▁and ▁is ▁useful ▁in ▁both ▁natural ▁wood ▁stands ▁and ▁commercial ▁for ests ▁such ▁as ▁orch ards ▁and ▁cit rus ▁gro ves . ▁It ▁is ▁benef icial ▁against ▁non ▁native ▁species . ▁An ▁introduced ▁Hem lock ▁p est , ▁the ▁el ong ate ▁hem lock ▁scale ▁( F ior in ia ▁extern a ▁Ferr is ), ▁which ▁has ▁been ▁doing ▁considerable ▁damage ▁to ▁Hem lock ▁trees ▁throughout ▁North ▁America , ▁can ▁be ▁moder ately ▁controlled ▁by ▁the ▁presence ▁of ▁C . ▁st igma . ▁C . ▁st igma ▁is ▁currently ▁not ▁a ▁lady ▁be et le ▁that ▁can ▁be ▁sold ▁for ▁commercial ▁use ▁in ▁orch ards ▁or ▁on ▁far ms . ▁ ▁Life ▁cycle ▁and ▁issues ▁C . ▁st igma ▁usually ▁comple tes ▁two ▁lif ec y cles ▁a ▁year ▁in ▁Canada ▁and ▁the ▁North ▁United ▁States ▁but ▁may ▁complete ▁several ▁lif ec y cles ▁a ▁year ▁further ▁down ▁South . ▁They ▁over w inter ▁in ▁ground ▁l itter ▁during ▁the ▁col der ▁months . ▁ ▁C . ▁st igma ▁has ▁been ▁shown , ▁like ▁other ▁lady be et les , ▁to ▁be ▁sus cept ible ▁to ▁the ▁use ▁of ▁insect ic ides ▁dimin ishing ▁its ▁population ▁in ▁the ▁wild . ▁ ▁In ▁order ▁to ▁preserve ▁the ▁benefits ▁of ▁this ▁insect , ▁p estic ide ▁users ▁are ▁encourag ed ▁to ▁use ▁natural ▁alternatives ▁to ▁p estic ide ▁in ▁order ▁to ▁cur b ▁the ▁decl ine ▁of ▁C . ▁st igma . ▁ ▁Ch rom os ome ▁variation ▁ ▁The ▁chrom os om es ▁(