Effect of Microsporidia MB infection on the development and fitness of Anopheles arabiensis under different diet regimes.

BACKGROUND: Microsporidia MB (MB) is a naturally occurring symbiont of Anopheles and has recently been identified as having a potential to inhibit the transmission of Plasmodium in mosquitoes. MB intensity is high in mosquito gonads, with no fitness consequences for the mosquito, and is linked to horizontal (sexual) and vertical (transovarial) transmission from one mosquito to another. Maximising MB intensity and transmission is important for maintaining heavily infected mosquito colonies for experiments and ultimately for mosquito releases. We have investigated how diet affects the MB-Anopheles arabiensis symbiosis phenotypes, such as larval development and mortality, adult size and survival, as well as MB intensity in both larvae and adults. METHODS: F1 larvae of G0 females confirmed to be An. arabiensis and infected with MB were either combined (group lines [GLs]) or reared separately (isofemale lines [IMLs]) depending on the specific experiment. Four diet regimes (all mg/larva/day) were tested on F1 GLs: Tetramin 0.07, Tetramin 0.3, Gocat 0.3 and Cerelac 0.3. GLs reared on Tetramin 0.3 mg/larva/day were then fed either a 1% or 6% glucose diet to determine adult survival. Larvae of IMLs were fed Tetramin 0.07 mg and Tetramin 0.3 mg for larval experiments. The mosquitoes in the adult experiments with IMLs were reared on 1% or 6% glucose. RESULTS: Amongst the four larval diet regimes tested on An. arabiensis development in the presence of MB, the fastest larval development highest adult emergence, largest body size of mosquitoes, highest prevalence and highest density of MB occurred in those fed Tetramin 0.3 mg/larva/day. Although adult MB-positive mosquitoes fed on 6% glucose survived longer than MB-negative mosquitoes, there was no such effect for those fed on the 1% glucose diet. Development time, wing length and adult survival were not significantly different between MB-infected and uninfected An. arabiensis fed on the Tetramin 0.07 mg/larva/day diet, demonstrating that the MB-conferred fitness advantage was diet-dependent. CONCLUSIONS: Microsporidia MB does not adversely impact the development and fitness of An. arabiensis, even under limited dietary conditions. The diet regime of Tetramin 0.3 mg/larva/day + 6% glucose for adults is the superior diet for the mass rearing of MB-infected An. arabiensis mosquitoes. These results are important for rearing MB-infected An. arabiensis in the laboratory for experiments and the mass rearing required for field releases.

Diet and Nutrition of Adult Spalangia cameroni (Hymenoptera: Pteromalidae), a Parasitoid of Filth Flies.

Most parasitoid wasps parasitize herbivorous insects, so nectar from flowers is readily available. However, parasitoid wasps are also an important component of the rich invertebrate communities at livestock facilities in large accumulations of manure, where flowers are largely absent. Little is known about adult parasitoid diet and nutrition in these communities. The present study examined this in Spalangia cameroni Perkins, a pupal parasitoid of filth flies. Like many parasitoid wasps, S. cameroni feed on host fluids, and in the laboratory readily feed on honey or a sucrose solution, which increases their longevity. Here adult longevity in the presence of six potential food sources, bovine manure, sorghum silage, bovine milk, buckwheat inflorescence (Polygonaceae), sweet alyssum inflorescence (Brassicaceae), or dandelion inflorescence (Asteraceae), was compared to that with water or honey. Only parasitoids given buckwheat lived as long as parasitoids given honey, and parasitoids given honey or buckwheat lived longer than parasitoids given water. Parasitoids readily ate buckwheat nectar, avoiding pollen grains. Diet affected the amount of free sugars, glycogen, and lipids in complex ways. Compared to parasitoids that were given just water, parasitoids with access to honey or sucrose had higher sugar and glycogen levels, but not detectably higher lipid levels. Access to buckwheat had no detectable effect on a parasitoid's free sugar, glycogen, or lipid levels; however, then after 4 d with just water, sugar levels were lower and glycogen levels were higher compared to parasitoids that had been given access to only water the entire time.

The longevity of Aedes aegypti mosquitoes is determined by carbohydrate intake / [A longevidade de mosquitos Aedes aegypti é determinada pela ingestão de carboidrato]

Aedes aegypti is the vector of several viral diseases. The main way to control these diseases is to fight the vector. Thus, it is necessary to breed mosquitoes in the laboratory in order to develop strategies to control these insects. In laboratories, different carbohydrates are used for feeding mosquitoes. The aim of this study is to evaluate the longevity and the weight of Ae. aegypti fed with different carbohydrates diets. As methods, 120 mosquitoes were distributed in insectaries and each group received a different diet, based on honey, dextrose or maltodextrin. To assess the longevity, survival analysis was performed using the Long Rank test and chi square test. To assess the weight, the dead insects were frozen and weighed at the end of the experiment. As results it was observed that mosquitoes fed with the honey, maltodextrin and dextrose diet lived on average 33, 35 and 47 days respectively. When weight was assessed, mosquitoes fed with honey weighed 125 ± (35.3) µg, while those fed with dextrose and maltodextrin weighed 225 ± (35.3) µg and 275 ± (35.3) µg respectively. The results show that the intake of dextrose and maltodextrin by Ae. aegypti adults increases their survival and their weight.(AU)

O Aedes aegypti é vetor de várias doenças virais. A principal maneira de controlar essas doenças é combatendo o seu vetor. Nesse sentido, é necessário criar esses mosquitos em laboratório, visando desenvolver estratégias de controle. Nos laboratórios, diferentes carboidratos são utilizados na alimentação de mosquitos. O objetivo deste estudo é avaliar longevidade e peso de Ae. aegypti alimentados com diferentes fontes de carboidratos. Como método, distribuíram-se 120 mosquitos insetários. Cada grupo recebeu uma dieta diferente à base de mel, dextrose ou maltodextrina. Para avaliar a longevidade, a análise de sobrevida foi realizada pelo teste de Logrank e pelo teste de qui quadrado. Para avaliar o peso, os insetos mortos foram congelados e pesados ​​no final do experimento. Como resultado, observou-se que os mosquitos alimentados com a dieta à base de mel, maltodextrina e dextrose viveram em média 33, 35 e 47 dias, respectivamente. Com relação ao peso, os mosquitos alimentados com mel pesavam 125 ± (35,3)µg, enquanto os alimentados com dextrose e maltodextrina pesavam 225 ± (35,3)µg e 275 ± (35,3)µg, respectivamente. Os resultados mostram que a ingestão de dieta à base de dextrose e maltodextrina por Ae. aegypti adultos aumenta sua sobrevivência e seu peso.(AU)

The effect of adult diet on the biology of butterflies : 1. The common imperial blue, Jalmenus evagoras.

This study examines the effect that sugars and amino acids in the adult diet of Jalmenus evagoras can have on female feeding behaviour, somatic maintenance, longevity, fecundity and egg weight. The presence of sugars in their adult food stimulated butterflies of this species to feed, and they appeared to compensate for low (1% wt/wt) sugar diets by feeding for longer periods. Butterflies were also more likely to feed on diets containing amino acids than on water controls. The availability of sugar allowed females to maintain or even increase their body weight and fat body size, but amino acids had no effect on these variables. Individuals on the medium (25% wt/wt) sugar diet attained the greatest longevity. Female fecundity was increased as much as threefold by the availability of sugar. However, amino acids in the diet had no effect on either longevity or fecundity. Egg weight was not affected by the concentration of sugars or amino acids in the adult diet, but was correlated with the weight of the female butterfly. These results demonstrate that the availability of carbohydrates in the adult diet could play an important role in the population dynamics of this species. However, the presence of amino acids had little effect on most of the variables measured, nor was there any interaction effect between sugars and amino acids.

The effect of adult diet on the biology of butterflies : 2. The common crow butterfly, Euploea core corinna.

Euploea core is a long lived butterfly which lays a few relatively large eggs each day. In such a species it is unlikely that reserves of carbohydrate and amino acid accumulated during the larval instars would be sufficient to last its entire adult life. Female E. core were kept in a large flight cage and assigned to one of four treatments. Each treatment comprised a different concentration of sugar and amino acid in the adult diet of the butterflies. Individuals with 25% sugar in their diet lived for longer and attained higher fecundities than those with 1% sugar in their diet. Butterflies on the 1% sugar diet removed greater volumes of food solution than those on the 25% sugar diet. The availability of amino acids in the adult diet had no marked effect on longevity and, if anything, had a negative effect on fecundity. The composition of the adult diet had no discernable effect on egg weight in this species. Sugar is shown to be an important component of the adult diet of E. core but their requirement for amino acids in their adult diet remains unresolved. Finally, using the known volume of food solution removed each day, estimates were made of the minimum amount of energy required by this species each day and the amount of energy required to produce an egg.