• Korean journal of applied entomology
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• v.54 no.4
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• pp.383-392
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• 2015

We investigated the induction of pupal diapause and number of generation for H. armigera using outdoor rearing and sex pheromone trapping in Suwon, Korea. Over-wintering pupae were induced when neonate larvae were reared in the outdoors from late Aug. to early Oct. in 2013 and 2014. H. armigera adults emerged from late May to early Jun. for 2013 colonies and from late May to late Jun. for 2014 colonies. The colonies placed after mid September produced only diapause pupae, to show environmental conditions that day-lengths on the rearing start date were 11 h 49 min~12 h 24 min, and mean temperatures before pupation were $14.8{\sim}20.7^{\circ}C$. Summer diapause was not observed in all colonies. The peak occurrence of H. armigera adults from sex pheromone trap in Suwon and Hwaseong were pooled and showed four generations (1st: from late Apr. to mid Jun., 2nd: from mid Jun. to late Jul., 3rd: from mid Jul. to late Aug., 4th: from late Aug. to mid Oct.). A degree-day model for development of H. armigera developed by Mironidis and Savopoulou-Soultani (2008) was used to validate the number of generation from field observations using pheromone traps. The 3rd and over-wintering generations were mainly overlapped. It was decided that H. armigera has one over-wintering and three complete generations in a year, and diapause is induced from offsprings of the 3rd and 4th generations adults. It is expected that larvae of the 1st and 2nd generations give a damage to ear zone in maize fields in which have been planted during April.

• Korean journal of applied entomology
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• v.40 no.2
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• pp.131-136
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• 2001

Cabbage butterfly, Pieris rapae was reared in a room to establish a year-round rearing system. The eggs oviposited by the parent fed on host plant showed 89.2% of hatchability and hatched in 3.9 days after oviposition. The larval period was 18.1 days under high temperature, long day condition ($25^{\circ}C$, 16L : 8D), showing 97.8% pupal ratio and emergence rate. However, under low temperature, short day condition ($21^{\circ}C$, 10L : 14D) the larval period extended to 23.6 days and the pupal ratio was 70%. All of those pupae went into diapause. The oviposition preference experiment on different hosts (Chinese cabbage, cabbage, tulip and kale) showed that hot-water extract was preferred over methanol extracts or squeezed raw juices. The host preference showed that Chinese cabbage was less preferred than the other three. The artificial ovipositing kit was constructed for the oviposition in a room. The 48-hours old eggs could be stored for 7 days at$ 5^{\circ}C$ and showed 70% of hatchability. Non-diapausing pupae could be stored for 30 days at 5 to $15^{\circ}C$, showing 85% of emergence rate. However, the pupae stored at $5^{\circ}C$ showed longer storage period and higher emergence rate. The systematic successive rearing method of cabbage butterfly in a room was completed, based on the above experiments.

• International Journal of Industrial Entomology and Biomaterials
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• v.24 no.2
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• pp.69-74
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• 2012

Tropical tasar silkworm Antheraea mylitta Drury experiences extreme temperature stress conditions during its life cycle particularly during diapauses and first crop. The present study witnessed the impact of high temperature on some biochemical profiles and egg production (fecundity) of semi-domesticated Daba and Shorea robusta (Sal) based wild ecorace Laria during seed cocoon (pupa) preservation. Cocoons of Daba and Laria were treated with high temperature at $40^{\circ}C$ for 10 days in a BOD incubator. The protein profile and carbohydrate content in the hemolymph and fat body and total haemocyte count (THC) in the hemolymph of pupa were investigated. Further, the fecundity and fertility of egg was assessed. Significant increase in the protein concentration was observed in the hemolymph with reduction in the fat body (p<0.05). The difference in protein concentration was highly significant between the semidomesticated Daba and wild ecorace Laria (p<0.05). High pupal mortality (20%) and reduced fecundity (10-15%) in Daba was noticed compared to wild Laria. Also an increased THC (>28000) was recorded in Laria. The study infers the potentials of wild ecoraces in sustaining the extreme temperature conditions and need of adopting suitable package of practices for the preservation of diapause seed cocoons during extreme summer conditions. There is possibility to introgression thermal stress resistant traits in the semi-domesticated races of tasar silkworm by resorting to conventional breeding plans with wild races and keeping the thermal stress induced response as markers.