• Korean journal of applied entomology
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• v.31 no.4
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• pp.486-491
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• 1992

The aboveground activities of the larger black chafer (Holotrichia morosa Waterhouse) and the Korean black chafer (H. diomphalia Bates) adults were investigated in the field and laboratory from 1991 through 1992. In a field cage, H. morosa adults emerged from the ground between 7 : 40-9 : 00 p.m. and H. diomphalia adults emerged between 7 : 30-10 : 00 p.m. After emergence, both females and males flied actively for less than one minute in H. morosa, while males flied inactively and females did not fly at all in H. diomphalia. Once emerged, adults of the two species mated or fed on plant leaves and seemed to stay aboveground till dawn. H. mOTOsa adults were attracted to a blacklight trap mainly between 8 : 10-10 : 00 p.m. in the field. H. morosa males and females emerged from soil every other day in a glass cistern.

• Korean journal of applied entomology
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• v.27 no.1
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• pp.21-27
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• 1988

A study was carried out to investigate the morphological characteristics and life histories of H. morosa and H. diomPhalia during the period from 1984 to 1986. The head capsule width and bOdy length of H. Morosa larvae were slightly greater than those of H. diomPhalia. Otherwise, the two species looked very similar and were hard to be differentiated from each other in all life stages. H. morosa adults emerged in late June and laid eggs in soil during the period between mid July and mid August. Larvae developed by September to the last(3rd) instar which overwintered to pupate in late May. H. diomPhalia adults emerged from mid August but remained under the soil until next spring after which females laid eggs in soil from late May to early July. Larvae developed in most cases to the last instar by September and overwintered thereafter. Unlike H. morosa, they resumed feeding next April and began to pupate in late July. The egg periods of H. morosa and H. diomPhalia did not significantly differ but the larval and pupal periods of the latter were longer than those of the former.

• Korean journal of applied entomology
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• v.27 no.4
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• pp.194-199
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• 1988

The seasonal movements of Holotrichia morosa and H. diomphalia in soil were investigated during the period from 1984 to 1986 in Suwon. Most cf the eggs, active larvae and adults of the two species could be found at the soil depth of I-IDem. The larvae began downward movement in late October and early November in order for overwintering when soil tempe¬rature at 5cm below ground reached about $10^{\circ}C$. The overwintering depths of the larvae were 10-40cm for H. morosa and 30-80cm for H. diomPhalia. After the overwintering, pupation and adult emergence of H. morosa occurred at the overwintered sites, \vhereas H. diomPhalia larvae returned to near soil surface next April, and resumed feeding. H.diomphalia larvae began to move downward again in late June for pupation and adult emergence, and overwintered thereafter as adults at the depth of 1O-40cm.

• Korean journal of applied entomology
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• v.29 no.4
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• pp.222-229
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• 1990

The flight activities of Holotrichia morosa Watershouse and H. diomphaia Bates adults were monitored by blacklight traps for six years from 1984 to 1989. The flight activity of H. morosa adults was most prominent from late June to early August with a peak flight in mid July, and that of H. diomphalia adults mainly occurred from early May to late June of odd years with the peak flight dates varying year by year. The flight activities of the two species during the fight period became vigorous after moderate to heavy rainfalls. The overwintered adults of H. diomphalia seemed to begin flying when the daily mean temperature rose above $15^{\circ}C$. The ratios of the females to the total adults collected by the blacklight traps were 53.3% for H. morosa and 0% for H. diomphalia, although the female sex ratio of the latter species was 57.4% in the field.

• Journal of Ginseng Research
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• v.13 no.2
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• pp.174-177
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• 1989

The ovipositional preferences of Holotrichia morosa were investigated to defermine several environmental factors related to its incidence in ginseng fields. H. moroia paid no eggs in naked soil without ground color plants, and shouted ovipositional preference among weed plants in the order to Aurmisin prinrcps var oripntnlis, Epigrren canadensis Diuitarin sanguinalis, and Porttulaca oleracea. More oviposition was observed in the denser vegetation of D. sanguinalis and in soft soil. The egg-laying females were seldom attracted to fresh rice straw mulched on soil surface or decayred rite straw mixed into soil. The number of eggs laid by a female decreased considerably when the soil moisture content was below 5% or above 35%.

• Korean journal of applied entomology
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• v.30 no.4
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• pp.265-270
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• 1991

Oviposition activities of the larger black chafer(HolotTichia mOTosa Waterhouse) and Korean black chafer(H. diomphalia Bates) were examined in the laboratory and field from 1985 to 1990. In H. mOTosa and H. diomphalia, total durations of oviposition were 31.70$\pm$17.33 days and 61.17$\pm$23.15 days, numbers of days of actual oviposition were 9.00$\pm$5.03 days and 22.33 $\pm$11.72 days, total numbers of eggs laid laid per female were 23.43$\pm$16.26 and 65.67$\pm$37.97, and numbers of eggs laid per female per day were 2.60$\pm$2.50 and 2.94$\pm$2.34, under laboratory conditions. Difference of total numbers of eggs per female between both species seemed to be due mainly to numbers of days of actual oviposition. Oviposition period under laboratory conditions was considerably delayed behind that in the field in H. morosa but the two oviposition periods were almost overlapped in H. diomphalia. In the field, rates of gravid females of H. diomphalia were obviously higher than those of H. mOTosa, but numbers of eggs per gravid female were almost same in the two species, H. diomphalia adults did not show marked oviposition and feeding preference among several species of weed plants in the insect net chamber.

• Journal of Ginseng Research
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• v.15 no.3
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• pp.200-204
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• 1991

Densities and larval food habits of Holotrichia titanis belonging to Melolonthinae, and of Anomala corpulenta and A. mfocuprea belonging to Rutelinae, collected from surroundings of ginseng fields, were investigated to determine potentia]s as ginseng pests in scarabaeids. H. titanis had similar food habit to the ginseng pests, H. morosa and H. diomphalia, although the density of H. titanis was relatively low during the period of survey, which indicates that the scarabaeid may have potentials to be a major pest with build-up or the population in the fields. However, A. corpulenta and A. rufacuprea with higher populations than H. morose and H. dicmphalia had no or low potency as ginseng pests since they had little preference to ginseng roots or did not feed on these. The latter two species in Rutelinae showed different food habits in relation to dead organic matter.

• Korean journal of applied entomology
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• v.32 no.4
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• pp.414-419
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• 1993

Species and seasonal occurrences of Sencinae, Melolonthinae and Rutelinae chafers captured b by blacklight traps were investigated from 1989 to 1991 in Suwon and Chonju. Numbers of s species captured in Suwon and Chonju were 6 and 6 for Sericinae, 8 and 7 for Melolothinae, 7 a and 8 for Rutelinae, 21 and 21 in total, respectively. Species with more captures from both districts in each subfamily were Maladera orientalis of Sericinae, Holotrichia morosa and H. diomphalia of Melolonthinae, and Anomala corpulenta, and A. rufocuprea of Rutelinae. Adults of t the above five species were captured 1O~20 days earlier in Chonju than in Suwon. H. d diomphalia adults occurred mamly In odd years in Chonju, which is the same pattern as in S Suwon.

• Korean journal of applied entomology
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• v.24 no.4 s.65
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• pp.179-182
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• 1986

The white grubs were collected from ginseng field and fallow lands to examine their external morphology and species components. They were divided into 3 subfamilies, i.e., Melolonthinae, Rutellinae, and Sericinae by the shape of anal slit and/or presence of elevated lines in stridulating area of mandible. Eight species were identified by means of comparing the shape of anal slit, setal arrangement of decasternite, and frontoepicranial series of setae. Larvae of Holotrichia diomphalia and H. morosa were observed to damage ginseng root in field.