Morphometrics of eggs, nymphs, and adults of bactericera cockerelli (hemiptera: Triozidae), grown on two varieties of tomato under greenhouse conditions

The effects of 2 varieties of tomato, Solanum lycopersicum L., i.e., 'Charanda F1' and 'Rafaello', were evaluated on the morphometries of Bactericera cockerelli (Sulc). Eggs, nymphs, and adults of B. cockerelli were collected from 2 varieties of tomato, 'Charanda F1' and 'Rafaello', under greenhouse conditions in the Colegio de Postgraduados, Campus Montecillo, Texcoco, the State of Mexico, during the periods Oct-Dec 2009 and Jan-Mar 2010. Since 2000-2001 the B. cockerelli cultures were maintained on tomato with no exposure to agro-chemicals. Adult B. cockerelli were kept in individual growth chambers constructed of wooden frames covered with organza cloth, under 14:10 h L:D and temperatures ranging from 10 to 25 ^°C. For morphometric analysis of the eggs, the following variables were investigated: egg length (LH), egg width (AH), and pedicel length (PED). For nymphs, the variables were: body length (LC), body width (AC), and antennal length (ANT). For adults, the variables were: body length (LC), body width at thorax (ACT), wing length (LALA), and wing width (ANALA). The 2 tomato varieties were found to have differential morphometric effects on B. cockerelli as follows: no significant differences on egg length (F1,41 = 0.57; P = 0.4551), but egg width was differentially affected by the variety of tomato (F1,41 = 11.92; P = 0.0013). There were significant differential effects of tomato variety on nymphs: body length (F4,324 = 1199.2; P < 0.0001), body width (F4,324 = 900.72; P = 0.0001); and antennae length (F4,324 = 883.93; P = 0.0001). Body length of the adults (F1,117 = 7.11; P = 0.0087) was differentially affected by the 2 different tomato varieties. None of the plants showed any symptoms of infection by 'Candidatus Liberibacter solanacearum', which is known to cause effects on B. cockerelli fitness traits. Body width and antennal length of nymphs can be recommended to differentiate all 5 nymphal instars on this pest species, which has practical implications.