Illustrated technical descriptions of adult and/or immature stages have been published by Cuscianna (1934), Tams and Bowden (1953), Frediani (1952) and Badolato (1976).
Eggs
Eggs are hemispherical (about 1.5 mm across), ribbed, white when newly laid, changing to orange-pink before hatching.
Larvae
Larvae generally develop through five or six instars but up to eight have been recorded in Egypt, plus an inactive prepupal stage (Hafez et al., 1970).
Full-grown larvae are up to 4 cm long, cream-yellow with pink suffusions. Larval chaetotaxy has been described and illustrated by Badolato (1976).
Pupae
Pupae are light brown, up to about 20 mm long, and with a terminal cremaster bearing one pair of long, fine spines and a smaller subsidiary pair. The pupae are often enclosed in a light, silken cocoon that is spun by the larvae before pupation.
Adults
Adult wing span is 26-40 mm, with males generally smaller than females. The forewings are pale whitish brown, variously marked with darker brown, and the hindwings are white. Male antennae are biciliate. The male and female genitalia are described and illustrated in Tams and Bowden (1953).
Tams and Bowden (1953) recognized three races of S. cretica: an ochraceous to ochraceous-buff form from the Balkans;a very pale yellowish-buff form from Morocco and the south-west Mediterranean, and a light cartridge-buff form with well-defined fuscous markings from Saudi Arabia, Somalia, Ethiopia and possibly Italy.
Field infestations are easily detected by walking through crops looking for the symptoms (see Symptoms). Care must be taken to distinguish between dead hearts caused by shootflies (Atherigona spp.), chloropids and some plant pathogens, especially Fusarium. Identical symptoms are also caused by other species of stem borer and the presence of S. cretica is best confirmed by collecting larvae and pupae from damaged stems and rearing adults for identification by specialists.
Related invasive species
- Sesamia cretica
Related Farm Practice
- Light
The geographical range of S. cretica includes most of the countries and islands of the Mediterranean basin and extends through the Middle East and Arabia to Pakistan, northern India and northern Africa, extending south to northern Kenya and northern Cameroon. According to Tams and Bowden (1953) this species does not extend westward of Cameroon;however, earlier records from Mali, Niger and Togo have again been included on the recently revised CABI/EPPO (2001) distribution map. This is a pest species linked to graminaceous crops with a preference for sorghum, maize and sugarcane. It is present on wild Gramineae with a preference for Panicum repens. S. cretica could extend its range following these crops/wild hosts and in correlation with climatic change. More studies on the distribution of this species are necessary. It belongs to the 'Sesamia' group of noctuids, a group of very similar species that are difficult to identify, and therefore misidentifications can occur regarding new distribution data.
Recorded host plants of S. cretica are mainly graminaceous crops, especially cereals. Sorghum is often its main host;in Israel a decline in the incidence of S. cretica has been attributed to reductions in the area of sorghum during the 1970s (Melamed-Madjar and Tam, 1980). In Egypt S. cretica is a major pest of maize and sugarcane (Hafez et al., 1970). It has also been recorded on carnations in Egypt (Temerak, 1982a), but this record from a non-graminaceous host has not been authenticated by subsequent authors.
Ahmed (1980) made preliminary field observations on 11 species of grasses and cereal crops in the El-Serw region of Egypt and concluded that Panicum repens was the most favoured host plant for S. cretica, followed by maize.