Intrinsic Rate of Increase

Field studies were conducted on orange orchard in Middle Egypt. The seasonal abundance and parasitism of the citrus leaf-miner (CLM), Phyllocnistis citrella Stainton (Lepidoptera: Gracillariidae) were estimated from10 March, 2011 till 25 February, 2013.Three generations of P. citrella and four peaks of parasitism had been observed during the two seasons of investigation. Six species of parasitic insects, Baryscapus sp., Cirrospilus pictus, C. quadristriatus, Pnigalio mediterraneus, Semielacher petiolatus and Sympiesis sp. (F. Eulophidae) were obtained from larvae and pupae of this pest and reared in the laboratory under room temperature.

Orius strigicollis is a predatory bug that attacks small arthropods, such as thrips, and augmentative release of commercial strains has been widely conducted in greenhouses in Japan. The accurate evaluation of its effectiveness is essential for successful biological control programs. However, because Orius species occur naturally in the field, it is difficult to discriminate O. strigicollis from other Orius species. Furthermore, it is necessary to discriminate commercial strains of O. strigicollis from field populations. In this review, we introduce two types of molecular procedures: (1) a multiplex polymerase chain reaction technique to identify Japanese Orius species, and (2) microsatellite DNA markers that can be used to measure genetic diversity within populations of O. strigicollis and to discriminate field and commercial strains. The usefulness of molecular ecological approaches is also discussed.

The braconid wasp, Diachasmimorpha longicaudata (Ashmead), was introduced in Kenya from Hawaii for classical biological control of the invasive tephritid, Bactrocera dorsalis Hendel. Following reports that D. longicaudata had formed new associations with Ceratitis cosyra, laboratory experiments were conducted to assess the interaction between the introduced and the native parasitoid of C. cosyra; Psyttalia cosyrae (Wilkinson) under three scenarios: B. dorsalis only, C. cosyra only and mixed populations of the two species. Parasitoids were introduced to the host as sole, sequential and simultaneous releases. Host searching and probing events were five times higher for D. longicaudata than P. cosyrae with both hosts. Total parasitism was highest (78%) when D. longicaudata was released alone on C. cosyra, compared to 20% for P. cosyrae released on the same host. Releases of P. cosyrae on B. dorsalis resulted in 0% parasitism, compared to 64% parasitism by D. longicaudata. Specific para...

Background. The coastal floodplains of northern Australia are fire-prone, but the impact of fire on floodplain biota is not well understood. Aims. In this study, we sought to characterise the fire history of six adjacent floodplains in coastal Northern Territory, Australia. Methods. We built a fine-scale 31-year fire history to compare fire regimes on floodplains across land tenures and floodplain fire regimes with the surrounding savanna fire regime, determine the extent to which current fire regimes are meeting existing ecological fire thresholds, and investigate the relationship between rainfall totals and the extent of burning. Key results. Floodplains in conservation reserves burnt more frequently than those on pastoral lands, and savannas burnt more often than floodplains. Current floodplain fire regimes comfortably meet existing ecological fire thresholds. The proportion of floodplain burning is inversely proportional to the amount of rain in the previous wet season. Conclusions. Floodplain fire regimes vary markedly between land-use types, and floodplain fire regimes differ to those of savannas. The current management thresholds for floodplain fire regimes would benefit from further evidence of conservation outcomes. Implications. For more effective floodplain fire management, research is needed to generate floodplain-specific thresholds that best conserve their considerable conservation value.

The physiological and life history consequences of chronic temperatures are well studied in ectotherms. However, little is known about the consequences of short-term exposure to unusually high or low temperatures, as would occur during a weather front. What are the immediate life-history effects of such thermal transients? Can ectotherms recover quickly or do they suffer carry-over effects that persist after weather returns to normal? We measured the impact of thermal transients on egg and progeny production of Drosophila melanogaster Meigen from Washington State. We reared flies at 25 degrees C and then transferred 3- to 5-day old adults to one of three transient treatments (1 or 3 days at 18 degrees C, 1 day at 29 degrees C) before returning them to 25 degrees C. We monitored daily egg production and egg-to-adult viability before (as a control), during, and after the transient as well as fecundity and viability of flies held at constant 18 degrees , 25 degrees and 29 degrees C. Th...

Figure 1: Two competing hypotheses predict how the maximum population growth rate of ectotherms evolves in response to temperature adaptation. Here we present extreme versions of each. A, The thermodynamic hypothesis ("warmer is better") predicts that species adapted to warm body temperatures (gray curve) will have relatively high maximal rates of population growth (r max ) at their optimal temperature (T o ). B, The perfect-compensation hypothesis predicts that biochemical adaptation can overcome the rate-limiting effects of low temperature, so that r max will be independent of T o .

The morphology-performance-fitness paradigm is usually explored by determining whether natural or ''phenotypically engineered'' variation among individuals in morphology (physiology) or performance covaries with an index of fitness such as survival. Here we study between-line covariation between performance and fitness for 44 lines of flies that had undergone mutation accumulation (in the absence of natural selection) on the second chromosome for 62 generations, plus 13 control lines. These mutation accumulation (MA) lines were known to have reduced competitive fitness and life history scores, and to have positive between-line covariances among life history traits. We measured several performance traits of larvae and adults (and a life history trait), examined covariances among those trait means, and also examined covariances of traits with competitive fitness. MA lines had significantly lower performances than did control lines in most traits. However, because control lines had been unknowingly contaminated, a conclusion that MA reduces performance must be tentative. Correlations among performance traits were highly variable in sign, suggesting that MA does not negatively affect all traits equivalently. Even so, correlation matrices for MA and for control lines were very similar. In bivariate comparisons, only one performance trait (a ''geta-grip index,'' which measures the ability of a falling fly to catch itself on baffles) was positively correlated with competitive fitness. Multivariate analyses again suggested the importance primarily of get-a-grip. Two main patterns emerge from this study. First, MA negatively affects diverse aspects of physiological performance, but does so differentially across traits. Second, except for GAG, MA-induced variation in performance is at best weakly correlated with competitive fitness.

The effect of herbivory by Gratiana boliviana Spaeth (Coleoptera: Chrysomelidae) on the invasive, tropical soda apple (TSA) (Solanum viarum Dunal, Solanaceae), was investigated using exclusion methods and by monitoring the density of G. boliviana and the weed at four locations over a period of 40 months. TSA plants protected by insecticide were taller, wider, and had greater canopy cover that unprotected plants, and plants in closed cages were taller and wider than those in open cages. Survival of plants was higher in plots protected with insecticide than in unprotected plots in both years of a 2-year study. In the population dynamics study, the initial density of TSA was 4Á5 times higher at one of the locations than at the other three sites, but within 3 years, TSA density at the high density site had declined by 90%. At the three sites which initially had a low abundance of TSA, density remained low throughout the study. The intrinsic rate of increase of G. boliviana varied between Á3.9 and 4.5, but over the 3-year study, was not different from zero, indicating a stable population. The intrinsic rate of increase was lower than zero for the period from October to January, and greater than zero during the January to April period. In the periods from April to July and July to October, the rate of increase was not different from zero. The implications of these results for biological control of TSA in Florida are discussed.

If a genetic sexing strain of Ceratitis capitata could be used to produce sterile males and to rear parasitoids at the same time, signiWcant amount of resources could be saved in comparison with the production of these two biological agents separately. We studied here the major biological parameters comparing two strains of the parasitoid Diachasmimorpha longicaudata, one of them reared on a wild type strain of C. capitata: DL(+), and the other on a genetic sexing strain of C. capitata: DL(sw). The mean longevity, fecundity, and sexual proportion of their respective oVspring showed no signiWcant diVerence. Moreover, no diVerence was observed in population parameters such as mean generation time, net reproductive rate, Wnite rate of increase, doubling time, and intrinsic rate of increase. The biological parameters of other artiWcially reared parasitoids in the Tephritidae family are reviewed, and the conclusion is reached that, rearing the parasitoid on this particular genetic sexing strain of C. capitata does not produce any negative eVect on the biological parameters studied.

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Oviposition, development and survivorship of Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) were evaluated on soybean and garden bean under laboratory conditions of 26.0 ± 0.5 o C, 70 -80% RH and a photoperiod of 14:10 (L:D). B. tabaci deposited more eggs and survivorship of nymphs was significantly greater in a choice-test on soybean, Glycine max L. (Merr.) (Fabeles: Fabaceae), compared to the garden bean, Phaseolus vulgaris L. Overall developmental time from egg to adult eclosion was longer on garden bean than on soybean. Also, B. tabaci was more fecund and long-lived on soybean compared to garden bean. Demographic parameters calculated from life tables on the two bean species indicate that soybean is a better host plant for B. tabaci than garden bean.

The mulberry is a perennial, fast growing plant mainly cultivated worldwide for rearing of mulberry
silkworm, Bombyx mori. The B. mori which is a monophagous insect feeds only on mulberry leaves
for its proper growth and development. The mulberry plant during its growth is susceptible to
various diseases viz., leaf spot, powdery mildew, leaf rust etc. and pests viz., leaf roller, Bihar hairy
caterpillar, mealy bugs etc. in the field which deteriorates its leaf quality and quantity. Among these
pests, defoliators attain significant importance as they cause damage up to 12-25% thereby making
mulberry leaves unfit for silkworm rearing. The leaf rollers are major pests currently causing
devastation to mulberry plants both in India and other parts of the world. Thus, in this review an
attempt has been made regarding new insights about the leaf roller pests and devise more
sustainable management of this pest through integrated pest management (IPM) strategy to control
it, so that the overall cocoon crop production will be enhanced worldwide.

Oenopia conglobata is an important active predator of pistachio psyllid in pistachio orchards. Alternative host or prey has an important role in the stability of natural enemies population in nature. In this study, prey preference of 4 th larval instar, male and female of O. conglobata were examined in 10 replications. Nymphs and adults of Agonoscena pistaciae, Aphis fabae, Aphis gossypii and eggs of Ephestia kuehniella with corn pollen were used as preys. In order to study the effects of these preys on consumption rate of adult stage of O. conglobata when feeding only on the common pistachio psylla, it was reared on each diet separately and the feeding percentage was determined after 24 hours. The results showed that the larvae and adults of this predator prefer nymphs of pistachio psylla to other preys. They fed 87±1.52 and 85.5± 1.74 % of psyllid nymphs, respectively. The Manly preference index in the prey-preference test on different diets also showed more preference to nymphs of pistachio psylla compared to other diets. Those predators reared on psylla had more consumption rate on pistachio psylla nymphs (99.2±0.512 %) than to other preys. The results showed that O. conglobata preferred common pistachio psylla to other preys and the common pistachio psylla is a suitable prey for rearing of this predator, but due to feasibility and rearing expenses, A. fabae as a second prey is the most favourable prey for rearing of O. conglobata for biological control of A. pistaciae.

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°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.

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Agonoscena pistaciae (Hemiptera: Psyllidae) is a significant pest in pistachio (Pistacia vera L.) orchards in Türkiye. This study aimed to evaluate the effectiveness of yellow sticky traps as an alternative method for controlling A. pistaciae populations in pistachio orchards. Conducted in late September and early October of 2021 and 2022, during peak pest activity, the experiment was carried out in Siirt, with three replicates following a randomized block design. Five traps were hung on all sides of each tree for sampling. Repeated measures ANOVA (repeated measures; general linear model) was used to observe changes over time. The results indicated that yellow sticky traps were highly effective in mass trapping adults, capturing an average maximum of 12 332.67 adults per trap. A significant decrease in the number of nymphs and eggs on the leaves was observed in the yellow sticky trap-treated trees compared to the control plots by mid-October (P < 0.05). Specifically, the average number of nymphs per composite leaf dropped from 24.95 to 11.23 in 2021, and from 145.18 to 27.29 in 2022. Similarly, the average number of eggs per composite leaf decreased from 61.18 to 2.29 in 2021, and from 73.56 to 3.64 in 2022. These findings suggest that yellow sticky traps can significantly reduce psyllid populations in pistachio orchards over the long term and can be an effective control method when used early in the vegetative period for low- to medium-sized psyllid populations.

Soybean flour and wheat germ are the two most important protein components of wheat germ-based insect artificial diets. The effect of modifying the proportion of these two ingredients in a Noctuidae-specific diet was investigated utilizing the tobacco budworm Heliothis virescens (F.) (Lepidoptera: Noctuidae), with the goal of developing a suboptimal diet that, without drastically affecting this insect's growth and reproductive rates, could manifest subtle negative effects in this insect. The original diet formula contained 2.51% protein. When the proportions of soybean flour and wheat germ were changed to 2.15% protein the net reproductive rate of the first generation was significantly lower. In the second generation, the net reproductive rate, development time, percent female survivorship, fertility, intrinsic rate of increase, finite rate of increase and female longevity were significantly lower in both the 2.15% and 2.26% protein diets. The survival rate of immatures to the adult stage was 1% in the 2.05% protein diet in the first generation. Interestingly, females exposed to these suboptimal diets produced a significantly higher number of eggs but the survival of their larvae was significantly reduced. It is evident from these results that modifications to the protein content and the nutrient composition profile of the original wheat germ-based insect artificial formula can be used to produce subtle negative effects on the growth of tobacco budworm.

The sex pheromone of the scarab beetle, Phyllophaga anxia, is a blend of the methyl esters of two amino acids, L-valine and L-isoleucine. A field trapping study was conducted, deploying different blends of the two compounds at 59 locations in the United States and Canada. More than 57,000 males of 61 Phyllophaga species (Coleoptera: Scarabaeidae: Melolonthinae) were captured and identified. Three major findings included: (1) widespread use of the two compounds [of the 147 Phyllophaga (sensu stricto) species found in the United States and Canada, males of nearly 40% were captured]; (2) in most species intraspecific male response to the pheromone blends was stable between years and over geography; and (3) an unusual pheromone polymorphism was described from P. anxia. Populations at some locations were captured with L-valine methyl ester alone, whereas populations at other locations were captured with L-isoleucine methyl ester alone. At additional locations, the L-valine methyl ester-r...

The influence of leaf pubescence of three wheat cultivars (Pishtaz, Ghuds and Falat) on preference and biological parameters of Sipha maydis (Passerini) was investigated under greenhouse conditions (25 ± 2 °C, 70 ± 10% RH and 14: 10 h (L: D) photoperiod). The results showed that Pishtaz had a greater density of trichomes compared to the other cultivars. In the preference test with whole plant, the number of aphids on Pishtaz was significantly greater than that on other cultivars at 48 hrs after infestation. Similarly, in the preference test on leaves, the numbers of attracted aphids per leaf was highest on Pishtaz. In the life table study, there was no significant difference of intrinsic rate of natural increase (r m) among the three studied cultivars but it was highest on Pishtaz (0.187 /day). Aphids' net reproductive rate, doubling time, mean generation time and finite rate of increases did not show significant differences between the tested cultivars. According to our results, leaf surface pubescence of wheat is not an effective resistance mechanism against S. maydis.

To study the different parameters of the Bombyx mori four host viz S-146, S-1635, V-1 and TR-10 and one alternate host plants under natural conditions highest percent mortality of 13.2 species recorded at early stage larvae on V-1. Generation survival fraction revealed that S-146 was most preferred host plant. Life table studies, viz. stage specific and survival of B. mori on the four species of mulberry plants (Morus alba) i.e, S-1635, S-146, V-1 and TR-10 under natural condition indicate that the insect preferred all the four hosts species but S-146 was favored, suitable food for the development and shows the lowest mortality of Bombyx mori.

Investigations on the biology of the Honeydew moth [Cryptoblabes gnidiella Mill., 1867 (Lepidoptera: Pyralidae)] in natural conditions This study was carried out on pomegranate on nature during vegetation period in 2008. In this study, purposes were to determine some biological characters of Honeydew moth [Cryptoblabes gnidiella Mill., 1867 (Lepidoptera: Pyralidae)] such as adult longevity, egg fertility, egg hatching, larvae and pupa longevity for controlling. At the end of study, one generation of C. gnidiella was completed 28.90 days and 564,6 day-degree in nature conditions. At the same conditions, meanly developmental time and egg fertility was 4.55 days, 46.18 egg/female, respectively. On the other hand, egg incubation period, larval stages and pupae stages of C. gnidiella were determined as 3.53, 13.91 and 6.91 days, respectively.

Investigations on the biology of the Honeydew moth [Cryptoblabes gnidiella Mill., 1867 (Lepidoptera: Pyralidae)] in natural conditions This study was carried out on pomegranate on nature during vegetation period in 2008. In this study, purposes were to determine some biological characters of Honeydew moth [Cryptoblabes gnidiella Mill., 1867 (Lepidoptera: Pyralidae)] such as adult longevity, egg fertility, egg hatching, larvae and pupa longevity for controlling. At the end of study, one generation of C. gnidiella was completed 28.90 days and 564,6 day-degree in nature conditions. At the same conditions, meanly developmental time and egg fertility was 4.55 days, 46.18 egg/female, respectively. On the other hand, egg incubation period, larval stages and pupae stages of C. gnidiella were determined as 3.53, 13.91 and 6.91 days, respectively.

The sugarcane aphid Melanaphis sacchari (Zehntner) (Hemiptera: Aphididae) is the main vector of the Sugarcane yellow leaf virus (SCYLV; genus Polerovirus, family Luteoviridae), a disease of economical importance in the sugarcane growing area. Resistance was detected in the sugarcane cultivar R 365, using a three-year field trial in La Reunion island. In laboratory, R 365 reduced aphid populations on potted plantlets and excised leaves. Using the electrical penetration graph technique, we detected a delayeddelayed aphid salivation in phloem and inhibition of passive phloem sap uptake in R 365. Future research to evaluate the resistance durability and efficiency against Melanaphis sacchari diversity and its potential for reduction of SCYLV incidence through sugarcane cultivation schemes will be discussed

The common pistachio psylla, Agonoscena pistaciae Burckhardt and Lauterer (Hem: Aphalaridae) is one of the main and most destructive pests of pistachio orchards in Iran. Chemical control is a widely applied method to manage this pest problem. The intensive use of insecticides has led to the development of resistant populations of the common pistachio psylla. In this research, the activities of detoxifying enzymes (general esterase, glutathione S-transferase and cytochrome P450) were assessed against two populations of the common pistachio psylla, and the coccinellid predator, Oenopia conglobata L. (Col: Coccinellidae) in Kerman Province, under treatment of three rational insecticides, namely, acetamiprid, spirotetramat, and hexaflumuron in four concentrations (control, LC25, LC50 and LC75). The results indicated that the activities of detoxifying enzymes were higher in the resistant population of psylla compared to the susceptible one. Esterase was the predominant detoxifying enzyme...

Scads fishery in Blitar waters is a multispecies fishery applying harvest control rules (HCRs) from conventional single-species approaches which technically, may not be applicable to employ in such mixedspecies data composed from the multispecies fishery. The feedback HCR is an alternative validated harvest control rule that can be applied for a multispecies fishery. The aim of this study was to technically compare the application of the feedback HCR and conventional single species approaches in terms of estimating the future allowable biological catch (ABC). Therefore, in this study, ABC was estimated by applying three HCRs, the feedback HCR, and two conventional HCRs which was based on single-species approaches applying surplus production models, Schaefer Model and Fox model into catch and effort of scads fisheries data series of 2011-2020. The results showed that the ABC estimation of the feedback HCR was a half lower than that of both conventional models. It was biologically safer to apply the feedback HCR to set the annual total allowable catch (TAC) than the other two HCRs. The feedback HCR presented an initial step toward sustainably managing multispecies fisheries while dealing with data-limited conditions.

The size-class structure, abundance trends, sex-ratio, net reproductive rate, generation time and per capita rate of population growth were established for a population of Hyale nigra from the intertidal region at the Bryocladia thyrsigera belt. Marine algae often forms habitat patches occupied by an associated fauna composed mainly, by crustacean such as amphipods and isopods. Collections were taken once a month from March/1997 to February/1998. A total of 26909 individuals were sampled. There were two reproductive peaks one smaller in May and another one throughout the warmer months from November to February imposing, with the continual reproduction, the overlapping of generations. A sex ratio biased in favor of females was recorded in all sampling dates, a common pattern in epifaunal species. H. nigra appears to be r 1 strategist, with iteroparous females and multivoltine cycle. The net reproductive rate estimated was 3.1190 ± 3.2615, the generation time 4.6889 ± 0.6549 and the p...

The life table study of the arctiid moth, Diacrisia casignetum was conducted on young, mature and senescent jute, Chorchorus capsularis (cv. Sonali; JRC-321), leaves in the laboratory condition. The demographic parameters of D. casignetum on mature leaves were significantly differed (P young&gt;senescent leaves, whereas total generation mortality (K) are in the reverse order. These differences in the demographic parameters are due to the variation in their phytochemical regime of respective jute leaves which may help to understand how food quality influences the life table parameters of D. casignetum for appropriate control measures at their most vulnerable stage.

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Pulse beetle (Coleoptera: Chrysomelidae) is a notable insect pest of green grams, garden peas, chickpeas, cowpeas, lentils, black grams, and pigeon peas. Callosobruchus chinensis L. can cause huge quantitative and qualitative losses and also decrease the nutritional values of stored grains/pulses. The biology, life table parameters, and host preference of C. chinensis were studied in three pulses-green grams, lentils, and cowpeas. We also evaluated the green gram germplasms for resistance to C. chinensis. Cowpea was the most appropriate host for the culturing of C. chinensis under laboratory conditions among the three pulses. C. chinensis exhibited higher fecundity, shorter development period, and longer female longevity in cowpeas than green grams and lentils. The relative growth rate of C. chinensis was 0.101 ± 0.006 mg/day. The finite growth rate, intrinsic rate of increase, and net reproduction rate demonstrated a faster increase in the C. chinensis population in cowpeas than green grams and lentils. We observed the overlapping patterns in the life expectancy, survival rate, and reproductive results of C. chinensis on cowpea, green gram, and lentil; this universal pattern is important in assessing the life table parameters. Based on growth index, we graded 20 green gram germplasms as resistant (6), moderately resistant (7), moderately susceptible (2), susceptible (3), and highly susceptible (2). The green gram germplasms resistant to C. chinensis, EC920900, IC616111, IC616247, IC616161, IC616258, and IC616138 have the potential in reducing the loss of green grams during storage. To summarize, cowpeas can be utilized for continuous mass rearing of C. chinensis in the laboratory and the resistant germplasms can be used as donor in future breeding programmes.

The hawthorn red midget moth, Phyllonorycter corylifoliella (Hübner) (Lepidoptera: Gracillariidae), is one of the most serious pests of apple and pear orchards in Iran, however little is known about its biology and relationship with environmental factors. The reproduction and population growth parameters of P. corylifoliella were examined at six constant temperatures (15, 20, 25, 30, 33 and 35º C) on apple var. golden delicious. At 35° C, P. corylifoliella failed to develop beyond the first instar. The lowest (13%) and highest (64%) mortality rates of immature stages occurred at 25 and 33° C, respectively. The life expectancies (e x) decreased with increasing of age and the life expectancies of one-day-old larvae were estimated to be 38.

A metapopulation, time-invariant, stage-classified matrix model was developed to assess the dynamics of an important Pinna nobilis population in the marine Lake Vouliagmeni (Korinthiakos Gulf, Greece). The main aim of the study was to provide insight on the life cycle of the fan mussel and reveal influential factors for its population dynamics, with a special focus on the effect of poaching. The size of the fan mussel shell was selected as a state variable, and the model consisted of five size classes. The lake was divided in two regions, a shallow region of high (illegal) fishing mortality and high recruitment (region 1) and a deeper region of low mortality and low recruitment (region 2). The estimation of the transition matrix (stagespecific growth and mortality probabilities) was based on a tagging survey between 2005 and 2006, while independent annual surveys for abundance estimation using distance sampling techniques were utilized for the estimation of recruitment and stage-specific fertilities. The population was found to be increasing with an intrinsic rate of increase r = 0.038; however, r was not statistically different from zero. The life expectancy and expected lifetime offspring production of individuals in region 1 was markedly lower than that of individuals in region 2. Due to poaching, the life expectancy of a yearling fan mussel was less than 2.5 years in region 1, while it was almost 12 years in region 2. The highest expected annual natural mortality of fan mussels occurred on their first year of life after settlement (*43%) and greatly declined at greater sizes. Perturbation analysis revealed that the population growth rate was most sensitive to the vital rates of the larger size classes in region 2 and to fertilities corresponding to offspring that settled in the same region. The spatial distribution and abundance of the species was greatly dependent on the extent of poaching, which caused a size segregation of individuals, with small and young individuals being abundant in region 1, and larger and older individuals being restricted in region 2. If poaching ceased, the fan mussel population would be increasing with a significantly higher intrinsic rate of increase (r = 0.186), while if region 2 was also illegally exploited at the same intensity as region 1, the fan mussel population would be decreasing with r =-0.364 and would eventually collapse. The existence of refuge areas, where fan mussels may grow and reproduce, providing adjacent areas with offspring, seems crucial for the viability of local populations. Transplantation of fan mussels from high mortality areas to low mortality refuges might prove to be an effective measure to protect local populations of the species.

The developmental rate of immature stages and the reproduction of adults of Tyrophagus putrescentiae (Schrank), T. neiswanderi Johnston and Bruce and Acarus farris (Oudemans) were examined at 70, 80 and 90% r.h. and a constant temperature of 25°C. At 70% r.h., T. putrescentiae and A. farris immature stages failed to reach the protonymph stage as 100% of the larvae died, whereas T. neiswanderi was able to complete development. The developmental time of all immature stages for the three species was significantly increased as relative humidity was reduced. The mobile stages were particularly susceptible, as the time needed to complete their development at lower relative humidities suffered greater increases than the egg stage. At 70% r.h., T. putrescentiae and A. farris were not able to lay eggs and only 24% of T. neiswanderi pairs were fertile. The reproductive parameters of the three species at the relative humidities at which they were able to lay eggs showed significant differences, except for the percentage of fertile mating at 80 and 90% r.h. As relative humidity increased, preoviposition period was reduced and fecundity and daily fecundity was increased, whereas the oviposition period showed different patterns for the three species. The intrinsic rate of increase (r m) of T. neiswanderi at 70% r.h. was negative indicating that, at these conditions, mite populations of this species will diminish until they disappear. As relative humidity increased from 80 to 90% r.h. this parameter was almost twofold for both Tyrophagus species. The r m obtained for A. farris at 90% r.h. was similar to that of T. neiswanderi at the same humidity while at 80% r.h. it was very small so that the population doubling time was more than 84 days. The influence of relative humidity on biology of these mites and its practical application as control measure are discussed.

The black been aphid, Aphis fabae Scopoli (Homoptera: Aphididae), is an important pest of many garden, vegetable and ornamental plants in the world. To evaluate Orius albidipennis potential for biological control of the aphid, prey stage preference of the predator to different life stages of the aphid and functional responses of it to different densities of the most preferred life stage were studied under laboratory conditions. Free choice experiment was conducted for evaluation of the bug prey preference between different instar nymphs and wingless female adults of A. fabae. In functional response trials, densities of 5, 10, 15, 20, 25 and 30 s instar nymphs, as the most preferred life stage, per arena were exposed to male and female of the predatory bug for 24-h period. The logistic regression analysis and Roger's model were used for determinate the type and the parameters of predator's functional response, respectively. The results showed that O. albidipennis preferred first and second instar nymphs of the aphid in comparison with other life stages. Both sexes of O. albidipennis showed the type II functional response to different densities of the nymphs. The handling times (T h) of O. albidipennis female and male were 1.344 and 1.584 h, respectively. The attack rate value (a) of the female and male bugs were 0.0839 and 1.4814 h −1 , respectively. No significant differences were observed between the calculated T h and a for the female and male bugs. From the findings of this study, O. albidipennis can be used in biological control program of A. fabae.

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Eotetranychus uncatus Garman (Acari: Tetranychidae) was found in unsprayed and abandoned orchards in Turkey. It has the capability to become an important pest of deciduous fruit trees. In this study life-history parameters of E. uncatus Garman was studied at 25±1°C and 16:8 L:D photoperiod and 65±5% relative humidity on the apple leaf discs under controlled conditions. While the mean generation time of female (from egg to adult stage) was 13.65 days, it was 11.82 days for male. Pre-oviposition period of female was 2.95 days and total number of eggs laid per female was 26.30.

Life table parameters were assessed for seven strains of Trichogramma aurosum Sugonjaev and Sorokina (Hymenoptera: Trichogrammatidae) collected in different European countries, in order to compare their performance when reared on eggs of Ephestia kuehniella Zeller (Lepidoptera: Pyralidae) as a potential factitious host for mass-rearing. The average number of progeny per female, cumulative fertility and emergence rate did not differ significantly, whereas female longevity and sex ratio significantly differed between the seven parasitoid strains. The Danish strain survived the longest (6.05 days) and the Dutch strain survived the shortest (2.75 days). Progeny was always female-biased with varying proportions (57.7Á96.7%). Survival rates started to decrease after 3 days for some of the strains studied. The mean cohort generation duration (T c ) was 11.

The reproductive biology of Fidiobia dominica Evans (Hymenoptera: Platygastridae) was studied in the laboratory (25.6 Ϯ 1ЊC) using host eggs of Diaprepes abbreviatus L. (Coleoptera: Curculionidae). F. dominica readily parasitized D. abbreviatus eggs on both host plant and wax paper substrates. The number of egg masses parasitized and the number of offspring produced were higher when females were offered more than one host egg mass but did not differ when either two or three egg masses were offered. Female parasitoids that were provided with host eggs and a honey food source lived signiÞcantly longer than those that were not provided a food source; however, they did not parasitize more D. abbreviatus eggs. Oviposition occurred in host eggs from 0 to 7 d old, and host mortality was relatively consistent for eggs 0 Ð5 d old and lower for eggs 6 Ð7 d old. Successful parasitoid emergence seldom occurred after host eggs were 4 d old, and by 7 d, no adults successfully emerged. Developmental time from egg to adult was 19.3 Ϯ 0.2 d for males, signiÞcantly more rapid than the females (20.4 Ϯ 0.1 d). The mean longevity of adult females was 8.0 Ϯ 0.4 d, with a mean oviposition period of 2.7 Ϯ 0.3 d; males survived 8.1 Ϯ 0.4 d. The demographic parameters including intrinsic rate of increase (r m), generation time (T), and net reproduction (R o) were 0.142/d, 22 d, and 22.4 female eggs/d, respectively. KEY WORDS classical biological control, citrus integrated pest managment, oviposition, reproduction, nutrition Diaprepes abbreviatus L. (Coleoptera: Curculionidae) was Þrst reported in the United States in Orange County, FL, in 1964 (Woodruff 1964). It is now established across south and central Florida and is a major pest of the citrus industry, where it is estimated to cost producers tens of millions of dollars annually (Stanley 1996); it is also a signiÞcant pest for ornamental growers. D. abbreviatus has also established in the Rio Grande Valley of Texas (Skaria and French 2001) and at selected sites in Orange, Los Angeles, and San Diego Counties in California, where it poses a risk to multiple crops (Grafton-Cardwell et al. 2004, Klunk 2005, K. Godfrey, personal communication). The weevil is native to the Lesser Antilles of the Caribbean and was presumably introduced to the United States from Puerto Rico with imported ornamental plants (Woodruff 1985, McCoy and Simpson 1994). D. abbreviatus is highly polyphagous and has been associated with plants from 59 families (Simpson et al. 1996). Citrus and various woody ornamentals support the entire life cycle of this insect (Schroeder et al. 1979). Diaprepes abbreviatus is a relatively large weevil (10 Ð19 mm) that feeds along the edges of leaves,

Leslie matrices and life tables are demographic models commonly used to evaluate the ability of specific elasmobranch life history strategies to sustain given levels and patterns of fishing pressure. These models are generally density independent and provide an instantaneous rate of population growth for a specified set of life history traits that correspond to a specific population size. Many investigators are using these models to compute rates of population growth that they claim are estimates of the maximum population growth rate (r intrinsic); they then use these estimates to compute purported estimates of maximum sustainable fishing mortality. However, neither a Leslie matrix nor a life table can be used to estimate r intrinsic without additional information, except in the special case where a severely depleted population is modeled. Only in a severely depleted population will competition for resources be at a minimum and both density-dependent compensation and the rate of population growth be at a maximum (i.e., at r intrinsic). The fundamental problem is to determine the life history parameters that would occur if the population were extremely depleted because extensive observations on extremely depleted populations are rare. In the absence of such data, r intrinsic can only be estimated from these types of density-independent models by extrapolating observed population growth rates toward zero population size. We illustrate the problems in, and describe methods for, estimating r intrinsic and present information on two species of elasmobranch: barndoor skate Dipturus laevis and lemon shark Negaprion brevirostris.

Cuticular thickness and N P K contents for eleven host plants were tested as probable causes for host reference in six species of tetranychid and tenuipalpid mites. Host preference was based on the &rations of mite developmental stages and female fecundity upon rearing on differently favoured hosts. This study showed that development and fecundity were favoured on plants with thin cuticle, which was the case for the tetranychid mites reared (4 species). Preference for thin cuticle also positively correlated with the length of mite chelicerae. With tenuipal id mites, showing a more limited host range, cuticular thickness was not the factor that itermined preference. Nitrogen content of plant leaves stimulated development as well as fecundity of the tetranychids tested. Potassium showed a reversible effect, while no effect of phos horous could be detected. The tested hosts of tenuipalpid mites, pear, quince, apricot, a n i apple, did not considerably vary in N and K contents such that the effect of these factors on preference was not conclusive. However, the results ascertained the host specificity in these mites (2 species).

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°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.

The perennial monocarp Frasera speciosa (Gentianaceae) flowers at a wide range of sizes and ages with consequent variation in generation time (T), net replacement rate (Ro) and intrinsic rate of increase (r). Values of r were calculated for hypothetical cohorts composed of individuals flowering at the same age. Maximum rates of r are achieved by plants which flower at the earliest possible age. Although older plants produce more flowers, this increase is not sufficient to compensate for the effect of increased T on r. Few plants in each population flower at the youngest possible age, and for the majority reproduction is delayed, generation times are longer and r lower than achieved by plants flowering at younger ages. Delayed reproduction may be favored by greater seed set, due to pollinator attraction to larger flower stalks, as well as broader seed dispersal which could increase the probability of seedling establishment. Delays greater than those observed may be selected against by decreasing probability of survival, a decrease in the rate of addition of flowers with increasing size, and slower transitions between leaf number classes in larger plants. Staggered reproduction by an individual's offspring, whether environmentally or genetically determined, has the effect of insuring survival in an environment with high variability in pollinator effectiveness (see d set), germination, and seedling establishment.

Biological control commonly involves the commercialization and introduction of natural enemies. Phytoseiulus persimilis Athias-Henriot, a mite species widely used in the control of spider mites, was imported to Taiwan in the 1990s and was mass-reared and released into the field. However, none have been observed in comprehensive surveys of phytoseiid mites for over 30 years. In this study, the distribution of P. persimilis in Taiwan was predicted, and environmental variables that affect its distribution were analyzed. The mountainous region of southcentral Taiwan was determined to be suitable for the establishment of this species, whereas the four sites at which it was released in the 1990s, particularly those in southwestern Taiwan, exhibited low suitability. Notably, the minimum temperature of the coldest month was identified as a crucial limiting factor affecting the distribution of P. persimilis, indicating that a Mediterranean climate is more suitable for this species. To the be...

A biological control strategy aimed at enhancing the performance in the field of two predatory mites that are natural enemies of an invasive pest of avocado orchards was applied during two consecutive years. Unexpected poor pest control led us to analyse additional factors involved in the dynamics of the community such as summer environmental conditions, which were very hot and dry. Non-linear regressions considering biotic and abiotic effects suggested that high temperatures during the second half of the summer were central to predator/prey population dynamics. Harsh environmental conditions were therefore a direct cause of biological control disruption. We believe that, in the future, the success of biological control strategies will be limited by the natural enemy's capacity to respond adaptatively to rapid climate changes, and that research aimed at evaluating the evolutionary potential of natural enemies to rapid climate change should be the focus of future investigations.

To study the different parameters of the Bombyx mori four host viz S-146, S-1635, V-1 and TR-10 and one alternate host plants under natural conditions highest percent mortality of 13.2 species recorded at early stage larvae on V-1. Generation survival fraction revealed that S-146 was most preferred host plant. Life table studies, viz. stage specific and survival of B. mori on the four species of mulberry plants (Morus alba) i.e, S-1635, S-146, V-1 and TR-10 under natural condition indicate that the insect preferred all the four hosts species but S-146 was favored, suitable food for the development and shows the lowest mortality of Bombyx mori.

Throughout the five years this thesis have been performing I have received a great help by many people in any of the aspects this work involves, field surveys, insect identification and counting, laboratory experiments and articles preparation. Since it would be almost impossible to cite all of them I would like to express my deepest and sincere grateful to all persons that made this doctoral thesis possible. I would like to express my deepest gratitude to Dr. Ferran Garcia-Marí, my thesis advisor, for accept me in his research team to perform this fascinating work under his guidance, for transmitting to me his passion for the entomology scientific research and the accuracy in the articles performing, for his always measured and good advices and for being always available for the dialogue and discussion about the work. My deep appreciation to Dr. Joan van Baaren for receiving me at the ECOBIO Institute, her support and guidance with the laboratory experiments, her help with the articles writing and for showing me so many beautiful things from Bretagne. A very special thankful to Raquel Rodríguez, for sharing the effort of the parasitoids counting during so many hours, for her essential contribution in the identification of the species, her friendship and her help. I would like to acknowledge Dr. Jacques van Alphen his advices and correction of the first article and his help with the laboratory trials design and preparation and to Dr. Jean-Sébastien Pierre for admitting me in Ecobio Institute and for his help with the statistical analysis included in the third article.

BACKGROUNDSeveral phytoseiid species can potentially control the citrus rust mite (CRM). Their effectiveness varies, however, as do their intraguild interactions. Under laboratory conditions, Euseius stipulatus, E. scutalis and Iphiseius degenerans preyed effectively on CRM, whereas Amblyseius swirskii and Typhlodromus athiasae had no effect on CRM. In combination with A. swirskii, Euseius numbers were reduced due to intraguild predation, and consequently CRM suppression was less effective. In the field, predatory mite species can be variably provisioned by windborne pollen released from cover crops such as Rhodes grass (RG). We aimed to determine the effects of RG on the phytoseiid community in two field experiments, on different cultivars (pomelo and Shamouti orange). We also tested these communities for negative interspecific abundance relationships that are expected if their respective laboratory‐observed intraguild interactions are manifested in the field.RESULTSOverall, on pom...