The multicolored Asian ladybeetle Harmonia axyridis is characterized by polymorphism of the elytral pattern. Melanization in Harmonia axyridis is crucial for their elytral coloration, but the molecular mechanisms are not fully understood in this species. Tyrosine hydroxylase (TH) and dopa decarboxylase (DDC), two key enzymes in the melanin pathway, convert tyrosine and dopa into dopa and dopamine, respectively. In this study, it was to determine the role of TH and DDC of Harmonia axyridis (HaTH and HaDDC) in body and wing pigmentaion produced via melanin pathway. The cDNA sequences of HaTH and HaDDC were cloned to perform RNAi-based functional analysis. Injected dsRNA to the 4th larvae caused knockdown of target genes, and it was verified by quantative realtime PCR. Both TH and DDC RNAi adult show loss of black pigmentation in their body and wing pigmentaion. These results is expected to be helpful to investigate polymorphism by melanin pigment in Harmonia axyridis.

For the studying of effects of matrine and azadirachtine against Aphidius colemani, it was conducted to test the toxic effect of ecofriendly materials. Matrine and azadirachtine are active ingredient of the most commonly used eco-friendly insecticidal materials against insect pests. The effects of materials are investigated by spraying solution to mummies and adults in laborartory condition (Temp: 25℃; 16L:8D; RH: 50-60%). Each materials was diluted and treated with 5 concentrations, 10 wasps for each replications and 3 replications for each concentration. Fitness of A. colemani was assessed by measuring survival rate, emergence rate, longevity and fecundity. Wasps adults were used for experiments within 48 hours after their hatching. Emergence rates were checked for 12 days after spray to mummies of A. colemani, and survival rates were checked at 24 and 48 hours after vial test for adult parasitoids with 10% sugar solution. Adult wasps were exposed to dry residue of material for 24 hours. Longevity was monitored every 12 hours and fecundity was measured by the number of mummies produced by A. colemani adults.

This study was conducted to determine the effect of six different leguminous seeds a) cowpea, b) white kidney bean c) soybean (Cheongja) d) soybean (Daepung) e) mung bean and f) azuki bean on the nymphal development, mortality, adult longevity, fecundity and hatchability of Riptortus pedestris (F.) (Hemiptera: Alydidae). Total developmental time ranged from 18 to 25 days; R. pedestris fed on white kidney bean took the longest time. There was no difference in mortality among the bugs fed on the legumes except those fed on white kidney bean which had the highest mortality (94%). Also, adult bugs fed on white kidney bean showed the shortest longevity. Total number of eggs laid by adult female and the hatchability of the eggs were highest from the bugs fed on cowpea. Higher reproductive success of R. pedestris fed on cowpea suggests that cowpea could be very suitable legume for the bug and it can be used as a trap crop against the bean bug.

Several pentatomids and an alydid are reported inflicting losses in several host plants ranging from leguminous crops to fruit orchards in Korea. Understanding their visual preference would help develop mass trapping or efficient monitoring device. Visual preference of the major pentatomids and an alydid bugs to different colors and light emitting diodes (LED) of different wavelengths were observed. Adults of pentatomid such as Halyomorpha halys Stål, Plautia Stali Scott, and Nezara sp., and an alydid Riptortus pedestris (F.) were exposed to seven different colors (black, yellow, green, blue, white, cream, orange) in a multiple choice tests. Also, adult and second instar nymphs of the bugs were released inside a hexagonal LED boxes consisting of LED lamps of six different wavelengths (375 to 630 nm). Most of the pentatomids showed highest preference to blue color followed by yellow and 530 nm LED. However, R. pedestris showed higher preference to the yellow color followed by blue and black. Second instar nymphs of all the tested species also showed higher preference to 530 nm. Their color and LED lamp preference would help in development of mass trapping device.