Aspects of sorghum shootfly reproduction

Abstract

This paper includes a description of the internal reproductive system of the female sorghum shootfly. Athcrigona soccata, as well as studies on egg maturation and survival, and effects of mating and/or presence of the male on egg maturation, fecundity and fertility. The number of ovarioles per female ranged from 20 to 47. A. soccata exhibits autogeny, but carbohydrate is essential for egg production and survival. Nutritional deficiency led to a high incidence of oocyte resorption. A mixture of baker's yeast and sugar was a better adult food than brewer's yeast and glucose. Sorghum (cereal) aphid honeydew was a nutritious adult food. Shootflies provided with sorghum aphid honeydew showed an acceleration of vitellogenesis, a decrease in the frequency of oocyte resorption and a shortening of the preoviposition period. Egg maturation does not seem to be influenced directly by mating or by the presence of males. The continuous presence of the male also has no significant effect on fecundity. Shootfly females seem to mate only once and this single mating ensures fertilization of eggs laid even long after mating.

Daily rhythms in the sorghum shootfly, Atherigona soccata: oviposition, egg‐hatch and adult eclosion

“…In the shootfly, the first batch of eggs is ready for laying during the later part of the second day after adult emergence (Unnithan, 1982). No eggs are laid at night, however, and oviposition commences with a well-defined peak on the morning of the third day with another peak occurring in the late afternoon of the same day.…”

Off‐season survival and seasonal carry‐over of the sorghum shootfly,Atherigona soccataRondani (Diptera: Muscidae) in Kenya

“…These were (1) off-season shootflies (from off-season tillers in the farmers' fields), (2) shootflies whose larval and pupal stages were completed in CSH-1 seedlings subjected to dry conditions, and (3) those subjected to wet conditions in the greenhouse. These studies were conducted in the same way as described earlier (Unnithan, 1981).…”

Inheritance of resistance to shootfly in sorghum

“…The largest average number of eggs reported for a group of flies was 238 and the largest number for one female was 440 (Meksongsee et al, 1980b). A female fly mates only once, subsequently producing fertile eggs throughout her lifetime (Unnithan, 1980). Adult flies feed on cereal aphid honeydew (Soto, 1972) and perhaps plant exudates.…”

“…Adult flies feed on cereal aphid honeydew (Soto, 1972) and perhaps plant exudates. Unnithan (1980) demonstrated that including cereal aphid honeydew in the diet quickened oocyte maturation, but honeydew from the pea aphid was not suitable for survival. Shiang-Lin et al (1980) also stated that the presence of aphids seemed to increase shootfly attack.…”

“…In a quantitative study of parasitism, Jotwani ( , in Young, 1980 found a maximum total parasitism of 35%, and 15% parasitism of eggs by Aprostocetus spp. The observation that female shootflies breed only once (Shiang-Lin et al, 1980;Unnithan, 1980) suggests that a sterile male technique might be useful.…”