Studies on bionomics and occurrence regulation of Phigalia djakonovi Moltrecht

Investigation and observation were made on bionomics and occurrence regulation of Phigalia djakonovi Moltrecht, which is a major pest of white birch, in Daxing’an Mountain forest area of lnner Mongolia during 1997 to 1999. The pest has one generation per year and overwinters as pupae in the soil in this area.Development, bionomics and outbreak of the pest are closely related with the food and environment conditions.

Life circle and bionomics of Lymantria dispar L.

The life circle and bionomics ofLymantria dispar was studied from the May to the July of 1997 in Tulihe Forestry Enterprise of Inner Mongolia. The results showed thatL. dispar has one generation in a year, larvae overwinters in eggs, and last 50 days to grow up. From the completing of larvae period to the appearing of adults lasts 11 days. The study made a basis for the period forecasting of L.dispar in Inner Mongolia.

Bionomics of Biston betularia (L.) in Daxing'an Mountains forest area

Observations on life cycle, habits and characteristics ofBiston betularia (L.), which is a major pest infecting birch, were made in Daxing’an Mountain forest area, Heilongjiang Province during 1997–1998. In this area, the pest has one generation per year and overwinters as eggs in cracks of the lower part of stem. Adults emerge from mid-July to late August, and the damage of larvae occurs mainly in May and June. Life cycle table ofBiston betularia was given and control suggestions were made in this paper.

The Entomological Efficacy of Piperonyl Butoxide (PBO) Combined with a Pyrethroid in Insecticide-Treated Nets for Malaria Prevention: A Village-Based Cohort Study Prior to Large-Scale Deployment of New Generation Mosquito Nets in Burkina Faso

The efficacy of insecticide-treated nets (ITNs) is increasingly compromised by the prevalence of malaria vectors resistant to pyrethroids. In response to this issue, a new generation of ITNs has been developed that incorporate synergistic components, such as piperonyl butoxide (PBO). The purpose of this study is to provide entomological evidence for the efficacy of a PBO-based ITN brand at the village level, serving as a basis for decision-making before large-scale net deployment. During the high malaria transmission period, ITNs were distributed in each group and vector sampling was conducted biweekly in selected households. Bionomic data were collected to assess the resistance of wild An. gambiae populations to various chemical insecticides. There was a significant disparity in total An. gambiae sl. collected between the ITN arms, the intervention arm (ITN arms), and the control arm (P = 0.003). An. coluzzi was identified as the predominant species in the study area, as confirmed by PCR analysis. Analysis of the blood-feeding inhibition rate revealed that 100% permethrin + PBO ITN exhibited significantly greater inhibition than 66.81% permethrin only ITN. According to the log-time probit regression analysis, permethrin exhibited a knockdown time of 256 min without synergists, while it decreased to 139 min (P = 0.001) when pre-exposed to PBO. The evidence from this trial supports the use of PBO ITNs over standard ITNs for pyrethroids to combat pyrethroid resistance and improve protection against malaria for both individuals and communities, particularly in areas with high pyrethroid resistance.

Primary Culture of Alveolar Epithelial Type Ⅱ Cells and Its Bionomic Study

To establish a better method of primary culture for alveolar epithelial type Ⅱ cells （AEC Ⅱ ） and to study its bionomics, alveolar epithelial type Ⅱ cells were isolated by digestion with trypsin and collagenase, which were then purified by plated into culture flask coated with rat immunoglobulin （i The purified AEC Ⅱ were identified by alkaline phosphatase staining, electron mi- croscopy, immunocytochemical staining of pulmonary surfactant protein A （SPA）. The SPA expression and transfection characteristics were compared with those of A549 cell line. The results showed that AEC Ⅱ could be isolated by digestion with trysin and collagenase and purified by adhesive purification by using IgG, with a yield of about 2-3 × 10^7, and a purity of about 75%-84 %. Cells could be quickly identified with AKP staining. AEC Ⅱ were different from A549 cell line in terms of SPA expression and transfection characteristics. It is concluded that adhesive purification with IgG can improve the purity of AEC Ⅱ, and AKP staining is simple in cell identification. AEC Ⅱ can not be completely replaced by A549 cells in some studies because the differences between them, such as SPA expression.

Ecology and management of the black inch worm, Hyposidra talaca Walker (Geometridae： Lepidoptera) infesting Camellia sinensis (Theaceae)： A review

The black inch worm, Hyposidra talaca （Walker） （Geometridae： Lepidoptera） has earned considerable importance as a defoliator during last decade in north east India. Characteristic features of H. talaca, Such as switching from wild plants to Camellia sinensis, and completion of 6-8 generations in a year without winter diapause appear to be the major reasons for persistence of the defoliator on C. sinensis. There are reports on the aggressive infestation of the pest on C. sinensis than on alternate host plants and development of high tolerance^resistance to certain insecticides. Till date, more than one hundred alternate host plants have been recorded for H. talaca, but with very few natural enemies. To manage this pest chemically, synthetic pesticides are widely used. Integrated management is recently being encouraged wherein cultural, mechanical, physical, biological and chemical methods have been contemplated. This review collates the work and literature on the ecology of H. talaca and offers an analysis of the problems encountered in managing the defoliator in tea plantations. Further, future directions for better management of H. talaca are suggested.

Prey Predator Fishery Model with Stage Structure in Two Patchy Marine Aquatic Environment

In this paper, we propose and analyze a mathematical model to study the dynamics of a fishery resource system with stage structure in an aquatic environment that consists of two zones namely unreserved zone (fishing permitted) and reserved zone (fishing is strictly prohibited). In this model we introduce a stage structure in which predators are split into two kinds as immature predators and mature predators. It is assumed that immature predators cannot catch the prey and their foods are given by their parents (mature predators). It is also assumed that the fishing of immature predators prohibited in the unreserved zone and predator species are not allowed to enter inside the reserved zone. The local and global stability analysis has been specified. Biological and Bionomical equilibriums of the system are derived. Mathematical formulation of the optimal harvesting policy is given and its solution is derived in the equilibrium case by using Pontryagin’s maximum principle.

BIONOMIC OF CAMPOLETIS CHLORIDEAE (HYM:ICHNEUMONIDAE)AS A PARASITOID OF THE COTTON BOLLWORM HELICOVERPA ARMIGERA (LEP:NOCTUIDAE) *

The bionomics of Campoletis chlorideae and the regularity of its seasonal fluctuations were studied in Changsha district,Hunan province. Field investigation indicated that there were ten generations of C. chlorideae a year, of which seven occurred in cotton fields. Three peaks of cotton bollworm parasitization by C. chlorideae were observed, early May to late June, mid August to early September, mid September to mid October respectively. One peak occurred in tomato and tobacco fields, the other two in cotton fields. The parasitization rate ranged from 25.1%- 63.1%. The total development time from egg to adult ranged from 13.0 days at 32℃ to 75.5 days at 11.6℃. Each wasp could parasitize the 5-23 second instar larvae of tobacco caterpillar. C. chlorideae could parasitize the cotton bollworm, beet armyworm and tobacco caterpillar, but preferred the cotton bollworm larvae. C. chlorideae could parasitized 1st-3rd instar larvae of the tobacco caterpillar, but seldom parasitzed 4th-6th instar larvae. Moreover, C. chlorideae preferred second instar larvae. Theoretical models for developmental speed, adult longevity and the influence of temperature were proposed. The overwintering of C. chlorideae Uchida was also discussed. Moreover, methods for utilization of C. chlorideae Uchida in crop protection were presented and the bionomics of Campoletis chlorideae in both the Yangtze River Valley and Yellow River Valley were compared.

Bionomic notes of Isyndus reticulatus St?l(Hemiptera: Reduviidae)

The biological charchtiristics of the assassin bug Isyndus reticulatus Stal,1868（Hemiptera：Heteroptera：Reduviidae：Harpactorinae）,especially its life history are provided in detail.And the assassin bug is redescribed here.

NONCONSTANT PREY HARVESTING IN RATIO-DEPENDENT PREDATOR-PREY SYSTEM INCORPORATING A CONSTANT PREY REFUGE

This paper deals with the problem of nonconstant harvesting of prey in a ratio-dependent predator-prey system incorporating a constant prey refuge. Here we use the reasonable catch-rate function instead of usual catch-per-unit-effort hypothesis. The existence, as well as the stability of possible equilibria, is carried out. Bionomic equilibrium of the system is determined and optimal harvest policy is studied with the help of Pontryagin＇s maximum principle. The key results developed in this paper are illustrated using numer- ical simulations. Our results indicate that dynamic behavior of the system very much depends on the prey refuge parameter and increasing amount of refuge could increase prey density and may lead to the extinction of predator population density.

Interplay between reproduction and age selective harvesting:A case study of Hilsa(Tenualosa ilisha)fish at Sundarban estuary of northern Bay of Bengal,India

New offspring due to sexual reproduction is not an instantaneous process from its birth,it takes time to be sexually mature.On the other hand,harvesting of commercially profitable fish population before the perfect size or weight is reached is not only a commercial loss but also risks the extinction of the population.Now,we discuss the issue of Ganges-Brahmaputra-Meghna basin,northern Bay of Bengal for the age-selective harvesting of Hilsa shad(Tenualosa ilisha)which lays eggs after its sexual maturation.Harvesting of hilsa before its sexual maturation risks its extinction and due to lamer body weight,it is not a commercially profitable policy.This is a reality of Sundarban estuary for hilsa fish harvesting,therefore,biologically and economically both India and Bangladesh are facing several problems.Empirical data of Frasergunje Fishing Harbor shows a clear picture as the supporting document of this mathematical problem.

Prey-predator model with functional response for optimal harvesting incorporating prey refuge

This paper presents a prey-predator model considering the predator interacting with non-refuges prey by class of functional responses. Here we also consider harvesting for only non-refuges prey. We discuss the equilibria of the model, and their stability for hiding prey either in constant form or proportional to the densities of prey population. We also investigate various possibilities of bionomic equilibrium and optimal harvesting policy. Finally we present numerical examples with pictorial presentation of the various effects of the prey predator system parameter.