بیواکولوژی شب‎پره برگ‎خوار دو نواری Streblote siva (Lepidoptera: Lasiocampidae) یک آفت پلی فاژ در استان بوشهر، ایران

The Jujube lappet moth, Streblote siva (Lefebvre) (Lepidoptera: Lasiocampidae), is as a polyphagous defoliator on ornamental and forest communities include Conocarpus erectus, Ziziphus spina-christi and Acacia ampliceps in Bushehr, Khuzestan and Hormozgan provinces of Iran. The intensification and concentration of a single plant species or variety such as C. erectus in ever larger and more extensive monocultures increases, the simplification of agroecosystems compared with natural ecosystems and the reduction of diversity in large crop monocultures, has long been associated with reasons for pest such as S. siva outbreaks. This study was conducted to determine some characteristics of the biology and ecology of the moth. The region of Bushehr was divided into three zones to study the population dynamics and biology of S. siva. Then, stratified random sampling was used for the range of the insect abundance and dynamism. The spatial distribution of S. siva larva was studied in field conditions by using regression models; Taylor’s power law and Iwao’s patchinessregression during 2015-2016. S. siva spends May to September which is very hot period in the region, as pupae in thin sturdy silk cocoons on the branches and trunk of C. erectus, A. ampliceps and Z. spina-christi. In early October, the adult’s moths appear gradually and after mating, they start laying eggs on leave and branches. The autumn first generation had a clear pick point. Then, the average population was gradually declined and in early November was reached to the lowest amount in the first autumn generation. Oviposition of the second autumn generation was occurred in early November and the peak number of different larva instars was observed on November25th. After that the larval growth was started slowly and the insect population was reached to zero level on 21 January and overwintering stage began. The spring generation adults were appeared gradually since the middle of March. This larva’s generation reached a population peak in the early of April and in the early of May the population of larvae reached to zero, and pupae of this generation began their over summering. The insect has three full generations in cool winters. S. siva has been distributed randomly throughout the province. The spatial distribution of all larvae of S. siva on C. erectus was different in generations. It was estimated as an aggregated (clumped) and random distribution by using Taylor’s power law and Iwao’s patchiness regression.