Nutritive value of diets with different carbohydrates for adult Anastrepha obliqua (Macquart) (Diptera, Tephritidae)

Abstract

ABSTRACT. Adult Tephritidae, especially of the genus Al1aslrepha (Schiner, 1868), have been observed to feed on a wide variety of natural diets. The fruit on which they feed , in general, are rich in sugar content, chiefly glucose, frutose and sucrose, which are also the sugars that those insects utilise better. Neitherthe behavioural mechanisms, nor the physiological ones, that control food selection by insects, are well known. Because some of those aspects are not known for the spec ies A l1aslrepha obliqua (Macquart, 1835) either, and in order to understand their biology better, three experiments were conducted. In the first experiment, it was checked whether there was a difference in metabolic profit by those insects, when fed the carbohydrates more frequently found in nature, as resulting in a bigger egg production and higher survival rate at the end of the experiment. In the second, it was checked whether A. obliqua can regulate diet ingestion according to carbohydrate content in dry as well as wet diets. In the third experiment, measurements were made to establish the lowest carbohydrate concentration flies are able to recognise in the diet. Analysis of the data showed that ingestion of carbohydrates which are commonly found in nature, in association with a protein source, is vety well utilised by females of A. obliqua. It was also shown that _those insects are not probably able to compensate for the difference in carbohydrate content in dry diets, whereas they do so for wet diets. In relation to discrimination threshold, it seems that it is related to the higher occurrence of the carbohydrate in their normal diet, that is, they can recognise carbohydrates that are common in their natural diet better than the less frequent ones.

Morphological and electrophysiological analysis of tarsal sensilla in the medfly Ceratitis capitata (Wiedemann, 1824) (Diptera: Tephritidae)

“…Thus, sugars can play different roles during the life cycle of C. capitata, i.e. females produce more eggs when they feed on a diet containing sucrose, fructose or glucose (Fontellas & Zucoloto 1999), while the discrimination threshold of larvae was found to be 10 times higher than that of adults (Canato & Zucoloto 1998). Moreover, sugar concentration in the hemolymph of the medfly regulates the selection and the amount of food ingested (Canato & Zucoloto 1998).…”

Associative learning in wild Anastrepha obliqua females (Diptera, Tephritidae) related to a protein source

“…In this experiment, females received the brewer yeast + 25 mg quinine sulphate diet for 2 days before the test since flies do not survive longer than 5 days without sucrose (FONTELLAS & ZUCOLOTO, 1999). The flies were then submitted to the same procedure as described for experiment 2 (groups 1 and 2) using the brewer yeast + 25 mg quinine sulphate diet.…”

Influence of quantities of brewer yeast on the performance of Anastrepha obliqua wild females (Diptera, Tephritidae)

“…Studies with Anastrepha suspensa (Loew, 1873) showed that compensatory responses did not occur to hydrolyzed yeast, but they did to carbohydrates (SHARP & CHAMBERS, 1984). FONTELLAS & ZUCOLOTO (1999) found that A. obliqua (Macquart, 1835) females also ingested in a compensatory way when they were fed on solutions with different concentrations of sucrose. The same did not occur when the females were fed on solid diets with different concentrations of sucrose.…”