Part 2: Aspects of larval development, intershrub movement, and nut infestation by hazelnut weevils. Two 2nd-instars in 1 hazelnut

Proportions of infested nuts containing 2, 3, or 4 larvae. Proportions of multiply infested nuts containing 2 or more larvae of different instars

Weevil larva subsisting in gall of decaying nut also inhabited by maggots

Doomed 1st-instar larva in gall of nut shared with maggot that appears to be spreading decay

Grisly scene of remains of 2 weevil larvae in nut that has totally decayed.

Larval mortality factors: nut decay / missing kernel, multiple infestation, nut predators

Intershrub movement by adult weevils: Hypothesis

Host plant qualities affecting utilization by weevils: Hypotheses

Map of beaked hazelnut study site showing canopies of all trees in plot

Intershrub movements: Methods

Weevil emergence cages under beaked hazelnut shrub

Weevil emergence cage with trapped spider

Hazelnut weevil marked with dots of color identifying individual, and date and location of capture

Graph: Hazelnut weevil activity and nut infestation, 4 June to 4 Sept 1995

Graph: Mean rates of travel, mean days between release & recapture, and % of marked weevils recaptured, 4 June to 22 July 1995

Weevil on stem of beaked hazelnut

Shrub utilization by weevils: Methods

Shrub utilization: Methods (cont.)

Shrub utilization: Analysis methods

Graphs: Regressions of selected variables of 33 hazelnut shrubs x % of nuts infested by weevils

Graphs: Regressions of selected variables of 7 hazelnut shrubs x tenure time of recaptured weevils. Y-axis = no. days on same shrub

Graphs: Regressions of selected variables of 33 hazelnut shrubs x number of weevils observed/shrub

Conclusions

Resident of one of the study shrubs, a chestnut-sided warbler, Dendroica pensylvanica