Effect of Larval Crowding on Development, Growth and Reproduction of Earias vittella (F.) (Lepidoptera: Noctuidae)

Abstract

Effects of different levels of larval density (1, 5, 10, 15, 20, 25 larvae/container) on development, growth and reproduction of Earias vittella were examined under laboratory conditions when the temperature ranged from 22–33°C and R. H. varied from 57–91%‐Larval survival was found to be negatively correlated to the level of density. However, it reduced the larval and pupal weights. Crowding also decreased the fecundity of adults. Hatching of the eggs laid by the females was not affected by the larval crowding.

Preimaginal Environment Influences Adult Flight inCydia molesta(Lepidoptera: Tortricidae)

“…Choristoneura rosaceana Harris (Lepidoptera: Tortricidae) reared at low densities were four times as likely to survive to adulthood compared with those reared at high densities; high larval densities were also correlated with smaller pupae and longer pupal development (Poirier and Borden 1992). Longer developmental time and increased mortality among crowded larvae has also been recorded in Trichoplusia ni (Hubner) (Lepidoptera: Noctuidae) (Tignor and Eaton 1986) and E. vittella (Tripathi and Singh 1990). In contrast to this study, reduced pupal weight was correlated with larval crowding in Spodoptera exempta (Lepidoptera: Noctuidae) (Parker and Gatehouse 1985), Prodenia litura (Lepidoptera: Noctuidae) (Zaher and Moussa 1961), and E. postvittana (Danthanarayana et al 1982).…”

“…However, larval crowding led to an altered oviposition pattern, with signiÞcantly greater oviposition in later life, as described above for moths reared under decreasing photoperiod. In contrast, larval density had no effect on the fecundity of Mamestra brassicae L. (Lepidoptera: Noctuidae) (Kazimirova 1996), but was negatively correlated with fecundity in Earias vitella (F.) (Lepidoptera: Noctuidae) (Tripathi and Singh 1990). Density-regulated dispersal is common in insects (Price 1997).…”

Larval crowding effects during early development in the Chinese oak silkmoth Antheraea pernyi (Lepidoptera: Saturniidae)

“…Similar results of the lasting effects of early life crowding were found in the Epirrita autumnata Borkhausen (1794) (Lepidoptera: Geometridae) whereby early life crowding resulted in shorter growth periods and achieved overall lower weight in the last instar of development (Tammaru et al, 2000 ). Likewise, a negative relationship between larval survival and weight with larval crowding was also found in Earias vittella Fabricius (1794) (Lepidoptera: Noctuidae) (Tripathi & Singh, 1990 ) and cabbage moth Mamestra brassicae Linnaeus (1758) (Lepidoptera: Noctuidae) (see also Than et al, 2020 and references therein). Thus, the results presented here confirm previous findings in the literature on density‐dependent effects on larval development in insects, and suggest that larval crowding during early stages of development decrease growth and survival, with likely implications to the life histories of the adult as well as, from an economic perspective, lower silk yield.…”

“…Noctuidae) (Tripathi & Singh, 1990) and cabbage moth Mamestra brassicae Linnaeus (1758) (Lepidoptera: Noctuidae) (see also Than et al, 2020 and references therein). Thus, the results presented here confirm previous findings in the literature on density-dependent effects on larval development in insects, and suggest that larval crowding during early stages of development decrease growth and survival, with likely implications to the life histories of the adult as well as, from an economic perspective, lower silk yield.…”

Population dynamics of okra shoot and fruit borer<em></em>(<em>Earias vittella</em>) of okra in agro-climatic condition of Pantnagar

“…The important limiting factor in the successful cultivation of Okra is the damage caused by insect-pests, mainly fruit borers and sucking insects. The important species of fruit borers are Earias vittella (Fabricius) (Krishnaiah et al1980 [8] , Rawat and Sahu, 1973 [15] ), E. insulana (Bioduval) (Tripathi and Singh, 1990) [20] , and Helicoverpa armigera (Hubner) (Rawat and Sahu, 1973) [15] . The larvae of Okra shoot and fruit borer, E. vittella (Fab.)…”