Overview and evaluation of traps to monitor WCR

Transcription

1 Overview and evaluatin f traps t mnitr WCR TÓTH, MIKLÓS Plant Prtectin Institute, HAS, Budapest, Hungary

2 Trapping tls always explit ne r mre stimuli which shw sme kind af attractin twards the given target insect. In the case f WCR we are in the frtunate situatin that there are several such stimuli already knwn.

3 Clur sensitivity: Yellw sticky sheets Several hues f bright yellw clur are knwn t be attractive twards WCR. Sticky sheets painted these yellw hues can be used as simple mnitring tls. These traps usually pretty nndiscriminative - they catch many nn-target insects, and relatively few WCR, because the effect f the clur is nt very strng as cmpared t ther stimuli. Despite these drawbacks, especially in very high ppulatins, such yellw sticky sheets may be useful. In lwer ppulatin densities catches tend t be t lw t allw fr meaningful cnclusins.

4 Chemical attractants Chemical stimuli which can be used fr a mnitring trap are basically either f sex phermnal, r fd attractant (flral lure) activity. In sme high ppulatin areas the s-called cucurbitacin traps were als used. These are small tubes with dry plant material plus insecticide inside, and the plant material cmes frm Cucurbita spp., rich in cucurbitacin. This cmpund is a feeding stimulant fr WCR, s it keeps the arriving t the trap there, but DOES NOT ATTRACT them. In usual ppulatn density situatins cucurbitacin traps are f very lw sensitivity mean catch After Zlf, V. IWGO Newsletter, 16:16-17, 1996 phermne cucurbitacin yellw sticky

5 Sex phermne: Female WCR emits a phermne by which she attracts the males fr mating. The phermne is available in synthetic frm, and can be used as a bait. Phermne baited traps catch nly males, but they are f very high sensitivity. Such traps are the ideal tls fr detectin purpses. Cnventinal sticky Delta trap designs are nt suitable fr catching WCR, instead, trap designs with pen sticky surface are ptimal. Zemun, August 4-15, 1997 average catch/trap/inspectin 100 PANEL trap design PAL sticky clak Ttal caught in test: 6368 a a b b with PHEROMONE bait sticky Delta yellw sticky sheet NO chemical bait

6 The mst widespread phermne trap used in Eurpe tday is the CSALOMON PAL (sticky clak) trap. Infrmatin n the spread and ccurrence f WCR in Eurpean cuntries has largely been cllected by using PAL traps in the past decade. The EU-research prject DIABROTICA (QLK5-CT ) recmmends t use PAL traps baited with phermne as the standard detectin tl fr Diabrtica v. virgifera in Eurpe. In recent years similar phermne traps became available frm ther manufactureres als (i.e. Serbis, etc.) It is disadvantageus t make such sticky traps yellw, because this will increase nn-target insect captures and practically will nt significantly increase WCR captures.

7 Flral lure: In the case f WCR it was als knwn that certain flral cmpunds islated frm pumpkin flwers exerted strng attractin twards bth sexes f adult. This bait was tested in transparent and yellw sticky clak traps, and it appeared that the presence f yellw clur as visual cue was mre imprtant fr females than fr males, increasing female catches significantly. Therefre it is advantageus t have the sticky surface in yellw clur in sticky traps baited with the flral lure. Effect f yellw clur n WCR captures in traps baited with the flral bait after Tóth, M., Sivcev, I., Ujváry, I., Tmasek, I., Imrei, Z., Hrváth, P., Szarukán, I Develpment f trapping tls fr detectin and mnitring f Diabrtica v. virgifera in Eurpe. Acta Phytpath. Entml. Hung. 38: a b a b Szeged, Hungary Aug 3 - Sep 1, 1999 Ttal caught in test: 247 n n n n transparent YELLOW a b transparent YELLOW c b flral bait clur f trap (sticky clak )

8 Sticky clak traps baited with the flral lure in mst situatins are nt as sensitive as sticky traps baited with the phermne. The great advantage f such traps is that they catch predminantly females, and t a lesser extent als males. Mean catches/trap/inspectin (±S.E.) Ttal: Ttal: 4965 MALES FEMALES Szekszárd, 2001 PAL (phermne) PALs (flral) yellw sticky (NO chemical bait) 0 Jul 3 Jul 10 Jul 16 Jul 24 Jul 30 Aug 6 Aug 13 Aug 21 Aug 27

9 The basic requirement fr a sampling tl (i.e. trap) used fr the study f quantitative aspects (i.e. estimatin f ppulatin density, threshld catch levels, etc.) is that it shuld sample cnstantly the same prprtin f the ppulatin ver time (= its efficiency shuld remain cnstant). Althugh very sensitive in detectin, sticky traps have the inherent deficiency that their efficiency will cnstantly change ver time (due t meterlgical and many ther factrs), which makes them unsuitable fr the study f such quantitative aspects. The develpment f nnsaturating, nn-sticky traps may be an answer. FIG The first nn-sticky type available in Eurpe was the CSALOMON VARs+ trap, which culd be baited with bth the phermne and flral lures.

10 The VARs+ trap wrked very nicely, but it was quite cmplicated. An imprved, simplified versin, the new KLP ( hat ) trap KLP was recently felülrœl intrduced. The trap can be used either with the phermne, r with the flral bait (r the tw baits tgether). KLPflr+ KLPfer+ KLPflr+

11 KLPfer+ KLPfer PAL "KLPfer+ it is highly sensitive fr detectin f ccurrence and mnitring; it is baited with the synthetic sex phermne; it catches nly male insects; it has high catch capacity ( ); (it is highly selective; simple design, easy-t-use, n mre sticky fingers! Cmparisn f trap types KLPfer vs. PAL Szekszárd, Hungary, 2004 Ttal caught: "PAL" it is highly sensitive fr detectin f ccurrence and mnitring. PAL it is baited with the synthetic sex phermne it catches nly male insects; sticky sheet is transparent; it has a catch capacity f ; it is f simple design

12 "KLPflr+": it is f the same design as "KLPfer+", but: KLPflr it is baited with the flral lure; + it catches mainly females t a lesser extent als males); especially suitable fr detecting the ccurrence f females); it is highly selective). "PALs" it is f similar design as the "PAL", but the sticky sheet is yellw; it attracts by the synergistic cmbinatin f chemical (flral bait) and visual (yellw) stimuli; it catches females and als males; its use is recmmended in areas where ppulatins f Diabrtica have already been established KLPflr PALs Debrecen, Hungary, 2004 Ttal caught: Cmparisn f trap types KLPflr vs. PALs mean catch +SE P= N.S KLPflr + PALs PALs m f

13 mean female rati (+SE) nrmalized against rati in PALs KLPflr+ vs. PALs: female % in catch Debrecen, 2004 KLPflr+ PALs % mean female % (+SE) July August September Octber KLPflr+ P< PALs The KLPflr+ caught females in significantly higher rati than the PALs!

14 Cnsequently the mst effective tl fr catching females is at present the KLPflr+ trap (which is baited with the flral WCR bait).

15 An interesting new apprach is when the WCR Diabrtica bait is placed int click beetle phermne traps (Yf design, with fr example Agrites ustulatus phermne bait), in the hpe that such a dual-baited trap may be suitable fr the mnitring f bth pests at the same time. This tl is still at the experimental stage f its develpment, but the first results are encuraging, and we can nly hpe that this new variety will prve t be a useful additin t the rather wide array f mnitring tls fr WCR. FIG Yf trap

16 Summarising the characteristics f main WCR trap types Trap type Bait Sex caught Sex rati Hw selective Hw sensitive Catch capacity Design Maintenance Killing agent Sticky yellw sheets i.e. Phercn AM, Multigard etc. n chemical bait bth sexes mre females very many nntarget insects nt sensitive simple, sticky dirty, sticky glue Sticky, phermne i.e. PAL, Serbis etc. phermne males >99% males many nntarget insects very sensitive simple, sticky dirty, sticky glue Sticky yellw, flral baited i.e. PALs, etc. flral females & males mre females many nn-target insects medium sensitive simple, sticky dirty, sticky glue Nn-sticky phermne baited i.e. KLPfer+ phermne males >99% males high selectivity very sensitive > mre cmplicated clean insecticide has t be added Nn-sticky flral baited i.e. KLPflr+, CRW Trécé flral females & males mstly females high selectivity medium sensitive > mre cmplicated clean insecticide has t be added

17 Applicability f main WCR trap types fr different purpses Trap type Sticky yellw, n bait. Sticky, phermne baited Sticky yellw, flral baited Nn-sticky, phermne baited Nn-sticky, flral baited Detectin, new intrductins, very lw ppul. density Mnitring, flight dynamics, established ppulatins Capture f females fr different purpses nt suitable nt suitable nt suitable nt suitable maybe nt suitable maybe Capture f live specimens fr different purpses nt suitable nt suitable nt suitable Establishment f threshld values, crrrelatin w. damage Mass trapping fr decreasing ppulatins maybe maybe (very high (in lwer ppul. ppul. dens.) dens.) nt suitable nt suitable maybe nt suitable maybe maybe