!"#$%&'($&RWWRQZRRG/DQH&‡&DVD*UDQGH$=)""*‡  $!+,*‡)$;  *)-.#$ /&0'1&23456&1789:;36&0!"#$%&'($&RWWRQZRRG/DQH&‡&DVD*UDQGH$=$ )""*‡  $!+,*‡)$;  *)-.#$

/&0'1&23456&1789:;36&0$

Dead striped 4/2012 on soil; note faded color of pronotum !"#$%&'($&RWWRQZRRG/DQH&‡&DVD*UDQGH$=)""*‡  $!+,*‡)$;  *)-.#$ Pale-Striped Flea in Young Cotton Stands /&0'1&23456&1789:;36&0$ Peter C. Ellsworth and Lydia Brown Pale-Striped Flea Beetles, blanda, are small (3/16 inch) beetles that invade cotton early in the season. Adults Stripe Flea Beetle Damage Rating 1 bear brown & white longitudinal stripes & jump when !"#$%&'(on damaged$&RWWRQZRRG/DQH&‡&DVD*UDQGH$= )""*‡  $!+,*‡)$;  *)-.#$ disturbed. They feed on cotyledons early on & lower leaves cotyledon later in the season. Their chewing mouthparts score the upper Stripe Flea Beetle/&0'1&23456&1789:;36&0 on Cotton $

(most often) & lower surfaces of leaves without causing Damage Rating = 1 holes. Wounds bleed sap & scarred tissues turn brown. Flea beetles rarely attack true leaves while cotyledons are present & attractive. Damage is largely cosmetic & often limited to field edges, though remedial action (incl. advanced Other flea beetle species irrigations) may be needed when the water-balance of a may also be

young stand is jeopardized. $ present, but $ $ $ $ $ Stripetypically Flea do Beetle Damage Rating 1 Decisions on control actions or advancing irrigations to $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$ $ $ Feeding <''978$36$=92(>72&6/7$5=$?55;72&(3@7$%A(76'356$B52CD$&/('$5=$E&F$!$&68$G967$+#D$)H)ID$36$/55;72&(356$B3(>$(>7$J1K1$L7;&2(M76($5=$NO23/90(927D$G&M7'$N1$?>23'(76'56D$L327/(52D$?55;72&(3@7$%A(76'356D$not cause $ scars ?5007O7$5=$NO23/90(927$&68$P3=7$K/376/7'D$Q>7$J63@72'3(F$5=$N23456&1$ mitigate flea beetle damage require attention to many factors. Q>7$J63@72'3(F$5=$N23456&$3'$&6$7R9&0$5;;52(963(FD$&==32M&(3@7$&/(356$36'(3(9(3561$$$ economic Q>7$J63@72'3(F$857'$65($83'/23M36&(7$56$(>7$S&'3'$5=$2&/7D$/5052D$2703O356D$'7AD$6&(356&0$523O36D$&O7D$83'&S303(FD$@7(72&6$'(&(9'D$52$'7A9&0$52376(&(356$36$3('$;25O2&M'$&68$&/(3@3(37'1$ Damage Rating 2 Most critical is plant development. If severe damage occurs in damage the hours after cotyledons emerge, the stand may be Swollen femur found in all flea beetle species Stripe Flea Beetle Damage Rating 1 jeopardized and action justified. However, more often, Damage Rating = 2 Damage Rating = 3 damage occurs slowly as the plant develops. As long as there are not other complicating factors that weaken the stand First true leaf (injury from thrips, disease, etc., but especially poor water relations or suboptimal soil temperatures), the vast majority of stands outgrow this damage without penalty of yield or loss of time. Generally, emergence of the first true leaf signifies safety of the stand. Nevertheless, scarring can be First Fresh Old (tan) dramatic, and under poor growing conditions controls may be true leaf (green) scars required. scars Other factors to consider are location in the field and seed Severe striped flea beetle damage; Damage Rating 3 first true leaf insufficiently developed; treatments. Infestations tend to be spotty, favoring field $ Damage Rating 2 $ $ $ loss of plant likely $ borders, edges, and nearby drying weedy habitat. In these $ $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$ Damage Rating 2 $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$ $ cases, spot treatments with insecticides may be effective. $ <''978$36$=92(>72&6/7$5=$?55;72&(3@7$%A(76'356$B52CD$&/('$5=$E&F$!$&68$G967$+#D$)H)ID$36$/55;72&(356$B3(>$(>7$J1K1$L7;&2(M76($5=$NO23/90(927D$G&M7'$N1$?>23'(76'56D$L327/(52D$?55;72&(3@7$%A(76'356D$$ Also, many neonicotinoid seed treatments provide protection ?5007O7$5=$NO23/90(927$&68$P3=7$K/376/7'D$Q>7$J63@72'3(F$5=$N23456&1$ Q>7$J63@72'3(F$5=$N23456&$3'$&6$7R9&0$5;;52(963(FD$&==32M&(3@7$&/(356$36'(3(9(3561$$$ to cotyledons so that a foliar spray is generally unnecessary. Q>7$J63@72'3(F$857'$65($83'/23M36&(7$56$(>7$S&'3'$5=$2&/7D$/5052D$2703O356D$'7AD$6&(356&0$523O36D$&O7D$83'&S303(FD$@7(72&6$'(&(9'D$52$'7A9&0$52376(&(356$36$3('$;25O2&M'$&68$&/(3@3(37'1$ Flea beetles may still do some minor feeding despite the seed Attached treatment. They will normally hop when approached; more seed coat sluggish movements indicate effects of seed treatment. Foliar sprays, including broad-spectrum insecticides and neonicotinoids, provide sufficient control. Take great care in early season uses of insecticides, as secondary pest outbreaks can result (esp. mites) and the benefits in yield or timeliness are not proven under normal growing conditions in AZ. Beneficial colonize the field early in the season and set the stage for a season full of Damage Rating 3

$ $ natural controls of many primary and secondary pests. Under $ $ Damage Rating 3$ $ some limited conditions, as determined by examining root$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$ Striped flea beetle and the damage$$$$$$$$$$$$$$$$$$$$$$ this species$$$$$$$$$$ causes,$ $ $ including different damage ratings (1–3, with 3 the most $ $ $ development and soil water profile, coming back early with <''978$36$=92(>72&6/7$5=$?55;72&(3@7$%A(76'356$B52CD$&/('$5=$E&F$!$&68$G967$+#D$)H)ID$36$/55;72&(356$B3(>$(>7$J1K1$L7;&2(M76($5=$NO23/90(927D$G&M7'$N1$?>23'(76'56D$L327/(52D$?55;72&(3@7$%A(76'356D$$ $ severe). Damage rating of 3 without active development $ ?5007O7$5=$NO23/90(927$&68$P3=7$K/376/7'D$Q>7$J63@72'3(F$5=$N23456&1$ $ an irrigation on a field edge or small area may be$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$ needed to of the first true leafQ>7$J63@72'3(F$5=$N23456&$3'$&6$7R9&0$5;;52(963(FD$&==32M&(3@7$&/(356$36'(3(9(3561$$ can lead$$$$$$$$$$$$$$$$$$$$$$ to plant death and,$$$$$$$$$$ if $ $ $ Q>7$J63@72'3(F$857'$65($83'/23M36&(7$56$(>7$S&'3'$5=$2&/7D$/5052D$2703O356D$'7AD$6&(356&0$523O36D$&O7D$83'&S303(FD$@7(72&6$'(widespread, to stand loss. However, once the first true &(9'D$52$'7A9&0$52376(&(356$36$3('$;25O2&M'$&68$&/(3@3(37'1$ quicken plant development and avoid stand loss. $ <''978$36$=92(>72&6/7$5=$?55;72&(3@7$%A(76'356$B52CD$&/('$5=$E&F$!$&68$G967$+#D$)H)ID$36$/55;72&(356$B3(>$(>7$J1K1$L7;&2(M76(leaf is developing, the plant is generally safe from any $5=$NO23/90(927D$G&M7'$N1$?>23'(76'56D$L327/(52D$?55;72&(3@7$%A(76'356D$$ Any products, services, or organizations that are mentioned, shown, or indirectly loss of yield or timeliness?5007O7$5=$NO23/90(927$&68$P3=7$K/376/7'D$Q>7 in plant development. Photos:$J63@72'3(F$5=$N23456&1 $ Q>7$J63@72'3(F$5=$N23456&$3'$&6$7R9&0$5;;52(963(FD$&==32M&(3@7$&/(356$36'(3(9(3561$$$ implied in this publication do not imply endorsement by the University of Arizona. Q>7$J63@72'3(F$857'$65($83'/23M36&(7$56$(>7$S&'3'$5=$2&/7D$/5052D$2703O356D$'7AD$6&(356&0$523O36D$&O7D$83'&S303(FD$@7(72&6$'(Peter C. Ellsworth © 2012, University of Arizona &(9'D$52$'7A9&0$52376(&(356$36$3('$;25O2&M'$&68$&/(3@3(37'1$