Green muscardine diseases are caused by fungi from the genus Metarhizium. The cells are hypertrophed and ultimately destroyed. Than, the parasite penetrates through the gut wall into the hemolymph and progresses into different insect organs Figs. The midgut of diseased larvae becomes thick and white Fig. Rounded forms of resting spores. Scanning electron microscopy, 15,000x; c Thin section of polyhedron from nun moth, Lymantria monacha, 60,000x facilitate the disease diagnostic since they are visible under a standard light microscope.
The polyhedra contain numerous icosahedral-shaped virus particles with a size from 50 nm to 80 nm. The pathogenic bacteria usually infect an insect through the digestive tract using specific toxins to enable penetration through the gut into the body cavity. Many hundred species of microsporidia have been recorded in insects, predominantly in the order Lepidoptera, Diptera, Coleoptera, and Orthoptera. Selection of animals for establishment of healthy laboratory colonies -- 4. This method includes the following procedures: 1. Processing of pathological material for analyses -- 3.
The viruses responsible for cytoplasm polyhedroses family of Reoviridae , pox diseases family of Poxviridae and iridescent viral diseases family of Iridoviridae have seldom occurrence patterns. The cadavers become focal sources for living spores. Giemsa stain, Light microscope, phase contrast, objective 100x Fig. The microorganisms can be located both on the surface of the chorion or under it Fig. Descriptions of the different species or families of microorganism agents of disease varied according to the current scientific knowledge of the organisms being described, its pathogenic importance and management potential.
Initially, fungal mycelia can be observed on the intersegmental membranes of the host Fig. Our long time survey for entomopathogenic viruses in 2. Phase contrast, objective 40x and 70x, respectively 2. The polar filament destroys the cell wall and the parasite penetrates into the cytoplasm. Most of the amoebae species are commensals, dwelling into the digestive tract of insects. Phase contrast, objective 40x Fig.
Bacterial cells are movable and often form chains. Microscopic examination of pathological material -- Chapter 4. As a rule, intestinal excretions have black color and putrefied smell. Techniques described provide reliable alternatives for preliminary pathogen identification which do not require special equipment or intensive training, in a step by step protocol format, and for an easy orientation and accurate learning. Prophylactics and control of infectious disease in laboratory reared insect colonies were also covered in detail Chap. External signs and symptoms of disease A. Evans and Shapiro 1993 provide an alternative to color baculovirus inclusion bodies, which does not require a preliminary alkaline treatment, using Buffalo Black 12 stain.
The most part of mature gregarines gamonts or trophozoites are large, with approx. At present time, several hundred insects are registered as hosts of baculoviruses e. For example, if entomopathogenic fungi are continuously cultivated on artificial media they tend to lose their original levels of pathogenicity. Diseases of protozoan origin -- 1. It has been established that darkening indicates disturbance in physiological processes and decay in insect health conditions. Use forceps to place sharp objects into a sharps container.
Sporozoites and gametocytes have vermicular forms that vary in size. Some cells are able to transform into red oidia with a size of 3. Scanning electron microscopy, 15,000x under discussion. Among these families the Baculoviridae are responsible for the most important insect infections. Annu Rev Entomol 51:609—634 Pimentel D, Lach L, Zuniga R, Morrison D 2000 Environmental and economic costs of nonindigenous species in the United States. Phase contrast a Objective 40x; b Objective 90x Fig. Gives recommendations for prophylactics and control of infectious diseases in insect cultures.
The most characteristic external sign of nuclear polyhedroses is the white or yellow color of the insect integument. The infected cells are strongly vacuolated. Diseases of protozoan origin A. Phase contrast, objective 40x Fig. Commonalities were observed across the majority of the insects consumed across Africa, providing opportunities for related R4D activities.