Should I lay or should I wait? Egg-laying in the two-spotted spider mite Tetranychus urticae Koch.
Optimality theory predicts that females tend to maximize their offspring survival by choosing the egg-laying site. In this context, the use of conspecific cues allows a more reliable assessment of the habitat quality. To test this hypothesis, Tetranychus urticae Koch is an appropriate biological model as it is a phytophagous mite living in group, protected against external aggression by a common web. Experiments were conducted to determine the respective influence of substrate (living substrate: bean leaf vs. non-living substrate: glass plate), silk and presence of conspecific eggs on the egg-laying behavior of T. urticae females. On both living and non-living substrates, the presence of silk positively influenced the probability of a female to lay an egg, but had no influence on the number of eggs deposited. The egg-laying behavior was mainly determined by the nature of the substrate with mites laying fewer eggs on a non-living substrate than on a living one. The presence of a conspecific egg had no impact on either the probability of laying an egg or on the oviposition rate. This study showed a high variability among females in their fecundity and egg-laying performance. The physiology of females (individual fecundity), the egg-laying substrate and to a lesser extent the presence of silk impacted on the decision of spider mites to lay eggs.
Earth and Life Institute, Biodiversity Research Centre, Université catholique de Louvain, 4-5 Place Croix du Sud, 1438 Louvain-la-Neuve, Belgium. gwendoline.clotuche@uclouvain.be
Gwendoline
G
Clotuche
Camille
C
Turlure
Anne-Catherine
AC
Mailleux
Claire
C
Detrain
Thierry
T
Hance
D000818:Animals; D001522:Behavior, Animal / Q000502:physiology*; D003463:Cues; D017753:Ecosystem; D005260:Female; D005298:Fertility / Q000502:physiology; D010058:Oviposition / Q000502:physiology*; D047011:Silk; D040102:Tetranychidae / Q000033:anatomy & histology*
D047011:Silk