CHAPTER 3. The Solitary Bee Life Cycle

2019 ◽  
pp. 37-69
Keyword(s):  
2015 ◽  
Vol 59 (2) ◽  
pp. 73-83 ◽  
Author(s):  
Fabio Sgolastra ◽  
Simone Tosi ◽  
Piotr Medrzycki ◽  
Claudio Porrini ◽  
Giovanni Burgio

AbstractIn this paper we assessed, under laboratory conditions, the toxicity of an active substance on solitary bee larvae of Osmia cornuta (Hymenoptera: Megachilidae). A field-realistic dose of the systemic insecticide spirotetramat was applied to the mass provisions. The insecticide’s effects on several life-cycle parameters were studied in males and females. Our results showed a significantly shorter post-emergence longevity in bees exposed to spirotetramat during the larval stage, compared to the control. The observed reduction in longevity was 18 and 15%, respectively, in males and females. Mortality rate and other biological traits (larval and spinning duration, emergence time, food/body conversion rate) did not show significant differences between the two treatments. The method described in this study can be used to test the effects of toxic substances (i.e. agrochemicals) on bees. Moreover, it can constitute a basis for the development of a standardised protocol in the first tier of the Environmental Risk Assessment for solitary bees.


Author(s):  
Betty Ruth Jones ◽  
Steve Chi-Tang Pan

INTRODUCTION: Schistosomiasis has been described as “one of the most devastating diseases of mankind, second only to malaria in its deleterious effects on the social and economic development of populations in many warm areas of the world.” The disease is worldwide and is probably spreading faster and becoming more intense than the overall research efforts designed to provide the basis for countering it. Moreover, there are indications that the development of water resources and the demands for increasing cultivation and food in developing countries may prevent adequate control of the disease and thus the number of infections are increasing.Our knowledge of the basic biology of the parasites causing the disease is far from adequate. Such knowledge is essential if we are to develop a rational approach to the effective control of human schistosomiasis. The miracidium is the first infective stage in the complex life cycle of schistosomes. The future of the entire life cycle depends on the capacity and ability of this organism to locate and enter a suitable snail host for further development, Little is known about the nervous system of the miracidium of Schistosoma mansoni and of other trematodes. Studies indicate that miracidia contain a well developed and complex nervous system that may aid the larvae in locating and entering a susceptible snail host (Wilson, 1970; Brooker, 1972; Chernin, 1974; Pan, 1980; Mehlhorn, 1988; and Jones, 1987-1988).


Author(s):  
Randolph W. Taylor ◽  
Henrie Treadwell

The plasma membrane of the Slime Mold, Physarum polycephalum, process unique morphological distinctions at different stages of the life cycle. Investigations of the plasma membrane of P. polycephalum, particularly, the arrangements of the intramembranous particles has provided useful information concerning possible changes occurring in higher organisms. In this report Freeze-fracture-etched techniques were used to investigate 3 hours post-fusion of the macroplasmodia stage of the P. polycephalum plasma membrane.Microplasmodia of Physarum polycephalum (M3C), axenically maintained, were collected in mid-expotential growth phase by centrifugation. Aliquots of microplasmodia were spread in 3 cm circles with a wide mouth pipette onto sterile filter paper which was supported on a wire screen contained in a petri dish. The cells were starved for 2 hrs at 24°C. After starvation, the cells were feed semidefined medium supplemented with hemin and incubated at 24°C. Three hours after incubation, samples were collected randomly from the petri plates, placed in plancettes and frozen with a propane-nitrogen jet freezer.


1994 ◽  
Vol 11 (1) ◽  
pp. 47-56
Author(s):  
Virginia C. Day ◽  
Zachary F. Lansdowne ◽  
Richard A Moynihan ◽  
John A. Vitkevich

1978 ◽  
Vol 23 (2) ◽  
pp. 85-86
Author(s):  
BERTRAM J. COHLER
Keyword(s):  

1978 ◽  
Vol 23 (9) ◽  
pp. 697-697
Author(s):  
ALVIN G. BURSTEIN

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