Population densities of herbivorous lepidopterans in diverse cruciferous cropping habitats: Effects of mixed cropping and using a living mulch

Abstract

Two field experiments were conducted in Hawaii to determine the responses of lepidopteran pests and their associated natural enemies to broccoli (Brassica oleracea), grown in monoculture or interplanted with chili pepper (Capsicum annuum), or yellow sweetclover (YSC) (Melilotus officinalis). The population responses of Artogeia rapae and Trichoplusia ni to habitat types were not consistent during the field trials. Additionally, their reactions to habitat diversification differed according to non-host plant species. For example, Trichoplusia ni densities were significantly lower in the broccoliÀYSC habitat contrasted with the broccoliÀpepper habitat on most sampling dates. Similarly, the proportion of plants damaged by Hellula undalis was significantly lower in the broccoliÀYSC habitat contrasted with broccoliÀpepper habitat. Findings from the study, suggest that biological control agents (e.g., spiders, parasitoids, and entomopathogens) are the most significant factors influencing the abundance of A. rapae in habitat type and that these agents inflict greater mortality on A. rapae in diculture than monoculture habitats.

New methods of crop production and farmland birds: effects of plastic mulches on species richness and abundance

“…As we demonstrated, mulches altered habitat and food resources (weed species and adult butterflies and their larvae) even after foil removal, probably making those parts of the farmland less suitable for all group of birds. This result is in agreement with other studies on the effects of foils on invertebrates (Ricotta & Masiunas 1991;Hooks & Johnson 2003;Mahajan et al 2007). It is also possible that some nonterritorial individuals known as floaters (Newton 1998) and breeding dispersers may have settled in fields after the removal of the foil, since occupancy at the mulched points increased slightly after foil removal for some species such as grey partridge Perdix perdix, Eurasian skylark Alauda arvensis and corn bunting Miliaria calandra, while occupancy remained stable in the control areas.…”

“…As we demonstrated, mulches altered habitat and food resources (weed species and adult butterflies and their larvae) even after foil removal, probably making those parts of the farmland less suitable for all group of birds. This result is in agreement with other studies on the effects of foils on invertebrates (Ricotta & Masiunas ; Hooks & Johnson ; Mahajan et al . ).…”

Effects of Living Mulch and Fertilizer on the Performance of Broccoli in Plasticulture

“…One study found a consistent reduction in broccoli yield resulting from LM (Chase and Mbuya, 2008), and the other studies reported mixed or no effects of LM on broccoli yields (Brainard and Bellinder, 2004;Ellis et al, 2000;Johnson, 2001, 2004;Infante and Morse, 1996;Ponti et al, 2007;Theriault et al, 2009). In contrast, most of the studies reported beneficial effects of the LM on other aspects of agroecosystem performance, including suppression of weeds (Brainard and Bellinder, 2004;Chase and Mbuya, 2008;Infante and Morse, 1996) or insect pests (Bhan et al, 2010;Costello, 1994;Hooks and Johnson, 2001, 2006Kloen and Altieri, 1990;Ponti et al, 2007). Given these beneficial effects, there is a clear need to identify factors that could improve broccoli yields in LM systems so as to make them more valuable to growers.…”

the Diversity of Lepidopteron pests and assessing their infestation ratios and damages on cruciferous crops

“…The pests that we recorded from this study ( table 1) are supported by (Maltais et al, 1998, Bhat, 2018 recorded the Plutella xylosytella , imported cabbageworm., P. brassicae, and, Trichoplusia ni on broccoli, and Hellula undalis has been reported to be a pest insect on cruciferous crops (Hooks and Johnson, 2006), as well as Pontia daplidice was recorded as a pest insect on crucifers by (Bhat and Bhagat, 2009). However, other lepidopteron pests has been reported to a pest on brassicaceae crops included Helicoverpa armigera and Agrotis ipsilon (Bhat, 2018), Crocidolomia binotalis (L.), Diacrisia ZANCO Journal of Pure and Applied Sciences 2023 obliqua Walker, Spodoptera litura F. (Shelton et al, 2009).…”