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20211
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Subject: Entomology × Author: Aarti × End date: 2021 × Start date: 2021 × Type: Thesis ×
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    ThesisItemOpen Access
    Studies on insect pest complex of guava (Psidium guajava L.) with special reference to Bactrocera spp.
    (CCSHAU, Hisar, 2021-08) Aarti; Ram Karan
    The studies entitled “Insect pest complex of guava (Psidium guajava L.) with special reference to Bactrocera spp.” were carried out during 2020-21 at guava orchard of CCS Haryana Agricultural University, Regional Research Station (RRS), Bawal. Population dynamics of insect pest; incidence of fruit flies, fruit borer, bark eating caterpillar, red banded thrips and mealy bug was recorded. The first appearance of fruit fly was recorded in 16th standard meteorological week (SMW), 2020 and maximum fruit fly (132/trap/week) were recorded during 35th SMW, while fruit infestation by fruit fly was initially noticed during 25th SMW, 2020 and peak fruit infestation (75.0%) was recorded during 35th SMW. The castor capsule borer infestation was noticed in 28th SMW and maximum fruit infestation (12.0%) was during 43rd SMW. The castor capsule borer was not appeared during hasth bahar fruiting season. The first symptoms of bark eating caterpillar infestation recorded on 2nd fortnight of April, 2020 and maximum plant infestation (70.0%) with active holes 6.00 leaded to index of incidence 4.2 recorded on 2nd fortnight of August. There was no further increase in infestation of bark eating caterpillar after September. The first appearance of red banded thrips was recorded in 19th SMW, 2020 and maximum population (24.0/5apical shoots) recorded during 26th and 27th SMW. The maximum population of mealy bug (34.0/5apical shoots) recorded during 26th SMW. In correlation studies minimum temperature, relative humidity shows a highly significant and positive effect on all the insects. Two species of fruit fly, namely Bactrocera dorsalis and Bactrocera zonata were found in guava orchard. The maximum population of both species were found in 35th SMW, while B. dorsalis (55.13%) was dominant over B. zonata (44.87%). Maximum number of pupae were found in the 2nd fortnight of August and their viability was maximum in the 1st fortnight of July. The varietal/germplasms screening revealed that among the six varieties/germplasms screened, the susceptibility against fruit fly was maximum in Banarsi Surkha sequentially followed by L-49, Hisar Surkha, Allahabadi Safeda, Hisar Safeda and Desi. The correlation studies of physical traits showed that fruit firmness have highly significant and negative impact on fruit fly infestation while fruit weight, fruit size are positively related. The correlation studies of biochemical traits such as TSS, Vitamin C and total phenol showed highly significant and positive effect on fruit fly infestation, while acidity showed negative effect on fruit fly infestation. An analysis of all the parameters revealed that no single factor governed the fruit fly infestation independently and that the level of infestation was the result of the combined effects of all the factors.