Biological characteristics of Stator limbatus (Col.:Chrysomelidae(biocontrol agent of Prosopis farcta

Mesquite (Prosopis farcta)is a perennial weed that propagates by seeds and rhizomes. P. farcta became widespread in arid zones of Iran. During 2009-2010, the studies indicated that Stator limbatus feeds on seeds of P. farcta and the larvae can destroy up to 60% of the Mesquite seeds. Biological characteristics of S. limbatus were assessed in various temperatures ranging from 25.39 ± 0.5 to 21.17 ± 0.55 °C day:night, RH= 37.78 ± 1.38% and LD=11:13 hours. Some infected fruits were collected from Meibod. Infected seeds were retained in the breeding box until the larva transformed into the adult insects. Incubation period lasted an average of 8.85 ± 0.59 days. Eggs were laid individually on fruits. Each female insect laid an average of 47.57 ± 4.47 eggs on seeds. The roaches in Yazd climatic conditions had more than three generations in each year and overwintering of the insect is in the form of larvae and pupae inside the seeds and remained fruits on the host plant. The insect pupates and transform into the adult stage in late spring and early summer, coinciding with the start of Kahourak fruiting. After mating, adult females begin hatching on pods. Upon completion of the embryonic period, the larva enters to seed directly from egg shell. Only one larva grows in each seed and after feeding from all the internal parts come out and become white pupates in cocoons. In these conditions, the duration of a complete generation from egg to adult was 39 ± 1.04 days. The values for larva and pupa periods were 21.2 ± 0.7 and 8.8 ± 0.38 days, respectively. Mean adult longevity without feeding was 26.36 ± 2.06 days and over this period an average value of females lying was 47.57 ± 4.47 eggs. Data showed that in average 83.52±5.071% of the eggs were hatched. Therefore, this insect can be a suitable agent for biological control of this weed in Yazd province. In nature the pest larvae are attacked by big black wasps from Braconidae family.