Burrknots as Food Source for Larval Development ofGrapholita molesta(Lepidoptera: Tortricidae) on Apple Trees

Abstract

Grapholita molesta (Busck) is one of the main pests of apple trees, and lives on their shoots and fruits. In southern Brazil, the insect is also found on old branches and structures similar to aerial roots, so-called burrknots. This study evaluated the development and population growth potential of G. molesta fed on burrknots, compared with apple fruit cultivar. Fuji and a corn-based artiÞcial diet. The study was carried out in the laboratory under controlled temperature (25 Ϯ 1ЊC), relative humidity (70 Ϯ 10%), and photophase (16 h). The biological parameters of the immature and adult stages were determined, and a fertility life table was constructed. Insects fed on burrknots showed a longer duration and a lower survival for the egg-to-adult period (29.3 d and 22.5%) compared with those that fed on apples (25.1 d and 30.0%) and artiÞcial diet (23.9 d and 54.8%). Insects reared on aerial roots had a lower pupal weight (10.0 mg) compared with those reared on either artiÞcial diet (13.7 mg) or apple cultivar. Fuji (12.4 mg). The fecundity and longevity of males and females did not signiÞcantly differ for the three foods. Based on the fertility life table, insects reared on burrknots had the lowest net reproductive rate (Ro), intrinsic rate of population growth (r m ) and Þnite rate of increase (), compared with insects reared on artiÞcial diet and apple fruit. Burrknots support the development of the complete cycle of G. molesta, which allows populations of this pest to increase in orchards.

Assessment of SPLAT formulations to control Grapholita molesta (Lepidoptera: Tortricidae) in a Brazilian apple orchard

“…However, G. molesta larvae have been observed to feed on "burr knots" (adventitious root zones) after harvest. These knots can be a source of food that allows for the development of some individuals in the orchard (Bisognin et al, 2012).…”

Larval performance of the oriental fruit moth across fruits from primary and secondary hosts

“…The oriental fruit moth Cydia (= Grapholita ) molesta (Busck) (Lepidoptera: Tortricidae) is an oligophagous invasive insect of Asian origin that reproduces on plants within the family Rosaceae and produces several generations per year. It has spread across a large geographical range and is presently distributed in temperate and subtropical regions of Asia, Europe, the Americas, Africa and Australia (Tremblay, ; Rothschild & Vickers, ; Timm et al ., ; Lopez‐Vaamonde et al ., ; Bisognin et al ., ), with its economic relevance expected to continue increasing in the next decades (Torriani et al ., ). The larvae are internal feeders in stone and pome fruits mostly from the genera Prunus , Malus and Pyrus (Rothschild & Vickers, ).…”

Biological Characteristics of Grapholita molesta (Lepidoptera: Tortricidae) Induced to Diapause in Laboratory

“…However, in this period, larvae of oriental fruit moth are found feeding on “burrknots” (aerial root), assuming that they are a source of insect food at this stage, which would allow the development of subsequent generations in the orchard ( Arioli et al. 2007 , Santos and Leolato 2011 , Bisognin et al. 2012 ).…”