BioOne Complete (complete.BioOne.org) is a full-text database of 200 subscribed and open-access titles in the biological, ecological, and environmental sciences published by nonprofit societies, associations, museums, institutions, and presses.

Beauveria bassiana Vuillemin and Metarhizium anisopliae (Metschnikoff) Sorokin are fungi with potential for controlling Musca domestica L. However, the impact on this dipteral may vary depending on the fungal isolates and the methodology used. This study evaluated the pathogenicity of direct application and horizontal transmission of B. bassiana (CG240) and M. anisopliae (CG34) on adult M. domestica individuals. The impact of B. bassiana and M. anisopliae on M. domestica was evaluated at the concentrations 2 × 10(4), 2 × 10(5), 2 × 10(6), and 2 × 10(7) conidia/ml. Horizontal transmission was also estimated between sexes at different infection periods of the vector insect. The mortality of adult M. domestica individuals directly infected with B. bassiana was above 90%, and the mortality of those infected with M. anisopliae ranged from 25.50 to 97.78%. Horizontal transmission of B. bassiana caused the death of 100% of individuals, in turn, that of M. anisopliae killed 55% of male and 100% of female individuals. Horizontal transmission of fungi was negatively influenced by time. This study shows the potential of these fungi for controlling M. domestica, both with the direct implementation strategy and horizontal transmission. However, field studies are needed to evaluate the capacity to decrease the M. domestica population using these alternatives.

The insect immune system includes several mechanisms responsible for defending against pathogens, parasites, and parasitoids. Some botanical insecticides, such as Azadirachta indica oil, cause changes in the immune system of various insect species. Spodoptera frugiperda is an important agricultural pest; thus, knowledge about the effect of neem oil on the immune system of this species can assist in its management. This study aimed to evaluate the effect of A. indica oil on the immune system of S. frugiperda. Caterpillars (2–3 mg) were placed individually in containers (50 ml) with approximately 10 g of diet, containing 125, 250, and 500 ppm of neem oil with propanone; the control group received only the propanone diet. In four experiments, the total number of hemocytes, the phagocytic activity, the activity of lysozyme-like enzymes, and phenoloxidase activity were measured in caterpillars at the end of the sixth instar. The total number of hemocytes in insects exposed to neem oil was 21% lower than in the control group. The percentage of cells that phagocyted the latex beads was similar among the caterpillars that ingested the different concentrations. The mean diameter of cell lysis halos was reduced only at concentrations of 125 and 250 ppm. Absorbance did not differ between treatments. Knowing that this oil reduces the number of circulation cells and the activity of lysozyme-like enzymes is of great importance to design control strategies, once the neem oil could be added to other biological agents for mortality reducing the chances of this insect surviving in the environment.

Submetido em 30/11/2014 Aceito para publicação em 12/03/2015Resumo Sobrevivência e variação de peso de adultos de Periplaneta americana (Linnaeus, 1758) (Blattaria, Blattidae) submetidos a diferentes condições de estresse. Periplaneta americana é uma espécie de grande importância para a saúde pública, já que pode atuar como vetor de diversos patógenos e atinge altas populações em ambientes urbanos. Isso provavelmente se deve à sua capacidade de resistir à fome e a dessecação. O objetivo deste estudo foi avaliar os efeitos da ausência de água e alimento sobre a sobrevivência e variação de peso entre adultos de P. americana e veriicar se o peso inicial dos indivíduos inluencia em sua sobrevivência. Quatro grupos com 20 casais de P. americana foram formados e submetidos a: I) estresse hídrico e alimentar; II) estresse alimentar; III) estresse hídrico; e IV) grupo controle. Os insetos foram individualizados conforme os grupos, os quais foram pesados no início e no im das condições de estresse. Permaneceram sob essas condições até que todos os indivíduos de cada grupo de teste estivessem mortos. As condições de estresse causaram redução do tempo de sobrevivência quando comparados ao grupo controle. Adultos com massa corporal superior sobreviveram por mais tempo quando privados somente de alimento, enquanto que naqueles com ausência de água o peso não inluenciou na sobrevivência. A perda total de peso foi maior nos indivíduos privados de água do que naqueles privados somente de alimento. Palavras-chave:Barata; Desidratação; Inanição; Longevidade; Peso corporal AbstractPeriplaneta americana is a species of great importance to public health, since it can act as a vector of many pathogens and it reaches large populations in urban environments. This is probably due to its ability to resist starvation and desiccation. This study aimed to evaluate the effects of absence of water and food on survival and weight change among adult P. americana individuals and check whether the initial weight of individuals inluences on their survival. Four groups having twenty P. americana couples were formed and subject to: I) no water or food; II) no food; III) no water; and IV) control group. Insects were isolated according to the groups, which were weighed at the beginning and end of the stress conditions. They remained under these conditions until all individuals in each test group were dead. Stress conditions caused reduction in survival time when compared to the control group. Adults with higher body mass survived longer when deprived only of food, while among those lacking water, weight had no inluence on survival. Total weight loss was greater among individuals deprived of water than those deprived only of food.

Abstract Stresses can be caused by multiple biotic and abiotic factors and their effects can affect both the biology and the immune system of insects. American cockroach – Periplaneta americana (Linnaeus, 1758) (Blattaria: Blattidae) –besides being an excellent model species, has great medical importance because it can act as a mechanical vector of several pathogens. This study aimed to evaluate the influence of starvation, dehydration and both stresses on weight, and total and differential haemocyte count in P. americana adults. Each specimen was isolated in glass flasks containing or not food and/or water. They were weighed periodically. Another group received water for 24 h after the end of stress period. In the immunologic bioassay, we counted their haemocytes after the final weighing. All stresses reduced the insect weight, especially when the stresses were combined. Females of the control group gained weight and males had it unaltered. Different stress conditions and time did not influence on total haemocyte count. Insects without food and water had the proportion of prohaemocytes increased and plasmatocytes decreased. This study can serve as a basis of further studies of bioecology, behaviour and the ability of resisting insecticides, besides serving as a model to studies in other insect species.