Insect Mass Research Articles

Alternative Foraging Modes of Orb Web Weaving Spiders

Forest-understory, orb weaving spiders display at least two, alternative, foraging modes. Large spiders build one large web per feeding period. Although their webs intercept more prey than webs built by small spiders, the biomass of captured prey relative to spider biomass is low. In contrast, small spiders build three to five webs per feeding period. The ratio of prey biomass intake relative to spider biomass, however, is high. Small spiders may be able to tolerate high rates of web loss because of their potentially high rate of prey intake. However, for large spiders, the high rates of web loss may not be tolerable because of the low rate of prey biomass intake. This work shows that orb weaving spiders forage differently and that different patterns of web use have resulted in at least two very different, but equally effective, means of prey capture. ORB SPINNING SPIDERS SPAN body weights over four orders of magnitude. Nevertheless, almost all studies on the foraging ecology of orb weavers has focused on large and medium sized spiders (Kajak 1965; Robinson & Robinson 1972, 1974; Uetz, et al. 1978; Kajak 1978; Eberhard 1979; Wise 1979, 1981; Olive 1980, 1981; Wise & Barata 1983; Spiller 1984). Small orb spinners, including the immature stadia of large web spinners, are more abundant than large spiders and form an important group of terrestrial predators in tropical forests. For web weaving spiders, web silk and the web spinning process are the highest costs associated with foraging (Peakall 1969). Therefore, web loss without prey capture may result in an important energetic loss for the spider. If prey are abundant, however, high rates of web loss may not significantly affect spider foraging effectiveness. Although large and small prey are captured in strong webs, only minute prey can be captured in the webs spun by small spiders. Nevertheless, in a variety of habitats, the most abundant insects are less than or equal to 4 mm in body length (Olive 1980; Greenstone 1984; Nentwig 1983; Shelly 1983, 1984; Wise & Barata 1983; Spiller 1984). In this paper I compare two aspects of spider foraging modes, rate of prey capture, and rate of web breakdown, among five species of tropical forest orb weavers whose size varies over three orders of magnitude. This work predicts that for small spiders prey are abundant and small spiders tolerate high rates of web breakdown. For large spiders, however, resources are less abundant and high rates of web loss are not tolerable. Prey capture at spider orb webs depends on web size, where the web is suspended, and the ability of the web to intercept prey (Kajak 1965, Colebourn 1974, Enders 1977, Brown 1981, Olive 1982, Craig 1987b). The probability of insect encounter at webs and the ability of webs to intercept prey are greatest just after the web is spun. As the web breaks down during the spider's foraging period, however, its effectiveness decreases. Web breakdown results from a variety of both biotic and abiotic factors. The most important biotic events affecting web breakdown and function are prey interceptions. At interception, the kinetic energy an insect transfers to a web is a function of the insect's mass and velocity (E = mv2/2). Most investigators have assumed that small insects are weak fliers (for example see Shelly 1983). Goldsmith et al. (1980), however, have shown that Anartepritchardi (Diptera: Cecydomiidae) is capable of rapid flight velocities up to 3.8 ms-'. Because the kinetic energy of flying insects increases as a function of velocity squared, insect flight speed has a much greater effect on insect kinetic energy than does insect size. Therefore, even an insect of low mass may possess a high kinetic energy when flying fast. This effect is most obvious when insect kinetic energy is calculated relative to insect size or the potential insect area that the web may intercept. Craig (1987b) calculated that the kinetic energy for the small flies (family Cecydomiidae) caught in webs spun by Epilineutes globosus and Leucauge globosa, to be close to the breaking energy of the webs' viscid silk. Hence, when flying fast, even fragile insects are capable of damaging and breaking through

Is there an optimal sex ratio for insect mass rearing?

The optimal sex ratio ( sr) for insect mass rearing depends upon the use to which the insects will be put. Mass rearing for release in control programs and for producing insects for experimental purposes may require sr values in the breeding population that optimize the production of male offspring, female offspring, or some combination of both. We have developed a number of models to guide those in mass rearing in their choice of strains to be used in the rearing facility. We have considered the cases of both prezygotic and postzygotic determination of sr, as well as whether or not there is a limit to the resources and time available to raise the insects. In general the number of females or males and females together produced is maximized for a sr in which there is a maximum possible number of females in the breeding population. When males alone are required the optimal sr in the rearing facility lies between 0.1 and 0.5 its actual value being dependent upon a variety of parameters such as the number of generations available and the number of eggs laid per female.

Total quality control in insect mass production for insect pest management1

AbstractTotal quality control in insect mass production involves eight generic elements: Management, Research, Methods Development, Material, Production, Utilization, Personnel and Quality Control. Management determines policy, performs planning and administration and controls program design as it evolves. Research is the source of new technologies and Methods Development creates new operational procedures. Material encompasses purchasing, establishing specifications and standards, assigning responsibility for quality materials and verifying compliance, and storage. The components of production are facilities, equipment, operations, and production control. Utilization is the treatment, handling and distribution of finished insect products. Management delegates responsibility for the selection, training, motivation and health and safety of employees to personnel. Quality control impinges on all program elements with primary emphasis on process and product control. This element provides information management must have to optimize the entire pest management program.ZusammenfassungUmfassende Qualitätsüberwachung bei in Massen gezüchteten Insekten für die SchädlingsbekämpfungEine umfassende Qualitätsüberwachung erfolgt auf verschiedenen Stufen der Massenzucht und schließt acht Hauptkomponenten ein: Organisation und Koordination, Forschung, Methodenentwicklung, Ausrüstung, Zuchtverfahren, Lagerung und Transport, Personalausbildung, Kontrolle des Produktionsablaufs und des Endproduktes. Das gesamte Zucht‐ und Kontrollprogramm wird von einem verantwortlichen Leiter koordiniert, der laufend auf allen Stufen die Erfüllung der Qualitätsnormen überwacht. Die Forschung erarbeitet neue Technologien, die zu routinemäßigen Verfahren weiterentwickelt oder in bestehenden Prüfmethoden genutzt werden können. Die Anforderungen an die gezüchteten Organismen sind laufend zu überprüfen und möglicherweise neu zu definieren. Zudem müssen Qualitätsstandards festgelegt, Stichprobenpläne angepaßt und die Einflüsse der Lagerung und der Transporte auf die Organismen untersucht werden. Die Qualitätskomponenten des Produktionsablaufs umfassen die Überwachung der Maschinen und Zuchteinrichtungen sowie deren optimale Nutzung und deren Einflüsse auf das Produkt. Vor und während der Anwendung der Organismen müssen die Manipulationen (Verpackung, Transport, Applikation usw.) so überwacht werden, daß die Qualitätsnormen des fertigen Produktes erfüllt werden. Weil die Massenzucht von Insekten mit hoher Qualität große Anforderungen an das Personal stellt, müssen qualifizierte Kräfte damit betraut und durch ständige Schulung weitergebildet werden. Qualitätskontrolle greift in alle Produktions‐ und Anwendungsabläufe bei in Massen gezüchteten Insekten ein, wobei aber der Schwerpunkt bei den biologischen Parametern liegt, welche die “Innere Qualität” der Organismen bestimmen. Diese Elemente liefern die nötige Information über mögliche Qualitätsänderungen, so daß rechtzeitige Anpassungen, unter Berücksichtigung des gesamten Programms, vorgenommen werden können.

The relationship of research to total quality control with special reference to sterile insect technique1

AbstractResearch is but one of the elements of total quality control in insect mass rearing programs, but the pre‐operational research phase is usually very extensive and is likely to provide documentation and experience for virtually all of the elements of quality control. The duration of the research phases is largely program‐dependent, whereas the scope of research subject matter is generally similar from program to program. The relationship of pre‐operational research in release programs to program decision‐making and the establishment of quality control methodology is outlined in this report.ZusammenfassungBeziehung der Forschung zur gesamten Qualitätskontrolle unter besonderer Berücksichtigung der Sterilen‐Insekten‐TechnikDie Forschung bildet nur ein Element der gesamten Qualitätskontrolle innerhalb des Programms der Insekten‐Massenzucht, doch ist die präoperative Forschungsphase generell sehr umfassend und geeignet zum Sammeln von Quellenmaterial und Erfahrungen für alle Elemente der Qualitätskontrolle. Die Dauer der Forschungsphase ist stark programmabhängig, während der Umfang des Forschungsgegenstandes im allgemeinen von Programm zu Programm ähnlich ist. Die Beziehungen der präoperativen Forschung bei Freilassungsprogrammen zur programmentscheidenden Phase sowie die Schaffung der Methodik der Qualitätskontrolle werden in der vorliegenden Arbeit umrissen.

Mass Rearing and Harvesting Based on an Age-Stage, Two-Sex Life Table: A Potato Tuberworm (Lepidoptera: Gelechiidae) Case Study

Traditional age-specific life table analysis does not take variable development rates into account and deals only with the female population. In this paper, rearing and harvesting of specific life stages are analyzed in the context of a general age-stage, two-sex life table. The question of selecting optimal harvest and discard strategies for the design of insect mass rearing facilities is discussed. The method is demonstrated using data collected from a culture of the potato tuberworm, Phtharimaea aperculella (Zeller).

Influence of the Mexican Strain of Steinernema feltiae and Its Associated Bacterium Xenorhabdus nematophilus on Galleria mellonella

Axenic, third stage juveniles of the Mexican strain of Steinernema feltiae did not alter the total hemocyte counts of larval Galleria mellonella, whereas those of monoxenically cultured juveniles did. In the latter case, the hemocytes were vacuolated. The concentration of Xenorhabdus nematophilus subsp. nematophilus var. mexicanus increased 12-fold within 6 hr of injecting the bacteria into G. mellonella. The presence of the axenic Mexican strain of S. feltiae in G. mellonella hemocoel for up to 5 hr did not change the rate of removal of injected Bacillus subtilis or X. nematophilus subsp. nematophilus var. mexicanus from the hemolymph. Xenorhabdus nematophilus subsp. nematophilus var. mexicanus was cultured in synthetic Galleria serum supplemented with larval serum in the presence and absence of S. feltiae. These spent media, once sterilized and injected into G. mellonella, did not influence insect behavior, silk production, insect mass or mortality.

Demographic Analysis of Insect Mass Rearing: A Case Study of Three Tephritids

We examine mass-production strategies for insects, using life table techniques. Harvesting of target stages and discarding of reproductives are viewed simply as the imposition of new mortality rates on a population. Demographic formulae are given for computing production rates and stage relations within a rearing facility and for determining age and size structure in released, sterile populations. The methods are applied to data relating to the rearing of three tephritid fruit flies— Ceratitis capitata (Wiedemann), Dacus dorsalis Hendel, and D. cucurbitae Coquillet. Both specific and general implications of the findings are briefly discussed.

The seasonal incidence of cricket paralysis virus in a population of the New Zealand small field cricket, Pteronemobius nigrovus (Orthoptera: Gryllidae)

The use of insects as food for humans or as feed for animals is an alternative for the increasing high demand for meat and has various environmental and social advantages over the traditional intensive production of livestock. Mass rearing of insects, under insect farming conditions or even in industrial settings, can be the key for a change in the way natural resources are utilized in order to produce meat, animal protein and a list of other valuable animal products. However, because insect mass rearing technology is relatively new, little is known about the different factors that determine the quality and yield of the production process. Obtaining such knowledge is crucial for the success of insect-based product development. One of the issues that is likely to compromise the success of insect rearing is the outbreak of insect diseases. In particular, viral diseases can be devastating for the productivity and the quality of mass rearing systems. Prevention and management of viral diseases imply the understanding of the different factors that interact in insect mass rearing. This publication provides an overview of the known viruses in insects most commonly reared for food and feed. Nowadays with large-scale sequencing techniques, new viruses are rapidly being discovered. We discuss factors affecting the emergence of viruses in mass rearing systems, along with virus transmission routes. Finally we provide an overview of the wide range of measures available to prevent and manage virus outbreaks in mass rearing systems, ranging from simple sanitation methods to highly sophisticated methods including RNAi and transgenics.

Characterization of cricket paralysis virus- and Drosophila C virus-induced RNA species synthesized in infected Drosophila melanogaster cells

The use of insects as food for humans or as feed for animals is an alternative for the increasing high demand for meat and has various environmental and social advantages over the traditional intensive production of livestock. Mass rearing of insects, under insect farming conditions or even in industrial settings, can be the key for a change in the way natural resources are utilized in order to produce meat, animal protein and a list of other valuable animal products. However, because insect mass rearing technology is relatively new, little is known about the different factors that determine the quality and yield of the production process. Obtaining such knowledge is crucial for the success of insect-based product development. One of the issues that is likely to compromise the success of insect rearing is the outbreak of insect diseases. In particular, viral diseases can be devastating for the productivity and the quality of mass rearing systems. Prevention and management of viral diseases imply the understanding of the different factors that interact in insect mass rearing. This publication provides an overview of the known viruses in insects most commonly reared for food and feed. Nowadays with large-scale sequencing techniques, new viruses are rapidly being discovered. We discuss factors affecting the emergence of viruses in mass rearing systems, along with virus transmission routes. Finally we provide an overview of the wide range of measures available to prevent and manage virus outbreaks in mass rearing systems, ranging from simple sanitation methods to highly sophisticated methods including RNAi and transgenics.

A Chlamydial-Like Organism Isolated from Insects in Insect Mass Rearing Facilities

In examinations of larvae of cabbage looper, Trichoplusia ni, and cotton bollworm, Heliothis virescens, collected in an outbreak of disease in the Brownsville insect mass rearing facilities, one of the pathogens isolated was a chlamydial-like organism (CLO). This organism is infectious per os. Infected larvae are stunted, develop a tan coloration and finally become brown cadavers. One day old larvae inoculated with CLO became severely stunted and failed to reach pupation.

The social regulation of physical caste: the superorganism revived

Among the ants, the population of worker phenotypes made by a colony is closely regulated. For the first time, a model of the regulation of a particular size class, that of major workers, is developed within a new theory of the superorganismic activity of social insect colonies. A remarkable linkage is found to exist between caste homeostasis in a model polymorphic society and three well-known but previously unrelated social insect colony properties: the form of the caste distribution, the short-term nature of a colony's “memory”, and the existence of co-operative interactions among nestmates. The linkage consists of mass social processes and takes the form of a colony-level, negative feedback circuit controlling the production of the major workers. The implications of this case study for rigorous, substantive theories of social insect mass phenomena are discussed.

Ultrastructure of two viruslike particles in the myocardium of Acheta domesticus

The use of insects as food for humans or as feed for animals is an alternative for the increasing high demand for meat and has various environmental and social advantages over the traditional intensive production of livestock. Mass rearing of insects, under insect farming conditions or even in industrial settings, can be the key for a change in the way natural resources are utilized in order to produce meat, animal protein and a list of other valuable animal products. However, because insect mass rearing technology is relatively new, little is known about the different factors that determine the quality and yield of the production process. Obtaining such knowledge is crucial for the success of insect-based product development. One of the issues that is likely to compromise the success of insect rearing is the outbreak of insect diseases. In particular, viral diseases can be devastating for the productivity and the quality of mass rearing systems. Prevention and management of viral diseases imply the understanding of the different factors that interact in insect mass rearing. This publication provides an overview of the known viruses in insects most commonly reared for food and feed. Nowadays with large-scale sequencing techniques, new viruses are rapidly being discovered. We discuss factors affecting the emergence of viruses in mass rearing systems, along with virus transmission routes. Finally we provide an overview of the wide range of measures available to prevent and manage virus outbreaks in mass rearing systems, ranging from simple sanitation methods to highly sophisticated methods including RNAi and transgenics.

Interdisciplinary Programs in Insect Mass Rearing and in Insect Population Management

About 20 years ago, Harry B. Walker (1954), the distinguished Professor of Engineering, University of California, pointed out that “A virile nation is the product of the wisdom of its people. Nations which utilize their human and material resources intelligently reflect a high standard of living for their citizens.” We are concerned in this symposium about how wisely our institutions go about fostering basic and applied research in entomology with the help of the engineering sciences.

Evaluation Of Several Insecticides Against Malathion-Susceptible and -Resistant Indian Meal Moths

Abstract 1A malafhion-resistant and a malathion-susceptible strain of the Indian meal moth were reared in the laboratory (at 27±l°C and 65±5% RH) on the diet recommended by Boles, H. P. and Marzke, F. O. 1966. (In C. N. Smith (ed.) Insect Colonization and Mass Production. Academic Press, Ind., New York). The test insects were last-instar larvae that weighed between 15 and 18 mg. The insecticides (technical grade) were applied topically as acetone solutions of the desired concentrations according to the procedure of Zettler, J. L. et al., 1973, J. Econ. Entomol. 66: 1049-50. For treatment, the insects were briefly anesthetized by a continuous flow of CO2 in a Buchner funnel and were held individually with a Telvac(R) vaccum needle while 0.5 ul of the insecticide solution was applied to the pronotum with an Isco model M(R) microapolicator. Each strain was treated with at least 5 doses of each insecticide, and at least 100 insects/dose were treated. Control insects from each strain were treated only with acetone. The insects were treated in groups of 10, placed in clean petri dishes, and held at 27±l°C and 60±5% for mortality determinations 120 h after treatment. Insects showing little or no response when probed lightly with a pen-cil tip were considered dead or moribund. A probit analysis of the moribund.

Briefs

Briefs