• Journal of Korean Society of Forest Science
• /
• v.90 no.4
• /
• pp.543-547
• /
• 2001

An fungus gnat, Bradysia agrestis in the family Sciaridae was collected from Pinus spp. seedlings. This pest is a newly recorded insect from P. thunbergii, P. rigida, P. rigitaeda, and P. densiflora seedling. Brief morphological characters, damage symptom, host plants associated with the B. agrestis were recored. Significant variation in damaged of Pinus spp. seedling was attributed to differences between pine species(P. thunbergii : 15.4-20.0%, P. rigida : 23.1-48.8%, and P. rigitaeda : 13.8-67.5%, respectively) and sowing times(May : P. densiflora, 0%; P. rigida, 0%, July : P. densiflora, 20.0%; P. rigida, 49.4%, respectively).

• Mycobiology
• /
• v.45 no.3
• /
• pp.160-171
• /
• 2017

Larvae of Bradysia agrestis, an insect vector that transports plant pathogens, were sampled from geographically isolated regions in Korea to identify their cutaneous fungal and bacterial flora. Sampled areas were chosen within the distribution range of B. agrestis; each site was more than 91 km apart to ensure geographical segregation. We isolated 76 microbial (fungi and bacteria) strains (site 1, 29; site 2, 29; site 3, 18 strains) that were identified on the basis of morphological differences. Species identification was molecularly confirmed by determination of universal fungal internal transcribed spacer and bacterial 16S rRNA gene sequences in comparison to sequences in the EzTaxon database and the NCBI GenBank database, and their phylogenetic relationships were determined. The fungal isolates belonged to 2 phyla, 5 classes, and 7 genera; bacterial species belonged to 23 genera and 32 species. Microbial diversity differed significantly among the geographical groups with respect to Margalef's richness (3.9, 3.6, and 4.5), Menhinick's index (2.65, 2.46, and 3.30), Simpson's index (0.06, 0.12, and 0.01), and Shannon's index (2.50, 2.17, and 2.58). Although the microbial genera distribution or diversity values clearly varied among geographical groups, common genera were identified in all groups, including the fungal genus Cladosporium, and the bacterial genera Bacillus and Rhodococcus. According to classic principles of co-evolutionary relationship, these genera might have a closer association with their host insect vector B. agrestis than other genera identified. Some cutaneous bacterial genera (e.g., Pseudomonas) displaying weak interdependency with insect vectors may be hazardous to agricultural environments via mechanical transmission via B. agrestis. This study provides comprehensive information regarding the cutaneous microflora of B. agrestis, which can help in the control of such pests for crop management.

• Korean journal of applied entomology
• /
• v.43 no.2
• /
• pp.129-134
• /
• 2004

A simple and easy method was developed to monitor fungus gnats, Bradysia agrestis on sweet pepper in greenhouses. The larvae of B. agrestis were more attracted to potato discs than other sweetpotato, carrot, garlic, radish, and onion discs. The average numbers of B. agrestis found in each disc were 9.7 (potato), 6.0 (sweetpotato), 4.3 (carrot), 0.7 (garlic), 3.8 (radish), and 1.0 (onion). The number of larvae also increased by the size of disc surface and resulted in 2.1 larvae in 10${\times}$10${\times}$10 mm, 3.4 larvae in 20${\times}$20${\times}$10mm, and 3.9 larvae in 30${\times}$30${\times}$10 mm. The adults were more attracted to a yellow sticky trap (50.0 numbers) than a blue (18.0 numbers) or a white (3.7 numbers) traps. The optimal height for installing sticky trap in the greenhouse was determined as less than 50 cm from the rockwool bed based on the adults caught in the traps; 50.0 in less than 50 cm, 4.3 in 50-100 cm, and 2.0 in more than 100 cm height.

• Proceedings of the Korean Society of Applied Entomolohy Conference
• /
• 2001.11a
• /
• pp.91-91
• /
• 2001

• Korean journal of applied entomology
• /
• v.39 no.2
• /
• pp.89-97
• /
• 2000

Insect pests of eggplant, pepper, Chinese cabbage, watermelon, cucumber, melon, and tomato seedlings were surveyed in eleven propagation houses from 1998 to 1999. Ten species of insect pests of nine genera in eight families, two species of mites of one genus in one family, and three species of slugsor snails in three genera belonging to two families were found from the observed seedlings but Bradysia agrestis was the most serious pest out of them. Thus, occurrence and damage of B. agrestis were investigated in two propagation houses all the year round. In the observation of seedling mortalities of seven crops in May, July, October and the following February, only watermelon seedlings were withered and dead by the larva of B. agrestis with different mortality depending on time representing 81.9%, 41.3%, 54.9%, and 79.1%, respectively. All the developmental stages of B. agrestis were found every month throughout the year. Larval density and adult density were different according to season with the highest numbers in May showing 34.9 and 407.4, respectively. Mortality of watermelon seedlings was higher in April and May than the other months showing 83.3% in April and 82.4% in May. The number of adults attracted to sticky trap was also different depending on card colour. The number of adults was much higher on yellow sticky card (326.2) than blue sticky card (20.2). In the investigation of the number of adults on yellow sticky card at 25 cm and 120 cm above the bench and 10 cm under the bench, more numbers of adults were caught at 25 cm above the bench (273.7) and 10 cm under the bench (320.1) than 120 cm above the bench (27.9). Mortalities of cucumber, pepper, and watermelon seedlings after transplanting in greenhouses were not significantly different depending on culture method.

• Korean journal of applied entomology
• /
• v.58 no.2
• /
• pp.143-149
• /
• 2019

This study was conducted to examine the attractiveness of yellow sticky trap (YST) for insect pests by the angle of inclination of the trap surface. In strawberry farms with high bed system, YSTs were installed to attract insect pests in vertical direction with one surface, horizontal direction with upper and under surface, and angle of $45^{\circ}$ with upper and lower sticky surface. Thrips (Frankliniella occidentalis in dominance) and Sciaridae (Bradysia agrestis in dominance) species were more attracted on upper surface of $45^{\circ}$ angle trap, vertical surface and upper surface of horizontal trap than on lower surface of $45^{\circ}$ angle trap or horizontal trap. Cicadellidae (Empoasca vitis in dominance) species were caught more on vertical surface and upper surface of $45^{\circ}$ angle trap than on other traps. There were no specific trend in capture of aphid (Aphis gossypii in dominance) and white fly (Trialeurodes packardi in dominance) species among traps, probably because of a low density of the pest species.