dynamics of predation ofStethorus picipes(Coleoptera: Coccinellidae) andTyphlodromus floridanuson the preyOligonychus punicae(Acarina: Phytoseiidae, Tetranychidae): Part II. Effects of initial prey-predator ratios and prey distribution

Life history studies first were conducted for the prey, the avocado brown mite Oligonychus punicae (Hirst), and the predators, the phytoseiid mite Typhlodromus floridanus (Muma) and coccinellid Stesborus picipes Casey, in an insectary chamber on excised Persea indica Spreng leaves. Both mite species developed at a faster mean rate than did S. picipes. A life table was constructed for each species from the life history data. Despite a shorter oviposition period than that of either predator, O. punicae not only laid more eggs/female per day, but also had a higher mean-age specific fecundity rate. The intrinsic rate of increase, rm, was highest for O. punicae (0.222), followed by T. floridanus (0.159) and S. picipes (0.121). In feeding tests, T. floridanus females indicated a significant preference for the egg stage of O. punicae. In contrast, females of S. picipes did not show a significant preference for a particular life stage of O. punicae. Assuming no problem whatever in finding prey (an inapplicable assumption for field situations), an arithmetic model was generated from the rm values, fecundity, and the prey consumption rate of T. floridanus. At an initial ratio of 10 prey to 1 predator, this model indicated that T. floridanus preying on O. punicae eggs could annihilate such a population of O. punicae within 13 days.

The dynamics of predation ofStethorus picipes(Coleoptera: Coccinellidae) andTyphlodromus floridanuson the preyOligonychus punicae(Acarina: Phytoseiidae, Tetranychidae): Part I. Comparative life history and life table studies

Life history studies first were conducted for the prey, the avocado brown mite Oligonychus punicae (Hirst), and the predators, the phytoseiid mite Typhlodromus floridanus (Muma) and coccinellid Stesborus picipes Casey, in an insectary chamber on excised Persea indica Spreng leaves. Both mite species developed at a faster mean rate than did S. picipes. A life table was constructed for each species from the life history data. Despite a shorter oviposition period than that of either predator, O. punicae not only laid more eggs/female per day, but also had a higher mean-age specific fecundity rate. The intrinsic rate of increase, rm, was highest for O. punicae (0.222), followed by T. floridanus (0.159) and S. picipes (0.121). In feeding tests, T. floridanus females indicated a significant preference for the egg stage of O. punicae. In contrast, females of S. picipes did not show a significant preference for a particular life stage of O. punicae. Assuming no problem whatever in finding prey (an inapplicable assumption for field situations), an arithmetic model was generated from the rm values, fecundity, and the prey consumption rate of T. floridanus. At an initial ratio of 10 prey to 1 predator, this model indicated that T. floridanus preying on O. punicae eggs could annihilate such a population of O. punicae within 13 days.