Host resistance and influence of tuber surface on larval performance of potato tuberworm (Lepidoptera: Gelechiidae)

Abstract

Potato tuberworm (PTW), Phthorimaea operculella (Zeller) (Lepidoptera: Gelechiidae), is one of the most important pests of potatoes in tropic and subtropic regions. Previous studies suggested that tuber periderm may limit larval penetration and establishment of PTW. Short term inXuence of parental host plant acclimatization, inXuence of tuber dormancy and inXuence of tuber periderm (the outer cork layer of tubers) on aspects of PTW biology were investigated on tubers of a susceptible commercial potato cultivar, cv. Allegany (Solanum tuberosum L.), and a resistant hybrid potato clone, Q174-2 (S. tuberosum £ S. berthaultii Hawkes). Short-term parental host plant acclimatization did not aVect numbers of PTW larvae on resistant and susceptible tubers. Numbers of larvae produced on tubers of Q174-2, and Allegany, were similar although larval weight was less on Q174-2 than on Allegany. Larval production increased with tuber age on both susceptible and resistant potato clones, suggesting that bud sprouts may enhance Wtness by providing food and shelter for Wrst instars prior to tuber entry. Removal of tuber periderm led to a signiWcant increase in larval survival on Allegany and Q174-2, although proportional survival on Allegany and Q174-2 was similar to that on intact tubers, suggesting the involvement of internal rather than external periderm factors in tuber resistance of Q174-2. Weights of larvae reared on Q174-2 were consistently less than those of larvae reared on susceptible potato tubers in both intact and peeled tuber assays. Although the expression of periderm-mediated tuber resistance declines with tuber age, such resistance could signiWcantly reduce preharvest Weld infestations by PTW and constitute an important component of sustainable PTW management, particularly for fresh market crops and for those potato crops stored for several months or less in the absence of refrigeration.

Capturing of Phthorimaea operculella (Zeller) Male Moths by Sex- Pheromone Traps in Response to Trap Color, Direction and Height at Potato Fields

“…Because PTM larvae live inside leaves, stems, or tubers, it has become difficult to monitor and to effectively control this destructive insect pest. In addition, PTM populations have acquired resistance to many insecticides (Doğramacı and Tingey 2008). Some authers (Fetoh 2003 andAbbassy et al 2008) proposed optimizing time to plant potatoes to maximize output because of little PTM infestation, but this was found not satisfactory, as the potato is cultivated throughout the year, particularly in temperate climates.…”

Abundance and Diversity of Soil Macroarthropods in Qena Governorate, Upper Egypt

“…The category of macroarthropods encompasses several organisms such as millipedes, centipedes, numerous insect orders, certain crustaceans, and arachnids (Ishaya, 2019). Although certain types of soil macroarthropods are commonly regarded as pests (Jackson and Klein, 2006;Doğramaci and Tingey, 2009), they also play a crucial role in enhancing ecosystem processes through their substantial impact on the soil environment (Lavelle, 1997;Wolters, 2000). Ants, termites, millipedes, centipedes, woodlice, and beetles are significant contributors to macromixing and the creation of soil aggregates.…”

Diversity of soil macroarthropods in shifting cultivation and forest ecosystem of Mizoram, Northeast India

“…Soil macroarthropods are those soil organisms that are large enough to be sampled individually (Callaham et al, 2012). Although several groups of soil macroarthropods are considered as pests (Jackson and Klein, 2006;Doğramaci and Tingey, 2009), they are also known to positively influenced ecosystem functions by causing important modifications in the soil environment (Lavelle, 1997;Wolters, 2000). Despite their important roles and functions in the ecosystem, soil communities are still poorly known (Hunter, 2001).…”